Approaching the release of 6.0 we need to sort out the usage of
`Version#minimumCompatibilityVersion` which was still set to 5.0.0.
Now this change moves it to the latest released version of 5.x (5.4 at this point)
to ensure we are compatible with the latest minor of the previous major. This change
also removes all the `_UNRELEASED` from the versions that where released and drops versions
that were never released and are not expected to be released (bugfixes in minors that are not
the latest in the previous major).
This commit renames all rest test files to use the .yml extension
instead of .yaml. This way the extension used within all of
elasticsearch for yaml is consistent.
Range queries with now based date ranges were previously not allowed,
but since #23921 these queries were allowed. This change should really
fix range queries with now based date ranges.
* Add parent-join module
This change adds a new module named `parent-join`.
The goal of this module is to provide a replacement for the `_parent` field but as a first step this change only moves the `has_child`, `has_parent` queries and the `children` aggregation to this module.
These queries and aggregations are no longer in core but they are deployed by default as a module.
Relates #20257
This adds the `index.mapping.single_type` setting, which enforces that indices
have at most one type when it is true. The default value is true for 6.0+ indices
and false for old indices.
Relates #15613
The percolator doesn't close the IndexReader of the memory index any more.
Prior to 2.x the percolator had its own SearchContext (PercolatorContext) that did this,
but that was removed when the percolator was refactored as part of the 5.0 release.
I think an alternative way to fix this is to let percolator not use the bitset and fielddata caches,
that way we prevent the memory leak.
Closes#24108
This change simplifies how the rest test runner finds test files and
removes all leniency. Previously multiple prefixes and suffixes would
be tried, and tests could exist inside or outside of the classpath,
although outside of the classpath never quite worked. Now only classpath
tests are supported, and only one resource prefix is supported,
`/rest-api-spec/tests`.
closes#20240
We want to upgrade to Lucene 7 ahead of time in order to be able to check whether it causes any trouble to Elasticsearch before Lucene 7.0 gets released. From a user perspective, the main benefit of this upgrade is the enhanced support for sparse fields, whose resource consumption is now function of the number of docs that have a value rather than the total number of docs in the index.
Some notes about the change:
- it includes the deprecation of the `disable_coord` parameter of the `bool` and `common_terms` queries: Lucene has removed support for coord factors
- it includes the deprecation of the `index.similarity.base` expert setting, since it was only useful to configure coords and query norms, which have both been removed
- two tests have been marked with `@AwaitsFix` because of #23966, which we intend to address after the merge
Before now ranges where forbidden, because the percolator query itself could get cached and then the percolator queries with now ranges that should no longer match, incorrectly will continue to match.
By disabling caching when the `percolator` is being used, the percolator can now correctly support range queries with now based ranges.
I think this is the right tradeoff. The percolator query is likely to not be the same between search requests and disabling range queries with now ranges really disabled people using the percolator for their use cases.
Also fixed an issue that existed in the percolator fieldmapper, it was unable to find forbidden queries inside `dismax` queries.
Closes#23859
This commit renames the random ASCII helper methods in ESTestCase. This
is because this method ultimately uses the random ASCII methods from
randomized runner, but these methods actually only produce random
strings generated from [a-zA-Z].
Relates #23886
Removed `parse(String index, String type, String id, BytesReference source)` in DocumentMapper.java and replaced all of its use in Test files with `parse(SourceToParse source)`.
`parse(String index, String type, String id, BytesReference source)` was only used in test files and never in the main code so it was removed. All of the test files that used it was then modified to use `parse(SourceToParse source)` method that existing in DocumentMapper.java
We have many version constants in master that have already been
released, but are still marked (by naming convention) as unreleased.
This commit renames those version constants.
We have a bunch of interfaces that have only a single implementation
for 6 years now. These interfaces are pretty useless from a SW development
perspective and only add unnecessary abstractions. They also require
lots of casting in many places where we expect that there is only one
concrete implementation. This change removes the interfaces, makes
all of the classes final and removes the duplicate `foo` `getFoo` accessors
in favor of `getFoo` from these classes.
