Download: 3.9.1

Documentation: 3.9.1

Release highlights

Java 17

The language level used for Gerrit source code stays on Java 11, however, Gerrit is built and distributed for Java 17, which is the recommended JVM version for running it in production.

New stream events


Gerrit notifies all the refs of a single batch-refupdate as a single stream event JSON payload Issue 40015567. The new batch-ref-updated event is controlled by configuration and can be switched off for backward compatibility with legacy CI/CD systems.

ref-update for draft-comments

Gerrit generates the ref-update event for all the additions and removals of draft comments in the All-Users project (Change 382819). This is needed for replicating the All-Users project across sites, thanks to the replication plugins being notified of the updates.

Due to the nature of drafts, on busy installations the amount of ref-updated events created on draft operations could be high, possibly having an impact on performance.

For this reason this is disabled by default, you can enable it by configuring in gerrit.config Change 385714

New limits

There are new limit definitions which can be used to protect Gerrit from improper client activity.

  • change.topicLimit: defines the maximum number of changes in the same topic (Change 381055.

  • change.maxFileSizeDownload: prevents memory overload caused by clients downloading large files from REST-API (Change 381595).

  • change.maxFileSizeDiff: prevents memory overload caused by rendering large files diffs in a browser.

New diff3 view

A new change.diff3ConflictView option allows to enable a richer diff3 rendering of changes with conflict markers (Change 382894).

Attention-set improvements

Gerrit can return changes to the original attention set assignment if any of the new assignees do not provide feedback within a specific time (Issue 40015204). The behaviour is controlled by two new settings, attentionSet.readdAfter and attentionSet.readdMessage.

Indexing improvements

Allow to limit the queries that do not specify a default limit and also can now reindex changes with an asynchronous process when a change is updated from the UI, controlled by the index.indexChangesAsync.

The new option yields a much more responsive user-experience by releasing UI elements without waiting for the backend reindex execution to complete.

Account deletion

Users can now delete their own account, making it possible to be forgotten by the Gerrit Code Review platform. Please note that existing commits in the projects will stay and the account’s e-mail stored in Git commits will be preserved beyond account deletion.

User Suggested Edits

User Suggested Edits are an easy and fast way for reviewers to suggest code changes that can be easily applied by the change owner. They were introduced in 3.7.2 as an experimental feature, disabled by default. With Gerrit 3.9, this feature is no longer experimental and User Suggested Edits are now enabled by default.

Plugin development

Custom key/value pairs stored in NoteDb

Plugins may store additional string key/value pairs to change notes in NoteDb.

Change 372694 Added APIs to set/get custom keyed-value change metadata

Cross-plugin communication and dependency

Plugins can communicate and declare dependencies to other plugins thanks to the introduction of Gerrit-ApiModule Guice modules in plugin manifest (Issue 292114807).

Lookup changes by change number

Change 394440 flagged the API as deprecated to prevent using it from plugins and fail to locate changes imported from Gerrit servers with a different server-id.

Important notes

Upgrade from Gerrit v3.9.0 (defective release)

The release of Gerrit v3.9.0 has been impacted by the bad merge of Change 394445 due to the “implicit merge on moved changes issue” that has pulled 64 unwanted commits from the master branch. As a consequence, the version has been declared defective and withdrawn.

The upgrade from 3.9.0 to the following 3.9.* patch-releases needs to follow the instructions of the “Offline upgrade” because it contains an incompatible Lucene Engine that won’t be able to read the legacy index data.

Schema and index changes

This release doesn’t contain schema changes.

The accounts index version has been increased to version 13. The changes index version has been increased to version 84. The groups index version has been increased to version 10. The projects index version has been increased to version 8.

Online index schema upgrade from 3.7/3.8

By default, if you’re upgrading from 3.7/3.8, the index is automatically rebuilt upon Gerrit startup after the upgrade.

If you’re upgrading from 3.6 or an earlier version, you must use the Offline upgrade steps below.

