--- reading_time: true stage: Enablement group: Distribution info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#designated-technical-writers --- # Reference architecture: up to 2,000 users **(CORE ONLY)** This page describes GitLab reference architecture for up to 2,000 users. For a full list of reference architectures, see [Available reference architectures](index.md#available-reference-architectures). > - **Supported users (approximate):** 2,000 > - **High Availability:** No > - **Test requests per second (RPS) rates:** API: 40 RPS, Web: 4 RPS, Git: 4 RPS | Service | Nodes | Configuration | GCP | AWS | Azure | |------------------------------------------|--------|-------------------------|----------------|--------------|---------| | Load balancer | 1 | 2 vCPU, 1.8 GB memory | n1-highcpu-2 | c5.large | F2s v2 | | PostgreSQL | 1 | 2 vCPU, 7.5 GB memory | n1-standard-2 | m5.large | D2s v3 | | Redis | 1 | 1 vCPU, 3.75 GB memory | n1-standard-1 | m5.large | D2s v3 | | Gitaly | 1 | 4 vCPU, 15 GB memory | n1-standard-4 | m5.xlarge | D4s v3 | | GitLab Rails | 2 | 8 vCPU, 7.2 GB memory | n1-highcpu-8 | c5.2xlarge | F8s v2 | | Monitoring node | 1 | 2 vCPU, 1.8 GB memory | n1-highcpu-2 | c5.large | F2s v2 | | Object storage | n/a | n/a | n/a | n/a | n/a | | NFS server (optional, not recommended) | 1 | 4 vCPU, 3.6 GB memory | n1-highcpu-4 | c5.xlarge | F4s v2 | The Google Cloud Platform (GCP) architectures were built and tested using the [Intel Xeon E5 v3 (Haswell)](https://cloud.google.com/compute/docs/cpu-platforms) CPU platform. On different hardware you may find that adjustments, either lower or higher, are required for your CPU or node counts. For more information, see our [Sysbench](https://github.com/akopytov/sysbench)-based [CPU benchmark](https://gitlab.com/gitlab-org/quality/performance/-/wikis/Reference-Architectures/GCP-CPU-Benchmarks). Due to better performance and availability, for data objects (such as LFS, uploads, or artifacts), using an [object storage service](#configure-the-object-storage) is recommended instead of using NFS. Using an object storage service also doesn't require you to provision and maintain a node. ## Setup components To set up GitLab and its components to accommodate up to 2,000 users: 1. [Configure the external load balancing node](#configure-the-external-load-balancer) to handle the load balancing of the GitLab application services nodes. 1. [Configure PostgreSQL](#configure-postgresql), the database for GitLab. 1. [Configure Redis](#configure-redis). 1. [Configure Gitaly](#configure-gitaly), which provides access to the Git repositories. 1. [Configure the main GitLab Rails application](#configure-gitlab-rails) to run Puma/Unicorn, Workhorse, GitLab Shell, and to serve all frontend requests (which include UI, API, and Git over HTTP/SSH). 1. [Configure Prometheus](#configure-prometheus) to monitor your GitLab environment. 1. [Configure the object storage](#configure-the-object-storage) used for shared data objects. 1. [Configure Advanced Search](#configure-advanced-search) (optional) for faster, more advanced code search across your entire GitLab instance. 1. [Configure NFS](#configure-nfs-optional) (optional, and not recommended) to have shared disk storage service as an alternative to Gitaly or object storage. You can skip this step if you're not using GitLab Pages (which requires NFS). ## Configure the external load balancer NOTE: **Note:** This architecture has been tested and validated with [HAProxy](https://www.haproxy.org/). Although you can use a load balancer with a similar set of features, GitLab hasn't validated other load balancers. In an active/active GitLab configuration, you'll need a load balancer to route traffic to the application servers. The specifics for which load balancer to use or its exact configuration is out of scope for the GitLab documentation. If you're managing multi-node systems (including GitLab) you'll probably already have a load balancer of choice. Some examples including HAProxy (open-source), F5 Big-IP LTM, and Citrix Net Scaler. This documentation includes the ports and protocols for use with GitLab. The next question is how you will handle SSL in your environment. There are several different options: - [The application node terminates SSL](#application-node-terminates-ssl). - [The load balancer terminates SSL without backend SSL](#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](#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` instead of `HTTP(S)`. This will pass the connection unaltered to the application node's NGINX service, which has the