This commit upgrades the checkstyle configuration from version 5.9 to
version 7.5, the latest version as of today. The main enhancement
obtained via this upgrade is better detection of redundant modifiers.
Relates #22960
This change adds a strict mode for xcontent parsing on the rest layer. The strict mode will be off by default for 5.x and in a separate commit will be enabled by default for 6.0. The strict mode, which can be enabled by setting `http.content_type.required: true` in 5.x, will require that all incoming rest requests have a valid and supported content type header before the request is dispatched. In the non-strict mode, the Content-Type header will be inspected and if it is not present or not valid, we will continue with auto detection of content like we have done previously.
The content type header is parsed to the matching XContentType value with the only exception being for plain text requests. This value is then passed on with the content bytes so that we can reduce the number of places where we need to auto-detect the content type.
As part of this, many transport requests and builders were updated to provide methods that
accepted the XContentType along with the bytes and the methods that would rely on auto-detection have been deprecated.
In the non-strict mode, deprecation warnings are issued whenever a request with body doesn't provide the Content-Type header.
See #19388
Removes `AggregatorParsers`, replacing all of its functionality with
`XContentParser#namedObject`.
This is the third bit of payoff from #22003, one less thing to pass
around the entire application.
* Remove a checked exception, replacing it with `ParsingException`.
* Remove all Parser classes for the yaml sections, replacing them with static methods.
* Remove `ClientYamlTestFragmentParser`. Isn't used any more.
* Remove `ClientYamlTestSuiteParseContext`, replacing it with some static utility methods.
I did not rewrite the parsers using `ObjectParser` because I don't think it is worth it right now.
Introduces `XContentParser#namedObject which works a little like
`StreamInput#readNamedWriteable`: on startup components register
parsers under names and a superclass. At runtime we look up the
parser and call it to parse the object.
Right now the parsers take a context object they use to help with
the parsing but I hope to be able to eliminate the need for this
context as most what it is used for at this point is to move
around parser registries which should be replaced by this method
eventually. I make no effort to do so in this PR because it is
big enough already. This is meant to the a start down a road that
allows us to remove classes like `QueryParseContext`,
`AggregatorParsers`, `IndicesQueriesRegistry`, and
`ParseFieldRegistry`.
The goal here is to reduce the amount of plumbing required to
allow parsing pluggable things. With this you don't have to pass
registries all over the place. Instead you must pass a super
registry to fewer places and use it to wrap the reader. This is
the same tradeoff that we use for NamedWriteable and it allows
much, much simpler binary serialization. We think we want that
same thing for xcontent serialization.
The only parsing actually converted to this method is parsing
`ScoreFunctions` inside of `FunctionScoreQuery`. I chose this
because it is relatively self contained.
This commit makes mapping updates atomic when multiple types in an index are updated. Mappings for an index are now applied in a single atomic operation, which also allows to optimize some of the cross-type updates and checks.
With this commit we enable the Jackson feature 'STRICT_DUPLICATE_DETECTION'
by default. This ensures that JSON keys are always unique. While this has
a performance impact, benchmarking has indicated that the typical drop in
indexing throughput is around 1 - 2%.
As a last resort, we allow users to still disable strict duplicate checks
by setting `-Des.json.strict_duplicate_detection=false` which is
intentionally undocumented.
Closes#19614
Our query DSL supports empty queries (`{}`), which have a different meaning depending on the query that holds it, either ignored, match_all or match_none. We deprecated the support for empty queries in 5.0, where we log a deprecation warning wherever they are used.
The way we supported it once we moved query parsing to the coordinating node was having an Optional<QueryBuilder> return type in all of our parse methods (called fromXContent). See #17624. The central place for this was QueryParseContext#parseInnerQueryBuilder. We can now remove all the optional return types and simply throw an exception whenever an empty query is found.
To get #22003 in cleanly we need to centralize as much `XContentParser` creation as possible into `RestRequest`. That'll mean we have to plumb the `NamedXContentRegistry` into fewer places.
