Now that we're consistently using `cat_match` to filter which shards we
run on we can get this confusing case:
1. You have a search with, say, a range and a sub-agg.
2. That search has a query that `can_match` can recognize will match no
docs. On *any* shard.
3. So we dutifully run it on a single shard so it can produce the
"empty" aggs.
4. The shard we pick happens to not have the target of the range mapped.
5. This kicks in the special range aggregator that doesn't collect any
documents.
6. Before this commit, that range aggregator *also* never produced any
sub-aggs.
So, without this change, it was quite possible for a search that
happened to match no documents to "throw away" the sub-aggs of a range
and a few other aggs.
We've had this problem for a long, long time but it is more confusing
now because `can_match` is really kicking in and causing us to see cases
where it looks like you are targeting a lot of shards but you really are
only targeting a couple. It used to be that to get the "no sub-aggs"
behavior you had to explicitly target only shards that didn't map the
target field of the `range` agg. And, like, in that case it isn't too
bad because you targeted a sort of degenerate shard. But now that
`can_match` is doing its thing you can end up with the confusing steps
above. It took me several hours to track down what what happening I know
how the individual pieces of all of this works. It took four hours to
figure out how they fit together in this case....
Anyway! This replaces all the aggregator implementations that throw out
the sub-aggregators with ones that keep them. I think this'll be less
confusing in the future.
Closes#64142
In #57892 I broke *some* sub-aggregations inside of the `parent` and
`child` aggregator, specifically any sub-aggregations that do work in
the `postCollect` phase. This fixes it by delaying the post collect
phase of aggs under `parent` and `child` until `beforeBuildingBuckets`
because, well, we haven't done *any* collection until after that phase.
This PR adds factory methods for the most common implementations:
* `SourceValueFetcher.identity` to pass through the source value untouched.
* `SourceValueFetcher.toString` to simply convert the source value to a string.
When constructing a value fetcher, the 'parsesArrayValue' flag must match
`FieldMapper#parsesArrayValue`. However there is nothing in code or tests to
help enforce this.
This PR reworks the value fetcher constructors so that `parsesArrayValue` is
'false' by default. Just as for `FieldMapper#parsesArrayValue`, field types must
explicitly set it to true and ensure the behavior is covered by tests.
Follow-up to #62974.
For runtime fields, we will want to do all search-time interaction with
a field definition via a MappedFieldType, rather than a FieldMapper, to
avoid interfering with the logic of document parsing. Currently, fetching
values for runtime scripts and for building top hits responses need to
call a method on FieldMapper. This commit moves this method to
MappedFieldType, incidentally simplifying the current call sites and freeing
us up to implement runtime fields as pure MappedFieldType objects.
Most of our field types have the same implementation for their `existsQuery` method which relies on doc_values if present, otherwise it queries norms if available or uses a term query against the _field_names meta field. This standard implementation is repeated in many different mappers.
There are field types that only query doc_values, because they always have them, and field types that always query _field_names, because they never have norms nor doc_values. We could apply the same standard logic to all of these field types as `MappedFieldType` has the knowledge about what data structures are available.
This commit introduces a standard implementation that does the right thing depending on the data structure that is available. With that only field types that require a different behaviour need to override the existsQuery method.
At the same time, this no longer forces subclasses to override `existsQuery`, which could be forgotten when needed. To address this we introduced a new test method in `MapperTestCase` that verifies the `existsQuery` being generated and its consistency with the available data structures.
This implements the `fields` API in `_search` for runtime fields using
doc values. Most of that implementation is stolen from the
`docvalue_fields` fetch sub-phase, just moved into the same API that the
`fields` API uses. At this point the `docvalue_fields` fetch phase looks
like a special case of the `fields` API.
While I was at it I moved the "which doc values sub-implementation
should I use for fetching?" question from a bunch of `instanceof`s to a
method on `LeafFieldData` so we can be much more flexible with what is
returned and we're not forced to extend certain classes just to make the
fetch phase happy.
Relates to #59332
This PR adds support for the 'fields' option in the following places:
* Anytime `inner_hits` is used, for both fetching nested/ child docs and field collapsing
* The `top_hits` aggregation
Addresses #61949.
This commit introduces a new API that manages point-in-times in x-pack
basic. Elasticsearch pit (point in time) is a lightweight view into the
state of the data as it existed when initiated. A search request by
default executes against the most recent point in time. In some cases,
it is preferred to perform multiple search requests using the same point
in time. For example, if refreshes happen between search_after requests,
then the results of those requests might not be consistent as changes
happening between searches are only visible to the more recent point in
time.
A point in time must be opened before being used in search requests. The
`keep_alive` parameter tells Elasticsearch how long it should keep a
point in time around.
```
POST /my_index/_pit?keep_alive=1m
```
The response from the above request includes a `id`, which should be
passed to the `id` of the `pit` parameter of search requests.
```
POST /_search
{
"query": {
"match" : {
"title" : "elasticsearch"
}
},
"pit": {
"id": "46ToAwMDaWR4BXV1aWQxAgZub2RlXzEAAAAAAAAAAAEBYQNpZHkFdXVpZDIrBm5vZGVfMwAAAAAAAAAAKgFjA2lkeQV1dWlkMioGbm9kZV8yAAAAAAAAAAAMAWICBXV1aWQyAAAFdXVpZDEAAQltYXRjaF9hbGw_gAAAAA==",
"keep_alive": "1m"
}
}
```
Point-in-times are automatically closed when the `keep_alive` is
elapsed. However, keeping point-in-times has a cost; hence,
point-in-times should be closed as soon as they are no longer used in
search requests.
```
DELETE /_pit
{
"id" : "46ToAwMDaWR4BXV1aWQxAgZub2RlXzEAAAAAAAAAAAEBYQNpZHkFdXVpZDIrBm5vZGVfMwAAAAAAAAAAKgFjA2lkeQV1dWlkMioGbm9kZV8yAAAAAAAAAAAMAWIBBXV1aWQyAAA="
}
```
#### Notable works in this change:
- Move the search state to the coordinating node: #52741
- Allow searches with a specific reader context: #53989
- Add the ability to acquire readers in IndexShard: #54966
Relates #46523
Relates #26472
Co-authored-by: Jim Ferenczi <jimczi@apache.org>
We frequently use `long`s with `BitArray` in aggs and right now we have
to assert that the `long` fits in an `int`. This adds support for `long`
to `BitArray` so we don't need those assertions.
Runtime fields need to have a SearchLookup available, when building their fielddata implementations, so that they can look up other fields, runtime or not.
To achieve that, we add a Supplier<SearchLookup> argument to the existing MappedFieldType#fielddataBuilder method.
As we introduce the ability to look up other fields while building fielddata for mapped fields, we implicitly add the ability for a field to require other fields. This requires some protection mechanism that detects dependency cycles to prevent stack overflow errors.
With this commit we also introduce detection for cycles, as well as a limit on the depth of the references for a runtime field. Note that we also plan on introducing cycles detection at compile time, so the runtime cycles detection is a last resort to prevent stack overflow errors but we hope that we can reject runtime fields from being registered in the mappings when they create a cycle in their definition.
Note that this commit does not introduce any production implementation of runtime fields, but is rather a pre-requisite to merge the runtime fields feature branch.
This is a breaking change for MapperPlugins that plug in a mapper, as the signature of MappedFieldType#fielddataBuilder changes from taking a single argument (the index name), to also accept a Supplier<SearchLookup>.
Relates to #59332
Co-authored-by: Nik Everett <nik9000@gmail.com>
DeprecationLogger's constructor should not create two loggers. It was
taking parent logger instance, changing its name with a .deprecation
prefix and creating a new logger.
Most of the time parent logger was not needed. It was causing Log4j to
unnecessarily cache the unused parent logger instance.
depends on #61515
backports #58435
Splitting DeprecationLogger into two. HeaderWarningLogger - responsible for adding a response warning headers and ThrottlingLogger - responsible for limiting the duplicated log entries for the same key (previously deprecateAndMaybeLog).
Introducing A ThrottlingAndHeaderWarningLogger which is a base for other common logging usages where both response warning header and logging throttling was needed.
relates #55699
relates #52369
backports #55941
Before when a value was copied to a field through a parent field or `copy_to`,
we parsed it using the `FieldMapper` from the source field. Instead we should
parse it using the target `FieldMapper`. This ensures that we apply the
appropriate mapping type and options to the copied value.
To implement the fix cleanly, this PR refactors the value parsing strategy. Now
instead of looking up values directly, field mappers produce a helper object
`ValueFetcher`. The value fetchers are responsible for almost all aspects of
fetching, including looking up the right paths in the _source.
