Table of Contents
This chapter will be of interest only to those building and developing Apache HBase (TM) (i.e., as opposed to just downloading the latest distribution).
There are two different repositories for Apache HBase: Subversion (SVN) and Git. The former is the system of record for committers, but the latter is easier to work with to build and contribute. SVN updates get automatically propagated to the Git repo.
Under the dev-support folder, you will find hbase_eclipse_formatter.xml.
We encourage you to have this formatter in place in eclipse when editing HBase code. To load it into eclipse:
Go to Eclipse->Preferences...
In Preferences, Go to Java->Code Style->Formatter
Import... hbase_eclipse_formatter.xml
Click Apply
Still in Preferences, Go to Java->Editor->Save Actions
Check the following:
Perform the selected actions on save
Format source code
Format edited lines
Click Apply
In addition to the automatic formatting, make sure you follow the style guidelines explained in Section 1.11.5, “Common Patch Feedback”
Also, no @author tags - that's a rule. Quality Javadoc comments are appreciated. And include the Apache license.
Download and install the Subversive plugin.
Set up an SVN Repository target from Section 1.1.1, “SVN”, then check out the code.
If you cloned the project via git, download and install the Git plugin (EGit). Attach to your local git repo (via the Git Repositories window) and you'll be able to see file revision history, generate patches, etc.
The easiest way is to use the m2eclipse plugin for Eclipse. Eclipse Indigo or newer has m2eclipse built-in, or it can be found here:http://www.eclipse.org/m2e/. M2Eclipse provides Maven integration for Eclipse - it even lets you use the direct Maven commands from within Eclipse to compile and test your project.
To import the project, you merely need to go to File->Import...Maven->Existing Maven Projects and then point Eclipse at the HBase root directory; m2eclipse will automatically find all the hbase modules for you.
If you install m2eclipse and import HBase in your workspace, you will have to fix your eclipse Build Path.
Remove target folder, add target/generated-jamon
and target/generated-sources/java folders. You may also remove from your Build Path
the exclusions on the src/main/resources and src/test/resources
to avoid error message in the console 'Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.6:run (default) on project hbase:
'An Ant BuildException has occured: Replace: source file .../target/classes/hbase-default.xml doesn't exist'. This will also
reduce the eclipse build cycles and make your life easier when developing.
For those not inclined to use m2eclipse, you can generate the Eclipse files from the command line. First, run (you should only have to do this once):
mvn clean install -DskipTests
and then close Eclipse and execute...
mvn eclipse:eclipse
... from your local HBase project directory in your workspace to generate some new .project
and .classpathfiles. Then reopen Eclipse, or refresh your eclipse project (F5), and import
the .project file in the HBase directory to a workspace.
The M2_REPO classpath variable needs to be set up for the project. This needs to be set to
your local Maven repository, which is usually ~/.m2/repository
Description Resource Path Location Type
The project cannot be built until build path errors are resolved hbase Unknown Java Problem
Unbound classpath variable: 'M2_REPO/asm/asm/3.1/asm-3.1.jar' in project 'hbase' hbase Build path Build Path Problem
Unbound classpath variable: 'M2_REPO/com/github/stephenc/high-scale-lib/high-scale-lib/1.1.1/high-scale-lib-1.1.1.jar' in project 'hbase' hbase Build path Build Path Problem
Unbound classpath variable: 'M2_REPO/com/google/guava/guava/r09/guava-r09.jar' in project 'hbase' hbase Build path Build Path Problem
Unbound classpath variable: 'M2_REPO/com/google/protobuf/protobuf-java/2.3.0/protobuf-java-2.3.0.jar' in project 'hbase' hbase Build path Build Path Problem Unbound classpath variable:
Eclipse will currently complain about Bytes.java. It is not possible to turn these errors off.
Description Resource Path Location Type
Access restriction: The method arrayBaseOffset(Class) from the type Unsafe is not accessible due to restriction on required library /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar Bytes.java /hbase/src/main/java/org/apache/hadoop/hbase/util line 1061 Java Problem
Access restriction: The method arrayIndexScale(Class) from the type Unsafe is not accessible due to restriction on required library /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar Bytes.java /hbase/src/main/java/org/apache/hadoop/hbase/util line 1064 Java Problem
Access restriction: The method getLong(Object, long) from the type Unsafe is not accessible due to restriction on required library /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar Bytes.java /hbase/src/main/java/org/apache/hadoop/hbase/util line 1111 Java Problem
For additional information on setting up Eclipse for HBase development on Windows, see Michael Morello's blog on the topic.
Thanks to maven, building HBase is pretty easy. You can read about the various maven commands in Section 1.8, “Maven Build Commands”, but the simplest command to compile HBase from its java source code is:
mvn package -DskipTests
Or, to clean up before compiling:
mvn clean package -DskipTests
With Eclipse set up as explained above in Section 1.2.1, “Eclipse”, you can also simply use the build command in Eclipse. To create the full installable HBase package takes a little bit more work, so read on.
Pass -Dsnappy to trigger the snappy maven profile for building
snappy native libs into hbase. See also ???
Do the following to build the HBase tarball. Passing the -Prelease will generate javadoc and run the RAT plugin to verify licenses on source.
% MAVEN_OPTS="-Xmx2g" mvn clean site install assembly:assembly -DskipTests -Prelease
If you see Unable to find resource 'VM_global_library.vm', ignore it.
Its not an error. It is officially ugly though.
Follow the instructions at Publishing Maven Artifacts after reading the below miscellaney.
You must use maven 3.0.x (Check by running mvn -version).
Let me list out the commands I used first. The sections that follow dig in more on what is going on. In this example, we are releasing the 0.92.2 jar to the apache maven repository.
# First make a copy of the tag we want to release; presumes the release has been tagged already
# We do this because we need to make some commits for the mvn release plugin to work.
853 svn copy -m "Publishing 0.92.2 to mvn" https://svn.apache.org/repos/asf/hbase/tags/0.92.2 https://svn.apache.org/repos/asf/hbase/tags/0.92.2mvn
857 svn checkout https://svn.apache.org/repos/asf/hbase/tags/0.92.2mvn
858 cd 0.92.2mvn/
# Edit the version making it release version with a '-SNAPSHOT' suffix (See below for more on this)
860 vi pom.xml
861 svn commit -m "Add SNAPSHOT to the version" pom.xml
862 ~/bin/mvn/bin/mvn release:clean
865 ~/bin/mvn/bin/mvn release:prepare
866 # Answer questions and then ^C to kill the build after the last question. See below for more on this.
867 vi release.properties
# Change the references to trunk svn to be 0.92.2mvn; the release plugin presumes trunk
# Then restart the release:prepare -- it won't ask questions
# because the properties file exists.
868 ~/bin/mvn/bin/mvn release:prepare
# The apache-release profile comes from the apache parent pom and does signing of artifacts published
869 ~/bin/mvn/bin/mvn release:perform -Papache-release
# When done copying up to apache staging repository,
# browse to repository.apache.org, login and finish
# the release as according to the above
# "Publishing Maven Artifacts.
Below is more detail on the commmands listed above.
At the mvn release:perform step, before starting, if you are for example releasing hbase 0.92.2, you need to make sure the pom.xml version is 0.92.2-SNAPSHOT. This needs to be checked in. Since we do the maven release after actual release, I've been doing this checkin into a copy of the release tag rather than into the actual release tag itself (presumes the release has been properly tagged in svn). So, say we released hbase 0.92.2 and now we want to do the release to the maven repository, in svn, the 0.92.2 release will be tagged 0.92.2. Making the maven release, copy the 0.92.2 tag to 0.92.2mvn. Check out this tag and change the version therein and commit.
Currently, the mvn release wants to go against trunk. I haven't figured how to tell it to do otherwise
so I do the below hack. The hack comprises answering the questions put to you by the mvn release plugin properly,
then immediately control-C'ing the build after the last question asked as the build release step starts to run.
After control-C'ing it, You'll notice a release.properties in your build dir. Review it.
Make sure it is using the proper branch -- it tends to use trunk rather than the 0.92.2mvn or whatever
that you want it to use -- so hand edit the release.properties file that was put under ${HBASE_HOME}
by the release:perform invocation. When done, resstart the
release:perform.
Here is how I'd answer the questions at release:prepare time:
What is the release version for "HBase"? (org.apache.hbase:hbase) 0.92.2: : What is SCM release tag or label for "HBase"? (org.apache.hbase:hbase) hbase-0.92.2: : 0.92.2mvn What is the new development version for "HBase"? (org.apache.hbase:hbase) 0.92.3-SNAPSHOT: : [INFO] Transforming 'HBase'...
When you run release:perform, pass -Papache-release else it will not 'sign' the artifacts it uploads.
A strange issue I ran into was the one where the upload into the apache repository was being sprayed across multiple apache machines making it so I could not release. See INFRA-4482 Why is my upload to mvn spread across multiple repositories?.
Here is my ~/.m2/settings.xml.
This is read by the release plugin. The apache-release profile will pick up your
gpg key setup from here if you've specified it into the file. The password
can be maven encrypted as suggested in the "Publishing Maven Artifacts" but plain
text password works too (just don't let anyone see your local settings.xml).
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
http://maven.apache.org/xsd/settings-1.0.0.xsd">
<servers>
<!- To publish a snapshot of some part of Maven -->
<server>
<id>apache.snapshots.https</id>
<username>YOUR_APACHE_ID
</username>
<password>YOUR_APACHE_PASSWORD
</password>
</server>
<!-- To publish a website using Maven -->
<!-- To stage a release of some part of Maven -->
<server>
<id>apache.releases.https</id>
<username>YOUR_APACHE_ID
</username>
<password>YOUR_APACHE_PASSWORD
</password>
</server>
</servers>
<profiles>
<profile>
<id>apache-release</id>
<properties>
<gpg.keyname>YOUR_KEYNAME</gpg.keyname>
<!--Keyname is something like this ... 00A5F21E... do gpg --list-keys to find it-->
<gpg.passphrase>YOUR_KEY_PASSWORD
</gpg.passphrase>
</properties>
</profile>
</profiles>
</settings>
If you see run into the below, its because you need to edit version in the pom.xml and add
-SNAPSHOT to the version (and commit).
[INFO] Scanning for projects...
[INFO] Searching repository for plugin with prefix: 'release'.
[INFO] ------------------------------------------------------------------------
[INFO] Building HBase
[INFO] task-segment: [release:prepare] (aggregator-style)
[INFO] ------------------------------------------------------------------------
[INFO] [release:prepare {execution: default-cli}]
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] You don't have a SNAPSHOT project in the reactor projects list.
