| commit | 36eff93f31746eb1df6b0267d7a624730b7ec3a2 | [log] [tgz] |
|---|---|---|
| author | Luca Milanesio <luca.milanesio@gmail.com> | Sun Mar 16 11:58:30 2025 +0000 |
| committer | Luca Milanesio <luca.milanesio@gmail.com> | Fri Mar 21 17:41:28 2025 +0000 |
| tree | 3ee69605cc264ffee2e7fb460a5ca150fb3f4ed5 | |
| parent | ac443f88d002711ff838891d10ae1f484e2d3599 [diff] |
Implement filterAndLock in ReplicationFetchFilter The ReplicationFetchFilter allows to also lock refs whilst filtering them, which is paramount for preventing the refs to be fetch from being mutated and therefore causing potential split-brains. Lock local refs locally for allowing concurrent access to happen on other nodes that are not impacted by the local replication tasks. Change-Id: I0f8778dee71b3e3963403541b212058cdd42c784
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:
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
This plugin is released under the same Apache 2.0 license and copyright holders as of the Gerrit Code Review project.
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 .
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.
Each Gerrit server of the cluster must be identified with a globally unique instance-id defined in $GERRIT_SITE/etc/gerrit.config. When migrating from a multi-site configuration with Gerrit v3.3 or earlier, you must reuse the instance-id value stored under $GERRIT_SITE/data/multi-site.
Example:
[gerrit] instanceId = 758fe5b7-1869-46e6-942a-3ae0ae7e3bd2
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. This can be done with either pull or push replication plugin.
For information about available HTTP endpoints please refer to the documentation.