Reference architecture: Up to 500 RPS or 25,000 users

DETAILS: Tier: Premium, Ultimate Offering: Self-managed

This page describes the GitLab reference architecture designed to target a peak load of 500 requests per second (RPS) - The typical peak load of up to 25,000 users, both manual and automated, based on real data.

For a full list of reference architectures, see Available reference architectures.

NOTE: Before deploying this architecture it's recommended to read through the main documentation first, specifically the Before you start and Deciding which architecture to use sections.

• Target load: API: 500 RPS, Web: 50 RPS, Git (Pull): 50 RPS, Git (Push): 10 RPS
• High Availability: Yes (Praefect needs a third-party PostgreSQL solution for HA)
• Cost calculator template: See cost calculator templates section
• Cloud Native Hybrid Alternative: Yes
• Unsure which Reference Architecture to use? Go to this guide for more info

Footnotes:

1. Can be optionally run on reputable third-party external PaaS PostgreSQL solutions. See Provide your own PostgreSQL instance for more information.
2. Can be optionally run on reputable third-party external PaaS Redis solutions. See Provide your own Redis instances for more information.
   • Redis is primarily single threaded and doesn't significantly benefit from an increase in CPU cores. For this size of architecture it's strongly recommended having separate Cache and Persistent instances as specified to achieve optimum performance.
3. Recommended to be run with a reputable third-party load balancer or service (LB PaaS) which can provide HA capabilities. Also, the sizing depends on selected Load Balancer and additional factors such as Network Bandwidth. Refer to Load Balancers for more information.
4. Should be run on reputable Cloud Provider or Self Managed solutions. See Configure the object storage for more information.
5. Gitaly Cluster provides the benefits of fault tolerance, but comes with additional complexity of setup and management. Review the existing technical limitations and considerations before deploying Gitaly Cluster. If you want sharded Gitaly, use the same specs listed above for Gitaly.
6. Gitaly specifications are based on high percentiles of both usage patterns and repository sizes in good health. However, if you have large monorepos (larger than several gigabytes) or additional workloads these can significantly impact Git and Gitaly performance and further adjustments will likely be required.
7. Can be placed in Auto Scaling Groups (ASGs) as the component doesn't store any stateful data. However, Cloud Native Hybrid setups are generally preferred as certain components such as like migrations and Mailroom can only be run on one node, which is handled better in Kubernetes.

NOTE: For all PaaS solutions that involve configuring instances, it's recommended to implement a minimum of three nodes in three different availability zones to align with resilient cloud architecture practices.

@startuml 25k
skinparam linetype ortho

card "**External Load Balancer**" as elb #6a9be7
card "**Internal Load Balancer**" as ilb #9370DB

together {
  collections "**GitLab Rails** x5" as gitlab #32CD32
  collections "**Sidekiq** x4" as sidekiq #ff8dd1
}

together {
  card "**Prometheus**" as monitor #7FFFD4
  collections "**Consul** x3" as consul #e76a9b
}

card "Gitaly Cluster" as gitaly_cluster {
  collections "**Praefect** x3" as praefect #FF8C00
  collections "**Gitaly** x3" as gitaly #FF8C00
  card "**Praefect PostgreSQL***\n//Non fault-tolerant//" as praefect_postgres #FF8C00

  praefect -[#FF8C00]-> gitaly
  praefect -[#FF8C00]> praefect_postgres
}

card "Database" as database {
  collections "**PGBouncer** x3" as pgbouncer #4EA7FF
  card "**PostgreSQL** //Primary//" as postgres_primary #4EA7FF
  collections "**PostgreSQL** //Secondary// x2" as postgres_secondary #4EA7FF

  pgbouncer -[#4EA7FF]-> postgres_primary
  postgres_primary .[#4EA7FF]> postgres_secondary
}

card "redis" as redis {
  collections "**Redis Persistent** x3" as redis_persistent #FF6347
  collections "**Redis Cache** x3" as redis_cache #FF6347

  redis_cache -[hidden]-> redis_persistent
}

cloud "**Object Storage**" as object_storage #white

elb -[#6a9be7]-> gitlab
elb -[#6a9be7,norank]--> monitor

gitlab -[#32CD32,norank]--> ilb
gitlab -[#32CD32]r-> object_storage
gitlab -[#32CD32]----> redis
gitlab .[#32CD32]----> database
gitlab -[hidden]-> monitor
gitlab -[hidden]-> consul

sidekiq -[#ff8dd1,norank]--> ilb
sidekiq -[#ff8dd1]r-> object_storage
sidekiq -[#ff8dd1]----> redis
sidekiq .[#ff8dd1]----> database
sidekiq -[hidden]-> monitor
sidekiq -[hidden]-> consul

ilb -[#9370DB]--> gitaly_cluster
ilb -[#9370DB]--> database
ilb -[hidden]--> redis
ilb -[hidden]u-> consul
ilb -[hidden]u-> monitor

consul .[#e76a9b]u-> gitlab
consul .[#e76a9b]u-> sidekiq
consul .[#e76a9b]r-> monitor
consul .[#e76a9b]-> database
consul .[#e76a9b]-> gitaly_cluster
consul .[#e76a9b,norank]--> redis

monitor .[#7FFFD4]u-> gitlab
monitor .[#7FFFD4]u-> sidekiq
monitor .[#7FFFD4]> consul
monitor .[#7FFFD4]-> database
monitor .[#7FFFD4]-> gitaly_cluster
monitor .[#7FFFD4,norank]--> redis
monitor .[#7FFFD4]> ilb
monitor .[#7FFFD4,norank]u--> elb

@enduml

Requirements

Before starting, see the requirements for reference architectures.

Testing methodology

The 25k architecture is designed to cover a large majority of workflows and is regularly smoke and performance tested by the Test Platform team against the following endpoint throughput targets:

• API: 500 RPS
• Web: 50 RPS
• Git (Pull): 50 RPS
• Git (Push): 10 RPS

The above targets were selected based on real customer data of total environmental loads corresponding to the user count, including CI and other workloads.

If you have metrics to suggest that you have regularly higher throughput against the above endpoint targets, large monorepos or notable additional workloads these can notably impact the performance environment and further adjustments may be required. If this applies to you, we strongly recommended referring to the linked documentation and reaching out to your Customer Success Manager or our Support team for further guidance.

Testing is done regularly by using the GitLab Performance Tool (GPT) and its dataset, which is available for anyone to use. The results of this testing are available publicly on the GPT wiki. For more information on our testing strategy refer to this section of the documentation.

The load balancers used for testing were HAProxy for Linux package environments or equivalent Cloud Provider services with NGINX Ingress for Cloud Native Hybrids. These selections do not represent a specific requirement or recommendation as most reputable load balancers are expected to work.

Set up components

To set up GitLab and its components to accommodate up to 500 RPS or 25,000 users:

1. Configure the external load balancer to handle the load balancing of the GitLab application services nodes.
2. Configure the internal load balancer to handle the load balancing of GitLab application internal connections.
3. Configure Consul for service discovery and health checking.
4. Configure PostgreSQL, the database for GitLab.
5. Configure PgBouncer for database connection pooling and management.
6. Configure Redis, which stores session data, temporary cache information, and background job queues.
7. Configure Gitaly Cluster, provides access to the Git repositories.
8. Configure Sidekiq for background job processing.
9. Configure the main GitLab Rails application to run Puma, Workhorse, GitLab Shell, and to serve all frontend requests (which include UI, API, and Git over HTTP/SSH).
10. Configure Prometheus to monitor your GitLab environment.
11. Configure the object storage used for shared data objects.
12. Configure advanced search (optional) for faster, more advanced code search across your entire GitLab instance.

The servers start on the same 10.6.0.0/24 private network range, and can connect to each other freely on these addresses.

The following list includes descriptions of each server and its assigned IP:

• 10.6.0.10: External Load Balancer
• 10.6.0.11: Consul 1
• 10.6.0.12: Consul 2
• 10.6.0.13: Consul 3
• 10.6.0.21: PostgreSQL primary
• 10.6.0.22: PostgreSQL secondary 1
• 10.6.0.23: PostgreSQL secondary 2
• 10.6.0.31: PgBouncer 1
• 10.6.0.32: PgBouncer 2
• 10.6.0.33: PgBouncer 3
• 10.6.0.40: Internal Load Balancer
• 10.6.0.51: Redis - Cache Primary
• 10.6.0.52: Redis - Cache Replica 1
• 10.6.0.53: Redis - Cache Replica 2
• 10.6.0.61: Redis - Persistent Primary
• 10.6.0.62: Redis - Persistent Replica 1
• 10.6.0.63: Redis - Persistent Replica 2
• 10.6.0.91: Gitaly 1
• 10.6.0.92: Gitaly 2
• 10.6.0.93: Gitaly 3
• 10.6.0.131: Praefect 1
• 10.6.0.132: Praefect 2
• 10.6.0.133: Praefect 3
• 10.6.0.141: Praefect PostgreSQL 1 (non HA)
• 10.6.0.101: Sidekiq 1
• 10.6.0.102: Sidekiq 2
• 10.6.0.103: Sidekiq 3
• 10.6.0.104: Sidekiq 4
• 10.6.0.111: GitLab application 1
• 10.6.0.112: GitLab application 2
• 10.6.0.113: GitLab application 3
• 10.6.0.114: GitLab application 4
• 10.6.0.115: GitLab application 5
• 10.6.0.151: Prometheus

Configure the external load balancer

In a multi-node GitLab configuration, you'll need an external load balancer to route traffic to the application servers.

The specifics on which load balancer to use, or its exact configuration is beyond the scope of GitLab documentation but refer to Load Balancers for more information around general requirements. This section will focus on the specifics of what to configure for your load balancer of choice.

