Commit Graph

2639 Commits

Author SHA1 Message Date
Gian Merlino 9c925b4f09
Frame format for data transfer and short-term storage. (#12745)
* Frame format for data transfer and short-term storage.

As we move towards query execution plans that involve more transfer
of data between servers, it's important to have a data format that
provides for doing this more efficiently than the options available to
us today.

This patch adds:

- Columnar frames, which support fast querying.
- Row-based frames, which support fast sorting via memory comparison
  and fast whole-row copies via memory copying.
- Frame files, a container format that can be stored on disk or
  transferred between servers.

The idea is we should use row-based frames when data is expected to
be sorted, and columnar frames when data is expected to be queried.

The code in this patch is not used in production yet. Therefore, the
patch involves minimal changes outside of the org.apache.druid.frame
package.  The main ones are adjustments to SqlBenchmark to add benchmarks
for queries on frames, and the addition of a "forEach" method to Sequence.

* Fixes based on tests, static analysis.

* Additional fixes.

* Skip DS mapping tests on JDK 14+

* Better JDK checking in tests.

* Fix imports.

* Additional comment.

* Adjustments from code review.

* Update test case.
2022-07-08 20:42:06 -07:00
Rohan Garg bcff35f798
Pushdown join filter with right side referencing columns (#12749) 2022-07-08 19:59:41 +05:30
Jianhuan Liu 4574dea5e9
Use MXBeans to get GC metrics #12476 (#12481)
* jvm gc to mxbeans

* add zgc and shenandoah #12476

* remove tryCreateGcCounter

* separate the space collector

* blend GcGenerationCollector into GcCollector

* add jdk surefire argLine
2022-07-08 14:32:06 +08:00
Gian Merlino 49feffff1b
Add comment about double-close in ColumnSelectorColumnIndexSelector. (#12735) 2022-07-06 00:50:35 -07:00
Clint Wylie 36e38b319b
add virtual column support to search query (#12720) 2022-07-04 21:58:10 -07:00
imply-cheddar e3128e3fa3
Poison stupid pool (#12646)
* Poison StupidPool and fix resource leaks

There are various resource leaks from test setup as well as some
corners in query processing.  We poison the StupidPool to start failing
tests when the leaks come and fix any issues uncovered from that so
that we can start from a clean baseline.

Unfortunately, because of how poisoning works,
we can only fail future checkouts from the same pool,
which means that there is a natural race between a
leak happening -> GC occurs -> leak detected -> pool poisoned.

This race means that, depending on interleaving of tests,
if the very last time that an object is checked out
from the pool leaks, then it won't get caught.
At some point in the future, something will catch it,
 however and from that point on it will be deterministic.

* Remove various things left over from iterations

* Clean up FilterAnalysis and add javadoc on StupidPool

* Revert changes to .idea/misc.xml that accidentally got pushed

* Style and test branches

* Stylistic woes
2022-07-03 14:36:22 -07:00
Clint Wylie 48731710fb
precursor changes for nested columns to minimize files changed (#12714)
* precursor changes for nested columns to minimize files changed

* inspection fix

* visibility

* adjustment

* unecessary change
2022-07-01 02:27:19 -07:00
Abhishek Agarwal dbd45daf33
Flakiness and exceptions during tests (#12705) 2022-06-28 10:36:23 +05:30
Tejaswini Bandlamudi 1fc2f6e4b0
Throw BadQueryContextException if context params cannot be parsed (#12680) 2022-06-24 09:21:25 +05:30
Gian Merlino 818974f6e4
ScanQuery: Fix JsonIgnore for isLegacy. (#12674)
True, false, and null have different meanings: true/false mean "legacy"
and "not legacy"; null means use the default set by ScanQueryConfig.
So, we need to respect this in the JsonIgnore setup.
2022-06-18 15:55:54 -07:00
Gian Merlino e76a5077ef
Fix self-referential shape inspection in BaseExpressionColumnValueSelector. (#12669)
* Fix self-referential shape inspection in BaseExpressionColumnValueSelector.

The new test would throw StackOverflowError on the old code.

* Restore prior test.
2022-06-17 16:15:50 -07:00
Clint Wylie 18937ffee2
split out null value index (#12627)
* split out null value index

* gg spotbugs

* fix stuff
2022-06-17 15:29:23 -07:00
Paul Rogers 893759de91
Remove null and empty fields from native queries (#12634)
* Remove null and empty fields from native queries

* Test fixes

* Attempted IT fix.

* Revisions from review comments

* Build fixes resulting from changes suggested by reviews

* IT fix for changed segment size
2022-06-16 14:07:25 -07:00
Paul Rogers 45e3111549
Clean up query contexts (#12633)
* Clean up query contexts

Uses constants in place of literal strings for context keys.
Moves some QueryContext methods to QueryContexts for reuse.

* Revisions from review comments
2022-06-15 11:31:22 -07:00
Rohan Garg 28f2c8e112
Support LoadScope for Peons + Access Modifier Updates (#12640)
* Support LoadScope for Peons

* Update access modifiers for GroupByEngineV2
2022-06-14 21:52:50 -07:00
Rohan Garg afaea251f2
Push join build table values as filter incase of duplicates (#12225)
* Push join build table values as filter

* Add tests for JoinableFactoryWrapper

* fixup! Push join build table values as filter

* fixup! Add tests for JoinableFactoryWrapper

* fixup! Push join build table values as filter
2022-06-13 17:18:27 -07:00
Abhishek Agarwal 59a0c10c47
Add remedial information in error message when type is unknown (#12612)
Often users are submitting queries, and ingestion specs that work only if the relevant extension is not loaded. However, the error is too technical for the users and doesn't suggest them to check for missing extensions. This PR modifies the error message so users can at least check their settings before assuming that the error is because of a bug.
2022-06-07 20:22:45 +05:30
Gian Merlino abf0e0a159
CompressionStrategyTest: Fix thread-unsafe Closer usage. (#12605)
Closer is not thread-safe, so we need one per thread in the
concurrency tests.
2022-06-04 10:57:13 -07:00
Clint Wylie 98f6bca2cd
fix regression with ipv4_match and prefixes (#12542)
* fix issue with ipv4_match and prefixes
2022-06-01 14:03:08 -07:00
Clint Wylie 31f988ec76
fix backwards compatibility for explicit null columns (#12585) 2022-06-01 12:39:48 -07:00
Clint Wylie 0640c9c9ac
fix compression-strategy-test (#12575)
fixes an issue caused by a test modification in #12408 that was closing buffers allocated by the compression strategy instead of allowing the closer to do it
2022-05-31 11:48:32 -07:00
Gian Merlino 02ae3e74ff
RowBasedColumnSelectorFactory: Add "useStringValueOfNullInLists" parameter. (#12578)
RowBasedColumnSelectorFactory inherited strange behavior from
Rows.objectToStrings for nulls that appear in lists: instead of being
left as a null, it is replaced with the string "null". Some callers may
need compatibility with this strange behavior, but it should be opt-in.

