Testing Tips

Drill makes extensive use of JUnit and other libraries for testing. This page provides pointers to the information you need to work with Drill tests. We don't repeat that information; you will want to follow the links and read the original material to get a complete understanding of the libraries that Drill uses.

Caveat: information here about Drill is "reverse engineered" from the code; this page has not yet had the benefit of insight from the developers who created Drill's test structure.

Topics

"Classic" Drill testing techniques

• Testing with JUnit
• Testing with JMockit
• Test Logging
• Testing with Physical Plans and Mock Data

"Updated" Drill testing techniques

• Cluster Fixture Framework
• Operator Fixture Framework
• The Mock Record Reader

Mockito

Drill depends on the Mockito framework. (Need to find & document usages.)

Drill Test Structure

(TBD)

Maven

It is often helpful to know the set of properties that Maven defines and are available for use in the POM file.

Surefire Plugin

Drill uses the Maven Surefire plugin to run tests. The root POM contains significant test configuration that you may or may not want to include when running tests in a debugger:

          <configuration>
            <argLine>-Xms512m -Xmx3g -Ddrill.exec.http.enabled=false
              -Ddrill.exec.sys.store.provider.local.write=false
              -Dorg.apache.drill.exec.server.Drillbit.system_options=\
               "org.apache.drill.exec.compile.ClassTransformer.scalar_replacement=on"
              -Ddrill.test.query.printing.silent=true
              -Ddrill.catastrophic_to_standard_out=true
              -XX:MaxPermSize=512M -XX:MaxDirectMemorySize=3072M
              -Djava.net.preferIPv4Stack=true
              -Djava.awt.headless=true
              -XX:+CMSClassUnloadingEnabled -ea</argLine>
            <forkCount>${forkCount}</forkCount>
            <reuseForks>true</reuseForks>
            <additionalClasspathElements>
              <additionalClasspathElement>./exec/jdbc/src/test/resources/storage-plugins.json</additionalClasspathElement>
            </additionalClasspathElements>

You can run individual tests as follows. First, cd into the project that contains the test. Then, run the test. (You'll get an error if you try to run the test from the root Drill directory.)

cd /path/to/drill/project
mvn surefire:test -Dtest=TestCircle

Java Assertions

Drill code makes sparse use of Java exceptions, preferring the Guava equivalents. One area that assertions (-ea option) does affect is performance: queries run about 10x slower with assertions enabled due to allocator logging. When doing any performance-related work, ensure that assertions are not enabled.

class DrillBuf ...
  public boolean release(int decrement) {
    ...
    if (BaseAllocator.DEBUG) {
      historicalLog.recordEvent("release(%d). original value: %d", decrement, refCnt + decrement);
    }

IntelliJ

Hey IntelliJ users, what advice can we put here?