This commit introduces a new thread pool, `system_read`, which is
intended for use by system indices for all read operations (get and
search). The `system_read` pool is a fixed thread pool with a maximum
number of threads equal to lesser of half of the available processors
or 5. Given the combination of both get and read operations in this
thread pool, the queue size has been set to 2000. The motivation for
this change is to allow system read operations to be serviced in spite
of the number of user searches.
In order to avoid a significant performance hit due to pattern matching
on all search requests, a new metadata flag is added to mark indices
as system or non-system. Previously created system indices will have
flag added to their metadata upon upgrade to a version with this
capability.
Additionally, this change also introduces a new class, `SystemIndices`,
which encapsulates logic around system indices. Currently, the class
provides a method to check if an index is a system index and a method
to find a matching index descriptor given the name of an index.
Relates #50251
Relates #37867
Backport of #57936
Some of these characters are special to Asciidoctor and they ruin the
rendering on this page. Instead, we use a macro to passthrough these
characters without Asciidoctor applying any subtitutions to them. This
commit then addresses some rendering issues in the thread pool docs.
Co-authored-by: James Rodewig <james.rodewig@elastic.co>
The use of available processors, the terminology, and the settings
around it have evolved over time. This commit cleans up some places in
the codes and in the docs to adjust to the current terminology.
The `bulk` threadpool is now called `write`, but `bulk` is still
used in some examples. This commit fixes that.
Also, the only way `threadpool.bulk.write: 30` is a valid increase in the size
of this threadpool is if you have 29 processors, which is an odd number of
processors to have. This commit removes the "more threads" bit.
This commit adds a rest endpoint for freezing and unfreezing an index.
Among other cleanups mainly fixing an issue accessing package private APIs
from a plugin that got caught by integration tests this change also adds
documentation for frozen indices.
Note: frozen indices are marked as `beta` and available as a basic feature.
Relates to #34352
This commit renames the bulk thread pool to the write thread pool. This
is to better reflect the fact that the underlying thread pool is used to
execute any document write request (single-document index/delete/update
requests, and bulk requests).
With this change, we add support for fallback settings
thread_pool.bulk.* which will be supported until 7.0.0.
We also add a system property so that the display name of the thread
pool remains as "bulk" if needed to avoid breaking users.
Now that single-document indexing requests are executed on the bulk
thread pool the index thread pool is no longer needed. This commit
removes this thread pool from Elasticsearch.
We want to remove the index thread pool as it is no longer needed since
single-document indexing requests are executed as bulk requests
now. Analyze requests are also executed on the index thread pool though
and they need a thread pool to execute on. The bulk thread does not seem
like the right thread pool, let us keep that thread pool conceptually
for bulk requests and free for bulk requests. None of the existing
thread pools make sense for analyze requests either. The generic thread
pool would be a terrible choice since it has an unbounded queue and that
is a bad idea for user-facing APIs. This commit introduces a small by
default (size=1, queue_size=16) thread pool for analyze requests.
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
Jay Modi
James Rodewig
Tim Brooks
Jason Tedor
Yannick Welsch
István Zoltán Szabó
David Turner
Simon Willnauer
Ali El broudi
Clinton Gormley
Lee Hinman
wyukawa
Martijn van Groningen
Mike McCandless
Areek Zillur
Pius
Shaunak Kashyap
Mark Walkom
Shay Banon
Igor Motov