Hi!
Right after git clone today (my head commit is
1df116fe4a44fc5d3712817ea725a872d9d6402e) I’ve tried to build zeppelin, but
zeppelin-interpreter fails. I digged into it and discovered the following. The
proposal’s commit can be seen in my github branch:
https://github.com/fathersson/incubator-zeppelin/commit/0e5a2f4d958fe35e88d9c2bb57f05ae019a3d5d7
Some insights of what I discovered.
There is an RemoteInterpreterEventPoller, which is a Thread and while it’s
running it constantly gets and release clients, so with a little of debug
messages it looks like:
before getClient: 0
after getClient: 1
before release: 1
after release: 0
before getClient: 0
after getClient: 1
before release: 1
after release: 0
But then, in the test RemoteInterpreterProcessTest.testClientFactory() after it
creates RemoteInterpreterProcess and references it (thus starts that poller),
it gets another client. So, after this call RemoteInterpreterProcess would
contain either 1 or 2 clients at the same time. It just matter of timing if the
following will pass or not:
assertEquals(1, rip.getNumActiveClient());
Just out of the code itself, I’d propose to set new
RemoteInterpreterEventPoller(interpreterGroup, this) from outside and then
start it in the reference method. That helps to test it as it’s possible to
provide any Thread (including mock(theReal.class)) that would do nothing, but
not sure if it’s the best - don’t yet understand the code good enough. See the
link above.
But of what I see, the whole test basically checks if GenericObjectPool
(commons-pool2:2.3) is actually working. I bet apache has pretty thorough
testing for it.
Eugene Morozov
[email protected]