Readiness checks

Ensure the external load balancer only routes to working services with built in monitoring endpoints. The readiness checks all require additional configuration on the nodes being checked, otherwise, the external load balancer will not be able to connect.

Ports

The basic ports to be used are shown in the table below.

• (1): Web terminal support requires your load balancer to correctly handle WebSocket connections. When using HTTP or HTTPS proxying, this means your load balancer must be configured to pass through the Connection and Upgrade hop-by-hop headers. See the web terminal integration guide for more details.
• (2): When using HTTPS protocol for port 443, you will need to add an SSL certificate to the load balancers. If you wish to terminate SSL at the GitLab application server instead, use TCP protocol.

If you're using GitLab Pages with custom domain support you will need some additional port configurations. GitLab Pages requires a separate virtual IP address. Configure DNS to point the pages_external_url from /etc/gitlab/gitlab.rb at the new virtual IP address. See the GitLab Pages documentation for more information.

• (1): The backend port for GitLab Pages depends on the gitlab_pages['external_http'] and gitlab_pages['external_https'] setting. See GitLab Pages documentation for more details.
• (2): Port 443 for GitLab Pages should always use the TCP protocol. Users can configure custom domains with custom SSL, which would not be possible if SSL was terminated at the load balancer.

Alternate SSH Port

Some organizations have policies against opening SSH port 22. In this case, it may be helpful to configure an alternate SSH hostname that allows users to use SSH on port 443. An alternate SSH hostname will require a new virtual IP address compared to the other GitLab HTTP configuration above.

Configure DNS for an alternate SSH hostname such as altssh.gitlab.example.com.

SSL

The next question is how you will handle SSL in your environment. There are several different options:

• The application node terminates SSL.
• The load balancer terminates SSL without backend SSL and communication is not secure between the load balancer and the application node.
• The load balancer terminates SSL with backend SSL and communication is secure between the load balancer and the application node.

Application node terminates SSL

Configure your load balancer to pass connections on port 443 as TCP rather than HTTP(S) protocol. This will pass the connection to the application node's NGINX service untouched. NGINX will have the SSL certificate and listen on port 443.

See the HTTPS documentation for details on managing SSL certificates and configuring NGINX.

Load balancer terminates SSL without backend SSL

Configure your load balancer to use the HTTP(S) protocol rather than TCP. The load balancer will then be responsible for managing SSL certificates and terminating SSL.

Since communication between the load balancer and GitLab will not be secure, there is some additional configuration needed. See the proxied SSL documentation for details.

Load balancer terminates SSL with backend SSL

Configure your load balancers to use the 'HTTP(S)' protocol rather than 'TCP'. The load balancers will be responsible for managing SSL certificates that end users will see.

Traffic will also be secure between the load balancers and NGINX in this scenario. There is no need to add configuration for proxied SSL since the connection will be secure all the way. However, configuration will need to be added to GitLab to configure SSL certificates. See the HTTPS documentation for details on managing SSL certificates and configuring NGINX.

Configure the internal load balancer

The Internal Load Balancer is used to balance any internal connections the GitLab environment requires such as connections to PgBouncer and Praefect (Gitaly Cluster).

It's a separate node from the External Load Balancer and shouldn't have any access externally.

The following IP will be used as an example:

• 10.6.0.40: Internal Load Balancer

Here's how you could do it with HAProxy:

global
    log /dev/log local0
    log localhost local1 notice
    log stdout format raw local0

defaults
    log global
    default-server inter 10s fall 3 rise 2
    balance leastconn

frontend internal-pgbouncer-tcp-in
    bind *:6432
    mode tcp
    option tcplog

    default_backend pgbouncer

frontend internal-praefect-tcp-in
    bind *:2305
    mode tcp
    option tcplog
    option clitcpka

    default_backend praefect

backend pgbouncer
    mode tcp
    option tcp-check

    server pgbouncer1 10.6.0.31:6432 check
    server pgbouncer2 10.6.0.32:6432 check
    server pgbouncer3 10.6.0.33:6432 check

backend praefect
    mode tcp
    option tcp-check
    option srvtcpka

    server praefect1 10.6.0.131:2305 check
    server praefect2 10.6.0.132:2305 check
    server praefect3 10.6.0.133:2305 check

Refer to your preferred Load Balancer's documentation for further guidance.

Configure Consul

Next, we set up the Consul servers.

NOTE: Consul must be deployed in an odd number of 3 nodes or more. This is to ensure the nodes can take votes as part of a quorum.

The following IPs will be used as an example:

• 10.6.0.11: Consul 1
• 10.6.0.12: Consul 2
• 10.6.0.13: Consul 3

To configure Consul:

1. SSH in to the server that will host Consul.

2. Download and install the Linux package of your choice. Be sure to both follow only installation steps 1 and 2 on the page, and to select the correct Linux package, with the same version and type (Community or Enterprise editions) as your current install.

3. Edit /etc/gitlab/gitlab.rb and add the contents:

   roles(['consul_role'])
   
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      server: true,
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Reconfigure GitLab for the changes to take effect.

6. Go through the steps again for all the other Consul nodes, and make sure you set up the correct IPs.

A Consul leader is elected when the provisioning of the third Consul server is complete. Viewing the Consul logs sudo gitlab-ctl tail consul displays ...[INFO] consul: New leader elected: ....

You can list the current Consul members (server, client):

sudo /opt/gitlab/embedded/bin/consul members

You can verify the GitLab services are running:

sudo gitlab-ctl status

The output should be similar to the following:

run: consul: (pid 30074) 76834s; run: log: (pid 29740) 76844s
run: logrotate: (pid 30925) 3041s; run: log: (pid 29649) 76861s
run: node-exporter: (pid 30093) 76833s; run: log: (pid 29663) 76855s

Configure PostgreSQL

In this section, you'll be guided through configuring a highly available PostgreSQL cluster to be used with GitLab.

Provide your own PostgreSQL instance

You can optionally use a third party external service for PostgreSQL.

A reputable provider or solution should be used for this. Google Cloud SQL and Amazon RDS are known to work. However, Amazon Aurora is incompatible with load balancing enabled by default from 14.4.0.

See Recommended cloud providers and services for more information.

If you use a third party external service:

1. The HA Linux package PostgreSQL setup encompasses PostgreSQL, PgBouncer and Consul. These components would no longer be required when using a third party external service.
2. Set up PostgreSQL according to the database requirements document.
3. Set up a gitlab username with a password of your choice. The gitlab user needs privileges to create the gitlabhq_production database.
4. Configure the GitLab application servers with the appropriate details. This step is covered in Configuring the GitLab Rails application.
5. The number of nodes required to achieve HA may differ depending on the service compared to the Linux package and doesn't need to match accordingly.
6. However, if Database Load Balancing via Read Replicas is desired for further improved performance it's recommended to follow the node count for the Reference Architecture.

Standalone PostgreSQL using the Linux package

The recommended Linux package configuration for a PostgreSQL cluster with replication and failover requires:

• A minimum of three PostgreSQL nodes.

• A minimum of three Consul server nodes.

• A minimum of three PgBouncer nodes that track and handle primary database reads and writes.

  • An internal load balancer (TCP) to balance requests between the PgBouncer nodes.

• Database Load Balancing enabled.

  A local PgBouncer service to be configured on each PostgreSQL node. This is separate from the main PgBouncer cluster that tracks the primary.

The following IPs are used as an example:

• 10.6.0.21: PostgreSQL primary
• 10.6.0.22: PostgreSQL secondary 1
• 10.6.0.23: PostgreSQL secondary 2

First, make sure to install the Linux GitLab package on each node. Following the steps, install the necessary dependencies from step 1, and add the GitLab package repository from step 2. When installing GitLab in the second step, do not supply the EXTERNAL_URL value.

PostgreSQL nodes

1. SSH in to one of the PostgreSQL nodes.

2. Generate a password hash for the PostgreSQL username/password pair. This assumes you will use the default username of gitlab (recommended). The command will request a password and confirmation. Use the value that is output by this command in the next step as the value of <postgresql_password_hash>:

   sudo gitlab-ctl pg-password-md5 gitlab

3. Generate a password hash for the PgBouncer username/password pair. This assumes you will use the default username of pgbouncer (recommended). The command will request a password and confirmation. Use the value that is output by this command in the next step as the value of <pgbouncer_password_hash>:

   sudo gitlab-ctl pg-password-md5 pgbouncer

4. Generate a password hash for the PostgreSQL replication username/password pair. This assumes you will use the default username of gitlab_replicator (recommended). The command will request a password and a confirmation. Use the value that is output by this command in the next step as the value of <postgresql_replication_password_hash>:

   sudo gitlab-ctl pg-password-md5 gitlab_replicator

5. Generate a password hash for the Consul database username/password pair. This assumes you will use the default username of gitlab-consul (recommended). The command will request a password and confirmation. Use the value that is output by this command in the next step as the value of <consul_password_hash>:

   sudo gitlab-ctl pg-password-md5 gitlab-consul

6. On every database node, edit /etc/gitlab/gitlab.rb replacing values noted in the # START user configuration section:

   # Disable all components except Patroni, PgBouncer and Consul
   roles(['patroni_role', 'pgbouncer_role'])
   
   # PostgreSQL configuration
   postgresql['listen_address'] = '0.0.0.0'
   
   # Sets `max_replication_slots` to double the number of database nodes.
   # Patroni uses one extra slot per node when initiating the replication.
   patroni['postgresql']['max_replication_slots'] = 6
   
   # Set `max_wal_senders` to one more than the number of replication slots in the cluster.
   # This is used to prevent replication from using up all of the
   # available database connections.
   patroni['postgresql']['max_wal_senders'] = 7
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false
   