[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3 seconds
[INFO] Finished at: Sat Mar 26 18:11:07 PDT 2011
[INFO] Final Memory: 35M/423M
[INFO] -----------------------------------------------------------------------
The manual is marked up using docbook.
We then use the docbkx maven plugin
to transform the markup to html. This plugin is run when you specify the site
goal as in when you run mvn site or you can call the plugin explicitly to
just generate the manual by doing mvn docbkx:generate-html
(TODO: It looks like you have to run mvn site first because docbkx wants to
include a transformed hbase-default.xml. Fix).
When you run mvn site, we do the document generation twice, once to generate the multipage
manual and then again for the single page manual (the single page version is easier to search).
The Apache HBase apache web site (including this reference guide) is maintained as part of the main Apache HBase source tree, under /src/docbkx and /src/site. The former is this reference guide; the latter, in most cases, are legacy pages that are in the process of being merged into the docbkx tree.
To contribute to the reference guide, edit these files and submit them as a patch (see Section 1.11, “Submitting Patches”). Your Jira should contain a summary of the changes in each section (see HBASE-6081 for an example).
To generate the site locally while you're working on it, run:
mvn site
Then you can load up the generated HTML files in your browser (file are under /target/site).
As of INFRA-5680 Migrate apache hbase website,
to publish the website, build it, and then deploy it over a checkout of https://svn.apache.org/repos/asf/hbase/hbase.apache.org/trunk,
and then check it in. For example, if trunk is checked out out at /Users/stack/checkouts/trunk
and hbase.apache.org is checked out at /Users/stack/checkouts/hbase.apache.org/trunk, to update
the site, do the following:
# Build the site and deploy it to the checked out directory
# Getting the javadoc into site is a little tricky. You have to build it independent, then
# 'aggregate' it at top-level so the pre-site site lifecycle step can find it; that is
# what the javadoc:javadoc and javadoc:aggregate is about.
$ MAVEN_OPTS=" -Xmx3g" mvn clean -DskipTests javadoc:javadoc javadoc:aggregate site site:stage -DstagingDirectory=/Users/stack/checkouts/hbase.apache.org/trunk
# Check the deployed site by viewing in a brower.
# If all is good, commit it and it will show up at http://hbase.apache.org
#
$ cd /Users/stack/checkouts/hbase.apache.org/trunk
$ svn commit -m 'Committing latest version of website...'
Developers, at a minimum, should familiarize themselves with the unit test detail; unit tests in HBase have a character not usually seen in other projects.
As of 0.96, Apache HBase is split into multiple modules which creates "interesting" rules for
how and where tests are written. If you are writting code for hbase-server, see
Section 1.7.2, “Unit Tests” for how to write your tests; these tests can spin
up a minicluster and will need to be categorized. For any other module, for example
hbase-common, the tests must be strict unit tests and just test the class
under test - no use of the HBaseTestingUtility or minicluster is allowed (or even possible
given the dependency tree).
mvn testwhich will just run the tests IN THAT MODULE. If there are other dependencies on other modules, then you will have run the command from the ROOT HBASE DIRECTORY. This will run the tests in the other modules, unless you specify to skip the tests in that module. For instance, to skip the tests in the hbase-server module, you would run:
mvn clean test -PskipServerTestsfrom the top level directory to run all the tests in modules other than hbase-server. Note that you can specify to skip tests in multiple modules as well as just for a single module. For example, to skip the tests in
hbase-server and hbase-common, you would run:
mvn clean test -PskipServerTests -PskipCommonTests
Also, keep in mind that if you are running tests in the hbase-server module you will need to
apply the maven profiles discussed in Section 1.7.3, “Running tests” to get the tests to run properly.
Apache HBase unit tests are subdivided into four categories: small, medium, large, and
integration with corresponding JUnit categories:
SmallTests, MediumTests,
LargeTests, IntegrationTests.
JUnit categories are denoted using java annotations and look like this in your unit test code.
...
@Category(SmallTests.class)
public class TestHRegionInfo {
@Test
public void testCreateHRegionInfoName() throws Exception {
// ...
}
}The above example shows how to mark a unit test as belonging to the small category. All unit tests in HBase have a categorization.
The first three categories, small, medium, and large are for tests run when
you type $ mvn test; i.e. these three categorizations are for
HBase unit tests. The integration category is for not for unit tests but for integration
tests. These are run when you invoke $ mvn verify. Integration tests
are described in Section 1.7.5, “Integration Tests” and will not be discussed further
in this section on HBase unit tests.
Apache HBase uses a patched maven surefire plugin and maven profiles to implement its unit test characterizations.
Read the below to figure which annotation of the set small, medium, and large to put on your new HBase unit test.
Small tests are executed in a shared JVM. We put in this category all the tests that can be executed quickly in a shared JVM. The maximum execution time for a small test is 15 seconds, and small tests should not use a (mini)cluster.
Medium tests represent tests that must be executed before proposing a patch. They are designed to run in less than 30 minutes altogether, and are quite stable in their results. They are designed to last less than 50 seconds individually. They can use a cluster, and each of them is executed in a separate JVM.
Large tests are everything else. They are typically large-scale tests, regression tests for specific bugs, timeout tests, performance tests. They are executed before a commit on the pre-integration machines. They can be run on the developer machine as well.