Query-time call sites are changed to opt-out of this behavior, since it
is not consistent with query-time expectations. The IncrementalIndex
ingestion-time call site retains the old behavior, as this is traditionally
when Rows.objectToStrings would be used.
2022-05-31 11:38:56 -07:00
Gian Merlino 6d2ff796a3
Add RowIdSupplier to ColumnSelectorFactory. (#12577)
* Add RowIdSupplier to ColumnSelectorFactory.

This enables virtual columns to cache their outputs in case they are
called multiple times on the same underlying row. This is common for
numeric selectors, where the common pattern is to call isNull() and
then follow with getLong(), getFloat(), or getDouble(). Here, output
caching reduces the number of expression evals by half.

* Fix tests.
2022-05-31 11:38:03 -07:00
Clint Wylie b746bf9129
fix virtual column cycle bug, sql virtual column optimize bug (#12576)
* fix virtual column cycle bug, sql virtual column optimize bug

* more test
2022-05-30 23:51:21 -07:00
Dr. Sizzles 7291c92f4f
Adding zstandard compression library (#12408)
* Adding zstandard compression library

* 1. Took @clintropolis's advice to have ZStandard decompressor use the byte array when the buffers are not direct.
2. Cleaned up checkstyle issues.

* Fixing zstandard version to latest stable version in pom's and updating license files

* Removing zstd from benchmarks and adding to processing (poms)

* fix the intellij inspection issue

* Removing the prefix v for the version in the license check for ztsd

* Fixing license checks

Co-authored-by: Rahul Gidwani <r_gidwani@apple.com>
2022-05-28 17:01:44 -07:00
Clint Wylie d0c9c37e35
make query context changes backwards compatible (#12564)
Adds a default implementation of getQueryContext, which was added to the Query interface in #12396. Query is marked with @ExtensionPoint, and lately we have been trying to be less volatile on these interfaces by providing default implementations to be more chill for extension writers.

The way this default implementation is done in this PR is a bit strange due to the way that getQueryContext is used (mutated with system default and system generated keys); the default implementation has a specific object that it returns, and I added another temporary default method isLegacyContext that checks if the getQueryContext returns that object or not. If not, callers fall back to using getContext and withOverriddenContext to set these default and system values.

I am open to other ideas as well, but this way should work at least without exploding, and added some tests to ensure that it is wired up correctly for QueryLifecycle, including the context authorization stuff.

The added test shows the strange behavior if query context authorization is enabled, mainly that the system default and system generated query context keys also need to be granted as permissions for things to function correctly. This is not great, so I mentioned it in the javadocs as well. Not sure if it needs to be called out anywhere else.
2022-05-25 15:24:41 +05:30
Karan Kumar 9f9faeec81
object[] handling for DimensionHandlers for arrays (#12552)
Description
Fixes a bug when running q's like

 SELECT cntarray,
       Count(*)
FROM   (SELECT dim1,
               dim2,
               Array_agg(cnt) AS cntarray
        FROM   (SELECT dim1,
                       dim2,
                       dim3,
                       Count(*) AS cnt
                FROM   foo
                GROUP  BY 1,
                          2,
                          3)
        GROUP  BY 1,
                  2)
GROUP  BY 1  
This generates an error:

org.apache.druid.java.util.common.ISE: Unable to convert type [Ljava.lang.Object; to org.apache.druid.segment.data.ComparableList
        at org.apache.druid.segment.DimensionHandlerUtils.convertToList(DimensionHandlerUtils.java:405) ~[druid-xx]
Because it's an array of numbers it looks like it does the convertToList call, which looks like:

  @Nullable
  public static ComparableList convertToList(Object obj)
  {
    if (obj == null) {
      return null;
    }
    if (obj instanceof List) {
      return new ComparableList((List) obj);
    }
    if (obj instanceof ComparableList) {
      return (ComparableList) obj;
    }
    throw new ISE("Unable to convert type %s to %s", obj.getClass().getName(), ComparableList.class.getName());
  }
I.e. it doesn't know about arrays. Added the array handling as part of this PR.
2022-05-25 15:24:18 +05:30
Agustin Gonzalez 2f3d7a4c07
Emit state of replace and append for native batch tasks (#12488)
* Emit state of replace and append for native batch tasks

* Emit count of one depending on batch ingestion mode (APPEND, OVERWRITE, REPLACE)

* Add metric to compaction job

* Avoid null ptr exc when null emitter

* Coverage

* Emit tombstone & segment counts

* Tasks need a type

* Spelling

* Integrate BatchIngestionMode in batch ingestion tasks functionality

* Typos

* Remove batch ingestion type from metric since it is already in a dimension. Move IngestionMode to AbstractTask to facilitate having mode as a dimension. Add metrics to streaming. Add missing coverage.

* Avoid inner class referenced by sub-class inspection. Refactor computation of IngestionMode to make it more robust to null IOConfig and fix test.

* Spelling

* Avoid polluting the Task interface

* Rename computeCompaction methods to avoid ambiguous java compiler error if they are passed null. Other minor cleanup.
2022-05-23 12:32:47 -07:00
Gian Merlino 37853f8de4
ConcurrentGrouper: Add mergeThreadLocal option, fix bug around the switch to spilling. (#12513)
* ConcurrentGrouper: Add option to always slice up merge buffers thread-locally.

Normally, the ConcurrentGrouper shares merge buffers across processing
threads until spilling starts, and then switches to a thread-local model.
This minimizes memory use and reduces likelihood of spilling, which is
good, but it creates thread contention. The new mergeThreadLocal option
causes a query to start in thread-local mode immediately, and allows us
to experiment with the relative performance of the two modes.

* Fix grammar in docs.

* Fix race in ConcurrentGrouper.

* Fix issue with timeouts.

* Remove unused import.

