#### `EventReceiverFirehoseFactory`
Fixed several concurrency bugs in `EventReceiverFirehoseFactory`:
- Race condition over putting an entry into `producerSequences` in `checkProducerSequence()`.
- `Stopwatch` used to measure time across threads, but it's a non-thread-safe class.
- Use `System.nanoTime()` instead of `System.currentTimeMillis()` because the latter are [not suitable](https://stackoverflow.com/a/351571/648955) for measuring time intervals.
- `close()` was not synchronized by could be called from multiple threads concurrently.
Removed unnecessary `readLock` (protecting `hasMore()` and `nextRow()` which are always called from a single thread). Removed unnecessary `volatile` modifiers.
Documented threading model and concurrent control flow of `EventReceiverFirehose` instances.
**Important:** please read the updated Javadoc for `EventReceiverFirehose.addAll()`. It allows events from different requests (batches) to be interleaved in the buffer. Is this OK?
#### `TimedShutoffFirehoseFactory`
- Fixed a race condition that was possible because `close()` that was not properly synchronized.
Documented threading model and concurrent control flow of `TimedShutoffFirehose` instances.
#### `Firehose`
Refined concurrency contract of `Firehose` based on `EventReceiverFirehose` implementation. Importantly, now it states that `close()` doesn't affect `hasMore()` and `nextRow()` and could be called concurrently with them. In other words, specified that `close()` is for "row supply" side rather than "row consume" side. However, I didn't check that other `Firehose` implementatations adhere to this contract.
<hr>
This issue is the result of reviewing `EventReceiverFirehose` and `TimedShutoffFirehose` using [this checklist](https://medium.com/@leventov/code-review-checklist-java-concurrency-49398c326154).
* Remove DataSegmentFinder, InsertSegmentToDb, and descriptor.json file
* delete descriptor.file when killing segments
* fix test
* Add doc for ha
* improve warning
* index_parallel: support !appendToExisting with no explicit intervals
This enables ParallelIndexSupervisorTask to dynamically request locks at runtime
if it is run without explicit intervals in the granularity spec and with
appendToExisting set to false. Previously, it behaved as if appendToExisting
was set to true, which was undocumented and inconsistent with IndexTask and
Hadoop indexing.
Also, when ParallelIndexSupervisorTask allocates segments in the explicit
interval case, fail if its locks on the interval have been revoked.
Also make a few other additions/clarifications to native ingestion docs.
Fixes#6989.
* Review feedback.
PR description on GitHub updated to match.
* Make native batch ingestion partitions start at 0
* Fix to previous commit
* Unit test. Verified to fail without the other commits on this branch.
* Another round of review
* Slightly scarier warning
* document middle manager api
* re-arrange
* correction
* document more missing overlord api calls, minor re-arrange of some code i was referencing
* fix it
* this will fix it
* fixup
* link to other docs
* Support kafka transactional topics
* update kafka to version 2.0.0
* Remove the skipOffsetGaps option since it's not used anymore
* Adjust kafka consumer to use transactional semantics
* Update tests
* Remove unused import from test
* Fix compilation
* Invoke transaction api to fix a unit test
* temporary modification of travis.yml for debugging
* another attempt to get travis tasklogs
* update kafka to 2.0.1 at all places
* Remove druid-kafka-eight dependency from integration-tests, remove the kafka firehose test and deprecate kafka-eight classes
* Add deprecated in docs for kafka-eight and kafka-simple extensions
* Remove skipOffsetGaps and code changes for transaction support
* Fix indentation
* remove skipOffsetGaps from kinesis
* Add transaction api to KafkaRecordSupplierTest
* Fix indent
* Fix test
* update kafka version to 2.1.0
* maintenance mode for Historical
forbidden api fix, config deserialization fix
logging fix, unit tests
* addressed comments
* addressed comments
* a style fix
* addressed comments
* a unit-test fix due to recent code-refactoring
* docs & refactoring
* addressed comments
* addressed a LoadRule drop flaw
* post merge cleaning up
* Add published segment cache in broker
* Change the DataSegment interner so it's not based on DataSEgment's equals only and size is preserved if set
* Added a trueEquals to DataSegment class
* Use separate interner for realtime and historical segments
* Remove trueEquals as it's not used anymore, change log message
* PR comments
* PR comments
* Fix tests
* PR comments
* Few more modification to
* change the coordinator api
* removeall segments at once from MetadataSegmentView in order to serve a more consistent view of published segments
* Change the poll behaviour to avoid multiple poll execution at same time
* minor changes
* PR comments
* PR comments
* Make the segment cache in broker off by default
* Added a config to PlannerConfig
* Moved MetadataSegmentView to sql module
* Add doc for new planner config
* Update documentation
* PR comments
* some more changes
* PR comments
* fix test
* remove unintentional change, whether to synchronize on lifecycleLock is still in discussion in PR
* minor changes
* some changes to initialization
* use pollPeriodInMS
* Add boolean cachePopulated to check if first poll succeeds
* Remove poll from start()
* take the log message out of condition in stop()
* 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 "bloom_filter_test" druid expression to support bloom filters in ExpressionVirtualColumn and ExpressionDimFilter and sql expressions
* more docs
* use java.util.Base64, doc fixes
Justin Borromeo
Roman Leventov
Jihoon Son
Jonathan Wei
Mingming Qiu
David Glasser
Surekha
Clint Wylie
scrawfor
awelsh93
Edward Gan
Egor Riashin
lxqfy
jorbay-au
Furkan KAMACI
Gian Merlino
Navin Kumar
Janek Lasocki-Biczysko