The PR is fairly big but each commit can be reviewed individually.
Fixes#61033.
This commit removes the ability to test the top level result of an aggregator
before it runs the final reduce. All aggregator tests that use AggregatorTestCase#search
are rewritten with AggregatorTestCase#searchAndReduce in order to ensure that we test
the final output (the one sent to the end user) rather than an intermediary result
that could be different.
This change also removes spurious commits triggered on top of a random index writer.
These commits slow down the tests and are redundant with the commits that the
random index writer performs.
Currently, validation of mappers (checking that cross-references are correct, limits on
field name lengths and object depths, multiple definitions, etc) is performed by the
MapperService. This means that any mapper-specific validation, for example that done
on the CompletionFieldMapper, needs to be called specifically from core server code,
and so we can't add validation to mappers that live in plugins.
This commit reworks the validation framework so that mapper-specific validation is
done on the Mapper itself. Mapper gets a new `validate(MappingLookup)`
method (already present on `MetadataFieldMapper` and now pulled up to the parent
interface), which is called from a new `DocumentMapper.validate()` method. All
the validation code currently living on `MapperService` moves either to individual
mapper implementations (FieldAliasMapper, CompletionFieldMapper) or into
`MappingLookup`, an altered `DocumentFieldMappers` which now knows about
object fields and can check for duplicate definitions, or into DocumentMapper
which handles soft limit checks.
Previously if an inner_hits block required _ source, we would reload and parse
the root document's source for every hit. This PR adds a shared SourceLookup to
the inner hits context that allows inner hits to reuse parsed source if it's
already available. This matches our approach for sharing the root document ID.
Relates to #32818.
This feature adds a new `fields` parameter to the search request, which
consults both the document `_source` and the mappings to fetch fields in a
consistent way. The PR merges the `field-retrieval` feature branch.
Addresses #49028 and #55363.
Introduce a javaRestTest source set and task to compliment the yamlRestTest.
javaRestTest differs such that the code is sourced from Java and may have
different dependencies and setup requirements for the test clusters. This also
allows the tests to run in parallel in different cluster instances to prevent any
cross test contamination between the two types of tests.
Included in this PR is all :modules no longer use the integTest task. The tests
are now driven by test, yamlRestTest, javaRestTest, and internalClusterTest.
Since only :modules (and :rest-api-spec) have been converted to yamlRestTest
we can now disable the integTest task if either yamlRestTest or javaRestTest have
been applied. Once all projects are converted, we can delete the integTest task.
related: #56841
related: #59444
We never used the `IndexSettings` parameter and we only used the
`MappedFieldType` parameter to get the name of the field which we
already know everywhere where we build the `IFD.Builder`. This allows us
to drop a fair bit of ceremony from a couple of tests.
This commit moves the modules REST tests to the
newly introduced yamlRestTest source set. A few
tests have also been re-named to include the correct
IT suffix. Without changing the names, the testing
conventions task would fail since now that the YAML
tests are no longer present pacify the convention.
These tests have moved to the internalClusterTest
source set.
related: #56841
With the removal of mapping types and the immutability of FieldTypeLookup in #58162, we no longer
have any cause to compare MappedFieldType instances. This means that we can remove all equals
and hashCode implementations, and in addition we no longer need the clone implementations which
were required for equals/hashcode testing. This greatly simplifies implementing new MappedFieldTypes,
which will be particularly useful for the runtime fields project.
This makes a `parentCardinality` available to every `Aggregator`'s ctor
so it can make intelligent choices about how it collects bucket values.
This replaces `collectsFromSingleBucket` and is similar to it but:
1. It supports `NONE`, `ONE`, and `MANY` values and is generally
extensible if we decide we can use more precise counts.
2. It is more accurate. `collectsFromSingleBucket` assumed that all
sub-aggregations live under multi-bucket aggregations. This is
normally true but `parentCardinality` is properly carried forward
for single bucket aggregations like `filter` and for multi-bucket
aggregations configured in single-bucket for like `range` with a
single range.
While I was touching every aggregation I renamed `doCreateInternal` to
`createMapped` because that seemed like a much better name and it was
right there, next to the change I was already making.
Relates to #56487
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
This commit creates a new Gradle plugin to provide a separate task name
and source set for running YAML based REST tests. The only project
converted to use the new plugin in this PR is distribution/archives/integ-test-zip.
