There are cases where nodes should not connect to another node. For example, client nodes do not connect to other client nodes. When executing a nodes level API, we should have a nicer failure indicating that, and not log it by default, as its not a real failure
Supports sorting on sub-aggs down the current hierarchy. This is supported as long as the aggregation in the specified order path are of a single-bucket type, where the last aggregation in the path points to either a single-bucket aggregation or a metrics one. If it's a single-bucket aggregation, the sort will be applied on the document count in the bucket (i.e. doc_count), and if it is a metrics type, the sort will be applied on the pointed out metric (in case of a single-metric aggregations, such as avg, the sort will be applied on the single metric value)
NOTE: this commit adds a constraint on what should be considered a valid aggregation name. Aggregations names must be alpha-numeric and may contain '-' and '_'.
Closes#5253
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
Konrad Feldmeier
Benjamin Devèze
Adrien Grand
Alexander Reelsen
uboness
Shay Banon
javanna
Brusic
Clinton Gormley
James Brook
Igor Motov
Lee Hinman
Kevin
Holger Hoffstätte
Nils Dijk
Binh Ly
Zachary Tong
Martijn van Groningen
Costin Leau
Simon Willnauer