Integration tests are system level tests. See Section 1.7.5, “Integration Tests” for more info.
Below we describe how to run the Apache HBase junit categories.
Running
mvn test
will execute all small tests in a single JVM (no fork) and then medium tests in a separate JVM for each test instance. Medium tests are NOT executed if there is an error in a small test. Large tests are NOT executed. There is one report for small tests, and one report for medium tests if they are executed.
Running
mvn test -P runAllTests
will execute small tests in a single JVM then medium and large tests in a separate JVM for each test. Medium and large tests are NOT executed if there is an error in a small test. Large tests are NOT executed if there is an error in a small or medium test. There is one report for small tests, and one report for medium and large tests if they are executed.
To run an individual test, e.g. MyTest, do
mvn test -Dtest=MyTest
You can also pass multiple, individual tests as a comma-delimited list:
mvn test -Dtest=MyTest1,MyTest2,MyTest3
You can also pass a package, which will run all tests under the package:
mvn test -Dtest=org.apache.hadoop.hbase.client.*
When -Dtest is specified, localTests profile will be used. It will use the official release
of maven surefire, rather than our custom surefire plugin, and the old connector (The HBase build uses a patched
version of the maven surefire plugin). Each junit tests is executed in a separate JVM (A fork per test class).
There is no parallelization when tests are running in this mode. You will see a new message at the end of the
-report: "[INFO] Tests are skipped". It's harmless. While you need to make sure the sum of Tests run: in
the Results : section of test reports matching the number of tests you specified because no
error will be reported when a non-existent test case is specified.
Running
mvn test -P runSmallTests
will execute "small" tests only, using a single JVM.
Running
mvn test -P runMediumTests
will execute "medium" tests only, launching a new JVM for each test-class.
Running
mvn test -P runLargeTests
will execute "large" tests only, launching a new JVM for each test-class.
For convenience, you can run
mvn test -P runDevTests
to execute both small and medium tests, using a single JVM.
By default, $ mvn test -P runAllTests runs 5 tests in parallel.
It can be increased on a developer's machine. Allowing that you can have 2
tests in parallel per core, and you need about 2Gb of memory per test (at the
extreme), if you have an 8 core, 24Gb box, you can have 16 tests in parallel.
but the memory available limits it to 12 (24/2), To run all tests with 12 tests
in parallell, do this:
mvn test -P runAllTests -Dsurefire.secondPartThreadCount=12.
To increase the speed, you can as well use a ramdisk. You will need 2Gb of memory
to run all tests. You will also need to delete the files between two test run.
The typical way to configure a ramdisk on Linux is:
$ sudo mkdir /ram2G sudo mount -t tmpfs -o size=2048M tmpfs /ram2G
You can then use it to run all HBase tests with the command: mvn test -P runAllTests -Dsurefire.secondPartThreadCount=12 -Dtest.build.data.basedirectory=/ram2G
It's also possible to use the script hbasetests.sh. This script runs the medium and
large tests in parallel with two maven instances, and provides a single report. This script does not use
the hbase version of surefire so no parallelization is being done other than the two maven instances the
script sets up.
It must be executed from the directory which contains the pom.xml.
For example running
./dev-support/hbasetests.sh
will execute small and medium tests. Running
./dev-support/hbasetests.sh runAllTests
will execute all tests. Running
./dev-support/hbasetests.sh replayFailed
will rerun the failed tests a second time, in a separate jvm and without parallelisation.
A custom Maven SureFire plugin listener checks a number of resources before
and after each HBase unit test runs and logs its findings at the end of the test
output files which can be found in target/surefire-reports
per Maven module (Tests write test reports named for the test class into this directory.
Check the *-out.txt files). The resources counted are the number
of threads, the number of file descriptors, etc. If the number has increased, it adds
a LEAK? comment in the logs. As you can have an HBase instance
running in the background, some threads can be deleted/created without any specific
action in the test. However, if the test does not work as expected, or if the test
should not impact these resources, it's worth checking these log lines
...hbase.ResourceChecker(157): before... and
...hbase.ResourceChecker(157): after.... For example:
2012-09-26 09:22:15,315 INFO [pool-1-thread-1] hbase.ResourceChecker(157): after: regionserver.TestColumnSeeking#testReseeking Thread=65 (was 65), OpenFileDescriptor=107 (was 107), MaxFileDescriptor=10240 (was 10240), ConnectionCount=1 (was 1)
HBaseTestingUtility.
This class offers helper functions to create a temp directory and do the cleanup, or to start a cluster.
Whenever possible, tests should not use Thread.sleep, but rather waiting for the real event they need. This is faster and clearer for the reader.
Tests should not do a Thread.sleep without testing an ending condition. This allows understanding what the test is waiting for. Moreover, the test will work whatever the machine performance is.
Sleep should be minimal to be as fast as possible. Waiting for a variable should be done in a 40ms sleep loop. Waiting for a socket operation should be done in a 200 ms sleep loop.
Tests using a HRegion do not have to start a cluster: A region can use the local file system.
Start/stopping a cluster cost around 10 seconds. They should not be started per test method but per test class.
Started cluster must be shutdown using HBaseTestingUtility#shutdownMiniCluster, which cleans the directories.
