HBASE-4712 Document rules for writing tests
git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1211187 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack
parent
1f8162e80c
commit
ff8e1a53c5
|
|
@ -166,6 +166,221 @@ Access restriction: The method getLong(Object, long) from the type Unsafe is not
|
|||
</para>
|
||||
</section>
|
||||
</section> <!-- build -->
|
||||
|
||||
<section xml:id="hbase.tests">
|
||||
<title>Tests</title>
|
||||
|
||||
<para>HBase tests are divided into two groups: <xref linkend="hbase.unittests"/> and
|
||||
<xref linkend="integration.tests" />.
|
||||
Unit tests are run by the Apache Continuous Integration server and by developers
|
||||
when they are verifying a fix does not cause breakage elsewhere in the code base.
|
||||
Integration tests are generally long-running tests that are invoked out-of-bound of
|
||||
the CI server when you want to do more intensive testing beyond the unit test set.
|
||||
Integration tests, for example, are run proving a release candidate or a production
|
||||
deploy. Below we go into more detail on each of these test types. 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.</para>
|
||||
|
||||
<section xml:id="hbase.unittests">
|
||||
<title>Unit Tests</title>
|
||||
<para>HBase unit tests are subdivided into three categories: small, medium and large, with
|
||||
corresponding JUnit <link xlink:href="http://www.junit.org/node/581">categories</link>:
|
||||
<classname>SmallTests</classname>, <classname>MediumTests</classname>,
|
||||
<classname>LargeTests</classname>. JUnit categories are denoted using java annotations
|
||||
and look like this in your unit test code.
|
||||
<programlisting>...
|
||||
@Category(SmallTests.class)
|
||||
public class TestHRegionInfo {
|
||||
|
||||
@Test
|
||||
public void testCreateHRegionInfoName() throws Exception {
|
||||
// ...
|
||||
}
|
||||
}</programlisting>
|
||||
The above example shows how to mark a test as belonging to the small category.
|
||||
</para>
|
||||
<para>
|
||||
<emphasis>Small</emphasis> 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 test is 15 seconds,
|
||||
and they do not use a cluster. <emphasis>Medium</emphasis> 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.
|
||||
<emphasis>Large</emphasis> tests are everything else. They are typically integration-like
|
||||
tests (yes, some large tests should be moved out to be HBase <xref linkend="integration.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.
|
||||
</para>
|
||||
<para>HBase uses a patched maven surefire plugin and maven profiles to implement its
|
||||
unit test characterizations.</para>
|
||||
|
||||
<section xml:id="hbase.unittests.cmds">
|
||||
<title>Running tests</title>
|
||||
<para>Below we describe how to run the HBase junit categories.</para>
|
||||
|
||||
<section xml:id="hbase.unittests.cmds.test">
|
||||
<title>Default: small and medium category tests
|
||||
</title>
|
||||
<para>Running <programlisting>mvn run</programlisting> will execute all small tests in a single JVM and 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.
|
||||
</para>
|
||||
</section>
|
||||
|
||||
<section xml:id="hbase.unittests.cmds.test.runAllTests">
|
||||
<title>Running all tests</title>
|
||||
<para>Running <programlisting>mvn test -P runAllTests</programlisting>
|
||||
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
|
||||
</para>
|
||||
</section>
|
||||
|
||||
<section xml:id="hbase.unittests.cmds.test.localtests.mytest">
|
||||
<title>Running a single test or all tests in a package</title>
|
||||
<para>To run an individual test, <classname>MyTest</classname>, do
|
||||
<programlisting>mvn test -P localTests -Dtest=MyTest</programlisting> You can also
|
||||
pass multiple individual tests comma-delimited: e.g.
|
||||
<programlisting>mvn test -P localTests -Dtest=MyTest1,MyTest2,MyTest3</programlisting>
|
||||
You can also pass a package and all tests under the package will be run by doing as follows:
|
||||
<programlisting>mvn test -P localTests -Dtest=org.apache.hadoop.hbase.client.*</programlisting>.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
The <code>-P localTests</code> will remove the JUnit category effect (without this specific profile,
|
||||
the profiles are taken into account). It will actually use the official release of surefire
|
||||
and the old connector (The HBase build uses a patched version of the maven surefire plugin).
|
||||
junit tests are executed in separated JVM. You will see a new message at the end of the
|
||||
report: "[INFO] Tests are skipped". It's harmless.
|
||||
</para>
|
||||
</section>
|
||||
|
||||
<section xml:id="hbase.unittests.cmds.test.profiles">
|
||||
<title>Other test invocation permutations</title>
|
||||
<para>Running <programlisting>mvn test -P runSmallTests</programlisting> will execute small tests only, in a single JVM.
|
||||
</para>
|
||||
<para>Running <programlisting>mvn test -P runMediumTests</programlisting> will execute medium tests in a single JVM.