SSL certificate and listens to port 443. For details about managing SSL certificates and configuring NGINX, see the [NGINX HTTPS documentation](https://docs.gitlab.com/omnibus/settings/nginx.html#enable-https). ### Load balancer terminates SSL without backend SSL Configure your load balancer to use the `HTTP(S)` protocol instead of `TCP`. The load balancer will be responsible for both managing SSL certificates and terminating SSL. Due to communication between the load balancer and GitLab not being secure, you'll need to complete some additional configuration. For details, see the [NGINX proxied SSL documentation](https://docs.gitlab.com/omnibus/settings/nginx.html#supporting-proxied-ssl). ### Load balancer terminates SSL with backend SSL Configure your load balancers (or single balancer, if you have only one) to use the `HTTP(S)` protocol rather than `TCP`. The load balancers will be responsible for the managing SSL certificates for end users. Traffic will be secure between the load balancers and NGINX in this scenario, and there's no need to add a configuration for proxied SSL. However, you'll need to add a configuration to GitLab to configure SSL certificates. For details about managing SSL certificates and configuring NGINX, see the [NGINX HTTPS documentation](https://docs.gitlab.com/omnibus/settings/nginx.html#enable-https). ### Readiness checks Ensure the external load balancer only routes to working services with built in monitoring endpoints. The [readiness checks](../../user/admin_area/monitoring/health_check.md) all require [additional configuration](../monitoring/ip_whitelist.md) on the nodes being checked, otherwise, the external load balancer will not be able to connect. ### Ports The basic load balancer ports you should use are described in the following table: | Port | Backend Port | Protocol | | ------- | ------------ | ------------------------ | | 80 | 80 | HTTP (*1*) | | 443 | 443 | TCP or HTTPS (*1*) (*2*) | | 22 | 22 | TCP | - (*1*): [Web terminal](../../ci/environments/index.md#web-terminals) support requires your load balancer to correctly handle WebSocket connections. When using HTTP or HTTPS proxying, your load balancer must be configured to pass through the `Connection` and `Upgrade` hop-by-hop headers. For details, see the [web terminal](../integration/terminal.md) integration guide. - (*2*): When using the HTTPS protocol for port 443, you'll need to add an SSL certificate to the load balancers. If you need to terminate SSL at the GitLab application server, use the 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` to the new virtual IP address. For more information, see the [GitLab Pages documentation](../pages/index.md). | Port | Backend Port | Protocol | | ------- | ------------- | --------- | | 80 | Varies (*1*) | HTTP | | 443 | Varies (*1*) | TCP (*2*) | - (*1*): The backend port for GitLab Pages depends on the `gitlab_pages['external_http']` and `gitlab_pages['external_https']` settings. For details, see the [GitLab Pages documentation](../pages/index.md). - (*2*): Port 443 for GitLab Pages must use the TCP protocol. Users can configure custom domains with custom SSL, which wouldn't 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 instead allows users to use SSH over port 443. An alternate SSH hostname requires a new virtual IP address compared to the previously described GitLab HTTP configuration. Configure DNS for an alternate SSH hostname, such as `altssh.gitlab.example.com`: | LB Port | Backend Port | Protocol | | ------- | ------------ | -------- | | 443 | 22 | TCP |
## Configure PostgreSQL In this section, you'll be guided through configuring an external PostgreSQL database to be used with GitLab. ### Provide your own PostgreSQL instance If you're hosting GitLab on a cloud provider, you can optionally use a managed service for PostgreSQL. For example, AWS offers a managed relational database service (RDS) that runs PostgreSQL. If you use a cloud-managed service, or provide your own PostgreSQL: 1. Set up PostgreSQL according to the [database requirements document](../../install/requirements.md#database). 1. Create a `gitlab` username with a password of your choice. The `gitlab` user needs privileges to create the `gitlabhq_production` database. 1. Configure the GitLab application servers with the appropriate details. This step is covered in [Configuring the GitLab Rails application](#configure-gitlab-rails). See [Configure GitLab using an external PostgreSQL service](../postgresql/external.md) for further configuration steps. ### Standalone PostgreSQL using Omnibus GitLab 1. SSH into the PostgreSQL server. 