* Speed up String first/last aggregators when folding isn't needed.
Examines the value column, and disables fold checking via a needsFoldCheck
flag if that column can't possibly contain SerializableLongStringPairs. This
is helpful because it avoids calling getObject on the value selector when
unnecessary; say, because the time selector didn't yield an earlier or later
value.
* PR comments.
* Move fastLooseChop to StringUtils.
* Add HashJoinSegment, a virtual segment for joins.
An initial step towards #8728. This patch adds enough functionality to implement a joining
cursor on top of a normal datasource. It does not include enough to actually do a query. For
that, future patches will need to wire this low-level functionality into the query language.
* Fixups.
* Fix missing format argument.
* Various tests and minor improvements.
* Changes.
* Remove or add tests for unused stuff.
* Fix up package locations.
* Fix double-checked locking in predicate suppliers in BoundDimFilter
* Fix double-checked locking in predicate suppliers in BoundDimFilter
* 1. Use Suppliers.memoize() to initialize and publish singleton.
2. Fix coding style.
* Fix coding style
* Fix double-checked locking bug for predicate suppliers in InDimFilter
* Add FileUtils.createTempDir() and enforce its usage.
The purpose of this is to improve error messages. Previously, the error
message on a nonexistent or unwritable temp directory would be
"Failed to create directory within 10,000 attempts".
* Further updates.
* Another update.
* Remove commons-io from benchmark.
* Fix tests.
* Refactor parallel indexing perfect rollup partitioning
Refactoring to make it easier to later add range partitioning for
perfect rollup parallel indexing. This is accomplished by adding several
new base classes (e.g., PerfectRollupWorkerTask) and new classes for
encapsulating logic that needs to be changed for different partitioning
strategies (e.g., IndexTaskInputRowIteratorBuilder).
The code is functionally equivalent to before except for the following
small behavior changes:
1) PartialSegmentMergeTask: Previously, this task had a priority of
DEFAULT_TASK_PRIORITY. It now has a priority of
DEFAULT_BATCH_INDEX_TASK_PRIORITY (via the new PerfectRollupWorkerTask
base class), since it is a batch index task.
2) ParallelIndexPhaseRunner: A decorator was added to
subTaskSpecIterator to ensure the subtasks are generated with unique
ids. Previously, only tests (i.e., MultiPhaseParallelIndexingTest)
would have this decorator, but this behavior is desired for non-test
code as well.
* Fix forbidden apis and pmd warnings
* Fix analyze dependencies warnings
* Fix IndexTask json and add IT diags
* Fix parallel index supervisor<->worker serde
* Fix TeamCity inspection errors/warnings
* Fix TeamCity inspection errors/warnings again
* Integrate changes with those from #8823
* Address review comments
* Address more review comments
* Fix forbidden apis
* Address more review comments
* Tidy up lifecycle, query, and ingestion logging.
The goal of this patch is to improve the clarity and usefulness of
Druid's logging for cluster operators. For more information, see
https://twitter.com/cowtowncoder/status/1195469299814555648.
Concretely, this patch does the following:
- Changes a lot of INFO logs to DEBUG, and DEBUG to TRACE, with the
goal of reducing redundancy and improving clarity by avoiding
showing rarely-useful log messages. This includes most "starting"
and "stopping" messages, and most messages related to individual
columns.
- Adds new log4j2 templates that show operators how to enabled DEBUG
logging for certain important packages.
- Eliminate stack traces for query errors, unless log level is DEBUG
or more. This is useful because query errors often indicate user
error rather than system error, but dumping stack trace often gave
operators the impression that there was a system failure.
- Adds task id to Appenderator, AppenderatorDriver thread names. In
the default log4j2 configuration, this will put them in log lines
as well. It's very useful if a user is using the Indexer, where
multiple tasks run in the same JVM.
- More consistent terminology when it comes to "sequences" (sets of
segments that are handed-off together by Kafka ingestion) and
"offsets" (cursors in partitions). These terms had been confused in
some log messages due to the fact that Kinesis calls offsets
"sequence numbers".
- Replaces some ugly toString calls with either the JSONification or
something more operator-accessible (like a URL or segment identifier,
instead of JSON object representing the same).
* Adjustments.
* Adjust integration test.
* transformSpec + array expressions
changes:
* added array expression support to transformSpec
* removed ParseSpec.verify since its only use afaict was preventing transform expr that did not replace their input from functioning
* hijacked index task test to test changes
* remove docs about being unsupported
* re-arrange test assert
* unused imports
* imports
* fix tests
* preserve types
* suppress warning, fixes, add test
* formatting
* cleanup
* better list to array type conversion and tests
* fix oops
* use peekable iterator for numeric column selector null checking instead of bitmap.get for those sweet sweet nanoseconds
* remove unused method
* slight optimization i think
* remove clone from wrappers since we do not use and is confusing
* fixes and tests
* int instead of Integer
* fix it
* fixes, more tests
* fix
* SQL: EARLIEST, LATEST aggregators.
I chose these names instead of FIRST, LAST because those are already
reserved functions in Calcite that mean something different. I think
these are also better names anyway.
* Finalify.
* SQL updates.
* Adjust aggregator calls.
* Validations, test updates.
* Review docs.
There is a class of bugs due to the fact that BaseObjectColumnValueSelector
has both "getObject" and "isNull" methods, but in most selector implementations
and most call sites, it is clear that the intent of "isNull" is only to apply
to the primitive getters, not the object getter. This makes sense, because the
purpose of isNull is to enable detection of nulls in otherwise-primitive columns.
Imagine a string column with a numeric selector built on top of it. You would
want it to return isNull = true, so numeric aggregators don't treat it as
all zeroes.
Sometimes this design leads people to accidentally guard non-primitive get
methods with "selector.isNull" checks, which is improper.
This patch has three goals:
1) Fix null-handling bugs that already exist in this class.
2) Make interface and doc changes that reduce the probability of future bugs.
3) Fix other, unrelated bugs I noticed in the stringFirst and stringLast
aggregators while fixing null-handling bugs. I thought about splitting this
into its own patch, but it ended up being tough to split from the
null-handling fixes.
For (1) the fixes are,
- Fix StringFirst and StringLastAggregatorFactory to stop guarding getObject
calls on isNull, by no longer extending NullableAggregatorFactory. Now uses
-1 as a sigil value for null, to differentiate nulls and empty strings.
- Fix ExpressionFilter to stop guarding getObject calls on isNull. Also, use
eval.asBoolean() to avoid calling getLong on the selector after already
calling getObject.