|
||||
</para>
|
||||
<para>Running <programlisting>mvn test -P runLargeTests</programlisting> execute medium tests in a single JVM.
|
||||
</para>
|
||||
|
||||
<para>It's also possible to use the script <command>hbasetests.sh</command>. This script runs the medium and
|
||||
large tests in parallel with two maven instances, and provide a single report.
|
||||
It must be executed from the directory which contains the <filename>pom.xml</filename>.</para>
|
||||
<para>For example running
|
||||
<programlisting>./dev-support/hbasetests.sh</programlisting> will execute small and medium tests.
|
||||
Running <programlisting>./dev-support/hbasetests.sh runAllTests</programlisting> will execute all tests.
|
||||
Running <programlisting>./dev-support/hbasetests.sh replayFailed</programlisting> will rerun the failed tests a
|
||||
second time, in a separate jvm and without parallelisation.
|
||||
</para>
|
||||
</section>
|
||||
</section>
|
||||
|
||||
<section xml:id="hbase.tests.writing">
|
||||
<title>Writing Tests</title>
|
||||
<section xml:id="hbase.tests.rules">
|
||||
<title>General rules</title>
|
||||
<itemizedlist>
|
||||
<listitem>
|
||||
As much as possible, tests should be written as category small tests.
|
||||
</listitem>
|
||||
<listitem>
|
||||
All tests must be written to support parallel execution on the same machine, hence they should not use shared resources as fixed ports or fixed file names.
|
||||
</listitem>
|
||||
<listitem>
|
||||
Tests should not overlog. More than 100 lines/second makes the logs complex to read and use i/o that are hence not available for the other tests.
|
||||
</listitem>
|
||||
<listitem>
|
||||
Tests can be written with <classname>HBaseTestingUtility</classname>.
|
||||
This class offers helper functions to create a temp directory and do the cleanup, or to start a cluster.
|
||||
Categories and execution time
|
||||
</listitem>
|
||||
<listitem>
|
||||
All tests must be categorized, if not they could be skipped.
|
||||
</listitem>
|
||||
<listitem>
|
||||
All tests should be written to be as fast as possible.
|
||||
</listitem>
|
||||
<listitem>
|
||||
Small category tests should last less than 15 seconds, and must not have any side effect.
|
||||
</listitem>
|
||||
<listitem>
|
||||
Medium category tests should last less than 50 seconds.
|
||||
</listitem>
|
||||
<listitem>
|
||||
Large category tests should last less than 3 minutes. This should ensure a good parallelization for people using it, and ease the analysis when the test fails.
|
||||
</listitem>
|
||||
</itemizedlist>
|
||||
</section>
|
||||
<section xml:id="hbase.tests.sleeps">
|
||||
<title>Sleeps in tests</title>
|
||||
<para>Whenever possible, tests should not use <methodname>Thread.sleep</methodname>, but rather waiting for the real event they need. This is faster and clearer for the reader.
|
||||
Tests should not do a <methodname>Thread.sleep</methodname> 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.
|
||||
</para>
|
||||
</section>
|
||||
|
||||
<section xml:id="hbase.tests.cluster">
|
||||
<title>Tests using a cluster
|
||||
</title>
|
||||
|
||||
<para>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 <methodname>HBaseTestingUtility#shutdownMiniCluster</methodname>, 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.
|
||||
</para>
|
||||
</section>
|
||||
</section>
|
||||
</section>
|
||||
|
||||
<section xml:id="integration.tests">
|
||||
<title>Integration Tests</title>
|
||||
<para>HBase integration 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 asserring 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.
|
||||
</para>
|
||||
<para>
|
||||
Integration tests currently live under the <filename>src/test</filename> directory and
|
||||
will match the regex: <filename>**/IntegrationTest*.java</filename>.
|
||||
</para>
|
||||
<para>HBase 0.92 added a <varname>verify</varname> maven target.
|
||||
Invoking it, for example by doing <code>mvn verify</code>, will
|
||||
run all the phases up to and including the verify phase via the
|
||||
maven <link xlink:href="http://maven.apache.org/plugins/maven-failsafe-plugin/">failsafe plugin</link>,
|
||||
running all the above mentioned HBase unit tests as well as tests that are in the HBase integration test group.
|
||||
If you just want to run the integration tests, you need to run two commands. First:
|
||||
<code>mvn failsafe:integration-test</code>.
|
||||
This actually runs ALL the integration tests.
|
||||
<note><para>This command will always output <code>BUILD SUCCESS</code> even if there are test failures.
|
||||
</para></note>
|
||||
At this point, you could grep the output by hand looking for failed tests. However, maven will do this for us; just use:
|
||||
<programlisting>mvn failsafe:verify</programlisting>
|
||||
The above command basically looks at all the test results (so don't remove the 'target' directory) for test failures and reports the results.</para>
|
||||
|
||||
<section xml:id="maven.build.commanas.integration.tests2">
|
||||
<title>Running a subset of Integration tests</title>
|
||||
<para>This is very similar to how you specify running a subset of unit tests (see above).