1. [Download/install](https://about.gitlab.com/install/) the Omnibus GitLab package you want using **steps 1 and 2** from the GitLab downloads page. - Do not complete any other steps on the download page. 1. Generate a password hash for PostgreSQL. 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`. ```shell sudo gitlab-ctl pg-password-md5 gitlab ``` 1. Edit `/etc/gitlab/gitlab.rb` and add the contents below, updating placeholder values appropriately. - `POSTGRESQL_PASSWORD_HASH` - The value output from the previous step - `APPLICATION_SERVER_IP_BLOCKS` - A space delimited list of IP subnets or IP addresses of the GitLab application servers that will connect to the database. Example: `%w(123.123.123.123/32 123.123.123.234/32)` ```ruby # Disable all components except PostgreSQL roles ['postgres_role'] repmgr['enable'] = false consul['enable'] = false prometheus['enable'] = false alertmanager['enable'] = false pgbouncer_exporter['enable'] = false redis_exporter['enable'] = false gitlab_exporter['enable'] = false # Set the network addresses that the exporters used for monitoring will listen on node_exporter['listen_address'] = '0.0.0.0:9100' postgres_exporter['listen_address'] = '0.0.0.0:9187' postgres_exporter['dbname'] = 'gitlabhq_production' postgres_exporter['password'] = 'POSTGRESQL_PASSWORD_HASH' # Set the PostgreSQL address and port postgresql['listen_address'] = '0.0.0.0' postgresql['port'] = 5432 # Replace POSTGRESQL_PASSWORD_HASH with a generated md5 value postgresql['sql_user_password'] = 'POSTGRESQL_PASSWORD_HASH' # Replace APPLICATION_SERVER_IP_BLOCK with the CIDR address of the application node postgresql['trust_auth_cidr_addresses'] = %w(127.0.0.1/32 APPLICATION_SERVER_IP_BLOCK) # Disable automatic database migrations gitlab_rails['auto_migrate'] = false ``` 1. [Reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. 1. Note the PostgreSQL node's IP address or hostname, port, and plain text password. These will be necessary when configuring the [GitLab application server](#configure-gitlab-rails) later. Advanced [configuration options](https://docs.gitlab.com/omnibus/settings/database.html) are supported and can be added if needed. ## Configure Redis In this section, you'll be guided through configuring an external Redis instance to be used with GitLab. ### Provide your own Redis instance Redis version 5.0 or higher is required, as this is what ships with Omnibus GitLab packages starting with GitLab 13.0. Older Redis versions do not support an optional count argument to SPOP which is now required for [Merge Trains](../../ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/index.md). In addition, GitLab makes use of certain commands like `UNLINK` and `USAGE` which were introduced only in Redis 4. Managed Redis from cloud providers such as AWS ElastiCache will work. If these services support high availability, be sure it is not the Redis Cluster type. Note the Redis node's IP address or hostname, port, and password (if required). These will be necessary when configuring the [GitLab application servers](#configure-gitlab-rails) later. ### Standalone Redis using Omnibus GitLab The Omnibus GitLab package can be used to configure a standalone Redis server. The steps below are the minimum necessary to configure a Redis server with Omnibus: 1. SSH into the Redis server. 1. [Download/install](https://about.gitlab.com/install/) the Omnibus GitLab package you want using **steps 1 and 2** from the GitLab downloads page. - Do not complete any other steps on the download page. 1. Edit `/etc/gitlab/gitlab.rb` and add the contents: ```ruby ## Enable Redis redis['enable'] = true ## Disable all other services sidekiq['enable'] = false gitlab_workhorse['enable'] = false puma['enable'] = false unicorn['enable'] = false postgresql['enable'] = false nginx['enable'] = false prometheus['enable'] = false alertmanager['enable'] = false pgbouncer_exporter['enable'] = false gitlab_exporter['enable'] = false gitaly['enable'] = false grafana['enable'] = false redis['bind'] = '0.0.0.0' redis['port'] = 6379 redis['password'] = 'SECRET_PASSWORD_HERE' gitlab_rails['enable'] = false # Set the network addresses that the exporters used for monitoring 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://0.0.0.0:6379', 'redis.password' => 'SECRET_PASSWORD_HERE', } ``` 1. [Reconfigure Omnibus GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure) for the changes to take effect. 