[jira] [Commented] (HBASE-4712) Document rules for writing tests

["Jesse Yates (Commented) (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-4712?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13161464#comment-13161464 ] 

Jesse Yates commented on HBASE-4712:
------------------------------------

Couple of comments:

bq. there is one report for small tests and one report for medium and large tests if they are executed

Is that one report each for the medium and large or one report for the two? Just need a single word of clarification in there 

bq. 1.3) mvn test -P localTests -Dtest=myTests

Is this new behavior from what's in trunk currently? Because I'm pretty sure I can just run 
mvn test -Dtest=myTest and get it to run them.

{quote}
mvn test -P runMediumTests - execute medium tests in a single JVM.
mvn test -P runLargeTests - execute medium tests in a single JVM.
{quote}

I don't think we really want to have these options available, right? A lot of the large tests depend on the fact that jvms are forked.


bq. Categories and execution time

A simple example or two here with the annotations would make this super obvious. For example:

{quote}
 a small test would look like this:

<code>

@SmallTest
public class TestMyClass{
...
}
</code>

Or you could test each method:


public class TestMyClass{

	@SmallTest
	public void testMyMethod() ...
}
</code>
{quote}

This is assuming the per-method annotation still work as Todd suggested a while ago?

bq. Tests using a HRegion do not have to start a cluster: A region can use the local file system.

Do we need to add a MiniRegion just for testing these situations?

Otherwise, I'm fine with the rest of the comments.

However, with recent discussions(http://search-hadoop.com/m/q41O6YiyfN), there may be some changes coming to this soon.
                
> Document rules for writing tests
> --------------------------------
>
>                 Key: HBASE-4712
>                 URL: https://issues.apache.org/jira/browse/HBASE-4712
>             Project: HBase
>          Issue Type: Task
>          Components: test
>    Affects Versions: 0.92.0
>            Reporter: nkeywal
>            Assignee: nkeywal
>            Priority: Minor
>
> We saw that some tests could be improved. Documenting the general rules could help.
> Proposal:
> HBase tests are divided in three categories: small, medium and large, with corresponding JUnit categories: SmallTest, MediumTest, LargeTest
> Small tests are executed in parallel in a shared JVM. They must last less than 15 seconds. They must NOT use a cluster.
> Medium tests are executed in separate JVM. They must last less than 50 seconds. They can use a cluster. They must not fail occasionally.
> Small and medium tests must not need more than 30 minutes to run altogether.
> Small and medium tests should be executed by the developers before submitting a patch.
> Large tests are everything else. They are typically integration tests, non-regression tests for specific bugs, timeout tests, performance tests.
> Tests rules & hints are:
> - As most as possible, tests should be written as small tests.
> - All tests should be written to support parallel execution on the same machine, hence should not use shared resources as fixed ports or fixed file names.
> - All tests should be written to be as fast as possible.
> - 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.
> - Tests can be written with HBaseTestingUtility . This class offers helper function to create a temp directory and do the cleanup, or to start a cluster.
> - Sleeps:
>     - 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 performances.
>     - 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 cluster:
>     - 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 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.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira