Haven't had a chance to review the full note below, but one request: can we please put this in the code tree itself in a file like TESTING.txt or README.testing.txt or something?
It'd be nice to be able to refer back to it from within the code tree. -Todd On Mon, Nov 28, 2011 at 12:29 PM, N Keywal <[email protected]> wrote: > Hi, > > The surefire modification seems to work well, so we can move to the final > step. > Please find below the last proposition for the test. The behavior described > can be activated with: > - a commit of hbase-4847 > - a modification of the jenkins config to run mvn verify vs. mvn tests. > > The main points are: > - should we run small & medium tests only by default on a developer > machine => here answer is yes > - should we run all tests on the central build => here answer is yes > - should we stop when a small test fails => here answer is yes > - should we stop when a medium test fails => here answer is yes > > > Also, I just had a discussion with Jesse, who think we should keep/have the > notion of integration test. If retained, the points above must be impacted > to take this into account. > > > fyi, there are today: > - 416 small tests, executed in ~3 minutes > - 489 medium tests, executed in ~35 minutes (without parallelization) > - 280 large tests, executed in ~90 minutes (without parallelization) > > -- > 1) Running tests > HBase tests are divided in three categories: small, medium and large, with > corresponding JUnit categories: SmallTests, MediumTests, LargeTests. > > - Small tests are executed in a shared JVM. We put in this category all the > tests that can be executed quickly (the maximum execution time for a test > is 15 seconds, and they do not use a cluster) in a shared jvm. > - Medium tests represents 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're 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 integration tests, > regression tests for specific bugs, timeout tests, performance tests. Some > of them can be flaky. They are executed before a commit on the > pre-integration machines. They can be run on the developer machine as well. > > Commands are: > 1) mvn test > - execute small tests in a single JVM and medium tests in a separate JVM > for each test > - 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- > > 2) mvn verify > - execute small tests in a single JVM then medium tests in a separate JVM > for each test, then large tests in a separate JVM as well. > - medium 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 by test category, small, medium and large > > 3) mvn test -P localTests -Dtest=myTests > - remove any category effect (without this specific profile, the profiles > are taken into account) > - use actually the official release of surefire & the old connector to > 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. > > 4) mvn test -P runAllTests > - execute small tests in a single JVM then medium & 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 are one report for small tests, and one report for medium & large > tests -if they are executed- > > 5) Various other profiles > - mvn test -P runSmallTests - execute small tests only, in a single JVM. > - mvn test -P runMediumTests - execute medium tests in a single JVM. > - mvn test -P runLargeTests - execute medium tests in a single JVM. > > It's as well possible to use the script 'hbasetests.sh'. 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 pom.xml. Commands are: > ./dev-support/hbasetests.sh - execute small and medium tests > ./dev-support/hbasetests.sh runAllTests - execute all tests > ./dev-support/hbasetests.sh replayFailed - rerun the failed tests a second > time, in a separate jvm and without parallelisation. > > 2) Writing tests > Tests rules & hints are: > - As most as possible, tests should be written as small tests. > - All tests must be written to support parallel execution on the same > machine, hence should not use shared resources as fixed ports or fixed file > names. > - 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 > functions to create a temp directory and do the cleanup, or to start a > cluster. > > - Categories and execution time > - All tests must be categorized, if not they could be skipped. > - All tests should be written to be as fast as possible. > - Small tests should last less than 15 seconds, and must not have any > side effect. > - Medium tests should last less than 45 seconds. > - large tests should last less than 3 minutes, this ensure a good > parallelization for the ones using it, and ease the analysis when the test > fails. > > - Sleeps: > - Whenever possible, tests should not use sleep, but rather waiting for > the real event. 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 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 a 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 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. > -- Todd Lipcon Software Engineer, Cloudera