   # Configure the Consul agent
   consul['services'] = %w(postgresql)
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   # START user configuration
   # Please set the real values as explained in Required Information section
   #
   # Replace PGBOUNCER_PASSWORD_HASH with a generated md5 value
   postgresql['pgbouncer_user_password'] = '<pgbouncer_password_hash>'
   # Replace POSTGRESQL_REPLICATION_PASSWORD_HASH with a generated md5 value
   postgresql['sql_replication_password'] = '<postgresql_replication_password_hash>'
   # Replace POSTGRESQL_PASSWORD_HASH with a generated md5 value
   postgresql['sql_user_password'] = '<postgresql_password_hash>'
   
   # Set up basic authentication for the Patroni API (use the same username/password in all nodes).
   patroni['username'] = '<patroni_api_username>'
   patroni['password'] = '<patroni_api_password>'
   
   # Replace 10.6.0.0/24 with Network Address
   postgresql['trust_auth_cidr_addresses'] = %w(10.6.0.0/24 127.0.0.1/32)
   
   # Local PgBouncer service for Database Load Balancing
   pgbouncer['databases'] = {
      gitlabhq_production: {
         host: "127.0.0.1",
         user: "pgbouncer",
         password: '<pgbouncer_password_hash>'
      }
   }
   
   # Set the network addresses that the exporters will listen on for monitoring
   node_exporter['listen_address'] = '0.0.0.0:9100'
   postgres_exporter['listen_address'] = '0.0.0.0:9187'
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   #
   # END user configuration

PostgreSQL, with Patroni managing its failover, will default to use pg_rewind by default to handle conflicts. Like most failover handling methods, this has a small chance of leading to data loss. For more information, see the various Patroni replication methods.

1. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

2. Reconfigure GitLab for the changes to take effect.

Advanced configuration options are supported and can be added if needed.

PostgreSQL post-configuration

SSH in to any of the Patroni nodes on the primary site:

1. Check the status of the leader and cluster:

   gitlab-ctl patroni members

   The output should be similar to the following:

   | Cluster       | Member                            |  Host     | Role   | State   | TL  | Lag in MB | Pending restart |
   |---------------|-----------------------------------|-----------|--------|---------|-----|-----------|-----------------|
   | postgresql-ha | <PostgreSQL primary hostname>     | 10.6.0.21 | Leader | running | 175 |           | *               |
   | postgresql-ha | <PostgreSQL secondary 1 hostname> | 10.6.0.22 |        | running | 175 | 0         | *               |
   | postgresql-ha | <PostgreSQL secondary 2 hostname> | 10.6.0.23 |        | running | 175 | 0         | *               |

If the 'State' column for any node doesn't say "running", check the PostgreSQL replication and failover troubleshooting section before proceeding.

Configure PgBouncer

Now that the PostgreSQL servers are all set up, let's configure PgBouncer for tracking and handling reads/writes to the primary database.

NOTE: PgBouncer is single threaded and doesn't significantly benefit from an increase in CPU cores. Refer to the scaling documentation for more information.

The following IPs will be used as an example:

• 10.6.0.31: PgBouncer 1
• 10.6.0.32: PgBouncer 2
• 10.6.0.33: PgBouncer 3

1. On each PgBouncer node, edit /etc/gitlab/gitlab.rb, and replace <consul_password_hash> and <pgbouncer_password_hash> with the password hashes you set up previously:

   # Disable all components except Pgbouncer and Consul agent
   roles(['pgbouncer_role'])
   
   # Configure PgBouncer
   pgbouncer['admin_users'] = %w(pgbouncer gitlab-consul)
   pgbouncer['users'] = {
      'gitlab-consul': {
         password: '<consul_password_hash>'
      },
      'pgbouncer': {
         password: '<pgbouncer_password_hash>'
      }
   }
   
   # Configure Consul agent
   consul['watchers'] = %w(postgresql)
   consul['configuration'] = {
   retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13)
   }
   
   # Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] = true
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'

2. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

3. Reconfigure GitLab for the changes to take effect.

   If an error execute[generate databases.ini] occurs, this is due to an existing known issue. It will be resolved when you run a second reconfigure after the next step.

4. Create a .pgpass file so Consul is able to reload PgBouncer. Enter the PgBouncer password twice when asked:

   gitlab-ctl write-pgpass --host 127.0.0.1 --database pgbouncer --user pgbouncer --hostuser gitlab-consul

5. Reconfigure GitLab once again to resolve any potential errors from the previous steps.

6. Ensure each node is talking to the current primary:

   gitlab-ctl pgb-console # You will be prompted for PGBOUNCER_PASSWORD

7. Once the console prompt is available, run the following queries:

   show databases ; show clients ;

   The output should be similar to the following:

           name         |  host       | port |      database       | force_user | pool_size | reserve_pool | pool_mode | max_connections | current_connections
   ---------------------+-------------+------+---------------------+------------+-----------+--------------+-----------+-----------------+---------------------
    gitlabhq_production | MASTER_HOST | 5432 | gitlabhq_production |            |        20 |            0 |           |               0 |                   0
    pgbouncer           |             | 6432 | pgbouncer           | pgbouncer  |         2 |            0 | statement |               0 |                   0
   (2 rows)
   
    type |   user    |      database       |  state  |   addr         | port  | local_addr | local_port |    connect_time     |    request_time     |    ptr    | link | remote_pid | tls
   ------+-----------+---------------------+---------+----------------+-------+------------+------------+---------------------+---------------------+-----------+------+------------+-----
    C    | pgbouncer | pgbouncer           | active  | 127.0.0.1      | 56846 | 127.0.0.1  |       6432 | 2017-08-21 18:09:59 | 2017-08-21 18:10:48 | 0x22b3880 |      |          0 |
   (2 rows)

Configure Redis

Using Redis in scalable environment is possible using a Primary x Replica topology with a Redis Sentinel service to watch and automatically start the failover procedure.

NOTE: Redis clusters must each be deployed in an odd number of 3 nodes or more. This is to ensure Redis Sentinel can take votes as part of a quorum. This does not apply when configuring Redis externally, such as a cloud provider service.

NOTE: Redis is primarily single threaded and doesn't significantly benefit from an increase in CPU cores. For this size of architecture it's strongly recommended having separate Cache and Persistent instances as specified to achieve optimum performance. Refer to the scaling documentation for more information.

Redis requires authentication if used with Sentinel. See Redis Security documentation for more information. We recommend using a combination of a Redis password and tight firewall rules to secure your Redis service. You are highly encouraged to read the Redis Sentinel documentation before configuring Redis with GitLab to fully understand the topology and architecture.

The requirements for a Redis setup are the following:

1. All Redis nodes must be able to talk to each other and accept incoming connections over Redis (6379) and Sentinel (26379) ports (unless you change the default ones).
2. The server that hosts the GitLab application must be able to access the Redis nodes.
3. Protect the nodes from access from external networks (Internet), using a firewall.

In this section, you'll be guided through configuring two external Redis clusters to be used with GitLab. The following IPs will be used as an example:

• 10.6.0.51: Redis - Cache Primary
• 10.6.0.52: Redis - Cache Replica 1
• 10.6.0.53: Redis - Cache Replica 2
• 10.6.0.61: Redis - Persistent Primary
• 10.6.0.62: Redis - Persistent Replica 1
• 10.6.0.63: Redis - Persistent Replica 2

Provide your own Redis instances

You can optionally use a third party external service for the Redis Cache and Persistence instances with the following guidance:

• A reputable provider or solution should be used for this. Google Memorystore and AWS ElastiCache are known to work.
• Redis Cluster mode is specifically not supported, but Redis Standalone with HA is.
• You must set the Redis eviction mode according to your setup.

For more information, see Recommended cloud providers and services.

Configure the Redis Cache cluster

This is the section where we install and set up the new Redis Cache instances.

Both the primary and replica Redis nodes need the same password defined in redis['password']. At any time during a failover, the Sentinels can reconfigure a node and change its status from primary to replica (and vice versa).

Configure the primary Redis Cache node

1. SSH in to the Primary Redis server.

2. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page, and to select the correct Linux package, with the same version and type (Community or Enterprise editions) as your current install.

3. Edit /etc/gitlab/gitlab.rb and add the contents:

   # Specify server role as 'redis_sentinel_role' 'redis_master_role'
   roles ['redis_sentinel_role', 'redis_master_role', 'consul_role']
   
   # Set IP bind address and Quorum number for Redis Sentinel service
   sentinel['bind'] = '0.0.0.0'
   sentinel['quorum'] = 2
   
   # IP address pointing to a local IP that the other machines can reach.
   # You can also set bind to '0.0.0.0' which listen in all interfaces.
   # If you really need to bind to an external accessible IP, make
   # sure you add extra firewall rules to prevent unauthorized access.
   redis['bind'] = '10.6.0.51'
   
   # Define a port so Redis can listen for TCP requests which will allow other
   # machines to connect to it.
   redis['port'] = 6379
   
   # Port of primary Redis server for Sentinel, uncomment to change to non default.
   # Defaults to `6379`.
   # redis['master_port'] = 6379
   
   # Set up password authentication for Redis (use the same password in all nodes).
   redis['master_password'] = 'REDIS_PRIMARY_PASSWORD_OF_FIRST_CLUSTER'
   
   # Must be the same in every Redis node.
   redis['master_name'] = 'gitlab-redis-cache'
   
   # The IP of this primary Redis node.
   redis['master_ip'] = '10.6.0.51'
   
   # Set the Redis Cache instance as an LRU
   # 90% of available RAM in MB
   redis['maxmemory'] = '13500mb'
   redis['maxmemory_policy'] = "allkeys-lru"
   redis['maxmemory_samples'] = 5
   
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   redis_exporter['listen_address'] = '0.0.0.0:9121'
   redis_exporter['flags'] = {
        'redis.addr' => 'redis://10.6.0.51:6379',
        'redis.password' => 'redis-password-goes-here',
   }
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Reconfigure GitLab for the changes to take effect.