For which the testing has been moved to :rest-api-spec since it makes the most
sense and it avoids a small but awkward change to the distribution plugin.
The remaining cases in modules, plugins, and x-pack will be handled in followups.
This plugin is distinctly different from the plugin introduced in #55896 since
the YAML REST tests are intended to be black box tests over HTTP. As such they
should not (by default) have access to the classpath for that which they are testing.
The YAML based REST tests will be moved to separate source sets (yamlRestTest).
The which source is the target for the test resources is dependent on if this
new plugin is applied. If it is not applied, it will default to the test source
set.
Further, this introduces a breaking change for plugin developers that
use the YAML testing framework. They will now need to either use the new source set
and matching task, or configure the rest resources to use the old "test" source set that
matches the old integTest task. (The former should be preferred).
As part of this change (which is also breaking for plugin developers) the
rest resources plugin has been removed from the build plugin and now requires
either explicit application or application via the new YAML REST test plugin.
Plugin developers should be able to fix the breaking changes to the YAML tests
by adding apply plugin: 'elasticsearch.yaml-rest-test' and moving the YAML tests
under a yamlRestTest folder (instead of test)
Now that MappedFieldType no longer extends lucene's FieldType, we need to have a
way of getting the index information about a field necessary for building text queries,
building term vectors, highlighting, etc. This commit introduces a new TextSearchInfo
abstraction that holds this information, and a getTextSearchInfo() method to
MappedFieldType to make it available. Field types that do not support text search can
just return null here.
This allows us to remove the MapperService.getLuceneFieldType() shim method.
This is currently used to set the indexVersionCreated parameter on FieldMapper.
However, this parameter is only actually used by two implementations, and clutters
the API considerably. We should just remove it, and use it directly in the
implementations that require it.
MappedFieldType is a combination of two concerns:
* an extension of lucene's FieldType, defining how a field should be indexed
* a set of query factory methods, defining how a field should be searched
We want to break these two concerns apart. This commit is a first step to doing this, breaking
the inheritance relationship between MappedFieldType and FieldType. MappedFieldType
instead has a series of boolean flags defining whether or not the field is searchable or
aggregatable, and FieldMapper has a separate FieldType passed to its constructor defining
how indexing should be done.
Relates to #56814
Reworks the `parent` and `child` aggregation are not at the top level
using the optimization from #55873. Instead of wrapping all
non-top-level `parent` and `child` aggregators we now handle being a
child aggregator in the aggregator, specifically by adding recording
which global ordinals show up in the parent and then checking if they
match the child.
Pulls the way that the `ParentJoinAggregator` collects global ordinals
into a strategy object so it is a little simpler to reason about and
it'll be simpler to save memory by removing `asMultiBucketAggregator` in
the future.
Relates to #56487
When we had multiple mapping types, an update to a field in one type had to be
propagated to the same field in all other types. This was done using the
Mapper.updateFieldType() method, called at the end of a merge. However, now
that we only have a single type per index, this method is unnecessary and can
be removed.
Relates to #41059
Backport of #56986
Merging logic is currently split between FieldMapper, with its merge() method, and
MappedFieldType, which checks for merging compatibility. The compatibility checks
are called from a third class, MappingMergeValidator. This makes it difficult to reason
about what is or is not compatible in updates, and even what is in fact updateable - we
have a number of tests that check compatibility on changes in mapping configuration
that are not in fact possible.
This commit refactors the compatibility logic so that it all sits on FieldMapper, and
makes it called at merge time. It adds a new FieldMapperTestCase base class that
FieldMapper tests can extend, and moves the compatibility testing machinery from
FieldTypeTestCase to here.
Relates to #56814
Mapper.Builder currently has some complex generics on it to allow fluent builder
construction. However, the second parameter, a return type from the build() method,
is unnecessary, as we can use covariant return types. This commit removes this second
generic parameter.
Right now all implementations of the `terms` agg allocate a new
`Aggregator` per bucket. This uses a bunch of memory. Exactly how much
isn't clear but each `Aggregator` ends up making its own objects to read
doc values which have non-trivial buffers. And it forces all of it
sub-aggregations to do the same. We allocate a new `Aggregator` per
bucket for two reasons:
1. We didn't have an appropriate data structure to track the
sub-ordinals of each parent bucket.
2. You can only make a single call to `runDeferredCollections(long...)`
per `Aggregator` which was the only way to delay collection of
sub-aggregations.