- Fix ObjectBloomFilterAggregator to stop guarding DimensionSelector calls
on isNull. Also, refactored slightly to avoid the overhead of calling
getObject followed by another getter (see BloomFilterAggregatorFactory for
part of this).
For (2) the main changes are,
- Remove the "isNull" method from BaseObjectColumnValueSelector.
- Clarify "isNull" doc on BaseNullableColumnValueSelector.
- Rename NullableAggregatorFactory -> NullbleNumericAggregatorFactory to emphasize
that it only works on aggregators that take numbers as input.
- Similar naming changes to the Aggregator, BufferAggregator, and AggregateCombiner.
- Similar naming changes to helper methods for groupBy, ValueMatchers, etc.
For (3) the other fixes for StringFirst and StringLastAggregatorFactory are,
- Fixed buffer overrun in the buffer aggregators when some characters in the string
code into more than one byte (the old code used "substring" to apply a byte limit,
which is bad). I did this by introducing a new StringUtils.toUtf8WithLimit method.
- Fixed weird IncrementalIndex logic that led to reading nulls for the timestamp.
- Adjusted weird StringFirst/Last logic that worked around the weird IncrementalIndex
behavior.
- Refactored to share code between the four aggregators.
- Improved test coverage.
- Made the base stringFirst, stringLast aggregators adaptive, and streamlined the
xFold versions into aliases. The adaptiveness is similar to how other aggregators
like hyperUnique work.
* sketch of broker parallel merges done in small batches on fork join pool
* fix non-terminating sequences, auto compute parallelism
* adjust benches
* adjust benchmarks
* now hella more faster, fixed dumb
* fix
* remove comments
* log.info for debug
* javadoc
* safer block for sequence to yielder conversion
* refactor LifecycleForkJoinPool into LifecycleForkJoinPoolProvider which wraps a ForkJoinPool
* smooth yield rate adjustment, more logs to help tune
* cleanup, less logs
* error handling, bug fixes, on by default, more parallel, more tests
* remove unused var
* comments
* timeboundary mergeFn
* simplify, more javadoc
* formatting
* pushdown config
* use nanos consistently, move logs back to debug level, bit more javadoc
* static terminal result batch
* javadoc for nullability of createMergeFn
* cleanup
* oops
* fix race, add docs
* spelling, remove todo, add unhandled exception log
* cleanup, revert unintended change
* another unintended change
* review stuff
* add ParallelMergeCombiningSequenceBenchmark, fixes
* hyper-threading is the enemy
* fix initial start delay, lol
* parallelism computer now balances partition sizes to partition counts using sqrt of sequence count instead of sequence count by 2
* fix those important style issues with the benchmarks code
* lazy sequence creation for benchmarks
* more benchmark comments
* stable sequence generation time
* update defaults to use 100ms target time, 4096 batch size, 16384 initial yield, also update user docs
* add jmh thread based benchmarks, cleanup some stuff
* oops
* style
* add spread to jmh thread benchmark start range, more comments to benchmarks parameters and purpose
* retool benchmark to allow modeling more typical heterogenous heavy workloads
* spelling
* fix
* refactor benchmarks
* formatting
* docs
* add maxThreadStartDelay parameter to threaded benchmark
* why does catch need to be on its own line but else doesnt
* remove select query
* thanks teamcity
* oops
* oops
* add back a SelectQuery class that throws RuntimeExceptions linking to docs
* adjust text
* update docs per review
* deprecated
* Stateful auto compaction
* javaodc
* add removed test back
* fix test
* adding indexSpec to compactionState
* fix build
* add lastCompactionState
* address comments
* extract CompactionState
* fix doc
* fix build and test
* Add a task context to store compaction state; add javadoc
* fix it test
* groupBy query: optional limit push down to segment scan
* make segment level limit push down configurable
* fix teamcity errors
* fix segment limit pushdown flag handling on query level config override
* use equals for comparator check
* fix sql and null handling
* fix unused imports
* handle null offset in NullableValueGroupByColumnSelectorStrategy for buffer comparator similar to RowBasedGrouperHelper.NullableRowBasedKeySerdeHelper
* add timeout support for JsonParserIterator init future
* add queryId
* should be less than 1
* fix
* fix npe
* fix lgtm
* adjust exception, nullable
* fix test
* refactor
* revert queryId change
* add log.warn to tie exception to json parser iterator
* Fix dependency analyze warnings
Update the maven dependency plugin to the latest version and fix all
warnings for unused declared and used undeclared dependencies in the
compile scope. Added new travis job to add the check to CI. Also fixed
some source code files to use the correct packages for their imports and
updated druid-forbidden-apis to prevent regressions.
* Address review comments
* Adjust scope for org.glassfish.jaxb:jaxb-runtime
* Fix dependencies for hdfs-storage
* Consolidate netty4 versions
* update DimensionDictionarySelector.getValueCardinality() javadoc
* unknown cardinality in StringDictionaryEncodedColumn dim selector
* revert StringDictionaryEncodedColumn change as that fails GroupBy-v1 execution for many working queries
* fix/add more comments
* string column handling for long min/max/sum aggregators
* add apache license to new files
* use 'L' as suffix for long literal instead of 'l'
* return null in ParallelCombiner.SettableColumnSelectorFactory.getColumnCapabilities(String) as is required by contract of ColumnSelectorFactory interface
* fix more tests
* LoggingEmitter: print event as json
* use DefaultRequestLogEventBuilderFactory in emitting request logger by default
* print context in query metric as json
* removed unused jsonMapper from DefaultQueryMetrics
* add comment
* remove change to DefaultRequestLogEventBuilderFactory.java
* Fallback to parsing classpath for hadoop task in Java 9+
In Java 9 and above we cannot assume that the system classloader is an
instance of URLClassLoader. This change adds a fallback method to parse
the system classpath in that case, and adds a unit test to validate it matches
what JDK8 would do.
Note: This has not been tested in an actual hadoop setup, so this is mostly
to help us pass unit tests.
* Remove granularity test of dubious value
One of our granularity tests relies on system classloader being a URLClassLoaders to
catch a bug related to class initialization and static initializers using a subclass (see
#2979)
This test was added to catch a potential regression, but it assumes we would add back
the same type of static initializers to this specific class, so it seems to be of dubious value
as a unit test and mostly serves to illustrate the bug.
relates to #5589
When building column/dimension selectors, calling computeIfAbsent can
cause the applied function to modify the same cache through virtual
column references. The JDK11 map implementation detects this change and
will throw an exception.
This fix – while not as elegant – breaks the single call into two
steps to avoid this problem.