1. Note the Redis node's IP address or hostname, port, and Redis password. These will be necessary when [configuring the GitLab application servers](#configure-gitlab-rails) later. Advanced [configuration options](https://docs.gitlab.com/omnibus/settings/redis.html) are supported and can be added if needed. ## Configure Gitaly [Gitaly](../gitaly/index.md) server node requirements are dependent on data, specifically the number of projects and those projects' sizes. It's recommended that a Gitaly server node stores no more than 5TB of data. Although this reference architecture includes a single Gitaly server node, you may require additional nodes depending on your repository storage requirements. 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. These IOPS values are initial recommendations, and may be adjusted to greater or lesser values depending on the scale of your environment's workload. If you're running the environment on a Cloud provider, refer to their documentation about how to configure IOPS correctly. Be sure to note the following items: - The GitLab Rails application shards repositories into [repository storage paths](../repository_storage_paths.md). - A Gitaly server can host one or more storage paths. - A GitLab server can use one or more Gitaly server nodes. - Gitaly addresses must be specified to be correctly resolvable for *all* Gitaly clients. - Gitaly servers must not be exposed to the public internet, as Gitaly's network traffic 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](#gitaly-tls-support). NOTE: **Note:** The token referred to throughout the Gitaly documentation is an arbitrary password selected by the administrator. This token is unrelated to tokens created for the GitLab API or other similar web API tokens. The following procedure describes how to configure a single Gitaly server named `gitaly1.internal` with the secret token `gitalysecret`. We assume your GitLab installation has two repository storages: `default` and `storage1`. To configure the Gitaly server: 1. On the server node you want to use for Gitaly, [download and install](https://about.gitlab.com/install/) your selected Omnibus GitLab package using *steps 1 and 2* from the GitLab downloads page, but *without* providing the `EXTERNAL_URL` value. 1. Edit the Gitaly server node's `/etc/gitlab/gitlab.rb` file to configure storage paths, enable the network listener, and to configure the token: ```ruby # /etc/gitlab/gitlab.rb # Gitaly and GitLab use two shared secrets for authentication, one to authenticate gRPC requests # to Gitaly, and a second for authentication callbacks from GitLab-Shell to the GitLab internal API. # The following two values must be the same as their respective values # of the GitLab Rails application setup gitaly['auth_token'] = 'gitalysecret' gitlab_shell['secret_token'] = 'shellsecret' # Avoid running unnecessary services on the Gitaly server postgresql['enable'] = false redis['enable'] = false nginx['enable'] = false puma['enable'] = false unicorn['enable'] = false sidekiq['enable'] = false gitlab_workhorse['enable'] = false grafana['enable'] = false # If you run a separate monitoring node you can disable these services alertmanager['enable'] = false prometheus['enable'] = false # Prevent database connections during 'gitlab-ctl reconfigure' gitlab_rails['rake_cache_clear'] = false 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. # Don't forget to copy `/etc/gitlab/gitlab-secrets.json` from web server to Gitaly server. gitlab_rails['internal_api_url'] = 'https://gitlab.example.com' # 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 gitaly['listen_addr'] = "0.0.0.0:8075" gitaly['prometheus_listen_addr'] = "0.0.0.0:9236" # Set the network addresses that the exporters used for monitoring will listen on node_exporter['listen_address'] = '0.0.0.0:9100' git_data_dirs({ 'default' => { 'path' => '/var/opt/gitlab/git-data' }, 'storage1' => { 'path' => '/mnt/gitlab/git-data' }, }) ``` 1. Save the file, and then [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure). 