Configure the replica Redis Cache nodes

1. SSH in to the replica Redis server.

2. Download and install the Linux package of your choice. Be sure to both follow only installation steps 1 and 2 on the page, and to select the correct Linux package, with the same version and type (Community or Enterprise editions) as your current install.

3. Edit /etc/gitlab/gitlab.rb and add the same contents as the primary node in the previous section replacing redis_master_node with redis_replica_node:

   # Specify server role as 'redis_replica_role' and enable Consul agent
   roles ['redis_sentinel_role', 'redis_replica_role', 'consul_role']
   
   # Set IP bind address and Quorum number for Redis Sentinel service
   sentinel['bind'] = `0.0.0.0`
   sentinel['quorum'] = 2
   
   # IP address pointing to a local IP that the other machines can reach.
   # Set bind to '0.0.0.0' to listen on all interfaces.
   # If you really need to bind to an external accessible IP, make
   # sure you add extra firewall rules to prevent unauthorized access.
   redis['bind'] = '10.6.0.52'
   
   # Define a port so Redis can listen for TCP requests which will allow other
   # machines to connect to it.
   redis['port'] = 6379
   
   ## Port of primary Redis server for Sentinel, uncomment to change to non default. Defaults
   ## to `6379`.
   #redis['master_port'] = 6379
   
   # Set up password authentication for Redis and replicas (use the same password in all nodes).
   redis['master_password'] = 'REDIS_PRIMARY_PASSWORD_OF_FIRST_CLUSTER'
   
   # Must be the same in every Redis node
   redis['master_name'] = 'gitlab-redis-cache'
   
   # The IP of the primary Redis node.
   redis['master_ip'] = '10.6.0.51'
   
   # Set the Redis Cache instance as an LRU
   # 90% of available RAM in MB
   redis['maxmemory'] = '13500mb'
   redis['maxmemory_policy'] = "allkeys-lru"
   redis['maxmemory_samples'] = 5
   
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   redis_exporter['listen_address'] = '0.0.0.0:9121'
   redis_exporter['flags'] = {
        'redis.addr' => 'redis://10.6.0.52:6379',
        'redis.password' => 'redis-password-goes-here',
   }
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Reconfigure GitLab for the changes to take effect.

6. Go through the steps again for all the other replica nodes, and make sure to set up the IPs correctly.

   Advanced configuration options are supported and can be added if needed.

Configure the Redis Persistent cluster

This is the section where we install and set up the new Redis Persistent instances.

Both the primary and replica Redis nodes need the same password defined in redis['password']. At any time during a failover, the Sentinels can reconfigure a node and change its status from primary to replica (and vice versa).

Configure the primary Redis Persistent node

1. SSH in to the Primary Redis server.

2. Download and install the Linux package of your choice. Be sure to both follow only installation steps 1 and 2 on the page, and to select the correct Linux package, with the same version and type (Community or Enterprise editions) as your current install.

3. Edit /etc/gitlab/gitlab.rb and add the contents:

   # Specify server roles as 'redis_sentinel_role' and 'redis_master_role'
   roles ['redis_sentinel_role', 'redis_master_role', 'consul_role']
   
   # Set IP bind address and Quorum number for Redis Sentinel service
   sentinel['bind'] = '0.0.0.0'
   sentinel['quorum'] = 2
   
   # IP address pointing to a local IP that the other machines can reach to.
   # You can also set bind to '0.0.0.0' which listen in all interfaces.
   # If you really need to bind to an external accessible IP, make
   # sure you add extra firewall rules to prevent unauthorized access.
   redis['bind'] = '10.6.0.61'
   
   # Define a port so Redis can listen for TCP requests which will allow other
   # machines to connect to it.
   redis['port'] = 6379
   
   ## Port of primary Redis server for Sentinel, uncomment to change to non default. Defaults
   ## to `6379`.
   #redis['master_port'] = 6379
   
   # Set up password authentication for Redis and replicas (use the same password in all nodes).
   redis['password'] = 'REDIS_PRIMARY_PASSWORD_OF_SECOND_CLUSTER'
   redis['master_password'] = 'REDIS_PRIMARY_PASSWORD_OF_SECOND_CLUSTER'
   
   ## Must be the same in every Redis node
   redis['master_name'] = 'gitlab-redis-persistent'
   
   ## The IP of this primary Redis node.
   redis['master_ip'] = '10.6.0.61'
   
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   redis_exporter['listen_address'] = '0.0.0.0:9121'
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Reconfigure GitLab for the changes to take effect.

Configure the replica Redis Persistent nodes

1. SSH in to the replica Redis Persistent server.

2. Download and install the Linux package of your choice. Be sure to both follow only installation steps 1 and 2 on the page, and to select the correct Linux package, with the same version and type (Community or Enterprise editions) as your current install.

3. Edit /etc/gitlab/gitlab.rb and add the contents:

   # Specify server role as 'redis_replica_role' and enable Consul agent
   roles ['redis_sentinel_role', 'redis_replica_role', 'consul_role']
   
   # Set IP bind address and Quorum number for Redis Sentinel service
   sentinel['bind'] = '0.0.0.0'
   sentinel['quorum'] = 2
   
   # IP address pointing to a local IP that the other machines can reach to.
   # You can also set bind to '0.0.0.0' which listen in all interfaces.
   # If you really need to bind to an external accessible IP, make
   # sure you add extra firewall rules to prevent unauthorized access.
   redis['bind'] = '10.6.0.62'
   
   # Define a port so Redis can listen for TCP requests which will allow other
   # machines to connect to it.
   redis['port'] = 6379
   
   ## Port of primary Redis server for Sentinel, uncomment to change to non default. Defaults
   ## to `6379`.
   #redis['master_port'] = 6379
   
   # The same password for Redis authentication you set up for the primary node.
   redis['master_password'] = 'REDIS_PRIMARY_PASSWORD_OF_SECOND_CLUSTER'
   
   ## Must be the same in every Redis node
   redis['master_name'] = 'gitlab-redis-persistent'
   
   # The IP of the primary Redis node.
   redis['master_ip'] = '10.6.0.61'
   
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   redis_exporter['listen_address'] = '0.0.0.0:9121'
   redis_exporter['flags'] = {
        'redis.addr' => 'redis://10.6.0.62:6379',
        'redis.password' => 'redis-password-goes-here',
   }
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Reconfigure GitLab for the changes to take effect.

6. Go through the steps again for all the other replica nodes, and make sure to set up the IPs correctly.

Advanced configuration options are supported and can be added if needed.

Configure Gitaly Cluster

Gitaly Cluster is a GitLab-provided and recommended fault tolerant solution for storing Git repositories. In this configuration, every Git repository is stored on every Gitaly node in the cluster, with one being designated the primary, and failover occurs automatically if the primary node goes down.

WARNING: Gitaly specifications are based on high percentiles of both usage patterns and repository sizes in good health. However, if you have large monorepos (larger than several gigabytes) or additional workloads these can significantly impact the performance of the environment and further adjustments may be required. If this applies to you, we strongly recommended referring to the linked documentation as well as reaching out to your Customer Success Manager or our Support team for further guidance.

Gitaly Cluster provides the benefits of fault tolerance, but comes with additional complexity of setup and management. Review the existing technical limitations and considerations before deploying Gitaly Cluster.

For guidance on:

• Implementing sharded Gitaly instead, follow the separate Gitaly documentation instead of this section. Use the same Gitaly specs.
• Migrating existing repositories that aren't managed by Gitaly Cluster, see migrate to Gitaly Cluster.

The recommended cluster setup includes the following components:

• 3 Gitaly nodes: Replicated storage of Git repositories.
• 3 Praefect nodes: Router and transaction manager for Gitaly Cluster.
• 1 Praefect PostgreSQL node: Database server for Praefect. A third-party solution is required for Praefect database connections to be made highly available.
• 1 load balancer: A load balancer is required for Praefect. The internal load balancer is used.

This section details how to configure the recommended standard setup in order. For more advanced setups refer to the standalone Gitaly Cluster documentation.

Configure Praefect PostgreSQL

Praefect, the routing and transaction manager for Gitaly Cluster, requires its own database server to store data on Gitaly Cluster status.

If you want to have a highly available setup, Praefect requires a third-party PostgreSQL database. A built-in solution is being worked on.

Praefect non-HA PostgreSQL standalone using the Linux package

The following IPs will be used as an example:

• 10.6.0.141: Praefect PostgreSQL

First, make sure to install the Linux GitLab package in the Praefect PostgreSQL node. Following the steps, install the necessary dependencies from step 1, and add the GitLab package repository from step 2. When installing GitLab in the second step, do not supply the EXTERNAL_URL value.

1. SSH in to the Praefect PostgreSQL node.

2. Create a strong password to be used for the Praefect PostgreSQL user. Take note of this password as <praefect_postgresql_password>.

