This page is to help a Lucene/Solr committer create a new release (you need committer rights for some of the steps to create an official release). It does not reflect official release policy - many of the items may be optional, or may be modified as necessary.

See the ASF Releases Policy page.

Release Process

Prior to every major or minor release (i.e. all except bugfix-only point releases) a feature freeze phase takes place for about 1-2 weeks. At the beginning of the feature freeze the trunk is branched and no commits other than serious bug fixes, documentation or build updates are permitted. This period of time should be used for extensive testing, documentation improvements and for cleaning up old JIRA issues.


  1. (Optional) Edit your gnupg/gpg.conf file and add a default-key value with your Code Signing Key (as a HEX value) otherwise you may need to specify -Dgpg.key=XXXXXX later for signing. Make sure it is your 4K-bit key and not a 1K-bit key (esp. for ASF old timers). See for more information.

  2. You may need to setup as a known host for ssh if you haven't already. This happens when you log in manually and follow the prompts.


  1. On, decide on

    1. which JIRA issues shall be committed before a release is made; set the appropriate "Fix Version" in JIRA for these issues
    2. the date for branching the trunk and the start of the feature freeze phase
    3. the length of the feature freeze phase
    4. a tentative release date
  2. Put up (and/or fix up existing) release notes, at and and ask on dev@ for input

Branching & Feature Freeze

  1. Run ant precommit to run a bunch of sanity & quality checks, then fix any problems that are found.

  2. For the first release in a minor release series - i.e. X.Y.0 - create a minor release branch off the current major version branch, e.g. for minor release 4.2:
    svn copy \ -m "Starting Lucene/Solr 4.2 branch."
  3. Add a new version for the next release using the script. If it is a bugfix release, we will be adding the bugfix version, otherwise we will add the version to come after the release we are producing.

    • If a bugfix release, start on the release branch:
      •  python3 -u dev-tools/scripts/ X.Y.Z 

      •  svn commit 

      • Using the commit id from the previous commit, run on the stable branch, adding  --changeid ID --downstream-repo /path/to/release/branch/checkout

      •  svn commit 

      • Finally, run the script on trunk, modifying the stable branch command with the new change id and path to the stable branch checkout.
      •  svn commit 

    • If a minor release, start on the stable branch:
      •  python3 -u dev-tools/scripts/ X.Y+1.0 

      •  svn commit 

      • Using the commit id from the previous commit, run on trunk, adding  --changeid ID --downstream-repo /path/to/stable/branch/checkout

      •  svn commit 

    • If a major release, only run on trunk:
      •  python3 -u dev-tools/scripts/ X+1.0.0 

      • The script will print a list of items that need to be done manually for a major release bump.
      •  svn commit 

  4. Send a note to dev@ to inform the committers that the branch has been created and the feature freeze phase has started. Include Do's and Don'ts for the feature freeze phase:
    • No new features may be committed to the branch.
    • Documentation patches, build patches and serious bug fixes may be committed to the branch. However, you should submit all patches you want to commit to Jira first to give others the chance to review and possibly vote against the patch. Keep in mind that it is our main intention to keep the branch as stable as possible.

    • All patches that are intended for the branch should first be committed to trunk, merged into the minor release branch, and then into the current release branch.
    • Normal trunk and minor release branch development may continue as usual. However, if you plan to commit a big change to the trunk while the branch feature freeze is in effect, think twice: can't the addition wait a couple more days? Merges of bug fixes into the branch may become more difficult.
    • Only Jira issues with Fix version "X.Y" and priority "Blocker" will delay a release candidate build.

Release Workflow

  1. Go to the JIRA "Manage Versions" Administration pages ( and and add a new (unreleased) version for the next release on the trunk (for a major release) or branch (for a minor release).

  2. Check out the branch with: svn co

  3. Build the code and javadocs, and run the unit tests: ant clean javadocs test. Make sure that you are actually using the minimum compiler version supported for the release. For example, 4.x releases are on Java6 so make sure that you use Java6 for the release workflow.
  4. Examine the results. Did it build without errors? Were there Javadoc warnings? Did the tests succeed? Does the demo application work correctly? Does Test2BTerms pass?
  5. Remove lucene/benchmark/{work,temp}/ if present

  6. Build as defined below in the "Building the Release Artifacts" section.
  7. If during the feature freeze phase bug fixes are committed to the X.Y branch then build another release candidate and announce on dev@ and java-user@ that everyone should use the new RC for testing.
  8. Call a release vote on dev@ and cc .

Building the Release artifacts

If after the last day of the feature freeze phase no blocking issues are in JIRA with "Fix Version" X.Y then it's time to build the release artifacts.

  1. It is recommended to clean your Ivy cache by executing rm -rf ~/.ivy2/cache before building the artifacts. This ensures that all Ivy dependencies are freshly downloaded, so we emulate a user that never used the Lucene build system before (this step ensures downloadability of all artifacts).

