Today, even though our merge policy doesn't return new merge specs on SEGMENT_FLUSH, merge on the scheduler is still called on flush time, and can cause merges to stall indexing during merges. Both for the concurrent merge scheduler (the default) and the serial merge scheduler. This behavior become worse when throttling kicks in (today at 20mb per sec).
In order to solve it (outside of Lucene for now), we wrap the merge scheduler with an EnableMergeScheduler, where, on the thread level, using a thread local, the call to merge can be enabled/disabled.
A Merges helper class is added where all explicit merges operations should go through. If the scheduler is the enabled one, it will enable merges before calling the relevant explicit method call. In order to make sure Merges is the only class that calls the explicit merge calls, the IW variant of them is added to the forbidden APIs list.
closes#5319
Each plugin is now loaded in its own classloader to prevent class
conflicts when loading different versions of the same library. It
is enabled by default and is configurable through
`plugins.isolation` settings .Additionally, each plugin can
change its own isolation through the `isolation` property in
`es-plugin.properties`- if not specified, the global setting in
ES applies.
Closes#5261
The BigArrays utility class is useful to generate arrays of various sizes: when
small, arrays will be allocated directly on the heap while larger arrays are
going to be paged and to recycle pages through PageCacheRecycler. We already
have tracking for pages but this is not triggered very often since it only
happens on large amounts of data while our tests work on small amounts of data
in order to be fast.
Tracking arrays directly helps make sure that we never forget to release them.
This pull request also improves testing by:
- putting random content in the arrays upon release: this makes sure that
consumers don't use these arrays anymore when they are released as their
content may be subject to use for another purpose since pages are recycled
- putting random content in the arrays upon creation and resize when
`clearOnResize` is `false`.
The major difference with `master` is that the `BigArrays` class is now
instanciable, injected via Guice and usually available through the
`SearchContext`. This way, it can be mocked for tests.
It was being invoked once per reader and parent type combination resulting in more memory being reported to the circuit breaker than actually being used in field data.
Lucene 4.7 supports a setter for the `filler_token` that is
inserted if there are gaps in the token stream. This change exposes
this setting.
Closes#4307
Igor Motov
Shay Banon
Clinton Gormley
Lee Hinman
Kevin
Holger Hoffstätte
Adrien Grand
Nils Dijk
Binh Ly
Zachary Tong
Martijn van Groningen
javanna
Costin Leau
Simon Willnauer
Bill Hwang