3. Generate the password hash for the Praefect PostgreSQL username/password pair. This assumes you will use the default username of praefect (recommended). The command will request the password <praefect_postgresql_password> and confirmation. Use the value that is output by this command in the next step as the value of <praefect_postgresql_password_hash>:

   sudo gitlab-ctl pg-password-md5 praefect

4. Edit /etc/gitlab/gitlab.rb replacing values noted in the # START user configuration section:

   # Disable all components except PostgreSQL and Consul
   roles(['postgres_role', 'consul_role'])
   
   # PostgreSQL configuration
   postgresql['listen_address'] = '0.0.0.0'
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false
   
   # Configure the Consul agent
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   
   # START user configuration
   # Please set the real values as explained in Required Information section
   #
   # Replace PRAEFECT_POSTGRESQL_PASSWORD_HASH with a generated md5 value
   postgresql['sql_user_password'] = "<praefect_postgresql_password_hash>"
   
   # Replace XXX.XXX.XXX.XXX/YY with Network Address
   postgresql['trust_auth_cidr_addresses'] = %w(10.6.0.0/24 127.0.0.1/32)
   
   # Set the network addresses that the exporters will listen on for monitoring
   node_exporter['listen_address'] = '0.0.0.0:9100'
   postgres_exporter['listen_address'] = '0.0.0.0:9187'
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   #
   # END user configuration

5. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

6. Reconfigure GitLab for the changes to take effect.

7. Follow the post configuration.

Praefect HA PostgreSQL third-party solution

As noted, a third-party PostgreSQL solution for Praefect's database is recommended if aiming for full High Availability.

There are many third-party solutions for PostgreSQL HA. The solution selected must have the following to work with Praefect:

• A static IP for all connections that doesn't change on failover.
• LISTEN SQL functionality must be supported.

NOTE: With a third-party setup, it's possible to colocate Praefect's database on the same server as the main GitLab database as a convenience unless you are using Geo, where separate database instances are required for handling replication correctly. In this setup, the specs of the main database setup shouldn't need to be changed as the impact should be minimal.

A reputable provider or solution should be used for this. Google Cloud SQL and Amazon RDS are known to work. However, Amazon Aurora is incompatible with load balancing enabled by default from 14.4.0.

See Recommended cloud providers and services for more information.

Once the database is set up, follow the post configuration.

Praefect PostgreSQL post-configuration

After the Praefect PostgreSQL server has been set up, you'll then need to configure the user and database for Praefect to use.

We recommend the user be named praefect and the database praefect_production, and these can be configured as standard in PostgreSQL. The password for the user is the same as the one you configured earlier as <praefect_postgresql_password>.

This is how this would work with a Linux package PostgreSQL setup:

1. SSH in to the Praefect PostgreSQL node.

2. Connect to the PostgreSQL server with administrative access. The gitlab-psql user should be used here for this as it's added by default in the Linux package. The database template1 is used because it is created by default on all PostgreSQL servers.

   /opt/gitlab/embedded/bin/psql -U gitlab-psql -d template1 -h POSTGRESQL_SERVER_ADDRESS

3. Create the new user praefect, replacing <praefect_postgresql_password>:

   CREATE ROLE praefect WITH LOGIN CREATEDB PASSWORD '<praefect_postgresql_password>';

4. Reconnect to the PostgreSQL server, this time as the praefect user:

   /opt/gitlab/embedded/bin/psql -U praefect -d template1 -h POSTGRESQL_SERVER_ADDRESS

5. Create a new database praefect_production:

   CREATE DATABASE praefect_production WITH ENCODING=UTF8;

Configure Praefect

Praefect is the router and transaction manager for Gitaly Cluster and all connections to Gitaly go through it. This section details how to configure it.

NOTE: Praefect must be deployed in an odd number of 3 nodes or more. This is to ensure the nodes can take votes as part of a quorum.

Praefect requires several secret tokens to secure communications across the Cluster:

• <praefect_external_token>: Used for repositories hosted on your Gitaly cluster and can only be accessed by Gitaly clients that carry this token.
• <praefect_internal_token>: Used for replication traffic inside your Gitaly cluster. This is distinct from praefect_external_token because Gitaly clients must not be able to access internal nodes of the Praefect cluster directly; that could lead to data loss.
• <praefect_postgresql_password>: The Praefect PostgreSQL password defined in the previous section is also required as part of this setup.

Gitaly Cluster nodes are configured in Praefect via a virtual storage. Each storage contains the details of each Gitaly node that makes up the cluster. Each storage is also given a name and this name is used in several areas of the configuration. In this guide, the name of the storage will be default. Also, this guide is geared towards new installs, if upgrading an existing environment to use Gitaly Cluster, you may need to use a different name. Refer to the Praefect documentation for more information.

The following IPs will be used as an example:

• 10.6.0.131: Praefect 1
• 10.6.0.132: Praefect 2
• 10.6.0.133: Praefect 3

To configure the Praefect nodes, on each one:

1. SSH in to the Praefect server.

2. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page.

3. Edit the /etc/gitlab/gitlab.rb file to configure Praefect:

   NOTE: You can't remove the default entry from virtual_storages because GitLab requires it.

   # Avoid running unnecessary services on the Praefect server
   gitaly['enable'] = false
   postgresql['enable'] = false
   redis['enable'] = false
   nginx['enable'] = false
   puma['enable'] = false
   sidekiq['enable'] = false
   gitlab_workhorse['enable'] = false
   prometheus['enable'] = false
   alertmanager['enable'] = false
   gitlab_exporter['enable'] = false
   gitlab_kas['enable'] = false
   
   # Praefect Configuration
   praefect['enable'] = true
   
   # Prevent database migrations from running on upgrade automatically
   praefect['auto_migrate'] = false
   gitlab_rails['auto_migrate'] = false
   
   # Configure the Consul agent
   consul['enable'] = true
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] = true
   
   # START user configuration
   # Please set the real values as explained in Required Information section
   #
   
   praefect['configuration'] = {
      # ...
      listen_addr: '0.0.0.0:2305',
      auth: {
         # ...
         #
         # Praefect External Token
         # This is needed by clients outside the cluster (like GitLab Shell) to communicate with the Praefect cluster
         token: '<praefect_external_token>',
      },
      # Praefect Database Settings
      database: {
         # ...
         host: '10.6.0.141',
         port: 5432,
         dbname: 'praefect_production',
         user: 'praefect',
         password: '<praefect_postgresql_password>',
      },
      # Praefect Virtual Storage config
      # Name of storage hash must match storage name in git_data_dirs on GitLab
      # server ('praefect') and in gitaly['configuration'][:storage] on Gitaly nodes ('gitaly-1')
      virtual_storage: [
         {
            # ...
            name: 'default',
            node: [
               {
                  storage: 'gitaly-1',
                  address: 'tcp://10.6.0.91:8075',
                  token: '<praefect_internal_token>'
               },
               {
                  storage: 'gitaly-2',
                  address: 'tcp://10.6.0.92:8075',
                  token: '<praefect_internal_token>'
               },
               {
                  storage: 'gitaly-3',
                  address: 'tcp://10.6.0.93:8075',
                  token: '<praefect_internal_token>'
               },
            ],
         },
      ],
      # Set the network address Praefect will listen on for monitoring
      prometheus_listen_addr: '0.0.0.0:9652',
   }
   
   # Set the network address the node exporter will listen on for monitoring
   node_exporter['listen_address'] = '0.0.0.0:9100'
   
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   #
   # END user configuration

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Praefect requires to run some database migrations, much like the main GitLab application. For this you should select one Praefect node only to run the migrations, AKA the Deploy Node. This node must be configured first before the others as follows:

   1. In the /etc/gitlab/gitlab.rb file, change the praefect['auto_migrate'] setting value from false to true

   2. To ensure database migrations are only run during reconfigure and not automatically on upgrade, run:

   sudo touch /etc/gitlab/skip-auto-reconfigure

   1. Reconfigure GitLab for the changes to take effect and to run the Praefect database migrations.

6. On all other Praefect nodes, reconfigure GitLab for the changes to take effect.

Configure Gitaly

The Gitaly server nodes that make up the cluster have requirements that are dependent on data and load.

WARNING: Gitaly specifications are based on high percentiles of both usage patterns and repository sizes in good health. However, if you have large monorepos (larger than several gigabytes) or additional workloads these can significantly impact the performance of the environment and further adjustments may be required. If this applies to you, we strongly recommended referring to the linked documentation as well as reaching out to your Customer Success Manager or our Support team for further guidance.

Due to Gitaly having notable input and output requirements, we strongly recommend that all Gitaly nodes use solid-state drives (SSDs). These SSDs should have a throughput of at least 8,000 input/output operations per second (IOPS) for read operations and 2,000 IOPS for write operations. If you're running the environment on a Cloud provider, refer to their documentation about how to configure IOPS correctly.

Gitaly servers must not be exposed to the public internet, as network traffic on Gitaly is unencrypted by default. The use of a firewall is highly recommended to restrict access to the Gitaly server. Another option is to use TLS.

For configuring Gitaly you should note the following:

• gitaly['configuration'][:storage] should be configured to reflect the storage path for the specific Gitaly node
• auth_token should be the same as praefect_internal_token

The following IPs will be used as an example:

• 10.6.0.91: Gitaly 1
• 10.6.0.92: Gitaly 2
• 10.6.0.93: Gitaly 3

On each node:

1. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page, and do not provide the EXTERNAL_URL value.