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* check ctyle for constant field name
* merging with upstream
* review-1
* unknow changes
* unknow changes
* review-2
* merging with master
* review-2 1 changes
* review changes-2 2
* bug fix
* use Number instead of long for response context to be forgiving of json serde to int or long
* test that encounters issue without fix
* now with more test
* is ints
* Enable code coverage
Code coverage was disabled via
https://github.com/apache/incubator-druid/pull/3122 due to an issue with
cobertura in Travis CI. Switch code coverage tool from cobertura to
jacoco to avoid issue and re-enable coveralls for Travis CI.
* Exclude non-production code
* Exclude benchmark generated code
* Exclude DruidTestRunnerFactory
* make double sum/min/max agg work on string columns
* style and compilation fixes
* fix tests
* address review comments
* add comment on SimpleDoubleAggregatorFactory
* make checkstyle happy
* Refactored ResponseContext and aggregated its keys into Enum
* Added unit tests for ResponseContext and refactored the serialization
* Removed unused methods
* Fixed code style
* Fixed code style
* Fixed code style
* Made SerializationResult static
* Updated according to the PR discussion:
Renamed an argument
Updated comparator
Replaced Pair usage with Map.Entry
Added a comment about quadratic complexity
Removed boolean field with an expression
Renamed SerializationResult field
Renamed the method merge to add and renamed several context keys
Renamed field and method related to scanRowsLimit
Updated a comment
Simplified a block of code
Renamed a variable
* Added JsonProperty annotation to renamed ScanQuery field
* Extension-friendly context key implementation
* Refactored ResponseContext: updated delegate type, comments and exceptions
Reducing serialized context length by removing some of its'
collection elements
* Fixed tests
* Simplified response context truncation during serialization
* Extracted a method of removing elements from a response context and
added some comments
* Fixed typos and updated comments
* Add IPv4 druid expressions
New druid expressions for filtering IPv4 addresses:
- ipv4address_match: Check if IP address belongs to a subnet
- ipv4address_parse: Convert string IP address to long
- ipv4address_stringify: Convert long IP address to string
These expressions operate on IP addresses represented as either strings
or longs, so that they can be applied to dimensions with mixed
representation of IP addresses. The filtering is more efficient when
operating on IP addresses as longs. In other words, the intended use
case is:
1) Use ipv4address_parse to convert to long at ingestion time
2) Use ipv4address_match to filter (on longs) at query time
3) Use ipv4adress_stringify to convert to (readable) string at query
time
* Fix licenses and null handling
* Simplify IPv4 expressions
* Fix tests
* Fix check for valid ipv4 address string
* GroupBy array-based result rows.
Fixes#8118; see that proposal for details.
Other than the GroupBy changes, the main other "interesting" classes are:
- ResultRow: The array-based result type.
- BaseQuery: T is no longer required to be Comparable.
- QueryToolChest: Adds "decorateObjectMapper" to enable query-aware serialization
and deserialization of result rows (necessary due to their positional nature).
- QueryResource: Uses the new decoration functionality.
- DirectDruidClient: Also uses the new decoration functionality.
- QueryMaker (in Druid SQL): Modifications to read ResultRows.
These classes weren't changed, but got some new javadocs:
- BySegmentQueryRunner
- FinalizeResultsQueryRunner
- Query
* Adjustments for TC stuff.
* Fix dependency analyze warnings
Update the maven dependency plugin to the latest version and fix all
warnings for unused declared and used undeclared dependencies in the
compile scope. Added new travis job to add the check to CI. Also fixed
some source code files to use the correct packages for their imports.
* Fix licenses and dependencies
* Fix licenses and dependencies again
* Fix integration test dependency
* Address review comments
* Fix unit test dependencies
* Fix integration test dependency
* Fix integration test dependency again
* Fix integration test dependency third time
* Fix integration test dependency fourth time
* Fix compile error
* Fix assert package
* remove unecessary lock in ForegroundCachePopulator leading to a lot of contention
* mutableboolean, javadocs,document some cache configs that were missing
* more doc stuff
* adjustments
* remove background documentation
* 1. Added TimestampExtractExprMacro.Unit for MILLISECOND 2. expr eval for MILLISECOND 3. Added a test case to test extracting millisecond from expression. #7935
* 1. Adding DATASOURCE4 in tests. 2. Adding test TimeExtractWithMilliseconds
* Fixing testInformationSchemaTables test
* Fixing failing tests in DruidAvaticaHandlerTest
* Adding cannotVectorize() call before the test
* Extract time function - Adding support for MICROSECOND, ISODOW, ISOYEAR and CENTURY time units, documentation changes.
* Adding MILLISECOND in test case
* Adding support DECADE and MILLENNIUM, updating test case and documentation
* Fixing expression eval for DECADE and MILLENIUM
* add CachingClusteredClient benchmark, refactor some stuff
* revert WeightedServerSelectorStrategy to ConnectionCountServerSelectorStrategy and remove getWeight since felt artificial, default mergeResults in toolchest implementation for topn, search, select
* adjust javadoc
* adjustments
* oops
* use it
* use BinaryOperator, remove CombiningFunction, use Comparator instead of Ordering, other review adjustments
* rename createComparator to createResultComparator, fix typo, firstNonNull nullable parameters
* doc updates and changes to use the CollectionUtils.mapValues utility method
* Add Structural Search patterns to intelliJ
* refactoring from PR comments
* put -> putIfAbsent
* do single key lookup
* Benchmarks: New SqlBenchmark, add caching & vectorization to some others.
- Introduce a new SqlBenchmark geared towards benchmarking a wide
variety of SQL queries. Rename the old SqlBenchmark to
SqlVsNativeBenchmark.
- Add (optional) caching to SegmentGenerator to enable easier
benchmarking of larger segments.
- Add vectorization to FilteredAggregatorBenchmark and GroupByBenchmark.
* Query vectorization.
This patch includes vectorized timeseries and groupBy engines, as well
as some analogs of your favorite Druid classes:
- VectorCursor is like Cursor. (It comes from StorageAdapter.makeVectorCursor.)
- VectorColumnSelectorFactory is like ColumnSelectorFactory, and it has
methods to create analogs of the column selectors you know and love.
- VectorOffset and ReadableVectorOffset are like Offset and ReadableOffset.
- VectorAggregator is like BufferAggregator.
- VectorValueMatcher is like ValueMatcher.
There are some noticeable differences between vectorized and regular
execution:
- Unlike regular cursors, vector cursors do not understand time
granularity. They expect query engines to handle this on their own,
which a new VectorCursorGranularizer class helps with. This is to
avoid too much batch-splitting and to respect the fact that vector
selectors are somewhat more heavyweight than regular selectors.