As most as possible, tests should use the default settings for the cluster. When they don't, they should document it. This will allow to share the cluster later.
HBase integration/system tests are tests that are beyond HBase unit tests. They are generally long-lasting, sizeable (the test can be asked to 1M rows or 1B rows), targetable (they can take configuration that will point them at the ready-made cluster they are to run against; integration tests do not include cluster start/stop code), and verifying success, integration tests rely on public APIs only; they do not attempt to examine server internals asserting success/fail. Integration tests are what you would run when you need to more elaborate proofing of a release candidate beyond what unit tests can do. They are not generally run on the Apache Continuous Integration build server, however, some sites opt to run integration tests as a part of their continuous testing on an actual cluster.
Integration tests currently live under the src/test directory
in the hbase-it submodule and will match the regex: **/IntegrationTest*.java.
All integration tests are also annotated with @Category(IntegrationTests.class).
Integration tests can be run in two modes: using a mini cluster, or against an actual distributed cluster.
Maven failsafe is used to run the tests using the mini cluster. IntegrationTestsDriver class is used for
executing the tests against a distributed cluster. Integration tests SHOULD NOT assume that they are running against a
mini cluster, and SHOULD NOT use private API's to access cluster state. To interact with the distributed or mini
cluster uniformly, IntegrationTestingUtility, and HBaseCluster classes,
and public client API's can be used.
On a distributed cluster, integration tests that use ChaosMonkey or otherwise manipulate services thru cluster manager (e.g. restart regionservers) use SSH to do it.
To run these, test process should be able to run commands on remote end, so ssh should be configured accordingly (for example, if HBase runs under hbase
user in your cluster, you can set up passwordless ssh for that user and run the test also under it). To facilitate that, hbase.it.clustermanager.ssh.user,
hbase.it.clustermanager.ssh.opts and hbase.it.clustermanager.ssh.cmd configuration settings can be used. "User" is the remote user that cluster manager should use to perform ssh commands.
"Opts" contains additional options that are passed to SSH (for example, "-i /tmp/my-key").
Finally, if you have some custom environment setup, "cmd" is the override format for the entire tunnel (ssh) command. The default string is {/usr/bin/ssh %1$s %2$s%3$s%4$s "%5$s"} and is a good starting point. This is a standard Java format string with 5 arguments that is used to execute the remote command. The argument 1 (%1$s) is SSH options set the via opts setting or via environment variable, 2 is SSH user name, 3 is "@" if username is set or "" otherwise, 4 is the target host name, and 5 is the logical command to execute (that may include single quotes, so don't use them). For example, if you run the tests under non-hbase user and want to ssh as that user and change to hbase on remote machine, you can use {/usr/bin/ssh %1$s %2$s%3$s%4$s "su hbase - -c \"%5$s\""}. That way, to kill RS (for example) integration tests may run {/usr/bin/ssh some-hostname "su hbase - -c \"ps aux | ... | kill ...\""}.
The command is logged in the test logs, so you can verify it is correct for your environment.
HBase 0.92 added a verify maven target.
Invoking it, for example by doing mvn verify, will
run all the phases up to and including the verify phase via the
maven failsafe plugin,
running all the above mentioned HBase unit tests as well as tests that are in the HBase integration test group.
After you have completed
mvn install -DskipTests
You can run just the integration tests by invoking:
cd hbase-it mvn verify
If you just want to run the integration tests in top-level, you need to run two commands. First:
mvn failsafe:integration-test
This actually runs ALL the integration tests.
This command will always output BUILD SUCCESS even if there are test failures.
At this point, you could grep the output by hand looking for failed tests. However, maven will do this for us; just use:
mvn failsafe:verify
The above command basically looks at all the test results (so don't remove the 'target' directory) for test failures and reports the results.
This is very similar to how you specify running a subset of unit tests (see above), but use the property
it.test instead of test.
To just run IntegrationTestClassXYZ.java, use:
mvn failsafe:integration-test -Dit.test=IntegrationTestClassXYZ
The next thing you might want to do is run groups of integration tests, say all integration tests that are named IntegrationTestClassX*.java:
mvn failsafe:integration-test -Dit.test=*ClassX*
This runs everything that is an integration test that matches *ClassX*. This means anything matching: "**/IntegrationTest*ClassX*". You can also run multiple groups of integration tests using comma-delimited lists (similar to unit tests). Using a list of matches still supports full regex matching for each of the groups.This would look something like:
mvn failsafe:integration-test -Dit.test=*ClassX*, *ClassY
If you have an already-setup HBase cluster, you can launch the integration tests by invoking the class IntegrationTestsDriver. You may have to
run test-compile first. The configuration will be picked by the bin/hbase script.
mvn test-compile
Then launch the tests with:
bin/hbase [--config config_dir] org.apache.hadoop.hbase.IntegrationTestsDriver [-test=class_regex]
This execution will launch the tests under hbase-it/src/test, having @Category(IntegrationTests.class) annotation,
and a name starting with IntegrationTests. If specified, class_regex will be used to filter test classes. The regex is checked against full class name; so, part of class name can be used.
IntegrationTestsDriver uses Junit to run the tests. Currently there is no support for running integration tests against a distributed cluster using maven (see HBASE-6201).