2. Edit the Gitaly server node's /etc/gitlab/gitlab.rb file to configure storage paths, enable the network listener, and to configure the token:

   # Avoid running unnecessary services on the Gitaly server
   postgresql['enable'] = false
   redis['enable'] = false
   nginx['enable'] = false
   puma['enable'] = false
   sidekiq['enable'] = false
   gitlab_workhorse['enable'] = false
   prometheus['enable'] = false
   alertmanager['enable'] = false
   gitlab_exporter['enable'] = false
   gitlab_kas['enable'] = false
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false
   
   # Configure the gitlab-shell API callback URL. Without this, `git push` will
   # fail. This can be your 'front door' GitLab URL or an internal load
   # balancer.
   gitlab_rails['internal_api_url'] = 'https://gitlab.example.com'
   
   # Gitaly
   gitaly['enable'] = true
   
   # Configure the Consul agent
   consul['enable'] = true
   ## Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] = true
   
   # START user configuration
   # Please set the real values as explained in Required Information section
   #
   ## The IPs of the Consul server nodes
   ## You can also use FQDNs and intermix them with IPs
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13),
   }
   
   # Set the network address that the node exporter will listen on for monitoring
   node_exporter['listen_address'] = '0.0.0.0:9100'
   
   gitaly['configuration'] = {
      # Make Gitaly accept connections on all network interfaces. You must use
      # firewalls to restrict access to this address/port.
      # Comment out following line if you only want to support TLS connections
      listen_addr: '0.0.0.0:8075',
      # Set the network address that Gitaly will listen on for monitoring
      prometheus_listen_addr: '0.0.0.0:9236',
      auth: {
         # Gitaly Auth Token
         # Should be the same as praefect_internal_token
         token: '<praefect_internal_token>',
      },
      pack_objects_cache: {
         # Gitaly Pack-objects cache
         # Recommended to be enabled for improved performance but can notably increase disk I/O
         # Refer to https://docs.gitlab.com/ee/administration/gitaly/configure_gitaly.html#pack-objects-cache for more info
         enabled: true,
      },
   }
   
   #
   # END user configuration

3. Append the following to /etc/gitlab/gitlab.rb for each respective server:

   • On Gitaly node 1:

     gitaly['configuration'] = {
        # ...
        storage: [
           {
              name: 'gitaly-1',
              path: '/var/opt/gitlab/git-data',
           },
        ],
     }

   • On Gitaly node 2:

     gitaly['configuration'] = {
        # ...
        storage: [
           {
              name: 'gitaly-2',
              path: '/var/opt/gitlab/git-data',
           },
        ],
     }

   • On Gitaly node 3:

     gitaly['configuration'] = {
        # ...
        storage: [
           {
              name: 'gitaly-3',
              path: '/var/opt/gitlab/git-data',
           },
        ],
     }

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Save the file, and then reconfigure GitLab.

Gitaly Cluster TLS support

Praefect supports TLS encryption. To communicate with a Praefect instance that listens for secure connections, you must:

• Use a tls:// URL scheme in the gitaly_address of the corresponding storage entry in the GitLab configuration.
• Bring your own certificates because this isn't provided automatically. The certificate corresponding to each Praefect server must be installed on that Praefect server.

Additionally the certificate, or its certificate authority, must be installed on all Gitaly servers and on all Praefect clients that communicate with it following the procedure described in GitLab custom certificate configuration (and repeated below).

Note the following:

• The certificate must specify the address you use to access the Praefect server. You must add the hostname or IP address as a Subject Alternative Name to the certificate.
• You can configure Praefect servers with both an unencrypted listening address listen_addr and an encrypted listening address tls_listen_addr at the same time. This allows you to do a gradual transition from unencrypted to encrypted traffic, if necessary. To disable the unencrypted listener, set praefect['configuration'][:listen_addr] = nil.
• The Internal Load Balancer will also access to the certificates and need to be configured to allow for TLS passthrough. Refer to the load balancers documentation on how to configure this.

To configure Praefect with TLS:

1. Create certificates for Praefect servers.

2. On the Praefect servers, create the /etc/gitlab/ssl directory and copy your key and certificate there:

   sudo mkdir -p /etc/gitlab/ssl
   sudo chmod 755 /etc/gitlab/ssl
   sudo cp key.pem cert.pem /etc/gitlab/ssl/
   sudo chmod 644 key.pem cert.pem

3. Edit /etc/gitlab/gitlab.rb and add:

   praefect['configuration'] = {
      # ...
      tls_listen_addr: '0.0.0.0:3305',
      tls: {
         # ...
         certificate_path: '/etc/gitlab/ssl/cert.pem',
         key_path: '/etc/gitlab/ssl/key.pem',
      },
   }

4. Save the file and reconfigure.

5. On the Praefect clients (including each Gitaly server), copy the certificates, or their certificate authority, into /etc/gitlab/trusted-certs:

   sudo cp cert.pem /etc/gitlab/trusted-certs/

6. On the Praefect clients (except Gitaly servers), edit git_data_dirs in /etc/gitlab/gitlab.rb as follows:

   git_data_dirs({
     "default" => {
       "gitaly_address" => 'tls://LOAD_BALANCER_SERVER_ADDRESS:3305',
       "gitaly_token" => 'PRAEFECT_EXTERNAL_TOKEN'
     }
   })

7. Save the file and reconfigure GitLab.

Configure Sidekiq

Sidekiq requires connection to the Redis, PostgreSQL and Gitaly instances. It also requires a connection to Object Storage as recommended.

NOTE: Because it's recommended to use Object storage instead of NFS for data objects, the following examples include the Object storage configuration.

NOTE: If you find that the environment's Sidekiq job processing is slow with long queues you can scale it accordingly. Refer to the scaling documentation for more information.

NOTE: When configuring additional GitLab functionality such as Container Registry, SAML, or LDAP, update the Sidekiq configuration in addition to the Rails configuration. Refer to the external Sidekiq documentation for more information.

• 10.6.0.101: Sidekiq 1
• 10.6.0.102: Sidekiq 2
• 10.6.0.103: Sidekiq 3
• 10.6.0.104: Sidekiq 4

To configure the Sidekiq nodes, on each one:

1. SSH in to the Sidekiq server.

2. Confirm that you can access the PostgreSQL, Gitaly, and Redis ports:

   telnet <GitLab host> 5432 # PostgreSQL
   telnet <GitLab host> 8075 # Gitaly
   telnet <GitLab host> 6379 # Redis

3. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page.

4. Create or edit /etc/gitlab/gitlab.rb and use the following configuration:

   # https://docs.gitlab.com/omnibus/roles/#sidekiq-roles
   roles(["sidekiq_role"])
   
   # External URL
   ## This should match the URL of the external load balancer
   external_url 'https://gitlab.example.com'
   
   # Redis
   ## Redis connection details
   ## First cluster that will host the cache data
   gitlab_rails['redis_cache_instance'] = 'redis://:<REDIS_PRIMARY_PASSWORD_OF_FIRST_CLUSTER>@gitlab-redis-cache'
   
   gitlab_rails['redis_cache_sentinels'] = [
     {host: '10.6.0.51', port: 26379},
     {host: '10.6.0.52', port: 26379},
     {host: '10.6.0.53', port: 26379},
   ]
   
   ## Second cluster that hosts all other persistent data
   redis['master_name'] = 'gitlab-redis-persistent'
   redis['master_password'] = '<REDIS_PRIMARY_PASSWORD_OF_SECOND_CLUSTER>'
   
   gitlab_rails['redis_sentinels'] = [
     {host: '10.6.0.61', port: 26379},
     {host: '10.6.0.62', port: 26379},
     {host: '10.6.0.63', port: 26379},
   ]
   
   # Gitaly Cluster
   ## git_data_dirs get configured for the Praefect virtual storage
   ## Address is Internal Load Balancer for Praefect
   ## Token is praefect_external_token
   git_data_dirs({
     "default" => {
       "gitaly_address" => "tcp://10.6.0.40:2305", # internal load balancer IP
       "gitaly_token" => '<praefect_external_token>'
     }
   })
   
   # PostgreSQL
   gitlab_rails['db_host'] = '10.6.0.20' # internal load balancer IP
   gitlab_rails['db_port'] = 6432
   gitlab_rails['db_password'] = '<postgresql_user_password>'
   gitlab_rails['db_load_balancing'] = { 'hosts' => ['10.6.0.21', '10.6.0.22', '10.6.0.23'] } # PostgreSQL IPs
   
   ## Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false
   
   # Sidekiq
   sidekiq['listen_address'] = "0.0.0.0"
   
   ## Set number of Sidekiq queue processes to the same number as available CPUs
   sidekiq['queue_groups'] = ['*'] * 4
   
   # Monitoring
   consul['enable'] = true
   consul['monitoring_service_discovery'] =  true
   
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13)
   }
   
   ## Set the network addresses that the exporters will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   
   ## Add the monitoring node's IP address to the monitoring whitelist
   gitlab_rails['monitoring_whitelist'] = ['10.6.0.151/32', '127.0.0.0/8']
   
   # Object Storage
   # This is an example for configuring Object Storage on GCP
   # Replace this config with your chosen Object Storage provider as desired
   gitlab_rails['object_store']['enabled'] = true
   gitlab_rails['object_store']['connection'] = {
     'provider' => 'Google',
     'google_project' => '<gcp-project-name>',
     'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }
   gitlab_rails['object_store']['objects']['artifacts']['bucket'] = "<gcp-artifacts-bucket-name>"
   gitlab_rails['object_store']['objects']['external_diffs']['bucket'] = "<gcp-external-diffs-bucket-name>"
   gitlab_rails['object_store']['objects']['lfs']['bucket'] = "<gcp-lfs-bucket-name>"
   gitlab_rails['object_store']['objects']['uploads']['bucket'] = "<gcp-uploads-bucket-name>"
   gitlab_rails['object_store']['objects']['packages']['bucket'] = "<gcp-packages-bucket-name>"
   gitlab_rails['object_store']['objects']['dependency_proxy']['bucket'] = "<gcp-dependency-proxy-bucket-name>"
   gitlab_rails['object_store']['objects']['terraform_state']['bucket'] = "<gcp-terraform-state-bucket-name>"
   
   gitlab_rails['backup_upload_connection'] = {
     'provider' => 'Google',
     'google_project' => '<gcp-project-name>',
     'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }
   gitlab_rails['backup_upload_remote_directory'] = "<gcp-backups-state-bucket-name>"
   
   gitlab_rails['ci_secure_files_object_store_enabled'] = true
   gitlab_rails['ci_secure_files_object_store_remote_directory'] = "gcp-ci_secure_files-bucket-name"
   
   gitlab_rails['ci_secure_files_object_store_connection'] = {
      'provider' => 'Google',
      'google_project' => '<gcp-project-name>',
      'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }

5. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

6. To ensure database migrations are only run during reconfigure and not automatically on upgrade, run:

   sudo touch /etc/gitlab/skip-auto-reconfigure

   Only a single designated node should handle migrations as detailed in the GitLab Rails post-configuration section.