This removes `RestAction.hasBody`, `RestAction.guessBodyContentType`, and `RestActions.getRestContent`, moving callers over to `RestRequest.hasContentOrSourceParam`, `RestRequest.contentOrSourceParam`, and `RestRequest.contentOrSourceParamParser` and `RestRequest.withContentOrSourceParamParserOrNull`. The idea is to use `withContentOrSourceParamParserOrNull` if you need to handle requests without any sort of body content and to use `contentOrSourceParamParser` otherwise.
I believe the vast majority of this PR to be purely mechanical but I know I've made the following behavioral change (I'll add more if I think of more):
* If you make a request to an endpoint that requires a request body and has cut over to the new APIs instead of getting `Failed to derive xcontent` you'll get `Body required`.
* Template parsing is now non-strict by default. This is important because we need to be able to deprecate things without requests failing.
This adds the `_primary_term` field internally to the mappings. This field is
populated with the current shard's primary term.
It is intended to be used for collision resolution when two document copies have
the same sequence id, therefore, doc_values for the field are stored but the
filed itself is not indexed.
This also fixes the `_seq_no` field so that doc_values are retrievable (they
were previously stored but irretrievable) and changes the `stats` implementation
to more efficiently use the points API to retrieve the min/max instead of
iterating on each doc_value value. Additionally, even though we intend to be
able to search on the field, it was previously not searchable. This commit makes
it searchable.
There is no user-visible `_primary_term` field. Instead, the fields are
updated by calling:
```java
index.parsedDoc().updateSeqID(seqNum, primaryTerm);
```
This includes example methods in `Versions` and `Engine` for retrieving the
sequence id values from the index (see `Engine.getSequenceID`) that are only
used in unit tests. These will be extended/replaced by actual implementations
once we make use of sequence numbers as a conflict resolution measure.
Relates to #10708
Supercedes #21480
P.S. As a side effect of this commit, `SlowCompositeReaderWrapper` cannot be
used for documents that contain `_seq_no` because it is a Point value and SCRW
cannot wrap documents with points, so the tests have been updated to loop
through the `LeafReaderContext`s now instead.
This adds a fromXContent method and unit test to the HighlightField class so we
can parse it as part of a serch response. This is part of the preparation for
parsing search responses on the client side.
For the record, I also had to remove the geo-hash cell and geo-distance range
queries to make the code compile. These queries already throw an exception in
all cases with 5.x indices, so that does not hurt any more.
I also had to rename all 2.x bwc indices from `index-${version}` to
`unsupported-${version}` to make `OldIndexBackwardCompatibilityIT`
happy.
Lucene 6.2 added index and query support for numeric ranges. This commit adds a new RangeFieldMapper for indexing numeric (int, long, float, double) and date ranges and creating appropriate range and term queries. The design is similar to NumericFieldMapper in that it uses a RangeType enumerator for implementing the logic specific to each type. The following range types are supported by this field mapper: int_range, float_range, long_range, double_range, date_range.
Lucene does not provide a DocValue field specific to RangeField types so the RangeFieldMapper implements a CustomRangeDocValuesField for handling doc value support.
When executing a Range query over a Range field, the RangeQueryBuilder has been enhanced to accept a new relation parameter for defining the type of query as one of: WITHIN, CONTAINS, INTERSECTS. This provides support for finding all ranges that are related to a specific range in a desired way. As with other spatial queries, DISJOINT can be achieved as a MUST_NOT of an INTERSECTS query.
* Scripting: Remove groovy scripting language
Groovy was deprecated in 5.0. This change removes it, along with the
legacy default language infrastructure in scripting.
* master: (516 commits)
Avoid angering Log4j in TransportNodesActionTests
Add trace logging when aquiring and releasing operation locks for replication requests
Fix handler name on message not fully read
Remove accidental import.
Improve log message in TransportNodesAction
Clean up of Script.