The tests interact with the distributed cluster by using the methods in the DistributedHBaseCluster (implementing HBaseCluster) class, which in turn uses a pluggable ClusterManager. Concrete implementations provide actual functionality for carrying out deployment-specific and environment-dependent tasks (SSH, etc). The default ClusterManager is HBaseClusterManager, which uses SSH to remotely execute start/stop/kill/signal commands, and assumes some posix commands (ps, etc). Also assumes the user running the test has enough "power" to start/stop servers on the remote machines. By default, it picks up HBASE_SSH_OPTS, HBASE_HOME, HBASE_CONF_DIR from the env, and uses bin/hbase-daemon.sh to carry out the actions. Currently tarball deployments, deployments which uses hbase-daemons.sh, and Apache Ambari deployments are supported. /etc/init.d/ scripts are not supported for now, but it can be easily added. For other deployment options, a ClusterManager can be implemented and plugged in.
In 0.96, a tool named ChaosMonkey has been introduced. It is modeled after the same-named tool by Netflix.
Some of the tests use ChaosMonkey to simulate faults in the running cluster in the way of killing random servers,
disconnecting servers, etc. ChaosMonkey can also be used as a stand-alone tool to run a (misbehaving) policy while you
are running other tests.
ChaosMonkey defines Action's and Policy's. Actions are sequences of events. We have at least the following actions:
Policies on the other hand are responsible for executing the actions based on a strategy. The default policy is to execute a random action every minute based on predefined action weights. ChaosMonkey executes predefined named policies until it is stopped. More than one policy can be active at any time.
To run ChaosMonkey as a standalone tool deploy your HBase cluster as usual. ChaosMonkey uses the configuration from the bin/hbase script, thus no extra configuration needs to be done. You can invoke the ChaosMonkey by running:
bin/hbase org.apache.hadoop.hbase.util.ChaosMonkey
This will output smt like:
12/11/19 23:21:57 INFO util.ChaosMonkey: Using ChaosMonkey Policy: class org.apache.hadoop.hbase.util.ChaosMonkey$PeriodicRandomActionPolicy, period:60000 12/11/19 23:21:57 INFO util.ChaosMonkey: Sleeping for 26953 to add jitter 12/11/19 23:22:24 INFO util.ChaosMonkey: Performing action: Restart active master 12/11/19 23:22:24 INFO util.ChaosMonkey: Killing master:master.example.com,60000,1353367210440 12/11/19 23:22:24 INFO hbase.HBaseCluster: Aborting Master: master.example.com,60000,1353367210440 12/11/19 23:22:24 INFO hbase.ClusterManager: Executing remote command: ps aux | grep master | grep -v grep | tr -s ' ' | cut -d ' ' -f2 | xargs kill -s SIGKILL , hostname:master.example.com 12/11/19 23:22:25 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output: 12/11/19 23:22:25 INFO hbase.HBaseCluster: Waiting service:master to stop: master.example.com,60000,1353367210440 12/11/19 23:22:25 INFO hbase.ClusterManager: Executing remote command: ps aux | grep master | grep -v grep | tr -s ' ' | cut -d ' ' -f2 , hostname:master.example.com 12/11/19 23:22:25 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output: 12/11/19 23:22:25 INFO util.ChaosMonkey: Killed master server:master.example.com,60000,1353367210440 12/11/19 23:22:25 INFO util.ChaosMonkey: Sleeping for:5000 12/11/19 23:22:30 INFO util.ChaosMonkey: Starting master:master.example.com 12/11/19 23:22:30 INFO hbase.HBaseCluster: Starting Master on: master.example.com 12/11/19 23:22:30 INFO hbase.ClusterManager: Executing remote command: /homes/enis/code/hbase-0.94/bin/../bin/hbase-daemon.sh --config /homes/enis/code/hbase-0.94/bin/../conf start master , hostname:master.example.com 12/11/19 23:22:31 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output:starting master, logging to /homes/enis/code/hbase-0.94/bin/../logs/hbase-enis-master-master.example.com.out .... 12/11/19 23:22:33 INFO util.ChaosMonkey: Started master: master.example.com,60000,1353367210440 12/11/19 23:22:33 INFO util.ChaosMonkey: Sleeping for:51321 12/11/19 23:23:24 INFO util.ChaosMonkey: Performing action: Restart random region server 12/11/19 23:23:24 INFO util.ChaosMonkey: Killing region server:rs3.example.com,60020,1353367027826 12/11/19 23:23:24 INFO hbase.HBaseCluster: Aborting RS: rs3.example.com,60020,1353367027826 12/11/19 23:23:24 INFO hbase.ClusterManager: Executing remote command: ps aux | grep regionserver | grep -v grep | tr -s ' ' | cut -d ' ' -f2 | xargs kill -s SIGKILL , hostname:rs3.example.com 12/11/19 23:23:25 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output: 12/11/19 23:23:25 INFO hbase.HBaseCluster: Waiting service:regionserver to stop: rs3.example.com,60020,1353367027826 12/11/19 23:23:25 INFO hbase.ClusterManager: Executing remote command: ps aux | grep regionserver | grep -v grep | tr -s ' ' | cut -d ' ' -f2 , hostname:rs3.example.com 12/11/19 23:23:25 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output: 12/11/19 23:23:25 INFO util.ChaosMonkey: Killed region server:rs3.example.com,60020,1353367027826. Reported num of rs:6 12/11/19 23:23:25 INFO util.ChaosMonkey: Sleeping for:60000 12/11/19 23:24:25 INFO util.ChaosMonkey: Starting region server:rs3.example.com 12/11/19 23:24:25 INFO hbase.HBaseCluster: Starting RS on: rs3.example.com 12/11/19 23:24:25 INFO hbase.ClusterManager: Executing remote command: /homes/enis/code/hbase-0.94/bin/../bin/hbase-daemon.sh --config /homes/enis/code/hbase-0.94/bin/../conf start regionserver , hostname:rs3.example.com 12/11/19 23:24:26 INFO hbase.ClusterManager: Executed remote command, exit code:0 , output:starting regionserver, logging to /homes/enis/code/hbase-0.94/bin/../logs/hbase-enis-regionserver-rs3.example.com.out 12/11/19 23:24:27 INFO util.ChaosMonkey: Started region server:rs3.example.com,60020,1353367027826. Reported num of rs:6
As you can see from the log, ChaosMonkey started the default PeriodicRandomActionPolicy, which is configured with all the available actions, and ran RestartActiveMaster and RestartRandomRs actions. ChaosMonkey tool, if run from command line, will keep on running until the process is killed.