This change switches the method that builds aggregation results from
building them one at a time to building all of the results for the
entire aggregator at the same time.
It also adds a fairly simplistic data structure to track the sub-ordinals
for `long`-keyed buckets.
It uses both of those to power numeric `terms` aggregations and removes
the per-bucket allocation of their `Aggregator`. This fairly
substantially reduces memory consumption of numeric `terms` aggregations
that are not the "top level", especially when those aggregations contain
many sub-aggregations. It also is a pretty big speed up, especially when
the aggregation is under a non-selective aggregation like
the `date_histogram`.
I picked numeric `terms` aggregations because those have the simplest
implementation. At least, I could kind of fit it in my head. And I
haven't fully understood the "bytes"-based terms aggregations, but I
imagine I'll be able to make similar optimizations to them in follow up
changes.
`FieldMapper#parseCreateField` accepts the parse context, plus a list of fields
as an output parameter. These fields are immediately added to the document
through `ParseContext#doc()`.
This commit simplifies the signature by removing the list of fields, and having
the mappers add the fields directly to `ParseContext#doc()`. I think this is
nicer for implementors, because previously fields could be added either through
the list, or the context (through `add`, `addWithKey`, etc.)
Some aggregations, such as the Terms* family, will use an alternate
class to represent unmapped shard results (while the rest of the aggs
use the same object but with some form of "empty" or "nullish" values
to represent unmapped).
This was problematic with AbstractWireSerializingTestCase because it
expects the instanceReader to always match the original class. Instead,
we need to use the NamedWriteable version so that the registry
can be consulted for the proper deserialization reader.
* Add ValuesSource Registry and associated logic (#54281)
* Remove ValuesSourceType argument to ValuesSourceAggregationBuilder (#48638)
* ValuesSourceRegistry Prototype (#48758)
* Remove generics from ValuesSource related classes (#49606)
* fix percentile aggregation tests (#50712)
* Basic thread safety for ValuesSourceRegistry (#50340)
* Remove target value type from ValuesSourceAggregationBuilder (#49943)
* Cleanup default values source type (#50992)
* CoreValuesSourceType no longer implements Writable (#51276)
* Remove genereics & hard coded ValuesSource references from Matrix Stats (#51131)
* Put values source types on fields (#51503)
* Remove VST Any (#51539)
* Rewire terms agg to use new VS registry (#51182)
Also adds some basic AggTestCases for untested code
paths (and boilerplate for future tests once the IT are
converted over)
* Wire Cardinality aggregation to work with the ValuesSourceRegistry (#51337)
* Wire Percentiles aggregator into new VS framework (#51639)
This required a bit of a refactor to percentiles itself. Before,
the Builder would switch on the chosen algo to generate an
algo-specific factory. This doesn't work (or at least, would be
difficult) in the new VS framework.
This refactor consolidates both factories together and introduces
a PercentilesConfig object to act as a standardized way to pass
algo-specific parameters through the factory. This object
is then used when deciding which kind of aggregator to create
Note: CoreValuesSourceType.HISTOGRAM still lives in core, and will
be moved in a subsequent PR.
* Remove generics and target value type from MultiVSAB (#51647)
* fix checkstyle after merge (#52008)
* Plumb ValuesSourceRegistry through to QuerySearchContext (#51710)
* Convert RareTerms to new VS registry (#52166)
* Wire up Value Count (#52225)
* Wire up Max & Min aggregations (#52219)
* ValuesSource refactoring: Wire up Sum aggregation (#52571)
* ValuesSource refactoring: Wire up SigTerms aggregation (#52590)
* Soft immutability for VSConfig (#52729)
* Unmute testSupportedFieldTypes, fix Percentiles/Ranks/Terms tests (#52734)
Also fixes Percentiles which was incorrectly specified to only accept
numeric, but in fact also accepts Boolean and Date (because those are
numeric on master - thanks `testSupportedFieldTypes` for catching it!)
* VS refactoring: Wire up stats aggregation (#52891)
* ValuesSource refactoring: Wire up string_stats aggregation (#52875)
* VS refactoring: Wire up median (MAD) aggregation (#52945)
* fix valuesourcetype issue with constant_keyword field (#53041)x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/job/RollupIndexer.java
this commit implements `getValuesSourceType` for
the ConstantKeyword field type.
master was merged into feature/extensible-values-source
introducing a new field type that was not implementing
`getValuesSourceType`.