Offline upgrade

  1. Download the new gerrit.war
  2. Stop Gerrit
  3. Ensure all installed plugins are compatible with the new API
  4. Run init
  java -jar gerrit.war init -d site_path --batch
  1. Reindex
  • If you are upgrading from a 3.7/3.8 versions you don’t need to run reindex (see Online index schema upgrade from 3.7/3.8 above). If you still want to you will need to run reindex:

      java -jar gerrit.war reindex -d site_path
  • If you are upgrading from a 3.6 or an earlier version, you must run a reindex of all indexes:

     java -jar gerrit.war reindex -d site_path

See the reindex program for other options.

  1. Start Gerrit

Online upgrade with zero-downtime

Gerrit v3.9.x supports zero-downtime upgrade from Gerrit v3.7 or later when configured using a high-availability configuration , and the Git repositories are stored in a shared filesystem such as NFS or similar.

During the zero-downtime upgrade, Gerrit end-users would not notice any outage or service disruption. They will be able to perform any read/write Gerrit operation on the GUI or using any API.

The zero-downtime upgrade consists of the following steps:

  1. Have Gerrit servers running v3.7 or later, in high-availability configuration, healthy and able to handle the incoming traffic properly.
  2. Set gerrit.experimentalRollingUpgrade to true in gerrit.config on both Gerrit primaries.
  3. Set one of the Gerrit servers to unhealthy.
  4. Shutdown the Gerrit server, update gerrit.war and plugins to v3.9.x and start Gerrit again.
  5. Verify that the Gerrit server is working properly (e.g. run automated smoke tests) and then make it healthy again.
  6. Wait for the Gerrit server to start serving traffic normally.
  7. Repeat steps 3. to 6. for all the other Gerrit servers.
  8. Remove gerrit.experimentalRollingUpgrade from gerrit.config on both Gerrit primaries.


Downgrade to any Gerrit v3.7/v3.8 release is possible, but requires the following manual steps:

  1. Shutdown all migrated Gerrit servers
  2. Update the gerrit.war and plugins to the previous v3.7/v3.8 version
  3. Run offline change reindexing using the previous gerrit.war version
  java -jar gerrit.war init -d site_path --batch
  java -jar gerrit.war reindex -d site_path
  1. Startup Gerrit server

Native packaging

Breaking changes

  • Change 369234 Return 400 BAD_REQUEST when a reviewer cannot be added by email

    When trying to add a user that cannot be added as a reviewer on a change, the API was returning a 200 Status Code with an error message.

  • Change 379475 Don’t call Java gc explicitly, remove –gc option from show-caches ssh command and REST API /config/server/summary

  • Change 378638 Remove change.stars field from ChangeInfo

    Remove the stars field from the ChangeInfo response. You should check whether you were relying on this field when using any REST endpoint returning ChangeInfo.

  • Change 373780 removed all performance/operations/* metrics because of the performance issues introduced (details)

  • Change 371198 Add option to populate ‘starred’ field for change queries

    star option can must now be provided to include the starred field in ChangeInfo, which indicates if the change is starred by the current user or not.

  • Change 387435 refreshAfterWrite and maxAge settings in gerrit config are now honored for both persistent and in-memory caches.

    Previously these settings were erroneously ignored for persistent caches. If you rely on them for persistent caches you should be aware they will be honoured now.

  • Change 379154 New patch sets will prefer the previous patch set’s committer email

    If one of the user’s secondary emails was used as the committer email in previous patchset, continue using it instead of preferred email.

  • Change 390986 Update mockito to 5.6.0 and bytebuddy to 1.14.9

    Mockito framework was upgraded from 3.3.3 to 5.6.0, hence if you have some custom plugins your test code might require some minor refactoring. Please refer to the mockito documentation and the release notes

Other changes

  • Change 394435: Support listing of patch-set files also for imported changes from other Gerrit server-ids

  • Change 377699: Allow generating safe local-only documentation, without reference to external fonts in CSS

  • Change 394654: Fix documentation attributes bug

  • Change 392517: Added ‘m’ alias for the ‘message’ operator

  • Change 392515 Groups Audit Log API - Gerrit now parses all commits in refs/groups/… branch

  • Change 392514 Support tracing requests that match a header

    Gerrit supports tracing requests that match a configured trace configuration. With this change we add a new parameter to the tracing configuration that allows matching requests by a header. E.g. this allows matching requests that are sent with a certain user agent (e.g. headerPattern = User-Agent=foo-.*).