All commands executed from the local HBase project directory.
Note: use Maven 3 (Maven 2 may work but we suggest you use Maven 3).
See the Section 1.7.3, “Running tests” section above in Section 1.7.2, “Unit Tests”
As of 0.96, Apache HBase supports building against Apache Hadoop versions: 1.0.3, 2.0.0-alpha and 3.0.0-SNAPSHOT. By default, we will build with Hadoop-1.0.3. To change the version to run with Hadoop-2.0.0-alpha, you would run:
mvn -Dhadoop.profile=2.0 ...
That is, designate build with hadoop.profile 2.0. Pass 2.0 for hadoop.profile to build against hadoop 2.0.
Tests may not all pass as of this writing so you may need to pass -DskipTests unless you are inclined
to fix the failing tests.
Similarly, for 3.0, you would just replace the profile value. Note that Hadoop-3.0.0-SNAPSHOT does not currently have a deployed maven artificat - you will need to build and install your own in your local maven repository if you want to run against this profile.
In earilier verions of Apache HBase, you can build against older versions of Apache Hadoop, notably, Hadoop 0.22.x and 0.23.x. If you are running, for example HBase-0.94 and wanted to build against Hadoop 0.23.x, you would run with:
mvn -Dhadoop.profile=22 ...
Apache HBase gets better only when people contribute!
As Apache HBase is an Apache Software Foundation project, see ??? for more information about how the ASF functions.
Sign up for the dev-list and the user-list. See the mailing lists page. Posing questions - and helping to answer other people's questions - is encouraged! There are varying levels of experience on both lists so patience and politeness are encouraged (and please stay on topic.)
Check for existing issues in Jira. If it's either a new feature request, enhancement, or a bug, file a ticket.
The following is a guideline on setting Jira issue priorities:
Most development is done on TRUNK. However, there are branches for minor releases (e.g., 0.90.1, 0.90.2, and 0.90.3 are on the 0.90 branch).
If you have any questions on this just send an email to the dev dist-list.
In HBase we use JUnit 4.
If you need to run miniclusters of HDFS, ZooKeeper, HBase, or MapReduce testing,
be sure to checkout the HBaseTestingUtility.
Alex Baranau of Sematext describes how it can be used in
HBase Case-Study: Using HBaseTestingUtility for Local Testing and Development (2010).
Sometimes you don't need a full running server
unit testing. For example, some methods can make do with a
a org.apache.hadoop.hbase.Server instance
or a org.apache.hadoop.hbase.master.MasterServices
Interface reference rather than a full-blown
org.apache.hadoop.hbase.master.HMaster.
In these cases, you maybe able to get away with a mocked
Server instance. For example:
TODO...
See Section 1.2.1.1, “Code Formatting” and Section 1.11.5, “Common Patch Feedback”.
Also, please pay attention to the interface stability/audience classifications that you will see all over our code base. They look like this at the head of the class:
@InterfaceAudience.Public @InterfaceStability.Stable
If the InterfaceAudience is Private,
we can change the class (and we do not need to include a InterfaceStability mark).
If a class is marked Public but its InterfaceStability
is marked Unstable, we can change it. If it's
marked Public/Evolving, we're allowed to change it
but should try not to. If it's Public and Stable
we can't change it without a deprecation path or with a really GREAT reason.
When you add new classes, mark them with the annotations above if publically accessible. If you are not cleared on how to mark your additions, ask up on the dev list.
This convention comes from our parent project Hadoop.
We don't have many but what we have we list below. All are subject to challenge of course but until then, please hold to the rules of the road.
ZooKeeper state should transient (treat it like memory). If deleted, hbase should be able to recover and essentially be in the same state[1].
If you are developing Apache HBase, frequently it is useful to test your changes against a more-real cluster than what you find in unit tests. In this case, HBase can be run directly from the source in local-mode. All you need to do is run:
${HBASE_HOME}/bin/start-hbase.shThis will spin up a full local-cluster, just as if you had packaged up HBase and installed it on your machine.
Keep in mind that you will need to have installed HBase into your local maven repository for the in-situ cluster to work properly. That is, you will need to run:
mvn clean install -DskipTests
to ensure that maven can find the correct classpath and dependencies. Generally, the above command is just a good thing to try running first, if maven is acting oddly.
