This commit actually bounds the size of the generic thread pool. The
generic thread pool was of type cached, a thread pool with an unbounded
number of workers and an unbounded work queue. With this commit, the
generic thread pool is now of type scaling. As such, the cached thread
pool type has been removed. By default, the generic thread pool is
constructed with a core pool size of four, a max pool size of 128 and
idle workers can be reaped after a keep-alive time of thirty seconds
expires. The work queue for this thread pool remains unbounded.
In #17198, we removed suggest transport action, which
used the `suggest` threadpool to execute requests. Now
`suggest` threadpool is unused and suggest requests are
executed on the `search` threadpool.
This commit forbids the changing of thread pool types for any thread
pool. The motivation here is that these are expert settings with
little practical advantage.
Closes#14294, relates #2509, relates #2858, relates #5152
Today, when executing an action (mainly when using the Java API), a listener threaded flag can be set to true in order to execute the listener on a different thread pool. Today, this thread pool is the generic thread pool, which is cached. This can create problems for Java clients (mainly) around potential thread explosion.
Introduce a new thread pool called listener, that is fixed sized and defaults to the half the cores maxed at 10, and use it where listeners are executed.
relates to #5152closes#7837
BlobContainer used to provide async APIs which are not used
internally. The implementation of these APIs are also not async
by nature and neither is any of the pluggable BlobContainers. This
commit simplifies the API to a simple input / output stream and
reduces the hierarchy of BlobContainer dramatically.
NOTE: This is a breaking change!
Closes#7551
Now that we properly fixed the ability to set the queue size on the index / bulk thread pool, we should actually set them to a somehow reasonable value to protect from users potentially overflowing our system.
I suggest defaults to be 50 for bulk, and 200 for indexing.
Also, set the thread pool for get, which we should set (in a similar value to a "read" queue size we have today).
closes#3888
Add a dedicated suggest thread pool for the suggest API. With the new completion suggest type, which is purely CPU bounded, it makes more sense to have a dedicated thread pool for suggest compared to having it share the search thread pool and "competing" against other search operations.
closes#3698