- Unlike FilteredOffset, FilteredVectorOffset does not leverage indexes
for filters that might partially support them (like an OR of one
filter that supports indexing and another that doesn't). I'm not sure
that this behavior is desirable anyway (it is potentially too eager)
but, at any rate, it'd be better to harmonize it between the two
classes. Potentially they should both do some different thing that
is smarter than what either of them is doing right now.
- When vector cursors are created by QueryableIndexCursorSequenceBuilder,
they use a morphing binary-then-linear search to find their start and
end rows, rather than linear search.
Limitations in this patch are:
- Only timeseries and groupBy have vectorized engines.
- GroupBy doesn't handle multi-value dimensions yet.
- Vector cursors cannot handle virtual columns or descending order.
- Only some filters have vectorized matchers: "selector", "bound", "in",
"like", "regex", "search", "and", "or", and "not".
- Only some aggregators have vectorized implementations: "count",
"doubleSum", "floatSum", "longSum", "hyperUnique", and "filtered".
- Dimension specs other than "default" don't work yet (no extraction
functions or filtered dimension specs).
Currently, the testing strategy includes adding vectorization-enabled
tests to TimeseriesQueryRunnerTest, GroupByQueryRunnerTest,
GroupByTimeseriesQueryRunnerTest, CalciteQueryTest, and all of the
filtering tests that extend BaseFilterTest. In all of those classes,
there are some test cases that don't support vectorization. They are
marked by special function calls like "cannotVectorize" or "skipVectorize"
that tell the test harness to either expect an exception or to skip the
test case.
Testing should be expanded in the future -- a project in and of itself.
Related to #3011.
* WIP
* Adjustments for unused things.
* Adjust javadocs.
* DimensionDictionarySelector adjustments.
* Add "clone" to BatchIteratorAdapter.
* ValueMatcher javadocs.
* Fix benchmark.
* Fixups post-merge.
* Expect exception on testGroupByWithStringVirtualColumn for IncrementalIndex.
* BloomDimFilterSqlTest: Tag two non-vectorizable tests.
* Minor adjustments.
* Update surefire, bump up Xmx in Travis.
* Some more adjustments.
* Javadoc adjustments
* AggregatorAdapters adjustments.
* Additional comments.
* Remove switching search.
* Only missiles.
Make static imports forbidden in tests and remove all occurrences to be
consistent with the non-test code.
Also, various changes to files affected by above:
- Reformat to adhere to druid style guide
- Fix various IntelliJ warnings
- Fix various SonarLint warnings (e.g., the expected/actual args to
Assert.assertEquals() were flipped)
* GroupBy: Fix improper uses of StorageAdapter#getColumnCapabilities.
1) A usage in "isArrayAggregateApplicable" that would potentially incorrectly use
array-based aggregation on a virtual column that shadows a real column.
2) A usage in "process" that would potentially use the more expensive multi-value
aggregation path on a singly-valued virtual column. (No correctness issue, but
a performance issue.)
* Add addl javadoc.
* ExpressionVirtualColumn: Set multi-value flag.
* more sql support for expression array functions
* prepend/slice
* doc fixes
* fix imports
* fix tests
* add null numeric expr for proper conversions between ExprEval and Expr and back to ExprEval
* re-arrange
* imports :(
* add append/prepend test
* array support for expression language for multi-value string columns
* fix tests?
* fixes
* more tests
* fixes
* cleanup
* more better, more test
* ignore inspection
* license
* license fix
* inspection
* remove dumb import
* more better
* some comments
* add expr rewrite for arrayfn args for more magic, tests
* test stuff
* more tests
* fix test
* fix test
* castfunc can deal with arrays
* needs more empty array
* more tests, make cast to long array more forgiving
* refactor
* simplify ExprMacro Expr implementations with base classes in core
* oops
* more test
* use Shuttle for Parser.flatten, javadoc, cleanup
* fixes and more tests
* unused import
* fixes
* javadocs, cleanup, refactors
* fix imports
* more javadoc
* more javadoc
* more
* more javadocs, nonnullbydefault, minor refactor
* markdown fix
* adjustments
* more doc
* move initial filter out
* docs
* map empty arg lambda, apply function argument validation
* check function args at parse time instead of eval time
* more immutable
* more more immutable
* clarify grammar
* fix docs
* empty array is string test, we need a way to make arrays better maybe in the future, or define empty arrays as other types..
* AggregatorUtil should cache parsed expression to avoid memory problem (OOM/FGC) when Expression is used in metricsSpec
* remove debug log check in Parser.parse
* remove cache and use suppliers.memorize
* Add checkstyle for "Local variable names shouldn't start with capital"
* Adjust some local variables to constants
* Replace StringUtils.LINE_SEPARATOR with System.lineSeparator()
* VirtualColumn updates for exploiting base column internal structure
* unit tests for virtual column interface updates
* groupBy needs to use VirtualizedColumnSelectorFactory if outer query in
nested groupBy has virtual columns.
* fix strict compile checks
* fix teamcity build errors
* add comment explaining useVirtualizedColumnSelectorFactory flag in RowBasedGrouperHelper.createGrouperAccumulatorPair(..)
* make ComplexColumn an interface and ExtensionPoint
* incorporate review comments
* make ColumnValueSelector @ExtensionPoint
* more java docs
* add close() method to ComplexColumn interface
* Bump Checkstyle to 8.20
Moderate severity vulnerability that affects:
com.puppycrawl.tools:checkstyle
Checkstyle prior to 8.18 loads external DTDs by default,
which can potentially lead to denial of service attacks
or the leaking of confidential information.
Affected versions: < 8.18
* Oops, missed one
* Oops, missed a few
* Set direct memory if unable to detect JVM config
Java 9 and above prevents us from detecting the maximum available direct
memory.
This change adds a fallback method to use at most 25% of maximum heap
size, which should be a reasonable default.
Unless -XX:MaxDirectMemorySize is set, recent JVMs will default maximum
direct memory to match the maximum heap size, so this should work out of
the box in most cases. For completeness we print instructions in the log
to explain how to adjust settings if necessary.
* skip test rather than succeeding
* reword log message
Co-Authored-By: Himanshu <g.himanshu@gmail.com>
* First set of changes for tDigest histogram
* Add license
* Address code review comments
* Add a doc page for new T-Digest sketch aggregators. Minor code cleanup and comments.
