Speed up ResourceManager tests on Travis

[ajkannan]

Tests that use the mock resource manager helper take a relatively long time to complete on Travis. LocalResourceManagerHelperTest takes ~100 seconds and ResourceManagerImplTest takes ~45 seconds. When running locally, these tests only tend to take 3-5 seconds. This is likely because the HttpServer library used for the mock spins up threads and also uses sockets, and Travis probably handles these operations more slowly. We should think of a way to speed up these tests.

[mziccard]

Not sure if this is a pattern but the two tests seem to take much less in oraclejdk8 builds:

• LocalResourceManagerHelperTest ~ 5 sec
• ResourceManagerImplTest ~ 3 sec

[ajkannan]

Interesting, the faster test runs in version 8 build seem to be a trend. Perhaps related, ConcurrentHashMap (used by the mock) seems to have radically changed in implementation between version 7 and 8. There must be a lot of lock contention if this is indeed the cause.

[aozarov]

see this.

A suggested workaround to add exchange.getResponseHeaders().add("Connection", "close");
just before exchange.sendResponseHeaders (line 189) seems to make it much faster.