If you are new to submitting patches to open source or new to submitting patches to Apache, I'd suggest you start by reading the On Contributing Patches page from Apache Commons Project. Its a nice overview that applies equally to the Apache HBase Project.
See the aforementioned Apache Commons link for how to make patches against a checked out subversion repository. Patch files can also be easily generated from Eclipse, for example by selecting "Team -> Create Patch". Patches can also be created by git diff and svn diff.
Please submit one patch-file per Jira. For example, if multiple files are changed make sure the selected resource when generating the patch is a directory. Patch files can reflect changes in multiple files.
Make sure you review Section 1.2.1.1, “Code Formatting” for code style.
The patch file should have the Apache HBase Jira ticket in the name. For example, if a patch was submitted for Foo.java, then
a patch file called Foo_HBASE_XXXX.patch would be acceptable where XXXX is the Apache HBase Jira number.
If you generating from a branch, then including the target branch in the filename is advised, e.g., HBASE-XXXX-0.90.patch.
Yes, please. Please try to include unit tests with every code patch (and especially new classes and large changes). Make sure unit tests pass locally before submitting the patch.
Also, see Section 1.10.2.1, “Mockito”.
If you are creating a new unit test class, notice how other unit test classes have classification/sizing annotations at the top and a static method on the end. Be sure to include these in any new unit test files you generate. See Section 1.7, “Tests” for more on how the annotations work.
The patch should be attached to the associated Jira ticket "More Actions -> Attach Files". Make sure you click the ASF license inclusion, otherwise the patch can't be considered for inclusion.
Once attached to the ticket, click "Submit Patch" and the status of the ticket will change. Committers will review submitted patches for inclusion into the codebase. Please understand that not every patch may get committed, and that feedback will likely be provided on the patch. Fear not, though, because the Apache HBase community is helpful!
The following items are representative of common patch feedback. Your patch process will go faster if these are taken into account before submission.
See the Java coding standards for more information on coding conventions in Java.
Rather than do this...
if ( foo.equals( bar ) ) { // don't do this
... do this instead...
if (foo.equals(bar)) {
Also, rather than do this...
foo = barArray[ i ]; // don't do this
... do this instead...
foo = barArray[i];
Auto-generated code in Eclipse often looks like this...
public void readFields(DataInput arg0) throws IOException { // don't do this
foo = arg0.readUTF(); // don't do this
... do this instead ...
public void readFields(DataInput di) throws IOException {
foo = di.readUTF();
See the difference? 'arg0' is what Eclipse uses for arguments by default.
Keep lines less than 100 characters.
Bar bar = foo.veryLongMethodWithManyArguments(argument1, argument2, argument3, argument4, argument5, argument6, argument7, argument8, argument9); // don't do this
... do something like this instead ...
Bar bar = foo.veryLongMethodWithManyArguments( argument1, argument2, argument3,argument4, argument5, argument6, argument7, argument8, argument9);
This happens more than people would imagine.
Bar bar = foo.getBar(); <--- imagine there's an extra space(s) after the semicolon instead of a line break.
Make sure there's a line-break after the end of your code, and also avoid lines that have nothing but whitespace.
In 0.96, HBase moved to protobufs. The below section on Writables applies to 0.94.x and previous, not to 0.96 and beyond.
Every class returned by RegionServers must implement Writable. If you
are creating a new class that needs to implement this interface, don't forget the default constructor.
This is also a very common feedback item. Don't forget Javadoc!
Javadoc warnings are checked during precommit. If the precommit tool gives you a '-1', please fix the javadoc issue. Your patch won't be committed if it adds such warnings.
Findbugs is used to detect common bugs pattern. As Javadoc, it is checked during the precommit build up on Apache's Jenkins, and as with Javadoc, please fix them. You can run findbugs locally with 'mvn findbugs:findbugs': it will generate the findbugs files locally. Sometimes, you may have to write code smarter than Findbugs. You can annotate your code to tell Findbugs you know what you're doing, by annotating your class with:
@edu.umd.cs.findbugs.annotations.SuppressWarnings(
value="HE_EQUALS_USE_HASHCODE",
justification="I know what I'm doing")
Note that we're using the apache licensed version of the annotations.
Don't just leave the @param arguments the way your IDE generated them. Don't do this...
/** * * @param bar <---- don't do this!!!! * @return <---- or this!!!! */ public Foo getFoo(Bar bar);
... either add something descriptive to the @param and @return lines, or just remove them. But the preference is to add something descriptive and useful.
If you submit a patch for one thing, don't do auto-reformatting or unrelated reformatting of code on a completely different area of code.
Likewise, don't add unrelated cleanup or refactorings outside the scope of your Jira.
Larger patches should go through ReviewBoard.
For more information on how to use ReviewBoard, see the ReviewBoard documentation.
Committers do this. See How To Commit in the Apache HBase wiki.
Commiters will also resolve the Jira, typically after the patch passes a build.
If a committer commits a patch it is their responsibility to make sure it passes the test suite. It is helpful if contributors keep an eye out that their patch does not break the hbase build and/or tests but ultimately, a contributor cannot be expected to be up on the particular vagaries and interconnections that occur in a project like hbase. A committer should.
[1] There are currently a few exceptions that we need to fix around whether a table is enabled or disabled