1. Confirm that Gitaly can perform callbacks to the internal API: ```shell sudo /opt/gitlab/embedded/bin/gitaly-hooks check /var/opt/gitlab/gitaly/config.toml ``` ### Gitaly TLS support Gitaly supports TLS encryption. To be able to communicate with a Gitaly instance that listens for secure connections you will need to use `tls://` URL scheme in the `gitaly_address` of the corresponding storage entry in the GitLab configuration. You will need to bring your own certificates as this isn't provided automatically. The certificate, or its certificate authority, must be installed on all Gitaly nodes (including the Gitaly node using the certificate) and on all client nodes that communicate with it following the procedure described in [GitLab custom certificate configuration](https://docs.gitlab.com/omnibus/settings/ssl.html#install-custom-public-certificates). NOTE: **Note:** The self-signed certificate must specify the address you use to access the Gitaly server. If you are addressing the Gitaly server by a hostname, you can either use the Common Name field for this, or add it as a Subject Alternative Name. If you are addressing the Gitaly server by its IP address, you must add it as a Subject Alternative Name to the certificate. [gRPC does not support using an IP address as Common Name in a certificate](https://github.com/grpc/grpc/issues/2691). NOTE: **Note:** It is possible to configure Gitaly 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 configure Gitaly with TLS: 1. Create the `/etc/gitlab/ssl` directory and copy your key and certificate there: ```shell 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 ``` 1. Copy the cert to `/etc/gitlab/trusted-certs` so Gitaly will trust the cert when calling into itself: ```shell sudo cp /etc/gitlab/ssl/cert.pem /etc/gitlab/trusted-certs/ ``` 1. Edit `/etc/gitlab/gitlab.rb` and add: ```ruby gitaly['tls_listen_addr'] = "0.0.0.0:9999" gitaly['certificate_path'] = "/etc/gitlab/ssl/cert.pem" gitaly['key_path'] = "/etc/gitlab/ssl/key.pem" ``` 1. Delete `gitaly['listen_addr']` to allow only encrypted connections. 1. Save the file and [reconfigure GitLab](../restart_gitlab.md#omnibus-gitlab-reconfigure). ## Configure GitLab Rails NOTE: **Note:** In our architectures we run each GitLab Rails node using the Puma webserver and have its number of workers set to 90% of available CPUs along with four threads. For nodes that are running Rails with other components the worker value should be reduced accordingly where we've found 50% achieves a good balance but this is dependent on workload. This section describes how to configure the GitLab application (Rails) component. On each node perform the following: 1. If you're [using NFS](#configure-nfs-optional): 1. If necessary, install the NFS client utility packages using the following commands: ```shell # Ubuntu/Debian apt-get install nfs-common # CentOS/Red Hat yum install nfs-utils nfs-utils-lib ``` 1. Specify the necessary NFS mounts in `/etc/fstab`. The exact contents of `/etc/fstab` will depend on how you chose to configure your NFS server. See the [NFS documentation](../nfs.md) for examples and the various options. 1. Create the shared directories. These may be different depending on your NFS mount locations. ```shell mkdir -p /var/opt/gitlab/.ssh /var/opt/gitlab/gitlab-rails/uploads /var/opt/gitlab/gitlab-rails/shared /var/opt/gitlab/gitlab-ci/builds /var/opt/gitlab/git-data ``` 1. Download/install Omnibus GitLab using **steps 1 and 2** from [GitLab downloads](https://about.gitlab.com/install/). Do not complete other steps on the download page. 1. Create/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 [load balancer](#configure-the-external-load-balancer) which will route traffic to the GitLab application server: ```ruby external_url 'https://gitlab.example.com' # Gitaly and GitLab use two shared secrets for authentication, one to authenticate gRPC requests # to Gitaly, and a second for authentication callbacks from GitLab-Shell to the GitLab internal API. # The following two values must be the same as their respective values # of the Gitaly setup gitlab_rails['gitaly_token'] = 'gitalysecret' gitlab_shell['secret_token'] = 'shellsecret' git_data_dirs({ 'default' => { 'gitaly_address' => 'tcp://gitaly1.internal:8075' }, 'storage1' => { 'gitaly_address' => 'tcp://gitaly1.internal:8075' }, 'storage2' => { 'gitaly_address' => 'tcp://gitaly2.internal:8075' }, }) ## Disable components that will not be on the GitLab application server roles ['application_role'] gitaly['enable'] = false nginx['enable'] = true ## PostgreSQL connection details gitlab_rails['db_adapter'] = 'postgresql' gitlab_rails['db_encoding'] = 'unicode' gitlab_rails['db_host'] = '10.1.0.5' # IP/hostname of database server gitlab_rails['db_password'] = 'DB password' ## Redis connection details gitlab_rails['redis_port'] = '6379' gitlab_rails['redis_host'] = '10.1.0.6' # IP/hostname of Redis server gitlab_rails['redis_password'] = 'Redis Password' # 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' sidekiq['listen_address'] = "0.0.0.0" 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. Replace placeholder `monitoring.gitlab.example.com` with # the address and/or subnets gathered from the monitoring node gitlab_rails['monitoring_whitelist'] = ['