This PR adds a new thread pool type: `fixed_auto_queue_size`. This thread pool
behaves like a regular `fixed` threadpool, except that every
`auto_queue_frame_size` operations (default: 10,000) in the thread pool,
[Little's Law](https://en.wikipedia.org/wiki/Little's_law) is calculated and
used to adjust the pool's `queue_size` either up or down by 50. A minimum and
maximum is taken into account also. When the min and max are the same value, a
regular fixed executor is used instead.
The `SEARCH` threadpool is changed to use this new type of thread pool. However,
the min and max are both set to 1000, meaning auto adjustment is opt-in rather
than opt-out.
Resolves#3890
Thread pool settings are no longer dynamically updatable since
da74323141. This commit removes a leftover
note from the thread pool module docs that incorrectly states that
thread pool settings are dynamically updatable.
This commit refactors the handling of thread pool settings so that the
individual settings can be registered rather than registering the top
level group. With this refactoring, individual plugins must now register
their own settings for custom thread pools that they need, but a
dedicated API is provided for this in the thread pool module. This
commit also renames the prefix on the thread pool settings from
"threadpool" to "thread_pool". This enables a hard break on the settings
so that:
- some of the settings can be given more sensible names (e.g., the max
number of threads in a scaling thread pool is now named "max" instead
of "size")
- change the soft limit on the number of threads in the bulk and
indexing thread pools to a hard limit
- the settings names for custom plugins for thread pools can be
prefixed (e.g., "xpack.watcher.thread_pool.size")
- remove dynamic thread pool settings
Relates #18674
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
Ali El broudi
Clinton Gormley
Lee Hinman
wyukawa
Martijn van Groningen
Jason Tedor
Mike McCandless
Areek Zillur
Pius
Shaunak Kashyap
Mark Walkom
Shay Banon
Simon Willnauer
Igor Motov