* Remove synchronization from BufferAggregators. Address code review comments
* Fix typo
* Fix exception when using complex aggs with result level caching
* Add test comments
* checkstyle
* Add helper function for getting aggs from cache
* Move method to CacheStrategy
* Revert QueryToolChest changes
* Update test comments
* update easymock / powermock for to 4.0.2 / 2.0.2 for JDK11 support
* update tests to use new easymock interfaces
* fix tests failing due to easymock fixes
* remove dependency on jmockit
* fix race condition in ResourcePoolTest
* Java 9 compatible specialized class compilation
We currently use Unsafe.defineClass to compile specialized classes,
which has been removed in Java 9 and above. This change switches to
MethodHandles.Lookup.defineClass at runtime, which provides similar
functionality in newer JDK versions.
* add comments
* fix incorrect comment
* add unsafe utility class
* make comments java-doc style
* fix checkstyle errors
* rename unsafe -> unsafeutil
* move defineClass method to utility class
* rename unsafeutil -> unsafeutils to match other utility class names
* remove extra lookup method
* add utiliy class docs
* more comments
* minor comments and formatting
* Initial commit
* Added test for int to long conversion
* Add appenderator test for realtime scan query
* get rid of todo
* Fix forbidden apis
* Jon's recommendations
* Formatting
* Make JavaScript and XML errors non-TeamCity errors; Update JavaScript language level to ES6 in IntelliJ settings
* Add license comment to assembly-2.0.0.xsd
* Add .idea/README.md with comments
* Add SegmentDescriptor interval in the hash while calculating Etag
* Add computeResultLevelCacheKey to CacheStrategy
Make HavingSpec cacheable and implement getCacheKey for subclasses
Add unit tests for computeResultLevelCacheKey
* Add more tests
* Use CacheKeyBuilder for HavingSpec's getCacheKey
* Initialize aggregators map to avoid NPE
* adjust cachekey builder for HavingSpec to ignore aggregators
* unused import
* PR comments
* Update scan query runner factory to accept SpecificSegmentSpec
* nit
* Sorry travis
* Improve logging and fix doc
* Bug fix
* Friendlier error msgs and tests to cover bug
* Address Gian's comments
* Fix doc
* Added tests for empty and null column list
* Style
* Fix checking wrong order (looking at query param when it should be
looking at the null-handled order)
* Add test case for null order
* Fix ScanQueryRunnerTest
* Forbidden APIs fixed
* refactor lookups to be more chill to router
* remove accidental change
* fix and combine LookupIntrospectionResourceTest
* fix inspection
* rename RouterLookupModule to LookupSerdeModule and RouterLookupExtractorFactoryContainerProvider to NoopLookupExtractorFactoryContainerProvider
* make comment generic
* use ConfigResourceFilter instead of StateResourceFilter
* fix indentation
* unused import
* another unused import
* refactor some stuff into processing module, split up LookupModule.java classes into their own files
* Moved Scan Builder to Druids class and started on Scan Benchmark setup
* Need to form queries
* It runs.
* Stuff for time-ordered scan query
* Move ScanResultValue timestamp comparator to a separate class for testing
* Licensing stuff
* Change benchmark
* Remove todos
* Added TimestampComparator tests
* Change number of benchmark iterations
* Added time ordering to the scan benchmark
* Changed benchmark params
* More param changes
* Benchmark param change
* Made Jon's changes and removed TODOs
* Broke some long lines into two lines
* nit
* Decrease segment size for less memory usage
* Wrote tests for heapsort scan result values and fixed bug where iterator
wasn't returning elements in correct order
* Wrote more tests for scan result value sort
* Committing a param change to kick teamcity
* Fixed codestyle and forbidden API errors
* .
* Improved conciseness
* nit
* Created an error message for when someone tries to time order a result
set > threshold limit
* Set to spaces over tabs
* Fixing tests WIP
* Fixed failing calcite tests
* Kicking travis with change to benchmark param
* added all query types to scan benchmark
* Fixed benchmark queries
* Renamed sort function
* Added javadoc on ScanResultValueTimestampComparator
* Unused import
* Added more javadoc
* improved doc
* Removed unused import to satisfy PMD check
* Small changes
* Changes based on Gian's comments
* Fixed failing test due to null resultFormat
* Added config and get # of segments
* Set up time ordering strategy decision tree
* Refactor and pQueue works
* Cleanup
* Ordering is correct on n-way merge -> still need to batch events into
ScanResultValues
* WIP
* Sequence stuff is so dirty :(
* Fixed bug introduced by replacing deque with list
* Wrote docs
* Multi-historical setup works
* WIP
* Change so batching only occurs on broker for time-ordered scans
Restricted batching to broker for time-ordered queries and adjusted
tests
Formatting
Cleanup
* Fixed mistakes in merge
* Fixed failing tests
* Reset config
* Wrote tests and added Javadoc
* Nit-change on javadoc
* Checkstyle fix
* Improved test and appeased TeamCity
* Sorry, checkstyle
* Applied Jon's recommended changes
* Checkstyle fix
* Optimization
* Fixed tests
* Updated error message
* Added error message for UOE
* Renaming
* Finish rename
* Smarter limiting for pQueue method
* Optimized n-way merge strategy
* Rename segment limit -> segment partitions limit
* Added a bit of docs
* More comments
* Fix checkstyle and test
* Nit comment
* Fixed failing tests -> allow usage of all types of segment spec
* Fixed failing tests -> allow usage of all types of segment spec
* Revert "Fixed failing tests -> allow usage of all types of segment spec"
This reverts commit ec470288c7.
* Revert "Merge branch '6088-Time-Ordering-On-Scans-N-Way-Merge' of github.com:justinborromeo/incubator-druid into 6088-Time-Ordering-On-Scans-N-Way-Merge"
This reverts commit 57033f36df, reversing
changes made to 8f01d8dd16.
* Check type of segment spec before using for time ordering
* Fix bug in numRowsScanned
* Fix bug messing up count of rows
* Fix docs and flipped boolean in ScanQueryLimitRowIterator
* Refactor n-way merge
* Added test for n-way merge
* Refixed regression
* Checkstyle and doc update
* Modified sequence limit to accept longs and added test for long limits
* doc fix
* Implemented Clint's recommendations
* Throw caught exception.
* Throw caught exceptions.
* Related checkstyle rule is added to prevent further bugs.
* RuntimeException() is used instead of Throwables.propagate().
* Missing import is added.
* Throwables are propogated if possible.
* Throwables are propogated if possible.
* Throwables are propogated if possible.
* Throwables are propogated if possible.
* * Checkstyle definition is improved.