* Add "tradeoff" to dictionary.
2022-05-21 10:28:54 -07:00
Gian Merlino 69aac6c8dd
Direct UTF-8 access for "in" filters. (#12517)
* Direct UTF-8 access for "in" filters.

Directly related:

1) InDimFilter: Store stored Strings (in ValuesSet) plus sorted UTF-8
   ByteBuffers (in valuesUtf8). Use valuesUtf8 whenever possible. If
   necessary, the input set is copied into a ValuesSet. Much logic is
   simplified, because we always know what type the values set will be.
   I think that there won't even be an efficiency loss in most cases.
   InDimFilter is most frequently created by deserialization, and this
   patch updates the JsonCreator constructor to deserialize
   directly into a ValuesSet.

2) Add Utf8ValueSetIndex, which InDimFilter uses to avoid UTF-8 decodes
   during index lookups.

3) Add unsigned comparator to ByteBufferUtils and use it in
   GenericIndexed.BYTE_BUFFER_STRATEGY. This is important because UTF-8
   bytes can be compared as bytes if, and only if, the comparison
   is unsigned.

4) Add specialization to GenericIndexed.singleThreaded().indexOf that
   avoids needless ByteBuffer allocations.

5) Clarify that objects returned by ColumnIndexSupplier.as are not
   thread-safe. DictionaryEncodedStringIndexSupplier now calls
   singleThreaded() on all relevant GenericIndexed objects, saving
   a ByteBuffer allocation per access.

Also:

1) Fix performance regression in LikeFilter: since #12315, it applied
   the suffix matcher to all values in range even for type MATCH_ALL.

2) Add ObjectStrategy.canCompare() method. This fixes LikeFilterBenchmark,
   which was broken due to calls to strategy.compare in
   GenericIndexed.fromIterable.

* Add like-filter implementation tests.

* Add in-filter implementation tests.

* Add tests, fix issues.

* Fix style.

* Adjustments from review.
2022-05-20 01:51:28 -07:00
machine424 90531fd53f
Do not alter query timeout in ScanQueryEngine (#12271)
Add test to detect timeout mutability
2022-05-19 09:24:42 -07:00
Gian Merlino 4631cff2a9
Free ByteBuffers in tests and fix some bugs. (#12521)
* Ensure ByteBuffers allocated in tests get freed.

Many tests had problems where a direct ByteBuffer would be allocated
and then not freed. This is bad because it causes flaky tests.

To fix this:

1) Add ByteBufferUtils.allocateDirect(size), which returns a ResourceHolder.
   This makes it easy to free the direct buffer. Currently, it's only used
   in tests, because production code seems OK.

2) Update all usages of ByteBuffer.allocateDirect (off-heap) in tests either
   to ByteBuffer.allocate (on-heap, which are garbaged collected), or to
   ByteBufferUtils.allocateDirect (wherever it seemed like there was a good
   reason for the buffer to be off-heap). Make sure to close all direct
   holders when done.

* Changes based on CI results.

* A different approach.

* Roll back BitmapOperationTest stuff.

* Try additional surefire memory.

* Revert "Roll back BitmapOperationTest stuff."

This reverts commit 49f846d9e3.

* Add TestBufferPool.

* Revert Xmx change in tests.

* Better behaved NestedQueryPushDownTest. Exit tests on OOME.

* Fix TestBufferPool.

* Remove T1C from ARM tests.

* Somewhat safer.

* Fix tests.

* Fix style stuff.

* Additional debugging.

* Reset null / expr configs better.

* ExpressionLambdaAggregatorFactory thread-safety.

* Alter forkNode to try to get better info when a JVM crashes.

* Fix buffer retention in ExpressionLambdaAggregatorFactory.

* Remove unused import.
2022-05-19 07:42:29 -07:00
Gian Merlino 5b6727f319
Enable vectorized virtual column processing by default. (#12520)
In the majority of cases, this improves performance.

There's only one case I'm aware of where this may be a net negative: for time_floor(__time, <period>) where there are many repeated __time values. In nonvectorized processing, SingleLongInputCachingExpressionColumnValueSelector implements an optimization to avoid computing the time_floor function on every row. There is no such optimization in vectorized processing.

IMO, we shouldn't mention this in the docs. Rationale: It's too fiddly of a thing: it's not guaranteed that nonvectorized processing will be faster due to the optimization, because it would have to overcome the inherent speed advantage of vectorization. So it'd always require testing to determine the best setting for a specific dataset. It would be bad if users disabled vectorization thinking it would speed up their queries, and it actually slowed them down. And even if users do their own testing, at some point in the future we'll implement the optimization for vectorized processing too, and it's likely that users that explicitly disabled vectorization will continue to have it disabled. I'd like to avoid this outcome by encouraging all users to enable vectorization at all times. Really advanced users would be following development activity anyway, and can read this issue
2022-05-16 15:43:53 +05:30
Gian Merlino ff253fd8a3
Add setProcessingThreadNames context parameter. (#12514)
setting thread names takes a measurable amount of time in the case where segment scans are very quick. In high-QPS testing we found a slight performance boost from turning off processing thread renaming. This option makes that possible.
2022-05-16 13:42:00 +05:30
Abhishek Radhakrishnan 9177515be2
Add IPAddress java library as dependency and migrate IPv4 functions to use the new library. (#11634)
* Add ipaddress library as dependency.

* IPv4 functions to use the inet.ipaddr package.

* Remove unused imports.

* Add new function.

* Minor rename.

* Add more unit tests.

* IPv4 address expr utils unit tests and address options.

* Adjust the IPv4Util functions.

* Move the UTs a bit around.

* Javadoc comments.

* Add license info for IPAddress.

* Fix groupId, artifact and version in license.yaml.

* Remove redundant subnet in messages - fixes UT.

* Remove unused commons-net dependency for /processing project.

* Make class and methods public so it can be accessed.

* Add initial version of benchmark

* Add subnetutils package for benchmarks.

* Auto generate ip addresses.

* Add more v4 address representations in setup to avoid bias.

* Use ThreadLocalRandom to avoid forbidden API usage.

* Adjust IPv4AddressBenchmark to adhere to codestyle rules.