  • Change 392518 Change .scl files to be highlighted as python

  • Change 392175 Reviewer’s votes are not restored back after the reviewer is deleted and added back

    When a reviewer votes for the patchset and then the reviewer is removed, Gerrit removes votes from this reviewer too. However if the reviewer is added back (to the same patchset) previous votes are restored back.

    This change ensures that after a reviewer is deleted, all votes from this reviewer are permanently removed.

  • Change 390897 Option to skip projects during change reindexing

    Introduce index.excludeProjectFromChangeReindex: A list of projects that will be excluded from reindexing. This can be used to exclude projects which are expensive to reindex to prioritize the other projects.

  • Change 390895 The revert UI now defaults to Revert^2 instead of “Revert “Revert “…”

  • Change 390614 Users can now upload changes to group refs except changes to group files

  • Change 389115 Improved error message when change cannot be submitted due to a missing dependency

  • Change 388914 Changing preferred email does not result in duplicate email

  • Change 368335 Rebase can be performed with a secondary email using REST API

  • Change 388336 Added ‘description’, ‘d’ aliases for the ‘message’ operator

  • Change 388554 committer_email field is removed from topic cherry-pick payload

  • Change 392534 Return approver/rejector for a label if DETAILED_LABELS is passed

  • Change 388054 Eliminated startup warning for plugins whose SshModule only provides Ssh* CommandInterceptors

  • Change 387217 Fixed case where an exception in change visibility checking could break visibility of all refs in that repo

  • Change 377154 REST API supports cherry-pick using a registered secondary email

  • Change 387055 SSH set-topic cmd is fixed to consider edit topic permission

  • Change 387103 Avoid NullPointerException when deleting a single ref

  • Change 387216 Fixed potential OOM due to SubmitRuleEvaluator creating new metrics whenever an instance was created

  • Change 387017 Fix NPE when auth.httpDisplaynameHeader is configured but header is unset

  • Change 387054 force topic edit’` permission is fixed to work with change owner rule

  • Change 386976 Fixed potential OOM due to *QueryProcessor classes creating new metrics whenever an instance was provided

  • Change 386974 SSH command set-reviewers now handles lock failures with retries

  • Change 386994 Fixed InactiveAccountDisconnector NPE due to race condition

  • Change 386777 Allow modules to provide different logic for the HTTP canonicalWebUrl

    This is useful to allow adding some logic to the way the canonical Web URL is computed. A use-case for this need is the virtualhost module, where the canonical Web URL is replaced by a virtual host name instead Change 386616

  • Change 383334 Allow to set instance ID from java system property

  • Change 385556 Allow pagination using continuation token for ‘list branches’

  • Issue 295457464 SSH queries now show copied approvals on respective patch-sets

  • Change 383955 Allow SubmitRequirement errors to be HTTP 500 errors

  • Change 384096 Exposed default branch in GerritInfo

  • Issue 296889346 Added placeholder text for “Default Branch” field in the create repo wizard

  • Change 383034 List/Query projects: Set flag in last returned project when result is limited

    If the number of projects matching a query exceeds either the internal limit or a supplied limit query parameter, the last project object has a _more_projects: true JSON field set now.

  • Change 382557 Added support for searching projects by substring

    The new substring:SUBSTRING predicate matches projects that have a name that contains SUBSTRING (case-insensitive).

  • Change 382295 Added support for querying projects by prefix.

    the new prefix:PREFIX predicate matches projects that have a name that starts with PREFIX.

  • Change 381915 Added support for matching all project by an empty project query

  • Change 382258 Fixed setting parent field in project index for direct children of All-Projects

  • Change 381594 Added response_format_options param to /review API

    Allow specifying a list of formatting options to the the /changes/{change-id}/revisions/{revision-id}/review endpoint.

    If response_format_options was provided, the response payload will contain a new change_info field showing post-update change information formatted by response_format_options.

  • Change 380914 Fixed NPE when submitting changes

  • Change 380916 Fixed ThreadMXBeanSun to only report allocated bytes when supported by the JVM

  • Change 379054 Fixed create merge patch-set API to use identity of caller as committer

  • Change 380314 Named queries are now supported on group refs

    You can now use group with the query predicate: query:group="GROUP"

  • Change 379714 Named destinations are now supported on group refs

    You can now use group with the destination predicate: destination:group="GROUP"

  • Change 379513 Add CustomKeyedValues field to change index, requires schema upgrade

  • Change 378999 Fail ‘Get Diff’ requests for file sizes that exceed 50Mb

  • Change 378899 ApplyPatch: Do not fail with 500 ISE if no patch is provided

  • Change 378535 Added config option that allows to disable change ID link footers

    Introduce the receive.enableChangeIdLinkFooters configuration to enables a Link footer to be used as an alternative Change-Id footer.