* Throwables.propagate() usages are removed.
* Checkstyle pattern is changed for only scanning "Throwables.propagate(" instead of checking lookbehind.
* Throwable is kept before firing a Runtime Exception.
* Fix unused assignments.
* Locale problem is fixed which fails tests.
* Forbidden apis definition is improved to prevent using com.ibm.icu.text.SimpleDateFormat and com.ibm.icu.text.DateFormatSymbols without using any Locale defined.
* Error message is improved.
Similar to other bugs fixed in #6220, but this one was missed. This bug would
cause "extraction" dimensionSpecs on the "__time" column with non-STRING
outputTypes to potentially be output as STRING sometimes instead of LONG,
causing incompletely merged results.
For selectors with internal caches (like SingleScanTimeDimensionSelector,
SingleLongInputCachingExpressionColumnValueSelector, etc) we can get a perf
boost and memory usage decrease by sharing selectors.
* Added checkstyle for "Methods starting with Capital Letters" and changed the method names violating this.
* Un-abbreviate the method names in the calcite tests
* Fixed checkstyle errors
* Changed asserts position in the code
* Moved Scan Builder to Druids class and started on Scan Benchmark setup
* Need to form queries
* It runs.
* Remove todos
* Change number of benchmark iterations
* Changed benchmark params
* More param changes
* Made Jon's changes and removed TODOs
* Broke some long lines into two lines
* Decrease segment size for less memory usage
* Committing a param change to kick teamcity
* Prohibit assigning concurrent maps into Map-types variables and fields; Fix a race condition in CoordinatorRuleManager; improve logic in DirectDruidClient and ResourcePool
* Enforce that if compute(), computeIfAbsent(), computeIfPresent() or merge() is called on a ConcurrentHashMap, it's stored in a ConcurrentHashMap-typed variable, not ConcurrentMap; add comments explaining get()-before-computeIfAbsent() optimization; refactor Counters; fix a race condition in Intialization.java
* Remove unnecessary comment
* Checkstyle
* Fix getFromExtensions()
* Add a reference to the comment about guarded computeIfAbsent() optimization; IdentityHashMap optimization
* Fix UriCacheGeneratorTest
* Workaround issue with MaterializedViewQueryQueryToolChest
* Strengthen Appenderator's contract regarding concurrency
* fix issue with SingleLongInputCachingExpressionColumnValueSelector when sql compatible null handling enabled
* add test with doubles to show same behavior for floats/doubles that lack the optimization of longs
* simplify
* fix import
* blooming aggs
* partially address review
* fix docs
* minor test refactor after rebase
* use copied bloomkfilter
* add ByteBuffer methods to BloomKFilter to allow agg to use in place, simplify some things, more tests
* add methods to BloomKFilter to get number of set bits, use in comparator, fixes
* more docs
* fix
* fix style
* simplify bloomfilter bytebuffer merge, change methods to allow passing buffer offsets
* oof, more fixes
* more sane docs example
* fix it
* do the right thing in the right place
* formatting
* fix
* avoid conflict
* typo fixes, faster comparator, docs for comparator behavior
* unused imports
* use buffer comparator instead of deserializing
* striped readwrite lock for buffer agg, null handling comparator, other review changes
* style fixes
* style
* remove sync for now
* oops
* consistency
* inspect runtime shape of selector instead of selector plus, static comparator, add inner exception on serde exception
* CardinalityBufferAggregator inspect selectors instead of selectorPluses
* fix style
* refactor away from using ColumnSelectorPlus and ColumnSelectorStrategyFactory to instead use specialized aggregators for each supported column type, other review comments
* adjustment
* fix teamcity error?
* rename nil aggs to empty, change empty agg constructor signature, add comments
* use stringutils base64 stuff to be chill with master
* add aggregate combiner, comment
* * Add few methods about base64 into StringUtils
* Use `java.util.Base64` instead of others
* Add org.apache.commons.codec.binary.Base64 & com.google.common.io.BaseEncoding into druid-forbidden-apis
* Rename encodeBase64String & decodeBase64String
* Update druid-forbidden-apis
* Replacing Math.random() with ThreadLocalRandom.current().nextDouble()
* Added java.lang.Math#random() in forbidden-apis.txt
* Minor change in the message - druid-forbidden-apis.txt
* use SqlLifecyle to manage sql execution, add sqlId
* add sql request logger
* fix UT
* rename sqlId to sqlQueryId, sql/time to sqlQuery/time, etc
* add docs and more sql request logger impls
* add UT for http and jdbc
* fix forbidden use of com.google.common.base.Charsets
* fix UT in QuantileSqlAggregatorTest, supressed unused warning of getSqlQueryId
* do not use default method in QueryMetrics interface
* capitalize 'sql' everywhere in the non-property parts of the docs
* use RequestLogger interface to log sql query
* minor bugfixes and add switching request logger
* add filePattern configs for FileRequestLogger
* address review comments, adjust sql request log format
* fix inspection error
* try SuppressWarnings("RedundantThrows") to fix inspection error on ComposingRequestLoggerProvider
* Use multi-guava version friendly direct executor implementation
* Don't use a singleton
* Fix strict compliation complaints
* Copy Guava's DirectExecutor
* Fix javadoc
* Imports are the devil
* make logs that are only useful for debugging be at debug level so log volume is much more chill
* info level messages for total merge buffer allocated/free
* more chill compaction logs
* FileUtils: Sync directory entry too on writeAtomically.
See the fsync(2) man page for why this is important:
https://linux.die.net/man/2/fsync
This also plumbs CompressionUtils's "zip" function through
writeAtomically, so the code for handling atomic local filesystem
writes is all done in the same place.
* Remove unused import.
* Avoid FileOutputStream.
* Allow non-atomic writes to overwrite.
* Add some comments. And no need to flush an unbuffered stream.
* Double-checked locking bug is fixed.
* @Nullable is removed since there is no need to use along with @MonotonicNonNull.
* Static import is removed.
* Lazy initialization is implemented.
* Local variables used instead of volatile ones.
* Local variables used instead of volatile ones.
* Fix travis timeout in BufferHashGrouperTest
* adjust buffer size
* adjust bufferSize and loadFactor
* increase memory
* add debug code
* cat error
* after script
* print logs
* print per 2 min
* use direct mem
* clean up
* autosize processing buffers based on direct memory sizing
* remove oops, more test
* max 1gb autosize buffers, test, start of docs
* fix oops
* revert accidental change
* print buffer size in exception
* change the things
Not putting this to 0.13 milestone because the found bugs are not critical (one is a harmless DI config duplicate, and another is in a benchmark.
