test parallel

Demos

There are four tests (30 seconds each) in two files.

rspec

rspec is painfully slow and takes 2 minutes due to serial execution.

$ rspec

Finished in 2 minutes 0 seconds (files took 0.20031 seconds to load)
4 examples, 0 failures

parallel_tests

parallel_tests is twice as fast as rspec finishing in 1 minute. Each file is run in a separate process. Tests run serially within the process.

$ export PARALLEL_TEST_PROCESSORS=4
$ parallel_rspec spec/
4 processes for 2 specs, ~ 0 specs per process

4 examples, 0 failures

Took 61 seconds (1:01)

parallel_split_test

parallel_split_test is twice as fast as parallel_tests finishing in 30 seconds. Each test is run in a separate process.

$ export PARALLEL_SPLIT_TEST_PROCESSES=4
$ parallel_split_test spec/

Running examples in 4 processes

Summary:
1 example, 0 failures
1 example, 0 failures
1 example, 0 failures
1 example, 0 failures
Took 30.28 seconds with 4 processes

sauce_ruby with parallel_tests

sauce_ruby default uses parallel_tests via rake sauce:spec

$ rake sauce:spec
4 processes for 4 specs, ~ 1 specs per process

8 examples, 0 failures

Took 62 seconds (1:02)

sauce_ruby branch with parallel_split_test

sauce_ruby runs the tests on two platforms (firefox & safari) using parallel_split_test. One instance of parallel_split_test is used per platform to run all the tests. sauce_ruby with parallel_split_test is twice as fast as parallel_tests (30 seconds vs 60 seconds).

$ rake sauce:spec
Running examples in 4 processes
Running examples in 4 processes

Took 30.54 seconds with 4 processes
Took 30.55 seconds with 4 processes

8 examples, 0 failures

Took 32 seconds

test-queue (unpatched)

By default test-queue runs tests by example group so it's the same result as parallel_tests.

$ rspec-queue --format progress spec
Starting test-queue master (/tmp/test_queue_9461_70230273870620.sock)

==> Summary (4 workers in 60.0197s)

    [ 4]                                       0 examples, 0 failures         0 suites in 0.0076s      (pid 9467 exit 0)
    [ 3]                                       0 examples, 0 failures         0 suites in 0.0086s      (pid 9466 exit 0)
    [ 1]                                       2 examples, 0 failures         1 suites in 60.0155s      (pid 9464 exit 0)
    [ 2]                                       2 examples, 0 failures         1 suites in 60.0163s      (pid 9465 exit 0)

test-queue (patched)

Patching test-queue to run each example individually improves the test time by 50%.

$ rspec-queue --format progress spec
Starting test-queue master (/tmp/test_queue_9586_70278316902940.sock)

==> Summary (4 workers in 30.0312s)

    [ 3]                                        1 example, 0 failures         1 suites in 30.0246s      (pid 9590 exit 0)
    [ 1]                                        1 example, 0 failures         1 suites in 30.0269s      (pid 9588 exit 0)
    [ 2]                                        1 example, 0 failures         1 suites in 30.0276s      (pid 9589 exit 0)
    [ 4]                                        1 example, 0 failures         1 suites in 30.0273s      (pid 9591 exit 0)

Note that test-queue does optimal scheduling of tests by keeping track of the slowest tests and running them first.

bootstraponline/test_parallel