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gerrit / plugins / multi-site / 6fe50747ff40870bc75f60d1119fdc45170b6382
commit6fe50747ff40870bc75f60d1119fdc45170b6382[log] [tgz]
authorFabio Ponciroli <ponch78@gmail.com>Fri May 07 16:06:19 2021 +0200
committerFabio Ponciroli <ponch78@gmail.com>Fri May 07 16:06:19 2021 +0200
tree82d8fb1a4248fad4da57c4dc2a61b9e095405f06
parente5add0f88597942ac80e231fe21686a21fc645ad [diff]
parentb1ccbc05f5f3fd11cdb0013fa4e5c10ef6892f52 [diff]
Merge branch 'stable-3.2' into stable-3.3

* stable-3.2:
  Remove unmaintained attempt to Dockerize the whole multi-site setup

Change-Id: I0eec9896cddcaccbc37f630d7baad07840ae0ddc
tree: 82d8fb1a4248fad4da57c4dc2a61b9e095405f06
  1. .settings/
  2. images/
  3. setup_local_env/
  4. src/
  5. .bazelrc
  6. .gitignore
  7. .mailmap
  8. BUILD
  9. DESIGN.md
  10. docker-compose.kafka-broker.yaml
  11. external_plugin_deps.bzl
  12. Jenkinsfile
  13. LICENSE
  14. README.md
README.md

Gerrit multi-site plugin

This plugin allows to deploy a distributed cluster of multiple Gerrit masters each using a separate site without sharing any storage. The alignment between the masters happens using the replication plugin and an external message broker.

Requirements for the Gerrit masters are:

  • Gerrit v2.16.5 or later
  • Migrated to NoteDb
  • Connected to the same message broker
  • Accessible via a load balancer (e.g. HAProxy)

NOTE: The multi-site plugin will not start if Gerrit is not yet migrated to NoteDb.

Supports multiple read/write masters across multiple sites across different geographic locations. The Gerrit nodes are kept synchronized between each other using the replication plugin and a global ref-database in order to detect and prevent split-brains.

For more details on the overall multi-site design and roadmap, please refer to the multi-site plugin DESIGN.md document

License

This plugin is released under the same Apache 2.0 license and copyright holders as of the Gerrit Code Review project.

How to build

The multi-site plugin can only be built in tree mode, by cloning Gerrit and the multi-site plugin code, and checking them out on the desired branch.

Example of cloning Gerrit and multi-site for a stable-2.16 build:

git clone -b stable-2.16 https://gerrit.googlesource.com/gerrit
git clone -b stable-2.16 https://gerrit.googlesource.com/plugins/multi-site

cd gerrit/plugins
ln -s ../../multi-site .
rm external_plugin_deps.bzl
ln -s multi-site/external_plugin_deps.bzl .

Example of building the multi-site plugin:

cd gerrit
bazel build plugins/multi-site

The multi-site.jar plugin is generated to bazel-bin/plugins/multi-site/multi-site.jar.

Example of testing the multi-site plugin:

cd gerrit
bazel test plugins/multi-site:multi_site_tests

NOTE: The multi-site tests include also the use of Docker containers for instantiating and using a Kafka/Zookeeper broker. Make sure you have a Docker daemon running (/var/run/docker.sock accessible) or a DOCKER_HOST pointing to a Docker server.

How to configure

Install the multi-site plugin into the $GERRIT_SITE/lib directory of all the Gerrit servers that are part of the multi-site cluster. Create a symbolic link from $GERRIT_SITE/lib/multi-site.jar into the $GERRIT_SITE/plugins.

Add the multi-site module to $GERRIT_SITE/etc/gerrit.config as follows:

[gerrit]
  installDbModule = com.googlesource.gerrit.plugins.multisite.GitModule
  installModule = com.googlesource.gerrit.plugins.multisite.Module

For more details on the configuration settings, please refer to the multi-site configuration documentation.

You also need to setup the Git-level replication between nodes, for more details please refer to the replication plugin documentation.