Accumulo Release Guide
Accumulo works on a very simple cycle of major releases with the minor releases when needed. The intent is for all major features to be implemented in a major release, with only bug fixes and minor features being included in minor releases. API changes should only be made on major releases, with continued support of the previous API for at least one major revision. This will give user code a major revision to convert from the old API to the new API.
Note: There will be times where API compatibility cannot be maintained, which we understand. However, this should only be considered when there is NO other option.
- Vote to start the major release process. This should be in consensus with the community and should be discussed on the accumulo-dev mailing list before the next steps take place. The majority of the committers must +1 the vote and all -1s need to be discussed.
- There is not a strict time limit between major releases, but some consideration should be made because we don't want to give our early adopters version fatigue.
- This will be the feature freeze for the version. Any features considered after this call need a very strong reason for implementation, which can be discussed via mailing list.
- Create a JIRA version for the proceeding release number. This is so we can begin the process of noting which features are bound for the current trunk vs. a future version.
- Handle all JIRA tickets assigned for the current major release version. Any ticket whose version is changed should have an explanation of why it is not to be handled in the current release.
- Once all JIRA tickets against the codebase (except documentation tickets) are resolved/redirected, the code will be branched in SVN.
- While there is currently a new trunk for the next release, it is highly discouraged to begin committing new features to it because this is when the current release is being tested. Any major bugs found will have to be patched in both versions and we want to make the process as seamless as possible.
- The new trunk needs to have its version information updated.
- Wrap up any standing documentation endeavors, whether or not there are tickets for them.
- Analyze API changes since last major release and ensure there are no changes that will cause pain for users.
- Analyze and update dependencies (e.g. with mvn dependency:analyze)
- Test the branch as per our testing criteria.
- Once testing is deemed successful and release documentation is complete, move on to Releasing.
- Upon detection and/or resolution of a bug, discussion needs to be made on the accumulo-dev list to determine if the community thinks the bug is critical or if there have been sufficient minor bug fixes to warrant a minor release.
- Make any necessary documentation changes, including a change log.
- Analyze and update dependencies (e.g. with mvn dependency:analyze)
- Test the now updated branch as per our testing criteria.
- Once testing is deemed successful and documentation is complete, move on to Releasing.
Testing for an Accumulo release includes a few steps that a developer may take without a Hadoop cluster and several that require a working cluster. For minor releases, the tests which run on a Hadoop cluster are recommended to be completed but are not required. Running even a reduced set of tests against real hardware is always encouraged even if the full test suite (in breadth of nodes or duration) is not executed. If PMC members do not believe adequate testing was performed for the sake of making the proposed release, the release should be vetoed via the normal voting process. New major releases are expected to run a full test suite.
The following steps can be taken without having an underlying cluster. They SHOULD be handled with each Hadoop profile available for a given release version. To activate an alternative profile specify e.g. "-Dhadoop.profile=2" for the Hadoop 2 profile on the Maven commandline. Some older versions of Accumulo referred to Hadoop profiles diferently; see the README that came with said versions for details on building against different Hadoop versions.
- All JUnit tests must pass. This should be a requirement of any patch so it should never be an issue of the codebase.
- Use "mvn package" to run against the default profile of a particular release
- Use "mvn -Dhadoop.profile=2 package" to test against the Hadoop 2 profile on e.g. 1.4 or 1.5
- Use "mvn -Dhadoop.profile=1 package" to test against the Hadoop 1 profile on e.g. 1.6 or later
- Analyze output of static analysis tools like Findbugs and PMD.
- For versions 1.6 and later, all functional tests must pass via the Maven failsafe plugin.
- Use "mvn verify" to run against the default profile of a particular release
- Use "mvn -Dhadoop.profile=1 verify" to run the functional tests against the Hadoop 1 profile
The following tests require a Hadoop cluster running a minimum of HDFS, MapReduce, and ZooKeeper. The cluster MAY have any number of worker nodes; it can even be a single node in pseudo-distributed mode. A cluster with multiple tablet servers SHOULD be used so that more of the code base will be exercised. For the purposes of release testing, you should note the number of nodes and versions used. See the Releasing section for more details.
- For versions prior to 1.6, all functional tests must complete successfully.
- See $ACCUMULO_HOME/test/system/auto/README for details on running the functional tests.
- Two 24-hour periods of the LongClean module of the RandomWalk test need to be run successfully. One of them must use agitation and the other should not.
- See $ACCUMULO_HOME/test/system/randomwalk/README for details on running the LongClean module.
- Two 24-hour periods of the continuous ingest test must be validated successfully. One test period must use agitation and the other should not.
- See $ACCUMULO_HOME/test/system/continuous/README for details on running and verifying the continuous ingest test.
- Two 72-hour periods of continuous ingest must run. One test period must use agitation and the other should not. No validation is necessary but the cluster should be checked to ensure it is still functional.
- Tag the tested branch. It should:
- Have its version set to note it is RC1.
- Be fully built, including a tar.gz of the entire project as well as the documentation.
- PGP Signatures of the tarball must be signed to a separate file and made available in the public_html folder of the user creating the release on people.apache.org, along with the tarball and MD5 and SHA512 checksums.
- A vote must be made on dev@accumulo. Lazy consensus is not sufficient for a release; at least 3 +1 votes from PMC members are required. All checksums and signatures need to be verified before any voter can +1 it. Voting shall last 72 hours.
- Voters SHOULD include with their vote details on the tests from the testing section they have successfully run. If given, said details for each test MUST include: the number of worker nodes in the cluster, the operating system and version, the Hadoop version, and the Zookeeper version. For testing done on a version other than the release candidate that is deemed relevant, include the commit hash. All such gathered testing information will be included in the release notes.
- Upon successful vote, the new releases can be retagged to remove the RC status and released on the Accumulo webpage.
- If at any time the tag needs to be remade due to any sort of error, it should be incremented to the next release candidate number.