* Update ipaddress library to latest 5.3.4

* Add ipaddress package dependency to benchmarks project.
2022-05-11 22:06:20 -07:00
Clint Wylie 9e5a940cf1
remake column indexes and query processing of filters (#12388)
Following up on #12315, which pushed most of the logic of building ImmutableBitmap into BitmapIndex in order to hide the details of how column indexes are implemented from the Filter implementations, this PR totally refashions how Filter consume indexes. The end result, while a rather dramatic reshuffling of the existing code, should be extraordinarily flexible, eventually allowing us to model any type of index we can imagine, and providing the machinery to build the filters that use them, while also allowing for other column implementations to implement the built-in index types to provide adapters to make use indexing in the current set filters that Druid provides.
2022-05-11 11:57:08 +05:30
Rohan Garg 75836a5a06
Add feature flag for sql planning of TimeBoundary queries (#12491)
* Add feature flag for sql planning of TimeBoundary queries

* fixup! Add feature flag for sql planning of TimeBoundary queries

* Add documentation for enableTimeBoundaryPlanning

* fixup! Add documentation for enableTimeBoundaryPlanning
2022-05-10 15:23:42 +05:30
somu-imply c68388ebcd
Vectorized version of string last aggregator (#12493)
* Vectorized version of string last aggregator

* Updating string last and adding testcases

* Updating code and adding testcases for serializable pairs

* Addressing review comments
2022-05-09 17:02:38 -07:00
Rohan Garg 2dd073c2cd
Pass metrics object for Scan, Timeseries and GroupBy queries during cursor creation (#12484)
* Pass metrics object for Scan, Timeseries and GroupBy queries during cursor creation

* fixup! Pass metrics object for Scan, Timeseries and GroupBy queries during cursor creation

* Document vectorized dimension
2022-05-09 10:40:17 -07:00
Gian Merlino 529b983ad0
GroupBy: Reduce allocations by reusing entry and key holders. (#12474)
* GroupBy: Reduce allocations by reusing entry and key holders.

Two main changes:

1) Reuse Entry objects returned by various implementations of
   Grouper.iterator.

2) Reuse key objects contained within those Entry objects.

This is allowed by the contract, which states that entries must be
processed and immediately discarded. However, not all call sites
respected this, so this patch also updates those call sites.

One particularly sneaky way that the old code retained entries too long
is due to Guava's MergingIterator and CombiningIterator. Internally,
these both advance to the next value prior to returning the current
value. So, this patch addresses that in two ways:

1) For merging, we have our own implementation MergeIterator already,
   although it had the same problem. So, this patch updates our
   implementation to return the current item prior to advancing to the
   next item. It also adds a forbidden-api entry to ensure that this
   safer implementation is used instead of Guava's.

2) For combining, we address the problem in a different way: by copying
   the key when creating the new, combined entry.

* Attempt to fix test.

* Remove unused import.
2022-04-28 23:21:13 -07:00
Gian Merlino a2bad0b3a2
Reduce allocations due to Jackson serialization. (#12468)
* Reduce allocations due to Jackson serialization.

This patch attacks two sources of allocations during Jackson
serialization:

1) ObjectMapper.writeValue and JsonGenerator.writeObject create a new
   DefaultSerializerProvider instance for each call. It has lots of
   fields and creates pressure on the garbage collector. So, this patch
   adds helper functions in JacksonUtils that enable reuse of
   SerializerProvider objects and updates various call sites to make
   use of this.

2) GroupByQueryToolChest copies the ObjectMapper for every query to
   install a special module that supports backwards compatibility with
   map-based rows. This isn't needed if resultAsArray is set and
   all servers are running Druid 0.16.0 or later. This release was a
   while ago. So, this patch disables backwards compatibility by default,
   which eliminates the need to copy the heavyweight ObjectMapper. The
   patch also introduces a configuration option that allows admins to
   explicitly enable backwards compatibility.

* Add test.

* Update additional call sites and add to forbidden APIs.
2022-04-27 14:17:26 -07:00
Gian Merlino 72d15ab321
JvmMonitor: Handle more generation and collector scenarios. (#12469)
* JvmMonitor: Handle more generation and collector scenarios.

ZGC on Java 11 only has a generation 1 (there is no 0). This causes
a NullPointerException when trying to extract the spacesCount for
generation 0. In addition, ZGC on Java 15 has a collector number 2
but no spaces in generation 2, which breaks the assumption that
collectors always have same-numbered spaces.

This patch adjusts things to be more robust, enabling the JvmMonitor
to work properly for ZGC on both Java 11 and 15.

* Test adjustments.

* Improve surefire arglines.

* Need a placeholder
2022-04-27 11:18:40 -07:00
Abhishek Agarwal 2fe053c5cb
Bump up the versions (#12480) 2022-04-27 14:28:20 +05:30
somu-imply 027935dcff
Vectorize numeric latest aggregators (#12439)
* Vectorizing Latest aggregator Part 1

* Updating benchmark tests

* Changing appropriate logic for vectors for null handling

* Introducing an abstract class and moving the commonalities there

* Adding vectorization for StringLast aggregator (initial version)

* Updated bufferized version of numeric aggregators

* Adding some javadocs

* Making sure this PR vectorizes numeric latest agg only

* Adding another benchmarking test

* Fixing intellij inspections

* Adding tests for double

* Adding test cases for long and float

* Updating testcases

* Checkstyle oops..

* One tiny change in test case

* Fixing spotbug and rhs not being used
2022-04-26 11:33:08 -07:00
Will Xu 4868ef9529
Enable Arm builds (#12451)
This PR enables ARM builds on Travis. I've ported over the changes from @martin-g on reducing heap requirements for some of the tests to ensure they run well on Travis arm instances.
2022-04-26 20:14:40 +05:30
Rohan Garg 95694b5afa
Convert simple min/max SQL queries on __time to timeBoundary queries (#12472)
* Support array based results in timeBoundary query

* Fix bug with query interval in timeBoundary

* Convert min(__time) and max(__time) SQL queries to timeBoundary

* Add tests for timeBoundary backed SQL queries

* Fix query plans for existing tests

* fixup! Convert min(__time) and max(__time) SQL queries to timeBoundary

* fixup! Add tests for timeBoundary backed SQL queries

* fixup! Fix bug with query interval in timeBoundary
2022-04-25 08:18:58 -07:00
Jihoon Son 73ce5df22d
Add support for authorizing query context params (#12396)
The query context is a way that the user gives a hint to the Druid query engine, so that they enforce a certain behavior or at least let the query engine prefer a certain plan during query planning. Today, there are 3 types of query context params as below.