  2. Option 1: use dev-tools/scripts/ to build a release candidate, and optionally push the results to, and optionally run dev-tools/scripts/ on it. Run with  --help  to learn the available options.

  3. Option 2: manually build a release candidate:
    1. Verify that svnversion reports a single revision with no modified changes

    2. Remove lucene/benchmark/{work,temp}/ if present

    3. Build the release artifacts: ant -Dversion=X.Y.Z [-Dgpg.exe=/path/to/gpg -Dgpg.key=YourKeyID -Dgpg.passphrase=YourPassPhrase] prepare-release (Items in [] may be optional)

    4. Sanity check the overall size of each artifact. EG, compare to the last release.
    5. Make sure that for each release file an md5 checksum file exists.
    6. ant -Dversion=X.Y.Z copy-to-stage to move the artifacts up to the staging area (see the build target for all the options for securly copying the artifacts up)

    Example for 3.1:
    •      PROMPT$ ANT_OPTS="-Xmx256m -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=128M" ant -Dversion=3.1.0 -Dgpg.key=FE045966 prepare-release
           # Inspect the artifacts
           PROMPT$ ant -Dversion=3.1.0 -Drc=rc3 -Dscp.user=gsingers copy-to-stage

Testing the Release artifacts

  1. There is a script in SVN to do automated checks on a release candidate, e.g.

python3.2 -u dev-tools/scripts/


Once three PMC members have voted for a release, it may be published.

  1. Tag the release from the same revision from which the passing release candidate's was built:
    svn copy -r1492800 \ -m "Lucene/Solr release X.Y.Z"
  2. If this is a point release, copy the CHANGES.txt entry for this point release back to the trunk's CHANGES.txt. Remove any duplicate entries from trunk's CHANGES.txt (ie, each issue should appear only once, in the earliest point-release that contains the fix, on the assumption that all future releases also contain the fix).
  3. Add the new releases to svnpubsub:
    1. Check out the Lucene PMC svnpubsub release area:
             svn co --depth=immediates lucene-dist
             cd lucene-dist
             svn update --depth=immediates java solr
    2. Make directories for the new release:
             mkdir java/X.Y.Z
             mkdir solr/X.Y.Z
    3. Copy the successfully voted RC to java/X.Y.Z and solr/X.Y.Z, excluding the maven/ directories.

    4. Commit the release candidate. # this might take some time: ~ 2 beers
  4. Publish Maven Artifacts

  5. Maven central should show the release after a short while, but you need to wait 24 hours to give the Apache mirrors a chance to copy the new release. There is a script that will continually check the number and percentage of mirrors (and Maven Central) that have the release: dev-tools/scripts/

Pushing website changes & Announcing

Website += javadocs

The problem: Lucene's and Solr's voluminous per-release javadocs break the standard CMS process for the website (i.e., committer commits to the source tree; the CMS buildbot generates the site, then commits to the staging tree; committer reviews and then publishes to the production tree), because dynamic website updates, currently scheduled at 21 minutes after the hour on the hour, interrupt the extremely long commit times for javadocs being staged by buildbot, resulting in failed commits, caused by conflicts with the dynamic updates: by the time the buildbot-triggered commit has finished, its svn tree has been rendered stale.

The solution: skip committing javadocs to the source tree, then staging, then publishing, and instead commit javadocs directly to the production tree. Ordinarily this would be problematic, because the CMS wants to keep the production tree in sync with the staging tree, so anything it finds in the production tree that's not in the staging tree gets nuked. However, the CMS has a built-in mechanism to allow exceptions to the keep-production-in-sync-with-staging rule: extpaths.txt.

extpaths.txt lists paths in the production tree, relative to the project website's root directory, that are allowed to be out of sync with the staging tree.

For more info, see the following sections in the Apache CMS Reference:

Update extpaths.txt

  1. svn co --depth=immediates website-source

  2. cd website-source

  3. Add Lucene javadocs dir: echo core/X_Y_Z >> extpaths.txt

  4. Add Solr javadocs dir: echo solr/X_Y_Z >> extpaths.txt

  5. svn commit -m "Update CMS production sync exceptions for X_Y_Z javadocs" extpaths.txt

  6. cd ..

  7. rm -rf website-source

Push javadocs to the CMS production tree

Don't be alarmed that you don't see your extpaths.txt changes yet in this production checkout: after you do this section you will then be able to publish the lucene website from staging and extpaths.txt will update in this repository automatically.

  1. Ensure your refridgerator has at least 4 beers.
  2. svn co --depth=immediates website-production

  3. untar the lucene and solr release .tgz to create lucene-X.Y.Z and solr-X.Y.Z
  4. cd website-production; svn update --depth=immediates core solr; cd ..

  5. cp -r lucene-X.Y.Z/docs website-production/core/X_Y_Z

  6. svn add core/X_Y_Z

  7. svn commit # this might take some time: ~ 3 beers

  8. cp -r solr-X.Y.Z/docs website-production/solr/X_Y_Z

  9. svn add solr/X_Y_Z

  10. svn commit # this might take some time: ~ 1 beer

  11. Confirm you can browse to these directories manually, and especially that solr javadocs link back to lucene's correctly.