Update Joda Time to version 2.9.5 (#21468)
Remove unused ClusterService dependency from SearchPhaseController (#21421)
Remove max_local_storage_nodes from elasticsearch.yml (#21467)
Wait for all reindex subtasks before rethrottling
Correcting a typo-Maan to Man-in README.textile (#21466)
Fix InternalSearchHit#hasSource to return the proper boolean value (#21441)
Replace all index date-math examples with the URI encoded form
Fix typos (#21456)
Adapt ES_JVM_OPTIONS packaging test to ubuntu-1204
Add null check in InternalSearchHit#sourceRef to prevent NPE (#21431)
Add VirtualBox version check (#21370)
Export ES_JVM_OPTIONS for SysV init
Skip reindex rethrottle tests with workers
Make forbidden APIs be quieter about classpath warnings (#21443)
...
At one point in the past when moving out the rest tests from core to
their own subproject, we had multiple test classes which evenly split up
the tests to run. However, we simplified this and went back to a single
test runner to have better reproduceability in tests. This change
removes the remnants of that multiplexing support.
The `IndexService#newQueryShardContext()` method creates a QueryShardContext on
shard `0`, with a `null` reader and that uses `System.currentTimeMillis()` to
resolve `now`. This may hide bugs, since the shard id is sometimes used for
query parsing (it is used to salt random score generation in `function_score`),
passing a `null` reader disables query rewriting and for some use-cases, it is
simply not ok to rely on the current timestamp (eg. percolation). So this pull
request removes this method and instead requires that all call sites provide
these parameters explicitly.
* Replace org.elasticsearch.common.lucene.search.MatchNoDocsQuery with its Lucene version (org.apache.lucene.search.MatchNoDocsQuery)
This change removes the ES version of the match no docs query and replaces it with the Lucene version.
relates #18030
* Add missing change
Today SearchContext expose the current context as a thread local which makes any kind of sane interface design very very hard. This PR removes the thread local entirely and instead passes the relevant context anywhere needed. This simplifies state management dramatically and will allow for a much leaner SearchContext interface down the road.
Today when parsing a request, Elasticsearch silently ignores incorrect
(including parameters with typos) or unused parameters. This is bad as
it leads to requests having unintended behavior (e.g., if a user hits
the _analyze API and misspell the "tokenizer" then Elasticsearch will
just use the standard analyzer, completely against intentions).
This commit removes lenient URL parameter parsing. The strategy is
simple: when a request is handled and a parameter is touched, we mark it
as such. Before the request is actually executed, we check to ensure
that all parameters have been consumed. If there are remaining
parameters yet to be consumed, we fail the request with a list of the
unconsumed parameters. An exception has to be made for parameters that
format the response (as opposed to controlling the request); for this
case, handlers are able to provide a list of parameters that should be
excluded from tripping the unconsumed parameters check because those
parameters will be used in formatting the response.
Additionally, some inconsistencies between the parameters in the code
and in the docs are corrected.
Relates #20722
* master: (1199 commits)
[DOCS] Remove non-valid link to mapping migration document
Revert "Default `include_in_all` for numeric-like types to false"
test: add a test with ipv6 address
docs: clearify that both ip4 and ip6 addresses are supported
Include complex settings in settings requests
Add production warning for pre-release builds
Clean up confusing error message on unhandled endpoint
[TEST] Increase logging level in testDelayShards()
change health from string to enum (#20661)
Provide error message when plugin id is missing
Document that sliced scroll works for reindex
Make reindex-from-remote ignore unknown fields
Remove NoopGatewayAllocator in favor of a more realistic mock (#20637)
Remove Marvel character reference from guide
Fix documentation for setting Java I/O temp dir
Update client benchmarks to log4j2
Changes the API of GatewayAllocator#applyStartedShards and (#20642)
Removes FailedRerouteAllocation and StartedRerouteAllocation
IndexRoutingTable.initializeEmpty shouldn't override supplied primary RecoverySource (#20638)
Smoke tester: Adjust to latest changes (#20611)
...
