| commit | 79eb98ddddae1d238ee2efa058554dec1fddb92d | [log] [tgz] |
|---|---|---|
| author | Luca Milanesio <luca.milanesio@gmail.com> | Thu Jan 30 09:05:07 2025 +0000 |
| committer | Luca Milanesio <luca.milanesio@gmail.com> | Thu Jan 30 15:15:12 2025 +0000 |
| tree | d0f3891449445f8669e0af011bee0165744cf197 | |
| parent | 7428ee32b13ca6e35244993d9a2f0d259141174e [diff] |
Disable replication lag tracking by configuration Introduce the new configuration settings ref-database.replicationLagEnabled for disabling the metric to trace the auto-replication lag between sites. The rationale for disabling this metric lies in the use of mono-repos with very frequent updates which would cause the ref refs/multi-site/version/* to be continuously updated causing packed-refs locks and consuming precious resources on the global-refdb. When using pull-replication and apply-object, the value of using the refs/multi-site/version/* for tracking is not very useful anyway because it gets replicated outside the batch. Bug: Issue 313856493 Change-Id: I6b32e0423ed894793f55ed57c60cc356ebe2a31a
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.