sure, the test is totally open source; the directory implementation based on Infinispan is hosted as submodule of Infinispan:
The test is
it is included in the default test suite but disabled in Maven's configuration, so you should run it manually
mvn clean test -Dtest=PerformanceCompareStressTest
(running it requires the jboss.org repositories to be enabled in maven settings)
To describe it at higher level: there are 5 IndexRead-ing threads using reopen() before each search, 2 threads writing to the index, 1 additional thread as a coordinator and asserting that readers find what they expect to see in the index.
Exactly the same test scenario is then applied in sequence to RAMDirectory (not having issues), NIOFSDirectory, and 4 differently configured Infinispan directories.
Only the FSDirectory is affected by the issue, and it can never complete the full hour of stresstest succesfully, while all other implementations behave fine.
IndexWriter is set to MaxMergeDocs(5000) and setUseCompoundFile(false); the issue is reveled both using SerialMergeScheduler and while using the default merger.
During the last execution the test managed to perform 22,192,006 searches and 26,875 writes before hitting the exceptional case.
If you deem it useful I'd be happy in contributing a similar testcase to Lucene, but I assume you won't be excited in having such a long running test. Open to ideas to build a simpler one.