  • Change 376877 Add a new parents_data field in RevisionInfo

    The new field is a list of ParentInfo entities and provides more information about the parent commit of the patch-set.

  • Change 377174 Add branch as a new field in RevisionInfo

    The name of the target branch that this revision is set to be merged into.

  • Change 375155 Fix GetRelated if multiple changes for the same commit exist

  • Change 356465 Add API method for deleting self account

  • Change 374995 Adding GET and POST requests for custom_keyed_values

  • Change 374695 Add verbose version output

    provide noteDb and index versions, in addition to the Gerrit version

  • Change 373997 Return 500 when a request is canceled due to an exceeded server deadline

  • Change 373854 The commit-msg hook now detects existing Link trailers.

    An additional $ was making detection of Link trailers to fail, causing Link trailers to repeatedly be added when amending a commit.

  • Change 370194 Add merge strategy to rebase REST API

    The strategy of the merge, can be recursive, resolve, simple-two-way-in-core, ours or theirs, default will use project settings.

  • Change 362774 Adds a new footer for changes for key-value storage.

    These can be used to store metadata on a change. The format on the change-message is for a given <key> <value> is: Custom-Values: <key>=<value>

  • Change 366776 Provide change number to patch set link plugins

Test framework changes

  • Change 392474 Add session support in FakeHttpServletRequest for tests

  • Change 392454 Include HTTP testutil package in the Gerrit acceptance framework

  • Change 392455 Fix FakeHttpServletRequest getRequestURI() returning query string

  • Change 385115 Fixed updating and publishing draft comment on old patch set

Plugin changes

Performance changes

  • Issue 309849905: Account external IDs are updated in a single commit

  • Change 390919 Skip already reindexed changes during reindexing

    During online reindexing after an upgrade, all changes were reindexed, even if they were already present in the new index. If the Gerrit instance was restarted before the index was ready, this caused a lot of repeated indexing.

    Now, changes that are already present in the newest index version won’t be reindexed anymore. However, they will still be checked for staleness and reindexed if necessary.

  • Change 376094 Add cache to speedup ref advertisements (particularly on replicas) and receive-pack

  • Change 224772 Reduced memory and storage needs for TagSet

  • Change 377814 Bloom filters are no longer built during offline reindex

  • Change 380594 Reduced memory and storage needs for TagSet by using RoaringBitmaps

Gerrit UI changes

  • Change 389894 Track diff page sidebar state as a user preference

  • Change 389700 Add a user preference for sidebar on the diff page

  • Change 376934 Rebase can be performed using a secondary email via UI

    updates the UI to show a list of relevant emails to choose from when rebasing a change.

  • Issue 303075739 New frontend extension point: auth-link

  • Change 387695 Show diff as User Suggested Edit Preview instead of code block

  • Issue 301481564 Fix the repository configuration loading and rendering when switching tabs

  • Change 382555 Introduce “showdiff” plugin event

    Any listeners are notified any time a diff is shown on the screen.

  • Change 379095 Add diff page sidebar for plugins

  • Change 378634 Experimental plugin endpoint for diff hover events

  • Change 378436 Fix copying Change-Id in dropdown

  • Change 373477 Fire SHOW_CHANGE event to plugins from diff page

  • Change 394834 Fix auto-completion of suggested accounts for imported changes

Documentation changes

  • Change 391858: Document ChecksApi.updateResult() in PolyGerrit plugins checks API

  • Change 391696: Document check-result-expanded plugin endpoint in PolyGerrit plugins checks API

  • Change 390454 Document gerrit set-head SSH command and fix old UI references

  • Change 388936 Explain in ls-projects SSH API when the “parent” field is “?-N”

  • Change 388936 Explain in /projects/ REST API when the “parent” field is “?-N”

