commit | 1d68ce24effa4a1ab0688061eb56c24fc2e7af6e | [log] [tgz] |
---|---|---|
author | Antonio Barone <syntonyze@gmail.com> | Mon Aug 12 16:32:54 2019 +0100 |
committer | Antonio Barone <syntonyze@gmail.com> | Tue Aug 13 13:46:03 2019 +0000 |
tree | 551aed92a2b2c3fa3a9ba824580195728f872e11 | |
parent | 3f98165141d32046802ef8815d596391bdd9b675 [diff] |
Bind SharedRefDB as DynamicItem to allow other implementations Decouple the multi-site engine from the shared ref-db implementation by using a DynamicItem. The multi-site library would ship and bind a NoOp impleentation, so that the whole functionality is preserved. Inside the multi-site.jar there is a Zookeeper implementation embendded which can be loaded by linking the multi-site.jar from the $GERRIT_SITE/lib into the $GERRIT_SITE/plugins and loaded as a plugin. Change-Id: I7f978b9ba4edf81bf5a170e2eb9a5829edabef2e
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. 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] 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.