Default context params. They are set via druid.query.default.context in runtime properties. Any user context params can be default params.
User context params. They are set in the user query request. See https://druid.apache.org/docs/latest/querying/query-context.html for parameters.
System context params. They are set by the Druid query engine during query processing. These params override other context params.
Today, any context params are allowed to users. This can cause 
1) a bad UX if the context param is not matured yet or 
2) even query failure or system fault in the worst case if a sensitive param is abused, ex) maxSubqueryRows.

This PR adds an ability to limit context params per user role. That means, a query will fail if you have a context param set in the query that is not allowed to you. To do that, this PR adds a new built-in resource type, QUERY_CONTEXT. The resource to authorize has a name of the context param (such as maxSubqueryRows) and the type of QUERY_CONTEXT. To allow a certain context param for a user, the user should be granted WRITE permission on the context param resource. Here is an example of the permission.

{
  "resourceAction" : {
    "resource" : {
      "name" : "maxSubqueryRows",
      "type" : "QUERY_CONTEXT"
    },
    "action" : "WRITE"
  },
  "resourceNamePattern" : "maxSubqueryRows"
}
Each role can have multiple permissions for context params. Each permission should be set for different context params.

When a query is issued with a query context X, the query will fail if the user who issued the query does not have WRITE permission on the query context X. In this case,

HTTP endpoints will return 403 response code.
JDBC will throw ForbiddenException.
Note: there is a context param called brokerService that is used only by the router. This param is used to pin your query to run it in a specific broker. Because the authorization is done not in the router, but in the broker, if you have brokerService set in your query without a proper permission, your query will fail in the broker after routing is done. Technically, this is not right because the authorization is checked after the context param takes effect. However, this should not cause any user-facing issue and thus should be OK. The query will still fail if the user doesn’t have permission for brokerService.

The context param authorization can be enabled using druid.auth.authorizeQueryContextParams. This is disabled by default to avoid any hassle when someone upgrades his cluster blindly without reading release notes.
2022-04-21 14:21:16 +05:30
Rohan Garg 4c6ba73823
Emit vectorized metric dimension by default (#12464) 2022-04-20 21:14:55 -07:00
Frank Chen 2677d279e2
Remove h2 database from dependency (#12447) 2022-04-19 10:25:17 +08:00
Maytas Monsereenusorn c25a556827
Fix bug in auto compaction preserveExistingMetrics feature (#12438)
* fix bug

* fix test

* fix IT
2022-04-15 15:47:47 -07:00
Clint Wylie 5824ab9608
fix issue with boolean expression input (#12429) 2022-04-13 16:34:01 -07:00
Jihoon Son 5e5625f3ae
Fix indexMerger to respect the includeAllDimensions flag (#12428)
* Fix indexMerger to respect flag includeAllDimensions flag; jsonInputFormat should set keepNullColumns if useFieldDiscovery is set

* address comments
2022-04-13 12:43:11 -07:00
Maytas Monsereenusorn 8edea5a82d
Add a new flag for ingestion to preserve existing metrics (#12185)
* add impl

* add impl

* fix checkstyle

* add impl

* add unit test

* fix stuff

* fix stuff

* fix stuff

* add unit test

* add more unit tests

* add more unit tests

* add IT

* add IT

* add IT

* add IT

* add ITs

* address comments

* fix test

* fix test

* fix test

* address comments

* address comments

* address comments

* fix conflict

* fix checkstyle

* address comments

* fix test

* fix checkstyle

* fix test

* fix test

* fix IT
2022-04-08 11:02:02 -07:00
Paul Rogers 2cc2088720
Method to specify eternity in the scan query builder (#12223)
* Method to specify eternity in the scan query builder

* Fix checkstyle issue

* Renamed eterity() to eternityInterval()

* Minor fixes
2022-04-04 15:11:32 -07:00
somu-imply a1ea658115
Introducing a new config to ignore nulls while computing String Cardinality (#12345)
* Counting nulls in String cardinality with a config

* Adding tests for the new config

* Wrapping the vectorize part to allow backward compatibility

* Adding different tests, cleaning the code and putting the check at the proper position, handling hasRow() and hasValue() changes

* Updating testcase and code

* Adding null handling test to improve coverage

* Checkstyle fix

* Adding 1 more change in docs

* Making docs clearer
2022-03-29 14:31:36 -07:00
Jihoon Son b6eeef31e5
Store null columns in the segments (#12279)
* Store null columns in the segments

* fix test

* remove NullNumericColumn and unused dependency

* fix compile failure

* use guava instead of apache commons

* split new tests

* unused imports

* address comments
2022-03-23 16:54:04 -07:00
Adarsh Sanjeev ef45a1551e
Convert inQueryThreshold into query context parameter. (#12357)
Added Calcites InQueryThreshold as a query context parameter. Setting this parameter appropriately reduces the time taken for queries with large number of values in their IN conditions.
2022-03-22 18:33:57 +05:30
Xavier Léauté 1f0447e613
fix use of deprecated initMocks method (#12351)
follow-up to #12341
- fix use of deprecated initMocks methods and properly close mocks on teardown
2022-03-19 10:19:02 -07:00
somu-imply b5195c5095
Graceful null handling and correctness in DoubleMean Aggregator (#12320)
* Adding null handling for double mean aggregator

* Updating code to handle nulls in DoubleMean aggregator

* oops last one should have checkstyle issues. fixed

* Updating some code and test cases

* Checking on object is null in case of numeric aggregator

* Adding one more test to improve coverage

* Changing one test as asked in the review

* Changing one test as asked in the review for nulls
2022-03-14 16:52:47 -07:00
mchades 3de1272926
bug fix: merge results of group by limit push down (#11969) 2022-03-11 09:04:34 -08:00
Gian Merlino cb2b2b696d
Fix error message for groupByEnableMultiValueUnnesting. (#12325)
* Fix error message for groupByEnableMultiValueUnnesting.

It referred to the incorrect context parameter.

Also, create a dedicated exception class, to allow easier detection of this
specific error.

* Fix other test.

* More better error messages.

