The wildcard cat API REST tests relied on bulk.max and bulk.min in
the thread_pool response. However due to the thread pool types being
randomized in InternalTestCluster, the min/max values were not guaranteed
to exist (the cached thread pool type is unbounded and thus does not have a
max value).
In order to prevent this, the test has been removed and now the cat
nodes test is used for wildcard testing, which always returns stats
about the heap.
cat/nodes currently does not report any details related to file descriptors. This adds the current number in use, the maximum number available as well as their ratio (percentage) to cat/nodes as hidden-by-default metrics. In addition, this also adds current heap usage (as a non-percentage of ts max) and ram usage (as a non-percerntage of its max) to allow tools to provide more granularity.
Closes#7652
Alexander Reelsen
Lee Hinman
Spencer
Chris Earle