* ValuesSource refactoring: Wire up Avg aggregation (#52752)
* Wire PercentileRanks aggregator into new VS framework (#51693)
* Add a VSConfig resolver for aggregations not using the registry (#53038)
* Vs refactor wire up ranges and date ranges (#52918)
* Wire up geo_bounds aggregation to ValuesSourceRegistry (#53034)
This commit updates the geo_bounds aggregation to depend
on registering itself in the ValuesSourceRegistry
relates #42949.
* VS refactoring: convert Boxplot to new registry (#53132)
* Wire-up geotile_grid and geohash_grid to ValuesSourceRegistry (#53037)
This commit updates the geo*_grid aggregations to depend
on registering itself in the ValuesSourceRegistry
relates to the values-source refactoring meta issue #42949.
* Wire-up geo_centroid agg to ValuesSourceRegistry (#53040)
This commit updates the geo_centroid aggregation to depend
on registering itself in the ValuesSourceRegistry.
relates to the values-source refactoring meta issue #42949.
* Fix type tests for Missing aggregation (#53501)
* ValuesSource Refactor: move histo VSType into XPack module (#53298)
- Introduces a new API (`getBareAggregatorRegistrar()`) which allows plugins to register aggregations against existing agg definitions defined in Core.
- This moves the histogram VSType over to XPack where it belongs. `getHistogramValues()` still remains as a Core concept
- Moves the histo-specific bits over to xpack (e.g. the actual aggregator logic). This requires extra boilerplate since we need to create a new "Analytics" Percentile/Rank aggregators to deal with the histo field. Doubly-so since percentiles/ranks are extra boiler-plate'y... should be much lighter for other aggs
* Wire up DateHistogram to the ValuesSourceRegistry (#53484)
* Vs refactor parser cleanup (#53198)
Co-authored-by: Zachary Tong <polyfractal@elastic.co>
Co-authored-by: Zachary Tong <zach@elastic.co>
Co-authored-by: Christos Soulios <1561376+csoulios@users.noreply.github.com>
Co-authored-by: Tal Levy <JubBoy333@gmail.com>
* First batch of easy fixes
* Remove List.of from ValuesSourceRegistry
Note that we intend to have a follow up PR dealing with the mutability
of the registry, so I didn't even try to address that here.
* More compiler fixes
* More compiler fixes
* More compiler fixes
* Precommit is happy and so am I
* Add new Core VSTs to tests
* Disabled supported type test on SigTerms until we can backport it's fix
* fix checkstyle
* Fix test failure from semantic merge issue
* Fix some metaData->metadata replacements that got lost
* Fix list of supported types for MinAggregator
* Fix list of supported types for Avg
* remove unused import
Co-authored-by: Zachary Tong <polyfractal@elastic.co>
Co-authored-by: Zachary Tong <zach@elastic.co>
Co-authored-by: Christos Soulios <1561376+csoulios@users.noreply.github.com>
Co-authored-by: Tal Levy <JubBoy333@gmail.com>
This commit introduces a new `geo` module that is intended
to be contain all the geo-spatial-specific features in server.
As a first step, the responsibility of registering the geo_shape
field mapper is moved to this module.
Co-authored-by: Nicholas Knize <nknize@gmail.com>
This removes pipeline aggregators from the aggregation result tree
except for a single field used for backwards compatibility with pre-7.8
versions of Elasticsearch. That field isn't populated unless we are
serializing to pre-7.8 Elasticsearch. So, good news! We no longer build
pipeline aggregators on the data node. Most of the time.
Some field name constants were not updaten when we moved from "string" to "text"
and "keyword" fields. Renaming them makes it easier and faster to know which
field type is used in test subclassing this base test case.
This is a simple naming change PR, to fix the fact that "metadata" is a
single English word, and for too long we have not followed general
naming conventions for it. We are also not consistent about it, for
example, METADATA instead of META_DATA if we were trying to be
consistent with MetaData (although METADATA is correct when considered
in the context of "metadata"). This was a simple find and replace across
the code base, only taking a few minutes to fix this naming issue
forever.
Nik Everett
Julie Tibshirani
Alan Woodward
Luca Cavanna
Nhat Nguyen
Przemyslaw Gomulka
Mark Tozzi
Jim Ferenczi
Jake Landis
Igor Motov
Zachary Tong
Tal Levy
Christoph Büscher
Jason Tedor