  • Change 387736 Be more explicit about using Bazelisk in dev docs

  • Change 382794 Update blurb for ldap.accountFullName

  • Change 378094 Add example for GerritSiteHeader.html

  • Change 372854 Add example to blurb for ldap.mandatoryGroup

JGit changes

  • Change 387495 Bump JGit version to b6b1e0a0a. You can retrieve the full list of changes with:

    git log --no-merges --format=oneline 74fa245b3c3ccf13afcbec7911c7c8459e48527d..b6b1e0a0adda605f7a62c915d1aef606b961e36f

    notable changes are:

    • a2bce029a WorkingTreeIterator: directly filter input stream
    • 642f16023 Use ShutdownHook to gracefully handle JVM shutdown
    • d4d6c2b5a Add ShutdownHook to cleanup FileLocks on graceful JVM shutdown
    • f94be665f Unregister ShutdownHook when GC#PidLock is closed
    • 82c6638c7 RevertCommand: support for inserting a Gerrit change ID
    • 7baa5a157 DfsPackFile: Record index loads only in one place
    • 30427485d DfsPackfile: Emit the index load with the index object
    • ba1653162 Ensure home directory not null before using in Sshdsessionfactory
    • 4f5afe9d7 CommitGraphWriter: Make the list of chunks immutable
    • f90f0717a CommitGraphWriter: Assert written bytes
    • c024cb23d Remove unused API problem filters
    • 13c8dacae CommitGraphWriter: throw exception on unknown chunk
    • fb51a2234 Document commit-graph options supported by JGit
    • a2f326b76 Handle global git config $XDG_CONFIG_HOME/git/config
    • e7a09e316 Introduce core.packedIndexGitUseStrongRefs config key
    • 551ca93cc DfsGarbageCollector: provide commit graph stats
    • 6f7333693 DfsGarbageCollector: put only GC commits into the commit graph
    • b4b8f05ee DfsReader: Expose when indices are loaded
    • 3a6eec9bb Express the explicit intention of creating bitmaps in GC
    • ac8d7838f GC: prune all packfiles after the loosen phase
    • c353645a0 Move footer-line parsing methods from RevCommit to FooterLine
    • c8f5a3f99 RevCommitCG: Read changed-path-filters directly from commit graph
    • ec3d919aa Identify a commit that generates a diffEntry on a rename Event.
    • f196c7a0e Pack: open reverse index from file if present
    • 000e7caf5 PackReverseIndexV1: reverse index parsed from version 1 file
    • 2eba4e5b4 PackReverseIndex: open file if present otherwise compute
    • 8123dcd69 PackReverseIndex: verify checksums
    • 7d2669587 ComputedPackReverseIndex: Clarify custom bucket sort algorithm
    • 3b77e33ad CommitGraphWriter: add option for writing/using bloom filters
    • 77aec6214 CommitGraphWriter: reuse changed path filters
    • d3b40e72a RevWalk: use changed path filters
    • ff0f7c174 CommitGraphLoader: read changed-path filters
    • 49beb5ae5 CommitGraphWriter: write changed-path filters
    • 23758d7a6 ssh: PKCS#11 support
    • db08835c6 GC: Remove handling of extra pack for RefTree
    • 760bdd09b DfsPackParser: Create object indices if config says so
    • cb99ff5bb DfsInserter: generate object size index if config says so
    • 4d2a003b9 DfsInserter: populate full size on object insertion
    • 12a4a4cca DFSGarbargeCollector: Write object size indices
    • 9dace2e6d DfsReader/PackFile: Implement isNotLargerThan using the obj size idx
    • 79b46a0ef Fix S3Repository getSize to handle larger object sizes
    • 8e6197162 PackReverseIndex: separate out the computed implementation
    • 74547f4a6 PackReverseIndex: use static builder instead of constructor
    • 181b629f7 Gc#writePack: write the reverse index file to disk
    • 6b3b2b33a GraphObjectIndex: fix search in findGraphPosition
    • 2cbf0c177 Also add suppressed exception if unchecked exception occurs in finally
    • d0564cf8a UploadPack: Record negotiation stats on fetchV2 call
    • ce88e62ed PackWriter: write the PackReverseIndex file

Other dependency changes

Other core changes

  • Change 327739 Update Java language level to Java 17 per default

Bugfix releases