|
||||
To just run <classname>IntegrationTestClassXYZ.java</classname>, use:
|
||||
<programlisting>mvn failsafe:integration-test -Dtest=IntegrationTestClassXYZ</programlisting>
|
||||
Pretty similar, right?
|
||||
The next thing you might want to do is run groups of integration tests, say all integration tests that are named IntegrationTestClassX*.java:
|
||||
<programlisting>mvn failsafe:integration-test -Dtest=*ClassX*</programlisting>
|
||||
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:
|
||||
<programlisting>mvn failsafe:integration-test -Dtest=*ClassX*, *ClassY</programlisting>
|
||||
</para>
|
||||
</section>
|
||||
</section>
|
||||
</section> <!-- tests -->
|
||||
|
||||
<section xml:id="maven.build.commands">
|
||||
<title>Maven Build Commands</title>
|
||||
|
|
@ -179,67 +394,17 @@ Access restriction: The method getLong(Object, long) from the type Unsafe is not
|
|||
mvn compile
|
||||
</programlisting>
|
||||
</section>
|
||||
|
||||
<section xml:id="maven.build.commands.unitall">
|
||||
<title>Run all Unit Tests</title>
|
||||
<programlisting>
|
||||
mvn test
|
||||
</programlisting>
|
||||
<title>Running all or individual Unit Tests</title>
|
||||
<para>See the <xref linkend="hbase.unittests.cmds" /> section
|
||||
above in <xref linkend="hbase.unittests" /></para>
|
||||
</section>
|
||||
<section xml:id="maven.build.commands.unit">
|
||||
<title>Run a Single Unit Test</title>
|
||||
<programlisting>
|
||||
mvn test -Dtest=TestXYZ
|
||||
</programlisting>
|
||||
</section>
|
||||
<section xml:id="maven.build.commands.unit2">
|
||||
<title>Run a Few Unit Tests</title>
|
||||
<programlisting>
|
||||
mvn test -Dtest=TestXYZ,TestABC
|
||||
</programlisting>
|
||||
</section>
|
||||
<section xml:id="maven.build.commands.unit.package">
|
||||
<title>Run all Unit Tests for a Package</title>
|
||||
<programlisting>
|
||||
mvn test -Dtest=org.apache.hadoop.hbase.client.*
|
||||
</programlisting>
|
||||
</section>
|
||||
|
||||
<section xml:id="maven.build.commanas.integration.tests">
|
||||
<title>Integration Tests</title>
|
||||
<para>HBase 0.92 added a <varname>verify</varname> maven target. Invoking it with run all the phases up to and including the verify phase via the maven <link xlink:href="http://maven.apache.org/plugins/maven-failsafe-plugin/">failsafe plugin</link>, running all the unit tests as well as the long running unit and integration tests.
|
||||
<title>Running all or individual Integration Tests</title>
|
||||
<para>See <xref linkend="integration.tests" />
|
||||
</para>
|
||||
<programlisting>
|
||||
mvn verify
|
||||
</programlisting>
|
||||
<para>However, sometimes you will want to run just the integration tests. In that case, you need to run two commands, first:</para>
|
||||
<programlisting>
|
||||
mvn failsafe:integration-test
|
||||
</programlisting>
|
||||
<para>This actually runs ALL the integration tests (anything in the tests folder fitting the regex: **/IntegrationTest*.java).
|
||||
NOTE: 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:</para>
|
||||
<programlisting>
|
||||
mvn failsafe:verify
|
||||
</programlisting>
|
||||
<para>The above command basically looks at all the test results (so don't remove the 'target' directory) for test failures and reports the results.</para>
|
||||
</section>
|
||||
<section xml:id="maven.build.commanas.integration.tests2">
|
||||
<title>Running a subset of Integration tests</title>
|
||||
<para>This is very similar to how you specify running a subset of unit tests (see above). To just run IntegrationTestClassXYZ.java, use:</para>
|
||||
<programlisting>
|
||||
mvn failsafe:integration-test -Dtest=IntegrationTestClassXYZ
|
||||
</programlisting>
|
||||
<para>Pretty similar, right?
|
||||
The next thing you might want to do is run groups of integration tests, say all integration tests that are named IntegrationTestClassX*.java:
|
||||
</para>
|
||||
<programlisting>
|
||||
mvn failsafe:integration-test -Dtest=*ClassX*
|
||||
</programlisting>
|
||||
<para>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:
|
||||
</para>
|
||||
<programlisting>
|
||||
mvn failsafe:integration-test -Dtest=*ClassX*, *ClassY
|
||||
</programlisting>
|
||||
</section>
|
||||
</section>
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue