druid/integration-tests

Integration Testing

To run integration tests, you have to specify the druid cluster the tests should use.

Druid comes with the mvn profile integration-tests for setting up druid running in docker containers, and using that cluster to run the integration tests.

To use a druid cluster that is already running, use the mvn profile int-tests-config-file, which uses a configuration file describing the cluster.

Integration Testing Using Docker

For running integration tests using docker there are 2 approaches. If your platform supports docker natively, you can simply set DOCKER_IP environment variable to localhost and skip to Running tests section. Ensure that you have at least 4GiB of memory allocated to the docker engine (This can be set under Preferences > Advanced).

export DOCKER_IP=127.0.0.1

The other approach is to use separate virtual machine to run docker containers with help of docker-machine tool.

Installing Docker Machine

Please refer to instructions at https://github.com/druid-io/docker-druid/blob/master/docker-install.md.

Creating the Docker VM

Create a new VM for integration tests with at least 6GB of memory.

docker-machine create --driver virtualbox --virtualbox-memory 6000 integration

Set the docker environment:

eval "$(docker-machine env integration)"
export DOCKER_IP=$(docker-machine ip integration)
export DOCKER_MACHINE_IP=$(docker-machine inspect integration | jq -r .Driver[\"HostOnlyCIDR\"])

The final command uses the jq tool to read the Driver->HostOnlyCIDR field from the docker-machine inspect output. If you don't wish to install jq, you will need to set DOCKER_MACHINE_IP manually.

Running tests

To run all the tests using docker and mvn run the following command:

  mvn verify -P integration-tests

To run only a single test using mvn run the following command:

  mvn verify -P integration-tests -Dit.test=<test_name>

Add -rf :druid-integration-tests when running integration tests for the second time or later without changing the code of core modules in between to skip up-to-date checks for the whole module dependency tree.

Running Tests Using A Configuration File for Any Cluster

Make sure that you have at least 6GB of memory available before you run the tests.

To run tests on any druid cluster that is already running, create a configuration file:

{   
   "broker_host": "<broker_ip>",
   "broker_port": "<broker_port>",
   "router_host": "<router_ip>",
   "router_port": "<router_port>",
   "indexer_host": "<indexer_ip>",
   "indexer_port": "<indexer_port>",
   "coordinator_host": "<coordinator_ip>",
   "coordinator_port": "<coordinator_port>",
   "middlemanager_host": "<middle_manager_ip>",
   "zookeeper_hosts": "<comma-separated list of zookeeper_ip:zookeeper_port>",
}

Set the environment variable CONFIG_FILE to the name of the configuration file:

export CONFIG_FILE=<config file name>

To run all the tests using mvn run the following command:

  mvn verify -P int-tests-config-file

To run only a single test using mvn run the following command:

  mvn verify -P int-tests-config-file -Dit.test=<test_name>

Running a Test That Uses Hadoop

The integration test that indexes from hadoop is not run as part of the integration test run discussed above. This is because druid test clusters might not, in general, have access to hadoop. That's the case (for now, at least) when using the docker cluster set up by the integration-tests profile, so the hadoop test has to be run using a cluster specified in a configuration file.

The data file is integration-tests/src/test/resources/hadoop/batch_hadoop.data. Create a directory called batchHadoop1 in the hadoop file system (anywhere you want) and put batch_hadoop.data into that directory (as its only file).

Add this keyword to the configuration file (see above):

    "hadoopTestDir": "<name_of_dir_containing_batchHadoop1>"

Run the test using mvn:

  mvn verify -P int-tests-config-file -Dit.test=ITHadoopIndexTest

In some test environments, the machine where the tests need to be executed cannot access the outside internet, so mvn cannot be run. In that case, do the following instead of running the tests using mvn:

Compile druid and the integration tests

On a machine that can do mvn builds:

cd druid 
mvn clean package
cd integration_tests 
mvn dependency:copy-dependencies package

Put the compiled test code into your test cluster

Copy the integration-tests directory to the test cluster.

Set CLASSPATH

TDIR=<directory containing integration-tests>/target
VER=<version of druid you built>
export CLASSPATH=$TDIR/dependency/*:$TDIR/druid-integration-tests-$VER.jar:$TDIR/druid-integration-tests-$VER-tests.jar

Run the test

java -Duser.timezone=UTC -Dfile.encoding=UTF-8 -Ddruid.test.config.type=configFile -Ddruid.test.config.configFile=<pathname of configuration file> org.testng.TestNG -testrunfactory org.testng.DruidTestRunnerFactory -testclass org.apache.druid.tests.hadoop.ITHadoopIndexTest

Writing a New Test

What should we cover in integration tests

For every end-user functionality provided by druid we should have an integration-test verifying the correctness.

Rules to be followed while writing a new integration test

Every Integration Test must follow these rules:

1. Name of the test must start with a prefix "IT"
2. A test should be independent of other tests
3. Tests are to be written in TestNG style (http://testng.org/doc/documentation-main.html#methods)
4. If a test loads some data it is the responsibility of the test to clean up the data from the cluster

How to use Guice Dependency Injection in a test

A test can access different helper and utility classes provided by test-framework in order to access Coordinator,Broker etc.. To mark a test be able to use Guice Dependency Injection - Annotate the test class with the below annotation

 @Guice(moduleFactory = DruidTestModuleFactory.class)

This will tell the test framework that the test class needs to be constructed using guice.

Helper Classes provided

1. IntegrationTestingConfig - configuration of the test
2. CoordinatorResourceTestClient - httpclient for coordinator endpoints
3. OverlordResourceTestClient - httpclient for indexer endpoints
4. QueryResourceTestClient - httpclient for broker endpoints

Static Utility classes

1. RetryUtil - provides methods to retry an operation until it succeeds for configurable no. of times
2. FromFileTestQueryHelper - reads queries with expected results from file and executes them and verifies the results using ResultVerifier

Refer ITIndexerTest as an example on how to use dependency Injection