* Test getDimensionName method.
2022-03-10 11:37:24 -08:00
Clint Wylie 9cfb23935f
push value range and set index get operations into BitmapIndex (#12315)
* push value range and set index get operations into BitmapIndex

* fix bug

* oops, fix better

* better like, fix test, javadocs

* fix checkstyle

* simplify and fixes

* cache

* fix tests

* move indexOf into GenericIndexed

* oops

* fix tests
2022-03-09 13:30:58 -08:00
Rohan Garg 9f6a930462
Fix join query incase of filter explosion during CNF conversion (#12324) 2022-03-09 12:43:09 -08:00
Clint Wylie dc0372a28e
improve FileWriteOutBytes.readFully (#12323)
* improve FileWriteOutBytes.readFully

* no need to flush if out of bounds
2022-03-09 11:45:45 -08:00
Rohan Garg 56fbd2af6f
Guard against exponential increase of filters during CNF conversion (#12314)
Currently, the CNF conversion of a filter is unbounded, which means that it can create as many filters as possible thereby also leading to OOMs in historical heap. We should throw an error or disable CNF conversion if the filter count starts getting out of hand. There are ways to do CNF conversion with linear increase in filters as well but that has been left out of the scope of this change since those algorithms add new variables in the predicate - which can be contentious.
2022-03-09 13:19:52 +05:30
Agustin Gonzalez abe76ccb90
Batch ingestion replace (#12137)
* Tombstone support for replace functionality

* A used segment interval is the interval of a current used segment that overlaps any of the input intervals for the spec

* Update compaction test to match replace behavior

* Adapt ITAutoCompactionTest to work with tombstones rather than dropping segments. Add support for tombstones in the broker.

* Style plus simple queriableindex test

* Add segment cache loader tombstone test

* Add more tests

* Add a method to the LogicalSegment to test whether it has any data

* Test filter with some empty logical segments

* Refactor more compaction/dropexisting tests

* Code coverage

* Support for all empty segments

* Skip tombstones when looking-up broker's timeline. Discard changes made to tool chest to avoid empty segments since they will no longer have empty segments after lookup because we are skipping over them.

* Fix null ptr when segment does not have a queriable index

* Add support for empty replace interval (all input data has been filtered out)

* Fixed coverage & style

* Find tombstone versions from lock versions

* Test failures & style

* Interner was making this fail since the two segments were consider equal due to their id's being equal

* Cleanup tombstone version code

* Force timeChunkLock whenever replace (i.e. dropExisting=true) is being used

* Reject replace spec when input intervals are empty

* Documentation

* Style and unit test

* Restore test code deleted by mistake

* Allocate forces TIME_CHUNK locking and uses lock versions. TombstoneShardSpec added.

* Unused imports. Dead code. Test coverage.

* Coverage.

* Prevent killer from throwing an exception for tombstones. This is the killer used in the peon for killing segments.

* Fix OmniKiller + more test coverage.

* Tombstones are now marked using a shard spec

* Drop a segment factory.json in the segment cache for tombstones

* Style

* Style + coverage

* style

* Add TombstoneLoadSpec.class to mapper in test

* Update core/src/main/java/org/apache/druid/segment/loading/TombstoneLoadSpec.java

Typo

Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>

* Update docs/configuration/index.md

Missing

Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>

* Typo

* Integrated replace with an existing test since the replace part was redundant and more importantly, the test file was very close or exceeding the 10 min default "no output" CI Travis threshold.

* Range does not work with multi-dim

Co-authored-by: Jonathan Wei <jon-wei@users.noreply.github.com>
2022-03-08 20:07:02 -07:00
Clint Wylie dae53ae36a
adjust topn heap operation when string is dictionary encoded, but not uniquely (#12291)
* add topn heap optimization when string is dictionary encoded, but not uniquely

* use array instead

* is same

* fix javadoc

* fix

* Update StringTopNColumnAggregatesProcessor.java
2022-03-08 14:32:40 -08:00
Gian Merlino 875e0696e0
GroupBy: Cap dictionary-building selector memory usage. (#12309)
* GroupBy: Cap dictionary-building selector memory usage.

New context parameter "maxSelectorDictionarySize" controls when the
per-segment processing code should return early and trigger a trip
to the merge buffer.

Includes:

- Vectorized and nonvectorized implementations.
- Adjustments to GroupByQueryRunnerTest to exercise this code in
  the v2SmallDictionary suite. (Both the selector dictionary and
  the merging dictionary will be small in that suite.)
- Tests for the new config parameter.

* Fix issues from tests.

* Add "pre-existing" to dictionary.

* Simplify GroupByColumnSelectorStrategy interface by removing one of the writeToKeyBuffer methods.

* Adjustments from review comments.
2022-03-08 13:13:11 -08:00
Gian Merlino 3b373114dc
Officially support Java 11. (#12232)
There aren't any changes in this patch that improve Java 11
compatibility; these changes have already been done separately. This
patch merely updates documentation and explicit Java version checks.

The log message adjustments in DruidProcessingConfig are there to make
things a little nicer when running in Java 11, where we can't measure
direct memory _directly_, and so we may auto-size processing buffers
incorrectly.
2022-03-04 14:15:45 -08:00
Clint Wylie 1c004ea47e
use virtual columns for sql simple aggregators instead of inline expressions (#12251)
* use virtual columns for sql simple aggregators instead of inline expressions

* fixes

* always use virtual columns

* add more tests
2022-03-03 15:05:28 -08:00
Tejaswini Bandlamudi 1af4c9c933
Display row stats for multiphase parallel indexing tasks (#12280)
Row stats are reported for single phase tasks in the `/liveReports` and `/rowStats` APIs
and are also a part of the overall task report. This commit adds changes to report
row stats for multiphase tasks too.

Changes:
- Add `TaskReport` in `GeneratedPartitionsReport` generated during hash and range partitioning
- Collect the reports for `index_generate` phase in `ParallelIndexSupervisorTask`
2022-03-02 10:10:31 +05:30
Xavier Léauté 1434197ee1
update airline dependency to 2.x (#12270)
* upgrade Airline to Airline 2
  https://github.com/airlift/airline is no longer maintained, updating to
  https://github.com/rvesse/airline (Airline 2) to use an actively
  maintained version, while minimizing breaking changes.

  Note, this is a backwards incompatible change, and extensions relying on
  the CliCommandCreator extension point will also need to be updated.

* fix dependency checks where jakarta.inject is now resolved first instead
  of javax.inject, due to Airline 2 using jakarta
2022-02-27 15:19:28 -08:00
Jihoon Son e5ad862665
A new includeAllDimension flag for dimensionsSpec (#12276)
* includeAllDimensions in dimensionsSpec

* doc

* address comments

* unused import and doc spelling
2022-02-25 18:27:48 -08:00
Jason Koch eb1b53b7f8
perf: indexing: Introduce a bulk getValuesInto function to read values (#12105)
* perf: indexing: Introduce a bulk getValuesInto function to read values in bulk

If large number of values are required from DimensionDictionary
during indexing, fetch them all in a single lock/unlock instead of
lock/unlock each individual item.

