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All you need to know about #Elasticsearch 5.0 - Part 1 - Search https://t.co/nPDQk124oR
— Itamar Syn-Hershko (@synhershko) November 3, 2016
Changes in 2.x:
- Reduced memory usage on client nodes by changing ShardActiveResponseHandler from holding on to the entire cluster state to just keeping the cluster state version.
- Binary fields indexed in 1.x indices were not readable in 2.x.
Changes in 5.0:
- The vm.map_max_count on systemd settings required a reboot to take effect - now we apply this setting during package install.
- On Debian, the start-stop daemon was being backgrounded, which caused important exceptions to be swallowed.
- ES_JVM_OPTIONS were being ignored on SysV systems.
- Under failure conditions, a thread's original context could be changed before it returned to the pool, which means the context would persist when the thread is used in the future.
- The response consumer in the Java REST client is stateful and shouldn't be reused, which we were doing when retrying failed requests.
- 2.x indices with TTL enabled were failing because the TTL query tries to access now.
- Temporary index-* generational blobs created during snapshotting should be cleared up, otherwise they prevent further snapshots.
- Joda time has been updated to v2.9.5
- GET _snapshot/_all was returning duplicate in-progress snapshots.
Changes in 5.x:
- Painless now supports
Dto denote decimal constants, and will suggest using a long constant if an integer is too big. Also, it now supports null safe dereferences like
- Every cluster state update causes data nodes to check if there are shards that can be deleted. A cache now makes this process much more efficient.
- Task cancellation should wait for all child tasks to receive the cancellation request before returning.
- The simple query string learns to run an all-fields query across all fields, instead of the _all field.
- Alias names now have the same validation as index names (except for the lowercase restriction).
Changes in 6.0:
- Index template can now specify multiple patterns (and the parameter has changed from
- index and delete operations should not mutate the version and version type of a request. Instead, this is the caller's responsibility.
- The cluster state is now a truly immutable class.
- The cat-thread-pool request should return unbounded queues as -1 instead of null.
- Rank evaluation now treats unranked docs as irrelevant, and provides an option to ignore them.
- Adding support for range fields and the corresponding queries (similar to geoshape queries).
- REST URL parsing is undergoing a cleanup with the intention of being able to return 405 method not allowed.
- Closing a shard when the store was not initialised could cause an NPE.
- Painless is getting the Elvis operator.
- Index*AlreadyExistsExceptions to be replaced by ResourceAlreadyException.
- Delete requests should not have a body like the clear-scroll API has today.
- Should Painless support binary values?
- Plugins should have an extension point for adding custom cluster state metadata.
- Non-master nodes should not change the cluster state.
- Aliases and wildcards should be accepted in the indices_boost query.
- A few resources missed the migration from
- Index time sorting should allow sorting on multi-valued fields as well
- FST packing is rarely used and adds a lot of complex code so we removed it
- Multiple pre/post tags and phrase queries do not work together in
- It is time to upgrade ICU from 56.1 to 58.1
FastVectorHighlighterfails to highlight phrase queries that have stop words that were removed at index time
- The default sorting behaviour for missing values is always confusing
changes-to-htmlant task annoyingly fails when Apache's JIRA instance is not reachable
- The classic
QueryParsershould not parse an explicit query string differently depending on the default operator
JapaneseTokenizerFactoryleaks file handles
- Our release smoke testing tool does not work under cygwin on Windows
- Attempting to index a too-massive single text field now causes an
IllegalArgumentExceptioninstead of otherwise very confusing int overflow exceptions
TermAutomatonQuery,which is a powerful query that generalizes other proximity queries (
MultiPhraseQuery), now rewrites to simpler queries when the word-graph is trivial
UnifiedHighlighternow has extension points for custom queries
SpanNotQuerylets you specify the allowed range over overlap between sub-queries
- Similarities now also explain exactly how they compute inverse document frequency
- The new
BooleanSimilaritybypasses all scoring and uses just the query's boost as the hit score
- Fully dense norms and doc values should not waste memory on a fully set bitset
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