commit | d0a999f3d843f53b9490d2c06fda400edb47911f | [log] [tgz] |
---|---|---|
author | Luca Milanesio <luca.milanesio@gmail.com> | Thu Jun 27 23:38:34 2019 +0100 |
committer | Luca Milanesio <luca.milanesio@gmail.com> | Thu Jun 27 23:45:51 2019 +0100 |
tree | 1db192b829e05aefecc6cbc82a4561969f7e2f20 | |
parent | 460f1077a85583253f5d7da99313047cee01d198 [diff] | |
parent | 478f8b76342a5ca2d0889b344a7b89f05eef18e3 [diff] |
Merge branch 'stable-2.16' into stable-3.0 * stable-2.16: Extra logging when local ref-db is misaligned with shared-db Kafka module for multi-site Change-Id: I72b199478867deacaec7d0ab7ba025dc1311f23a
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.
Currently, the only mode supported is one primary read/write master and multiple read-only masters but eventually the plan is to support multiple read/write masters. The read/write master is handling any traffic while the read-only masters are serving the Gerrit GUI assets, the HTTP GET REST API and git fetch requests (git-upload-pack). The read-only masters are kept synchronized with the read/write master in order to be always ready to become a read/write master.
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 is built like any other Gerrit plugin 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.
Install the multi-site plugin into the $GERRIT_SITE/lib
directory of all the Gerrit servers that are part of the multi-site cluster.
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
Create the $GERRIT_SITE/etc/multi-site.config
on all Gerrit servers with the following basic settings:
[kafka] bootstrapServers = <kafka-host>:<kafka-port> [kafka "publisher"] enabled = true [kafka "subscriber"] enabled = true [ref-database] enabled = true [ref-database "zookeeper"] connectString = "localhost:2181"
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.