* refactor: rename key to keys in function args

* fix: check explicitly that argument length on arrays match

* refactor: getValuesInto renamed to getValues, now creates and returns a new T[] rather than filling
2022-02-25 12:19:04 -08:00
Karan Kumar 5794331eb1
Adding new config for disabling group by on multiValue column (#12253)
As part of #12078 one of the followup's was to have a specific config which does not allow accidental unnesting of multi value columns if such columns become part of the grouping key.
Added a config groupByEnableMultiValueUnnesting which can be set in the query context.

The default value of groupByEnableMultiValueUnnesting is true, therefore it does not change the current engine behavior.
If groupByEnableMultiValueUnnesting is set to false, the query will fail if it encounters a multi-value column in the grouping key.
2022-02-16 20:53:26 +05:30
somu-imply eae163a797
Moving in filter check to broker (#12195)
* Moving in filter check to broker

* Adding more unit tests, making error message meaningful

* Spelling and doc changes

* Updating default to -1 and making this feature hide by default. The number of IN filters can grow upto a max limit of 100

* Removing upper limit of 100, updated docs

* Making documentation more meaningful

* Moving check outside to PlannerConfig, updating test cases and adding back max limit

* Updated with some additional code comments

* Missed removing one line during the checkin

* Addressing doc changes and one forbidden API correction

* Final doc change

* Adding a speling exception, correcting a testcase

* Reading entire filter tree to address combinations of ANDs and ORs

* Specifying in docs that, this case works only for ORs

* Revert "Reading entire filter tree to address combinations of ANDs and ORs"

This reverts commit 81ca8f8496.

* Covering a class cast exception and updating docs

* Counting changed

Co-authored-by: Jihoon Son <jihoonson@apache.org>
2022-02-15 20:45:07 -08:00
Jason Koch 26bc4b7345
perf: cache row if it is a transformed row (#12113)
* perf: cache row if it is a transformed row

* perf: cache row if it is a transformed row (also cache DateTime object)
2022-02-15 10:08:41 -08:00
somu-imply 033989eb1d
Adding vectorized time_shift (#12254)
* Adding vectorized time_shift

* Vectorize time shift, addressing review comments

* Remove an unused import
2022-02-11 14:44:52 -08:00
Clint Wylie 3ee66bb492
allow optimizing sql expressions and virtual columns (#12241)
* rework sql planner expression and virtual column handling

* simplify a bit

* add back and deprecate old methods, more tests, fix multi-value string coercion bug and associated tests

* spotbugs

* fix bugs with multi-value string array expression handling

* javadocs and adjust test

* better

* fix tests
2022-02-09 14:55:50 -08:00
Clint Wylie ae71e05fc5
array_concat_agg and array_agg support for array inputs (#12226)
* array_concat_agg and array_agg support for array inputs
changes:
* added array_concat_agg to aggregate arrays into a single array
* added array_agg support for array inputs to make nested array
* added 'shouldAggregateNullInputs' and 'shouldCombineAggregateNullInputs' to fix a correctness issue with STRING_AGG and ARRAY_AGG when merging results, with dual purpose of being an optimization for aggregating

* fix test

* tie capabilities type to legacy mode flag about coercing arrays to strings

* oops

* better javadoc
2022-02-07 19:59:30 -08:00
Gian Merlino de82c611de
Harmonize implementations of "visit" for Exprs from ExprMacros. (#12230)
* Harmonize implementations of "visit" for Exprs from ExprMacros.

Many of them had bugs where they would not visit all of the original
arguments. I don't think this has user-visible consequences right now,
but it's possible it would in a future world where "visit" is used
for more stuff than it is today.

So, this patch all updates all implementations to a more consistent
style that emphasizes reapplying the macro to the shuttled args.

* Test fixes, test coverage, PR review comments.
2022-02-04 08:08:54 -08:00
Clint Wylie a3affe1471
make EncodedKeyComponent constructor public, remove nullable from DimensionIndexer.processRowValsToUnsortedEncodedKeyComponent (#12229) 2022-02-03 15:02:32 -08:00
Kashif Faraz e648b01afb
Improve memory estimates in Aggregator and DimensionIndexer (#12073)
Fixes #12022  

### Description
The current implementations of memory estimation in `OnHeapIncrementalIndex` and `StringDimensionIndexer` tend to over-estimate which leads to more persistence cycles than necessary.

This PR replaces the max estimation mechanism with getting the incremental memory used by the aggregator or indexer at each invocation of `aggregate` or `encode` respectively.

### Changes
- Add new flag `useMaxMemoryEstimates` in the task context. This overrides the same flag in DefaultTaskConfig i.e. `druid.indexer.task.default.context` map
- Add method `AggregatorFactory.factorizeWithSize()` that returns an `AggregatorAndSize` which contains
  the aggregator instance and the estimated initial size of the aggregator
- Add method `Aggregator.aggregateWithSize()` which returns the incremental memory used by this aggregation step
- Update the method `DimensionIndexer.processRowValsToKeyComponent()` to return the encoded key component as well as its effective size in bytes
- Update `OnHeapIncrementalIndex` to use the new estimations only if `useMaxMemoryEstimates = false`
2022-02-03 10:34:02 +05:30
Clint Wylie f9b406c8f2
add backwards compatibility mode for multi-value string array null value coercion (#12210) 2022-01-31 22:38:15 -08:00
Jihoon Son eeed156dc0
Fix compile error in VirtualizedColumnSelectorFactoryTest (#12208) 2022-01-27 17:35:50 -08:00
Gian Merlino 99a5c2f3d3
Harmonize behavior when virtual columns reference each other. (#11955)
* VirtualizedColumnSelectorFactory: Allow virtual columns to reference each other.

This matches the behavior of QueryableIndex and IncrementalIndex based cursors.