7. Reconfigure GitLab for the changes to take effect.

Configure GitLab Rails

This section describes how to configure the GitLab application (Rails) component.

Rails requires connections to the Redis, PostgreSQL and Gitaly instances. It also requires a connection to Object Storage as recommended.

NOTE: Because it's recommended to use Object storage instead of NFS for data objects, the following examples include the Object storage configuration.

The following IPs will be used as an example:

• 10.6.0.111: GitLab application 1
• 10.6.0.112: GitLab application 2
• 10.6.0.113: GitLab application 3
• 10.6.0.114: GitLab application 4
• 10.6.0.115: GitLab application 5

On each node perform the following:

1. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page.

2. Edit /etc/gitlab/gitlab.rb and use the following configuration. To maintain uniformity of links across nodes, the external_url on the application server should point to the external URL that users will use to access GitLab. This would be the URL of the external load balancer which will route traffic to the GitLab application server:

   external_url 'https://gitlab.example.com'
   
   # git_data_dirs get configured for the Praefect virtual storage
   # Address is Internal Load Balancer for Praefect
   # Token is praefect_external_token
   git_data_dirs({
     "default" => {
       "gitaly_address" => "tcp://10.6.0.40:2305", # internal load balancer IP
       "gitaly_token" => '<praefect_external_token>'
     }
   })
   
   ## Disable components that will not be on the GitLab application server
   roles(['application_role'])
   gitaly['enable'] = false
   sidekiq['enable'] = false
   
   ## PostgreSQL connection details
   # Disable PostgreSQL on the application node
   postgresql['enable'] = false
   gitlab_rails['db_host'] = '10.6.0.20' # internal load balancer IP
   gitlab_rails['db_port'] = 6432
   gitlab_rails['db_password'] = '<postgresql_user_password>'
   gitlab_rails['db_load_balancing'] = { 'hosts' => ['10.6.0.21', '10.6.0.22', '10.6.0.23'] } # PostgreSQL IPs
   
   # Prevent database migrations from running on upgrade automatically
   gitlab_rails['auto_migrate'] = false
   
   ## Redis connection details
   ## First cluster that will host the cache data
   gitlab_rails['redis_cache_instance'] = 'redis://:<REDIS_PRIMARY_PASSWORD_OF_FIRST_CLUSTER>@gitlab-redis-cache'
   
   gitlab_rails['redis_cache_sentinels'] = [
     {host: '10.6.0.51', port: 26379},
     {host: '10.6.0.52', port: 26379},
     {host: '10.6.0.53', port: 26379},
   ]
   
   ## Second cluster that hosts all other persistent data
   redis['master_name'] = 'gitlab-redis-persistent'
   redis['master_password'] = '<REDIS_PRIMARY_PASSWORD_OF_SECOND_CLUSTER>'
   
   gitlab_rails['redis_sentinels'] = [
     {host: '10.6.0.61', port: 26379},
     {host: '10.6.0.62', port: 26379},
     {host: '10.6.0.63', port: 26379},
   ]
   
   # Set the network addresses that the exporters used for monitoring will listen on
   node_exporter['listen_address'] = '0.0.0.0:9100'
   gitlab_workhorse['prometheus_listen_addr'] = '0.0.0.0:9229'
   puma['listen'] = '0.0.0.0'
   
   # Add the monitoring node's IP address to the monitoring whitelist and allow it to
   # scrape the NGINX metrics
   gitlab_rails['monitoring_whitelist'] = ['10.6.0.151/32', '127.0.0.0/8']
   nginx['status']['options']['allow'] = ['10.6.0.151/32', '127.0.0.0/8']
   
   #############################
   ###     Object storage    ###
   #############################
   
   # This is an example for configuring Object Storage on GCP
   # Replace this config with your chosen Object Storage provider as desired
   gitlab_rails['object_store']['enabled'] = true
   gitlab_rails['object_store']['connection'] = {
     'provider' => 'Google',
     'google_project' => '<gcp-project-name>',
     'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }
   gitlab_rails['object_store']['objects']['artifacts']['bucket'] = "<gcp-artifacts-bucket-name>"
   gitlab_rails['object_store']['objects']['external_diffs']['bucket'] = "<gcp-external-diffs-bucket-name>"
   gitlab_rails['object_store']['objects']['lfs']['bucket'] = "<gcp-lfs-bucket-name>"
   gitlab_rails['object_store']['objects']['uploads']['bucket'] = "<gcp-uploads-bucket-name>"
   gitlab_rails['object_store']['objects']['packages']['bucket'] = "<gcp-packages-bucket-name>"
   gitlab_rails['object_store']['objects']['dependency_proxy']['bucket'] = "<gcp-dependency-proxy-bucket-name>"
   gitlab_rails['object_store']['objects']['terraform_state']['bucket'] = "<gcp-terraform-state-bucket-name>"
   
   gitlab_rails['backup_upload_connection'] = {
     'provider' => 'Google',
     'google_project' => '<gcp-project-name>',
     'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }
   gitlab_rails['backup_upload_remote_directory'] = "<gcp-backups-state-bucket-name>"
   gitlab_rails['ci_secure_files_object_store_enabled'] = true
   gitlab_rails['ci_secure_files_object_store_remote_directory'] = "gcp-ci_secure_files-bucket-name"
   
   gitlab_rails['ci_secure_files_object_store_connection'] = {
      'provider' => 'Google',
      'google_project' => '<gcp-project-name>',
      'google_json_key_location' => '<path-to-gcp-service-account-key>'
   }

3. If you're using Gitaly with TLS support, make sure the git_data_dirs entry is configured with tls instead of tcp:

   git_data_dirs({
     "default" => {
       "gitaly_address" => "tls://10.6.0.40:2305", # internal load balancer IP
       "gitaly_token" => '<praefect_external_token>'
     }
   })

   1. Copy the cert into /etc/gitlab/trusted-certs:

      sudo cp cert.pem /etc/gitlab/trusted-certs/

4. Copy the /etc/gitlab/gitlab-secrets.json file from the first Linux package node you configured and add or replace the file of the same name on this server. If this is the first Linux package node you are configuring then you can skip this step.

5. Copy the SSH host keys (all in the name format /etc/ssh/ssh_host_*_key*) from the first Linux package node you configured and add or replace the files of the same name on this server. This ensures host mismatch errors aren't thrown for your users as they hit the load balanced Rails nodes. If this is the first Linux package node you are configuring, then you can skip this step.

6. To ensure database migrations are only run during reconfigure and not automatically on upgrade, run:

   sudo touch /etc/gitlab/skip-auto-reconfigure

   Only a single designated node should handle migrations as detailed in the GitLab Rails post-configuration section.

7. Reconfigure GitLab for the changes to take effect.

8. Enable incremental logging.

9. Confirm the node can connect to Gitaly:

   sudo gitlab-rake gitlab:gitaly:check

   Then, tail the logs to see the requests:

   sudo gitlab-ctl tail gitaly

10. Optionally, from the Gitaly servers, confirm that Gitaly can perform callbacks to the internal API:

    • For GitLab 15.3 and later, run sudo -u git -- /opt/gitlab/embedded/bin/gitaly check /var/opt/gitlab/gitaly/config.toml.
    • For GitLab 15.2 and earlier, run sudo -u git -- /opt/gitlab/embedded/bin/gitaly-hooks check /var/opt/gitlab/gitaly/config.toml.

When you specify https in the external_url, as in the previous example, GitLab expects that the SSL certificates are in /etc/gitlab/ssl/. If the certificates aren't present, NGINX will fail to start. For more information, see the HTTPS documentation.

GitLab Rails post-configuration

1. Designate one application node for running database migrations during installation and updates. Initialize the GitLab database and ensure all migrations ran:

   sudo gitlab-rake gitlab:db:configure

   This operation requires configuring the Rails node to connect to the primary database directly, bypassing PgBouncer. After migrations have completed, you must configure the node to pass through PgBouncer again.

2. Configure fast lookup of authorized SSH keys in the database.

Configure Prometheus

The Linux package can be used to configure a standalone Monitoring node running Prometheus.

The following IP will be used as an example:

• 10.6.0.151: Prometheus

To configure the Monitoring node:

1. SSH in to the Monitoring node.

2. Download and install the Linux package of your choice. Be sure to follow only installation steps 1 and 2 on the page.

3. Edit /etc/gitlab/gitlab.rb and add the contents:

   roles(['monitoring_role', 'consul_role'])
   
   external_url 'http://gitlab.example.com'
   
   # Prometheus
   prometheus['listen_address'] = '0.0.0.0:9090'
   prometheus['monitor_kubernetes'] = false
   
   # Enable service discovery for Prometheus
   consul['monitoring_service_discovery'] =  true
   consul['configuration'] = {
      retry_join: %w(10.6.0.11 10.6.0.12 10.6.0.13)
   }
   
   # Configure Prometheus to scrape services not covered by discovery
   prometheus['scrape_configs'] = [
      {
         'job_name': 'pgbouncer',
         'static_configs' => [
            'targets' => [
            "10.6.0.31:9188",
            "10.6.0.32:9188",
            "10.6.0.33:9188",
            ],
         ],
      },
      {
         'job_name': 'praefect',
         'static_configs' => [
            'targets' => [
            "10.6.0.131:9652",
            "10.6.0.132:9652",
            "10.6.0.133:9652",
            ],
         ],
      },
   ]
   
   nginx['enable'] = false

4. Save the file and reconfigure GitLab.

Configure the object storage

GitLab supports using an object storage service for holding numerous types of data. It's recommended over NFS for data objects and in general it's better in larger setups as object storage is typically much more performant, reliable, and scalable. See Recommended cloud providers and services for more information.