Today we hold on to all possible tokenizers, tokenfilters etc. when we create
an index service on a node. This was mainly done to allow the `_analyze` API to
directly access all these primitive. We fixed this in #19827 and can now get rid of
the AnalysisService entirely and replace it with a simple map like class. This
ensures we don't create a gazillion long living objects that are entirely useless since
they are never used in most of the indices. Also those objects might consume a considerable
amount of memory since they might load stopwords or synonyms etc.
Closes#19828
This change replaces the fields parameter with stored_fields when it makes sense.
This is dictated by the renaming we made in #18943 for the search API.
The following list of endpoint has been changed to use `stored_fields` instead of `fields`:
* get
* mget
* explain
The documentation and the rest API spec has been updated to cope with the changes for the following APIs:
* delete_by_query
* get
* mget
* explain
The `fields` parameter has been deprecated for the following APIs (it is replaced by _source filtering):
* update: the fields are extracted from the _source directly.
* bulk: the fields parameter is used but fields are extracted from the source directly so it is allowed to have non-stored fields.
Some APIs still have the `fields` parameter for various reasons:
* cat.fielddata: the fields paramaters relates to the fielddata fields that should be printed.
* indices.clear_cache: used to indicate which fielddata fields should be cleared.
* indices.get_field_mapping: used to filter fields in the mapping.
* indices.stats: get stats on fields (stored or not stored).
* termvectors: fields are retrieved from the stored fields if possible and extracted from the _source otherwise.
* mtermvectors:
* nodes.stats: the fields parameter is used to concatenate completion_fields and fielddata_fields so it's not related to stored_fields at all.
Fixes#20155
In 5.x we allowed this with a deprecation warning. This removes the code
added for that deprecation, requiring the cluster name to not be in the
data path.
Resolves#20391
** The default script language is now maintained in `Script` class.
* Added `script.legacy.default_lang` setting that controls the default language for scripts that are stored inside documents (for example percolator queries). This defaults to groovy.
** Added `QueryParseContext#getDefaultScriptLanguage()` that manages the default scripting language. Returns always `painless`, unless loading query/search request in legacy mode then the returns what is configured in `script.legacy.default_lang` setting.
** In the aggregation parsing code added `ParserContext` that also holds the default scripting language like `QueryParseContext`. Most parser don't have access to `QueryParseContext`. This is for scripts in aggregations.
* The `lang` script field is always serialized (toXContent).
Closes#20122
* master:
Increase visibility of deprecation logger
Skip transport client plugin installed on JDK 9
Explicitly disable Netty key set replacement
percolator: Fail indexing percolator queries containing either a has_child or has_parent query.
Make it possible for Ingest Processors to access AnalysisRegistry
Allow RestClient to send array-based headers
Silence rest util tests until the bogusness can be simplified
Remove unknown HttpContext-based test as it fails unpredictably on different JVMs
Tests: Improve rest suite names and generated test names for docs tests
Add support for a RestClient base path
Parsing a search request is currently split up among a number of
classes, using multiple public static methods, which take multiple
regstries of elements that may appear in the search request like query
parsers and aggregations. This change begins consolidating all this code
by collapsing the registries normally used for parsing search requests
into a single SearchRequestParsers class. It is also made available to
plugin services to enable templating of search requests. Eventually all
of the actual parsing logic should move to the class, and the registries
should be hidden, but for now they are at least co-located to reduce the
number of objects that must be passed around.
Squashes all the subpackages of `org.elasticsearch.rest.action` down to
the following:
* `o.e.rest.action.admin` - Administrative actions
* `o.e.rest.action.cat` - Actions that make tables for `grep`ing
* `o.e.rest.action.document` - Actions that act on documents
* `o.e.rest.action.ingest` - Actions that act on ingest pipelines
* `o.e.rest.action.search` - Actions that search
I'm tempted to merge `search` into `document` but the `document`
package feels fairly complete as is and `Suggest` isn't actually always
about documents either....
