Tips on making PAX (OSGI testing) framework faster

Question

I know PAX is doing a lot of stuff and that creating the container and copying all those jars is not cheap but are there any general tips to improve performance. I have tests that execute outside the container in a fraction of a second while inside they take much longer. I am using PAX primarily to verify that my manifests are accurate and the bundle would be deployable without any missing dependencies. I have tried Knopflerfish, Equinox, Felix and in general there is little difference they are relatively slow to a barebones containerless run.

Answer 1

As you realised, the underlying container does not make much of a difference.

If you want to have minimal bundles created on the fly, you can try out Pax Tinybundles: if this applies to your case, you can build a set of minimized bundles with only the content you actually need for testing. For example, you can just package your Manifest. I haven't benchmarked it myself for this particular purpose, but it is worth a shot.

As a sidenote, please consider that Pax Exam 2.3 introduced support (see here) for @Before and @After, thus coming to your rescue for more flexible load setup/teardown.

Answer 2

Using Native Container is faster than Pax Runner Container, saving the overhead of starting an external process.

Using EagerSingleStagedReactorFactory saves the overhead of restarting the framework for each test.

To avoid copying JARs, prefer mvn: URLs or mavenBundle() to general URLs, then bundles will be taken from your local Maven repository, once they have been downloaded.

A new feature in Pax Exam 2.3.0 is the reference: protocol which allows you to provision bundles in place, without copying - this works even for exploded bundles (i.e. an unzipped directory structure).