* Fixes to getColumnCapabilities.
2022-01-27 14:31:48 -08:00
Karan Kumar 96b3498a40
Grouping on arrays as arrays (#12078)
* init multiValue column group by

* Changing sorting to Lexicographic as default

* Adding initial tests

* 1.Fixing test cases adding
2.Optimized inmem structs

* Linking SQL layer to native layer

* Adding multiDimension support to group by column strategy

* 1. Removing array coercion in Calcite layer
2. Removing ResultRowDeserializer

* 1. Supporting all primitive array types
2. Removing dimension spec as part of columnSelector

* 1. Supporting all primitive array types
2. Removing dimension spec as part of columnSelector

* 1. Checkstyle things
2. Removing flag

* Minor naming things

* CheckStyle Things

* Fixing test case

* Fixing hashing

* 1. Adding the MV function
2. Added few test cases

* 1. Adding MV function test cases

* Adding Selector strategy function test cases

* Fixing ClientQuerySegmentWalkerTest

* Adding GroupByQueryRunnerTest test cases

* Fixing test cases

* Adding few more test cases

* Fixing Exception asset statement and intellij inspection

* Adding null compatibility tests

* Review comments

* Fixing few failing tests

* Fixing few failing tests

* Do no convert to topN Q incase of group by on array

* Fixing checkstyle

* Fixing differences between jdk's class cast exception message

* 1. Fixing ordering if the grouping key is an array

* Fixing DefaultLimitSpec

* Fixing CalciteArraysQueryTest

* Dummy commit for LGTM

* changes:
* only coerce multi-value string null values when `ExpressionPlan.Trait.NEEDS_APPLIED` is set
* correct return type inference for ARRAY_APPEND,ARRAY_PREPEND,ARRAY_SLICE,ARRAY_CONCAT
* fix bug with ExprEval.ofType when actual type of object from binding doesn't match its claimed type

* Review comments

* Fixing test cases

* Fixing spot bugs

* Fixing strict compile

Co-authored-by: Clint Wylie <cwylie@apache.org>
2022-01-25 20:30:56 -08:00
Clint Wylie fce62b2643
fix StringAnyAggregatorFactory to use single value selector for non-existent columns (#12194) 2022-01-25 12:52:30 -08:00
somu-imply cc8b9c0b6e
Handling OOM error in ExpressionVector setup by reducing number of rows (#12186)
* Handling OOM error in ExpressionVector setup by reducing number of rows

* Removing row size to 10K in sanity tests
2022-01-24 08:37:13 -08:00
Clint Wylie e0c4c568cb
fix incorrect ColumnInspector in IncrementalIndex.makeColumnSelectorFactory (#12155) 2022-01-13 18:09:06 -08:00
Clint Wylie f2ce76966c
add EARLIEST_BY/LATEST_BY to make EARLIEST/LATEST function signatures less ambiguous (#12145)
* add EARLIEST_BY/LATEST_BY to make EARLIEST/LATEST function signatures unambiguous

* switcheroo

* EARLIEST_BY/LATEST_BY use timestamp instead of numeric types, update docs

* revert unintended change

* fix docs

* fix docs better
2022-01-12 03:48:53 -08:00
Rohan Garg 81f0aba6cb
Use ListFilteredVirtualColumn for left/fact table expression in join condition (#12127)
* Pass VirtualColumnRegistry in PlannerContext for join expression planning

* Allow for including VCs from join fact table expression

* Optmize MV_FILTER functions to use a VC when in join fact table expression

* fixup! Allow for including VCs from join fact table expression

* Address review comments
2022-01-11 14:47:13 -08:00
imply-cheddar eb0bae49ec
Update PostAggregator to be backwards compat (#12138)
This change mimics what was done in PR #11917 to
fix the incompatibilities produced by #11713. #11917
fixed it with AggregatorFactory by creating default
methods to allow for extensions built against old
jars to still work.  This does the same for PostAggregator
2022-01-11 02:18:14 -08:00
Clint Wylie 7cf9192765
fix delegated smoosh writer and some new facilities for segment writeout medium (#12132)
* fix delegated smoosh writer and some new facilities for segment writeout medium
changes:
* fixed issue with delegated `SmooshedWriter` when writing files that look like paths, causing `NoSuchFileException` exceptions when attempting to open a channel to the file
* `FileSmoosher.addWithSmooshedWriter` when _not_ delegating now checks that it is still open when closing, making it a no-op if already closed (allowing column serializers to add additional files and avoid delegated mode if they are finished writing out their own content and ned to add additional files)
* add `makeChildWriteOutMedium` to `SegmentWriteOutMedium` interface, which allows users of a shared medium to clean up `WriteOutBytes` if they fully control the lifecycle. there are no callers of this yet, adding for future functionality
* `OnHeapByteBufferWriteOutBytes` now can be marked as not open so it `OnHeapMemorySegmentWriteOutMedium` can now behave identically to other medium implementations

* fix to address nit - use AtomicLong
2022-01-10 22:25:19 -08:00
Clint Wylie e583033231
add 'TypeStrategy' to types (#11888)
* add TypeStrategy - value comparators and binary serialization for any TypeSignature
2022-01-10 17:12:14 -08:00
somu-imply c267b65f97
Removing unused processing threadpool on broker (#12070)
* Thread pool for broker

* Updating two tests to improve coverage for new method added

* Updating druidProcessingConfigTest to cover coverage

* Adding missed spelling errors caused in doc

* Adding test to cover lines of new function added
2021-12-21 13:07:53 -08:00
Abhishek Agarwal 5d043cefbc
Fix test in ResponseContextTest (#12077) 2021-12-16 22:51:51 -08:00
Clint Wylie 244c2559e9
fix IncrementalIndex performance regression (#12048)
changes:
* IncrementalIndex is now a ColumnInspector
* fixes performance regression from using map of ColumnCapabilities from IncrementalIndex as a RowSignature
2021-12-09 22:04:32 -08:00
Jonathan Wei 229f82a6f0
Add parse error list API for stream supervisors, use structured object for parse exceptions, simplify parse exception message (#11961)
* Add parse error list API for stream supervisors, simplify parse exception message

* Add input string to parse exception

* Use structured ParseExceptionReport

* Fix tests

* Add test

* PR comments, add ParseExceptionReport equals verifier

* Fix test
2021-12-09 15:42:55 -06:00
Laksh Singla ca260dfef6
Intern RowSignature in DruidSchema to reduce its memory footprint (#12001)
DruidSchema consists of a concurrent HashMap of DataSource -> Segement -> AvailableSegmentMetadata. AvailableSegmentMetadata contains RowSignature of the segment, and for each segment, a new object is getting created. RowSignature is an immutable class, and hence it can be interned, and this can lead to huge savings of memory being used in broker, since a lot of the segments of a table would potentially have same RowSignature.
2021-12-08 15:11:13 +05:30