I'm also tempted to merge `ingest` into `admin.cluster` because the
latter contains the actions for dealing with stored scripts.
I've moved the `o.e.rest.action.support` into `o.e.rest.action`.
I've also added `package-info.java`s to all packges in `o.e.rest`. I
figure if the package is too small to deserve a `package-info.java` file
then it is too small to deserve to be a package....
Also fixes checkstyle in all moved classes.
As the most complicated `FetchSubPhase` highlighting gets its own package
(`o.e.seach.fetch.subphase.highlight`. No other `FetchSubPhase`s get their
own package. Instead they all reside together in `o.e.search.fetch.subphase`.
Add package descriptions to `o.e.search.fetch` and subpackages.
I also reduced the visibility of a couple classes and renamed/consolidated some
test classes for consistency, eg. removing the `Simple` prefix or using the
`<Type>FieldMapperTests` convention for testing field mappers.
testUnknownObjectException used to generate malformed json objects in some cases, due to the existence of arrays as it was not closing the injected object correctly. That is why the test was catching JsonParseException among the exception that are expected to be thrown. That is fixed by tracking where the new object is placed and placing its end object marker to the right level rather than always at the end.
Also introduced a mechanism to explicitly declare objects that won't cause any exception when they get additional objects injected, so that there is no need to override the method anymore as that caused copy pasting of the whole test method. This also makes sure that changes are reflected in tests, as those inner objects are not skipped but we actually check that what is declared is true (no exceptions get thrown when an additional object is added within them.
Some random operations were conditionally performed in the before test, which made tests not repeatable. For instance take the seed chain to repeat a specific iteration and try to reproduce it, this conditional code would get executed in both cases when trying to isolate the failure, but not among the different iterations (as only the first method/iteration executes it), hence the failure will not reproduce.
Moved the random operations to beforeClass and left the non random part in the before method, which is needed as it depends on some method that can be overridden by subclasses.
This makes it obvious that these tests are for running the client yaml
suites. Now that there are other ways of running tests using the REST
client against a running cluster we can't go on calling the shared
client yaml tests "REST tests". They are rest tests, but they aren't
**the** rest tests.
This adds a header that looks like `Location: /test/test/1` to the
response for the index/create/update API. The requirement for the header
comes from https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.htmlhttps://tools.ietf.org/html/rfc7231#section-7.1.2 claims that relative
URIs are OK. So we use an absolute path which should resolve to the
appropriate location.
Closes#19079
This makes large changes to our rest test infrastructure, allowing us
to write junit tests that test a running cluster via the rest client.
It does this by splitting ESRestTestCase into two classes:
* ESRestTestCase is the superclass of all tests that use the rest client
to interact with a running cluster.
* ESClientYamlSuiteTestCase is the superclass of all tests that use the
rest client to run the yaml tests. These tests are shared across all
official clients, thus the `ClientYamlSuite` part of the name.
Remove `ParseField` constants used for names where there are no deprecated
names and just use the `String` version of the registration method instead.
This is step 2 in cleaning up the plugin interface for extending
search time actions. Aggregations are next.
This is breaking for plugins because those that register a new query should
now implement `SearchPlugin` rather than `onModule(SearchModule)`.
* Removed `Template` class and unified script & template parsing logic. Templates are scripts, so they should be defined as a script. Unless there will be separate template infrastructure, templates should share as much code as possible with scripts.
* Removed ScriptParseException in favour for ElasticsearchParseException
* Moved TemplateQueryBuilder to lang-mustache module because this query is hard coded to work with mustache only
Switches most search behavior extensions from push (`onModule(SearchModule)`)
to pull (`implements SearchPlugin`). This effort in general gives plugin
authors a much cleaner view of how to extend Elasticsearch and starts to
set up portions of Elasticsearch as "the plugin API". This commit in
particular does that for search-time behavior like customized suggesters,
highlighters, score functions, and significance heuristics.
It also switches most such customization to being done at search module
construction time which is much, much easier to reason about from a testing
perspective. It also helps significantly in the process of de-guice-ing
Elasticsearch's startup.