Change in `DumpSegment` is just an indentation change.
* Add checkstyle rules about imports and empty lines between members
* Add suppressions
* Update Eclipse import order
* Add empty line
* Fix StatsDEmitter
* Expressions: Fix improper supplier reuse with missing columns.
ExpressionSelectors has an optimization that skips building a Map
when there is only one input supplier. However, this optimization
should not be used in the case where the is one input supplier but
more than one input identifier (which can happen when only one
input identifier corresponds to an actual column).
Fixes#6556.
* Add underscores to statics.
* Optimization for expressions that hit a single long column.
There was previously a single-long-input optimization that applied only
to the time column. These have been combined together. Also adds
type-specific value caching to ExprEval, which allowed simplifying
the SingleLongInputCachingExpressionColumnValueSelector code.
* Add more benchmarks.
* Don't use LRU cache for __time.
* Simplify a bit.
* Let the cache grow.
* Prohibit some guava collection APIs and use JDK APIs directly
* reset files that changed by accident
* sort codestyle/druid-forbidden-apis.txt alphabetically
* add PrefixFilteredDimensionSpec for multi-value dimensions
* add docs for PrefixFilteredDimensionSpec
* remove unnecessary null handling
* add null check to the result of NullHandling
* Add optional `name` to top level of FilteredAggregatorFactory
* Add compat constructor for tests
* Address comments
* Add equals and hash code updates
* Rename test
* Fix imports and code style
This PR accumulates many refactorings and small improvements that I did while preparing the next change set of https://github.com/druid-io/druid/projects/2. I finally decided to make them a separate PR to minimize the volume of the main PR.
Some of the changes:
- Renamed confusing "Generic Column" term to "Numeric Column" (what it actually implies) in many class names.
- Generified `ComplexMetricExtractor`
* Added backpressure metric
* Updated channelReadable to AtomicBoolean and fixed broken test
* Moved backpressure metric logic to NettyHttpClient
* Fix placement of calculating backPressureDuration
Possibly related to https://github.com/apache/incubator-druid/issues/4937
--------
There is currently a race condition in IncrementalIndexStorageAdapter that can lead to exceptions like the following, when running queries with filters on String dimensions that hit realtime tasks:
```
org.apache.druid.java.util.common.ISE: id[5] >= maxId[5]
at org.apache.druid.segment.StringDimensionIndexer$1IndexerDimensionSelector.lookupName(StringDimensionIndexer.java:591)
at org.apache.druid.segment.StringDimensionIndexer$1IndexerDimensionSelector$2.matches(StringDimensionIndexer.java:562)
at org.apache.druid.segment.incremental.IncrementalIndexStorageAdapter$IncrementalIndexCursor.advance(IncrementalIndexStorageAdapter.java:284)
```
When the `filterMatcher` is created in the constructor of `IncrementalIndexStorageAdapter.IncrementalIndexCursor`, `StringDimensionIndexer.makeDimensionSelector` gets called eventually, which calls:
```
final int maxId = getCardinality();
...
@Override
public int getCardinality()
{
return dimLookup.size();
}
```
So `maxId` is set to the size of the dictionary at the time that the `filterMatcher` is created.
However, the `maxRowIndex` which is meant to prevent the Cursor from returning rows that were added after the Cursor was created (see https://github.com/apache/incubator-druid/pull/4049) is set after the `filterMatcher` is created.
If rows with new dictionary values are added after the `filterMatcher` is created but before `maxRowIndex` is set, then it is possible for the Cursor to return rows that contain the new values, which will have `id >= maxId`.
This PR sets `maxRowIndex` before creating the `filterMatcher` to prevent rows with unknown dictionary IDs from being passed to the `filterMatcher`.
-----------
The included test triggers the error with a custom Filter + DruidPredicateFactory.
The DimensionSelector for predicate-based filter matching is created here in `Filters.makeValueMatcher`:
```
public static ValueMatcher makeValueMatcher(
final ColumnSelectorFactory columnSelectorFactory,
final String columnName,
final DruidPredicateFactory predicateFactory
)
{
final ColumnCapabilities capabilities = columnSelectorFactory.getColumnCapabilities(columnName);
// This should be folded into the ValueMatcherColumnSelectorStrategy once that can handle LONG typed columns.
if (capabilities != null && capabilities.getType() == ValueType.LONG) {
return getLongPredicateMatcher(
columnSelectorFactory.makeColumnValueSelector(columnName),
predicateFactory.makeLongPredicate()
);
}
final ColumnSelectorPlus<ValueMatcherColumnSelectorStrategy> selector =
DimensionHandlerUtils.createColumnSelectorPlus(
ValueMatcherColumnSelectorStrategyFactory.instance(),
DefaultDimensionSpec.of(columnName),
columnSelectorFactory
);
return selector.getColumnSelectorStrategy().makeValueMatcher(selector.getSelector(), predicateFactory);
}
```
The test Filter adds a row to the IncrementalIndex in the test when the predicateFactory creates a new String predicate, after `DimensionHandlerUtils.createColumnSelectorPlus` is called.
* Broker backpressure.
Adds a new property "druid.broker.http.maxQueuedBytes" and a new context
parameter "maxQueuedBytes". Both represent a maximum number of bytes queued
per query before exerting backpressure on the channel to the data server.
Fixes#4933.
* Fix query context doc.
* make COMPLEX column filterable in Druid code
* Revert "make COMPLEX column filterable in Druid code"
This reverts commit 9fc6ec768c.
* complex columns can be optionally made filterable
* some types are always filterable
* add ColumnCapabilitiesImpl serde tests
* add SuppresedWarnings annotation
* Rename io.druid to org.apache.druid.
* Fix META-INF files and remove some benchmark results.
* MonitorsConfig update for metrics package migration.
* Reorder some dimensions in inner queries for some reason.
* Fix protobuf tests.
* add subtotalsSpec attribute to groupBy query
* dont sent subtotalsSpec to downstream nodes from broker and other updates
* address review comment
* fix checkstyle issues after merge to master
* add docs for subtotalsSpec feature
* address doc review comments
The bug was caused by makeExprEvalSelector returning a null object, which
it isn't supposed to do. Fixed this by renaming ConstantColumnValueSelector
to ConstantExprEvalSelector (it was only used for ExprEval anyway) and
putting logic in that class to make sure the selectors behave as expected.
* Fix all inspection errors currently reported.
TeamCity builds on master are reporting inspection errors, possibly
because there was a while where it was not running due to the Apache
migration, and there was some drift.