Update redirect to latest Javadoc

We make it possible to link to latest javadoc by providing redirect links for e.g. which will auto redirect to whatever is the latest released version, i.e. for 4.3.0. This is handled in .htaccess:

  1. Goto CMS root

  2. Click on the CMS bookmarklet

  3. Scroll down to the file .htaccess and click [Edit]

  4. Locate the three lines starting with RedirectMatch temp /core|solr/api/... and change the version url component to match X_Y_Z above. Click Submit

  5. Click Commit, fill in a message and commit your change. No need to publish site yet - that will be done in next chapter.

NOTE As an alternative to CMS online editing, you can checkout the site from SVN and edit/commit .htaccess that way.

Update the rest of the website

NOTE: don't do this until you are ready to go to production. Every hour at :21 (e.g. 8:21, 9:21, ...) buildbot will commit all content from staging to production.

  1. Once mirrors are ready, use the bookmarklet or whatever to do the minor changes and news blurbs and stuff.
  2. Update the core & solr doap.rdf files to reflect the new versions using the Apache CMS

  3. Publish the site, e.g. by visiting, invoking the CMS bookmarklet, then clicking the publish link.

  4. Wait for these changes to appear on both of Apache's main webservers (US:, EU:, is dependent on your own geographic location, so the other mirror may still be outdated) before doing the next steps (see for details on how the site is mirrored to Apache's main web servers). Once they appear, verify all links are correct in your changes!

Announce the release

Release announcements can be shared/edited on the wiki at and

Mails to the list must be sent from an email address and should contain a signature.

Because you're likely not subscribed to the general, dev, and -user lists with your address, sending the announcement email to those list with your address will need to be moderated through, which will likely result in delayed transmission. To avoid this, send the emails these lists using your subscribed email address, and then separately send the announcements to

  1. Announce the Lucene release on mailing lists , , and

  2. Announce the Solr release on mailing lists , , and

  3. Add the new version to Wikipedia (english and maybe your own language)


Generate Backcompat Indexes

After each version of Lucene is released, compressed CFS and non-CFS indexes created with the newly released version are added to {lucene/backwards-codecs/src/test/org/apache/lucene/index/, for use in testing backward compatibility via org.apache.lucene.index.TestBackwardsCompatibility, which is also located under the backwards-codecs/ module. These indexes are created via methods on TestBackwardsCompatibility itself - see comments in the source for more information.

There is a script that automates creation of these per-release indexes, modifying so that they are used properly, and then running TestBackwardsCompatibility with the new indexes: dev-tools/scripts/ This script should be run on the stable branch and on trunk, and if the current release is a bugfix release, also on the release branch.

TestBackwardsCompatibility assumes that it will not test Version.LATEST, and will fail if it finds indexes from this version, so make sure dev-tools/scripts/ has been run with the next version to be released on each of the branches - see the bullet about adding a new version in the Branching & Feature Freeze section above before you run This will usually only be an issue if the current release is a bugfix release (i.e. X.Y.Z, where Z>0).

To print the script's usage, run it with the -h option.

Here's an example for the 5.1.0 release:

cd /path/to/lucene/dev/branches/branch_5x
svn up && svn stat   # Make sure no uncommitted changes

Update JIRA

  1. Go to the JIRA "Manage Versions" Administration pages ( and Next to the version you'll release, click the gear pop-up menu icon and choose "Release". It will ask you for the release date -- enter it. It will give the option of transitioning issues marked fix-for the released version to the next version, but do not do this as it will send an email for each issue -- we'll address that separately.

  2. Go to JIRA search in both Solr and Lucene and find all issues that were fixed in the release you just made, whose Status is Resolved. This URL may work (but edit the fixVersion part): (,SOLR)+AND+status=Resolved+AND+fixVersion=4.10.1). Do a bulk change (Under Tools... menu) to close all of these issues (this is a workflow transition task). Uncheck the box that says "send an email for these changes".

  3. Do another JIRA search in both Solr and Lucene to find all issues with Unresolved Resolution and fixVersion of the release you just made, and do a bulk change to the fixVersion to be both the trunk version and the next version on the branch you just released from. Uncheck the box that says "send an email for these changes".

Don't mirror old releases

Shortly after new releases are first mirrored, they are copied to the archives. Only the latest point release from each active branch should be kept under the Lucene PMC svnpubsub area dist/releases/lucene/. Older releases can be safely deleted from dist/releases/lucene/, since these releases are already backed up in the archives.

svn remove old releases, including X.Y-1, from dist/releases/lucene/java/ and dist/releases/lucene/solr/, then svn commit.

Update WIKI

The Solr WIKI has a page for every version which is often linked to from WIKI pages to indicate differences between versions, example: Do the following:

  1. Update the page for the released version with release date and link to release statement
  2. Create a new placeholder page for the "next" version, if it does not exist