There are at least two major search time extensions that aren't covered in
this commit that will simply have to wait for the next commit on the topic
because this one has already grown large: custom aggregations and custom
queries. These will likely live in the same SearchPlugin interface as well.
If there are percolator queries containing `range` queries with ranges based on the current time then this can lead to incorrect results if the `percolate` query gets cached. These ranges are changing each time the `percolate` query gets executed and if this query gets cached then the results will be based on how the range was at the time when the `percolate` query got cached.
The ExtractQueryTermsService has been renamed `QueryAnalyzer` and now only deals with analyzing the query (extracting terms and deciding if the entire query is a verified match) . The `PercolatorFieldMapper` is responsible for adding the right fields based on the analysis the `QueryAnalyzer` has performed, because this is highly dependent on the field mappings. Also the `PercolatorFieldMapper` is responsible for creating the percolate query.
* master: (192 commits)
[TEST] Fix rare OBOE in AbstractBytesReferenceTestCase
Reindex from remote
Rename writeThrowable to writeException
Start transport client round-robin randomly
Reword Refresh API reference (#19270)
Update fielddata.asciidoc
Fix stored_fields message
Add missing footer notes in mapper size docs
Remote BucketStreams
Add doc values support to the _size field in the mapper-size plugin
Bump version to 5.0.0-alpha5.
Update refresh.asciidoc
Update shrink-index.asciidoc
Change Debian repository for Vagrant debian-8 box
[TEST] fix test to account for internal empyt reference optimization
Upgrade to netty 3.10.6.Final (#19235)
[TEST] fix histogram test when extended bounds overlaps data
Remove redundant modifier
Simplify TcpTransport interface by reducing send code to a single send method (#19223)
Fix style violation in InstallPluginCommand.java
...
This commit renames writeThrowable to writeException. The situation here
stems from the fact that the StreamOutput method for serializing
Exceptions needs to accept Throwables too as Throwables can be the cause
of serialized Exceptions. Yet, we do not serialize Throwables in the
Error sub-hierarchy in a way that they can be deserialized into their
initial type. This leads to an asymmetry in the StreamOutput method for
serializing Exceptions and the StreamInput method for writing
Excpetions. Namely, the former will accept Throwables but the latter
will only return Exceptions. A goal with the stream methods has always
been symmetry in the method names so that serialization/deserialization
routines appear symmetrical in code. It is this asymmetry on the
input/output types for Exceptions on StreamOutput/StreamInput that
clashes with the desired symmetry of naming. Despite this, we should
favor symmetry in the naming of the methods. This commit renames
StreamOutput#writeThrowable to StreamOutput#writeException which leaves
us with Exception StreamInput#readException and void
StreamOutput#writeException(Throwable).
Today throughout the codebase, catch throwable is used with reckless
abandon. This is dangerous because the throwable could be a fatal
virtual machine error resulting from an internal error in the JVM, or an
out of memory error or a stack overflow error that leaves the virtual
machine in an unstable and unpredictable state. This commit removes
catch throwable from the codebase and removes the temptation to use it
by modifying listener APIs to receive instances of Exception instead of
the top-level Throwable.
Relates #19231
BytesReference should be a really simple interface, yet it has a gazillion
ways to achieve the same this. Methods like `#hasArray`, `#toBytesArray`, `#copyBytesArray`
`#toBytesRef` `#bytes` are all really duplicates. This change simplifies the interface
dramatically and makes implementations of it much simpler. All array access has been removed
and is streamlined through a single `#toBytesRef` method. Utility methods to materialize a
compact byte array has been added too for convenience.
Previously all rest handlers would take Client in their injected ctor.
However, it was only to hold the client around for runtime. Instead,
this can be done just once in the HttpService which handles rest
requests, and passed along through the handleRequest method. It also
should always be a NodeClient, and other types of Clients (eg a
TransportClient) would not work anyways (and some handlers can be
simplified in follow ups like reindex by taking NodeClient).