There are two ways of specifying object storage configuration in GitLab:

• Consolidated form: A single credential is shared by all supported object types.
• Storage-specific form: Every object defines its own object storage connection and configuration.

The consolidated form is used in the following examples when available.

Using separate buckets for each data type is the recommended approach for GitLab. This ensures there are no collisions across the various types of data GitLab stores. There are plans to enable the use of a single bucket in the future.

Enable incremental logging

GitLab Runner returns job logs in chunks which the Linux package caches temporarily on disk in /var/opt/gitlab/gitlab-ci/builds by default, even when using consolidated object storage. With default configuration, this directory needs to be shared through NFS on any GitLab Rails and Sidekiq nodes.

While sharing the job logs through NFS is supported, it's recommended to avoid the need to use NFS by enabling incremental logging (required when no NFS node has been deployed). Incremental logging uses Redis instead of disk space for temporary caching of job logs.

Configure advanced search

You can leverage Elasticsearch and enable advanced search for faster, more advanced code search across your entire GitLab instance.

Elasticsearch cluster design and requirements are dependent on your specific data. For recommended best practices about how to set up your Elasticsearch cluster alongside your instance, read how to choose the optimal cluster configuration.

Cloud Native Hybrid reference architecture with Helm Charts (alternative)

An alternative approach is to run specific GitLab components in Kubernetes. The following services are supported:

• GitLab Rails
• Sidekiq
• NGINX
• Toolbox
• Migrations
• Prometheus

Hybrid installations leverage the benefits of both cloud native and traditional compute deployments. With this, stateless components can benefit from cloud native workload management benefits while stateful components are deployed in compute VMs with Linux package installations to benefit from increased permanence.

Refer to the Helm charts Advanced configuration documentation for setup instructions including guidance on what GitLab secrets to sync between Kubernetes and the backend components.

NOTE: This is an advanced setup. Running services in Kubernetes is well known to be complex. This setup is only recommended if you have strong working knowledge and experience in Kubernetes. The rest of this section assumes this.

WARNING: Gitaly Cluster is not supported to be run in Kubernetes. Refer to epic 6127 for more details.

Cluster topology

The following tables and diagram detail the hybrid environment using the same formats as the typical environment above.

First are the components that run in Kubernetes. These run across several node groups, although you can change the overall makeup as desired as long as the minimum CPU and Memory requirements are observed.

• For this setup, we recommend and regularly test Google Kubernetes Engine (GKE) and Amazon Elastic Kubernetes Service (EKS). Other Kubernetes services may also work, but your mileage may vary.
• GCP and AWS examples of how to reach the Target Node Pool Total are given for convenience. These sizes are used in performance testing but following the example is not required. Different node pool designs can be used as desired as long as the targets are met, and all pods can deploy.
• The Webservice and Sidekiq target node pool totals are given for GitLab components only. Additional resources are required for the chosen Kubernetes provider's system processes. The given examples take this into account.
• The Supporting target node pool total is given generally to accommodate several resources for supporting the GitLab deployment as well as any additional deployments you may wish to make depending on your requirements. Similar to the other node pools, the chosen Kubernetes provider's system processes also require resources. The given examples take this into account.
• In production deployments, it's not required to assign pods to specific nodes. However, it is recommended to have several nodes in each pool spread across different availability zones to align with resilient cloud architecture practices.
• Enabling autoscaling, such as Cluster Autoscaler, for efficiency reasons is encouraged, but it's generally recommended targeting a floor of 75% for Webservice and Sidekiq pods to ensure ongoing performance.

Next are the backend components that run on static compute VMs using the Linux package (or External PaaS services where applicable):

Footnotes:

1. Can be optionally run on reputable third-party external PaaS PostgreSQL solutions. See Provide your own PostgreSQL instance for more information.
2. Can be optionally run on reputable third-party external PaaS Redis solutions. See Provide your own Redis instances for more information.
   • Redis is primarily single threaded and doesn't significantly benefit from an increase in CPU cores. For this size of architecture it's strongly recommended having separate Cache and Persistent instances as specified to achieve optimum performance.
3. Can be optionally run on reputable third-party load balancing services (LB PaaS). See Recommended cloud providers and services for more information.
4. Should be run on reputable Cloud Provider or Self Managed solutions. See Configure the object storage for more information.
5. Gitaly Cluster provides the benefits of fault tolerance, but comes with additional complexity of setup and management. Review the existing technical limitations and considerations before deploying Gitaly Cluster. If you want sharded Gitaly, use the same specs listed above for Gitaly.
6. Gitaly specifications are based on high percentiles of both usage patterns and repository sizes in good health. However, if you have large monorepos (larger than several gigabytes) or additional workloads these can significantly impact Git and Gitaly performance and further adjustments will likely be required.

NOTE: For all PaaS solutions that involve configuring instances, it's recommended to implement a minimum of three nodes in three different availability zones to align with resilient cloud architecture practices.

@startuml 25k
skinparam linetype ortho

card "Kubernetes via Helm Charts" as kubernetes {
  card "**External Load Balancer**" as elb #6a9be7

  together {
    collections "**Webservice**" as gitlab #32CD32
    collections "**Sidekiq**" as sidekiq #ff8dd1
  }

  card "**Supporting Services**" as support
}

card "**Internal Load Balancer**" as ilb #9370DB
collections "**Consul** x3" as consul #e76a9b

card "Gitaly Cluster" as gitaly_cluster {
  collections "**Praefect** x3" as praefect #FF8C00
  collections "**Gitaly** x3" as gitaly #FF8C00
  card "**Praefect PostgreSQL***\n//Non fault-tolerant//" as praefect_postgres #FF8C00

  praefect -[#FF8C00]-> gitaly
  praefect -[#FF8C00]> praefect_postgres
}

card "Database" as database {
  collections "**PGBouncer** x3" as pgbouncer #4EA7FF
  card "**PostgreSQL** (Primary)" as postgres_primary #4EA7FF
  collections "**PostgreSQL** (Secondary) x2" as postgres_secondary #4EA7FF

  pgbouncer -[#4EA7FF]-> postgres_primary
  postgres_primary .[#4EA7FF]> postgres_secondary
}

card "redis" as redis {
  collections "**Redis Persistent** x3" as redis_persistent #FF6347
  collections "**Redis Cache** x3" as redis_cache #FF6347

  redis_cache -[hidden]-> redis_persistent
}

cloud "**Object Storage**" as object_storage #white

elb -[#6a9be7]-> gitlab
elb -[hidden]-> sidekiq
elb -[hidden]-> support

gitlab -[#32CD32]--> ilb
gitlab -[#32CD32]r--> object_storage
gitlab -[#32CD32,norank]----> redis
gitlab -[#32CD32]----> database

sidekiq -[#ff8dd1]--> ilb
sidekiq -[#ff8dd1]r--> object_storage
sidekiq -[#ff8dd1,norank]----> redis
sidekiq .[#ff8dd1]----> database

ilb -[#9370DB]--> gitaly_cluster
ilb -[#9370DB]--> database
ilb -[hidden,norank]--> redis

consul .[#e76a9b]--> database
consul .[#e76a9b,norank]--> gitaly_cluster
consul .[#e76a9b]--> redis

@enduml

Kubernetes component targets

The following section details the targets used for the GitLab components deployed in Kubernetes.

Webservice

Each Webservice pod (Puma and Workhorse) is recommended to be run with the following configuration:

• 4 Puma Workers
• 4 vCPU
• 5 GB memory (request)
• 7 GB memory (limit)

For 500 RPS or 25,000 users we recommend a total Puma worker count of around 140 so in turn it's recommended to run at least 35 Webservice pods.

For further information on Webservice resource usage, see the Charts documentation on Webservice resources.

NGINX

It's also recommended deploying the NGINX controller pods across the Webservice nodes as a DaemonSet. This is to allow the controllers to scale dynamically with the Webservice pods they serve and take advantage of the higher network bandwidth larger machine types typically have.

This isn't a strict requirement. The NGINX controller pods can be deployed as desired as long as they have enough resources to handle the web traffic.

Sidekiq

Each Sidekiq pod is recommended to be run with the following configuration:

• 1 Sidekiq worker
• 900m vCPU
• 2 GB memory (request)
• 4 GB memory (limit)

Similar to the standard deployment above, an initial target of 14 Sidekiq workers has been used here. Additional workers may be required depending on your specific workflow.

For further information on Sidekiq resource usage, see the Charts documentation on Sidekiq resources.

Supporting

The Supporting Node Pool is designed to house all supporting deployments that don't need to be on the Webservice and Sidekiq pools.

This includes various deployments related to the Cloud Provider's implementation and supporting GitLab deployments such as GitLab Shell.

If you wish to make any additional deployments such as Container Registry, Pages or Monitoring, it's recommended to deploy these in this pool where possible and not in the Webservice or Sidekiq pools, as the Supporting pool has been designed specifically to accommodate several additional deployments. However, if your deployments don't fit into the pool as given, you can increase the node pool accordingly. Conversely, if the pool in your use case is over-provisioned you can reduce accordingly.

Example config file

An example for the GitLab Helm Charts targeting the above 500 RPS or 25,000 reference architecture configuration can be found in the Charts project.

Next steps

After following this guide you should now have a fresh GitLab environment with core functionality configured accordingly.

You may want to configure additional optional features of GitLab depending on your requirements. See Steps after installing GitLab for more information.

NOTE: Depending on your environment and requirements, additional hardware requirements or adjustments may be required to set up additional features as desired. Refer to the individual pages for more information.