* Fix one more location.
* Fix tests.
* Another fix.
* Fix four bugs with numeric dimension output types.
This patch includes the following bug fixes:
- TopNColumnSelectorStrategyFactory: Cast dimension values to the output type
during dimExtractionScanAndAggregate instead of updateDimExtractionResults.
This fixes a bug where, for example, grouping on doubles-cast-to-longs would
fail to merge two doubles that should have been combined into the same long value.
- TopNQueryEngine: Use DimExtractionTopNAlgorithm when treating string columns
as numeric dimensions. This fixes a similar bug: grouping on string-cast-to-long
would fail to merge two strings that should have been combined.
- GroupByQuery: Cast numeric types to the expected output type before comparing them
in compareDimsForLimitPushDown. This fixes#6123.
- GroupByQueryQueryToolChest: Convert Jackson-deserialized dimension values into
the proper output type. This fixes an inconsistency between results that came
from cache vs. not-cache: for example, Jackson sometimes deserializes integers
as Integers and sometimes as Longs.
And the following code-cleanup changes, related to the fixes above:
- DimensionHandlerUtils: Introduce convertObjectToType, compareObjectsAsType,
and converterFromTypeToType to make it easier to handle casting operations.
- TopN in general: Rename various "dimName" variables to "dimValue" where they
actually represent dimension values. The old names were confusing.
* Remove unused imports.
* Cache: Add maxEntrySize config.
The idea is this makes it more feasible to cache query types that
can potentially generate large result sets, like groupBy and select,
without fear of writing too much to the cache per query.
Includes a refactor of cache population code in CachingQueryRunner and
CachingClusteredClient, such that they now use the same CachePopulator
interface with two implementations: one for foreground and one for
background.
The main reason for splitting the foreground / background impls is
that the foreground impl can have a more effective implementation of
maxEntrySize. It can stop retaining subvalues for the cache early.
* Add CachePopulatorStats.
* Fix whitespace.
* Fix docs.
* Fix various tests.
* Add tests.
* Fix tests.
* Better tests
* Remove conflict markers.
* Fix licenses.
* order using IncrementalIndexRowComparator at persist time when rollup is disabled, allowing increased effectiveness of dimension compression, resolves#6066
* fix stuff from review
* Optimize per-segment queries
* Always optimize, add unit test
* PR comments
* Only run IntervalDimFilter optimization on __time column
* PR comments
* Checkstyle fix
* Add test for non __time column
* Add lastString and firstString aggregators extension
* Remove duplicated class
* Move first-last-string doc page to extensions-contrib
* Fix ObjectStrategy compare method
* Fix doc bad aggregatos type name
* Create FoldingAggregatorFactory classes to fix SegmentMetadataQuery
* Add getMaxStringBytes() method to support JSON serialization
* Fix null pointer exception at segment creation phase when the string value is null
* Control the valueSelector object class on BufferAggregators
* Perform all improvements
* Add java doc on SerializablePairLongStringSerde
* Refactor ObjectStraty compare method
* Remove unused ;
* Add aggregateCombiner unit tests. Rename BufferAggregators unit tests
* Remove unused imports
* Add license header
* Add class name to java doc class serde
* Throw exception if value is unsupported class type
* Move first-last-string extension into druid core
* Update druid core docs
* Fix null pointer exception when pair->string is null
* Add null control unit tests
* Remove unused imports
* Add first/last string folding aggregator on AggregatorsModule to support segment metadata query
* Change SerializablePairLongString to extend SerializablePair
* Change vars from public to private
* Convert vars to primitive type
* Clarify compare comment
* Change IllegalStateException to ISE
* Remove TODO comments
* Control possible null pointer exception
* Add @Nullable annotation
* Remove empty line
* Remove unused parameter type
* Improve AggregatorCombiner javadocs
* Add filterNullValues option at StringLast and StringFirst aggregators
* Add filterNullValues option at agg documentation
* Fix checkstyle
* Update header license
* Fix StringFirstAggregatorFactory.VALUE_COMPARATOR
* Fix StringFirstAggregatorCombiner
* Fix if condition at StringFirstAggregateCombiner
* Remove filterNullValues from string first/last aggregators
* Add isReset flag in FirstAggregatorCombiner
* Change Arrays.asList to Collections.singletonList
* Fix 'auto' encoded longs + compression serializer
Fixes#6044
changes:
* Fixes `VSizeLongSerde` serializers to treat 'close' as 'flush' when used with `BlockLayoutColumnarLongsSerializer`, allowing unwritten values to be flushed to the buffer when the block is compressed
* Add exhaustive unit test that flexes a variety of value sizes, row counts, and compression strategies to catch issues such as these
:
* refactor LongSerializer close to be named flush instead
* revert and just make new serializers per block
* Various changes about druid-services module
* Patch improvements from reviewer
* Add ToArrayCallWithZeroLengthArrayArgument & ArraysAsListWithZeroOrOneArgument into inspection profile
* Fix ArraysAsListWithZeroOrOneArgument
* Fix conflict
* Fix ToArrayCallWithZeroLengthArrayArgument
* Fix AliEqualsAvoidNull
* Remove blank line
* Remove unused import clauses
* Fix code style in TopNQueryRunnerTest
* Fix conflict
* Don't use Collections.singletonList when converting the type of array type
* Add argLine into maven-surefire-plugin in druid-process module & increase the timeout value for testMoveSegment testcase
* Roll back the latest commit
* Add java.io.File#toURL() into druid-forbidden-apis
* Using Boolean.parseBoolean instead of Boolean.valueOf for CliCoordinator#isOverlord
* Add a new regexp element into stylecode xml file
* Fix style error for new regexp
* Set the level of ArraysAsListWithZeroOrOneArgument as WARNING
* Fix style error for new regexp
* Add option BY_LEVEL for ToArrayCallWithZeroLengthArrayArgument in inspection profile
* Roll back the level as ToArrayCallWithZeroLengthArrayArgument as ERROR
* Add toArray(new Object[0]) regexp into checkstyle config file & fix them
* Set the level of ArraysAsListWithZeroOrOneArgument as ERROR & Roll back the level of ToArrayCallWithZeroLengthArrayArgument as WARNING until Youtrack fix it
* Add a comment for string equals regexp in checkstyle config
* Fix code format
* Add RedundantTypeArguments as ERROR level inspection
* Fix cannot resolve symbol datasource
False failures on Travis due to spurious timeout (in turn due to noisy
neighbors) is a bigger problem than legitimate failures taking too long
to time out. So it makes sense to extend timeouts.