* Affinity "strong" definition
Reworded "strong" to emphasise meaning and consequences - OTBO https://the-asf.slack.com/archives/CJ8D1JTB8/p1609558156092800
* Spelling corrections
* Update docs/configuration/index.md
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
* Update docs/configuration/index.md
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
This change updates doc to clarify when and how a change to druid.auth.authenticator.basic.credentialIterations takes effect: changes apply only to new users or existing users upon changing their password via the credentials API, which may not be the expectation.
Fixes#11297.
Description
Description and design in the proposal #11297
Key changed/added classes in this PR
*DataSegmentPusher
*ShuffleClient
*PartitionStat
*PartitionLocation
*IntermediaryDataManager
* add binary_byte_format/decimal_byte_format/decimal_format
* clean code
* fix doc
* fix review comments
* add spelling check rules
* remove extra param
* improve type handling and null handling
* remove extra zeros
* fix tests and add space between unit suffix and number as most size-format functions do
* fix tests
* add examples
* change function names according to review comments
* fix merge
Signed-off-by: frank chen <frank.chen021@outlook.com>
* no need to configure NullHandling explicitly for tests
Signed-off-by: frank chen <frank.chen021@outlook.com>
* fix tests in SQL-Compatible mode
Signed-off-by: frank chen <frank.chen021@outlook.com>
* Resolve review comments
* Update SQL test case to check null handling
* Fix intellij inspections
* Add more examples
* Fix example
This PR adds a new property druid.router.sql.enable which allows the
Router to handle SQL queries when set to true.
This change does not affect Avatica JDBC requests and they are still routed
by hashing the Connection ID.
To allow parsing of the request object as a SqlQuery (contained in module druid-sql),
some classes have been moved from druid-server to druid-services with
the same package name.
* fix little typo
* Update docs/misc/math-expr.md
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
Co-authored-by: Charles Smith <techdocsmith@gmail.com>
* Update default maxSegmentsInNodeLoadingQueue
Update the default maxSegmentsInNodeLoadingQueue from 0 (unbounded) to 100.
An unbounded maxSegmentsInNodeLoadingQueue can cause cluster instability.
Since this is the default druid operators need to run into this instability
and then look through the docs to see that the recommended value for a large
cluster is 1000. This change makes it so the default will prevent clusters
from falling over as they grow over time.
* update tests
* codestyle
* Add a note
* Update docs/configuration/index.md
Co-authored-by: sthetland <steve.hetland@imply.io>
* clarify that both of non-result level cache and result level cache are not supported
Co-authored-by: sthetland <steve.hetland@imply.io>
* Allow kill task to mark segments as unused
* Add IndexerSQLMetadataStorageCoordinator test
* Update docs/ingestion/data-management.md
Co-authored-by: Jihoon Son <jihoonson@apache.org>
* Add warning to kill task doc
Co-authored-by: Jihoon Son <jihoonson@apache.org>
This change allows the selection of a specific broker service (or broker tier) by the Router.
The newly added ManualTieredBrokerSelectorStrategy works as follows:
Check for the parameter brokerService in the query context. If this is a valid broker service, use it.
Check if the field defaultManualBrokerService has been set in the strategy. If this is a valid broker service, use it.
Move on to the next strategy
* HLL lgK and a tip
Knowledge transfer from https://the-asf.slack.com/archives/CJ8D1JTB8/p1600699967024200. Attempted to make a connection between the SQL HLL function and the HLL underneath without getting too complicated. Also added a note about using K over 16 being pretty much pointless.
* Corrected spelling
* Create datasketches-hll.md
Put roll-up back to rollup
* Update docs/development/extensions-core/datasketches-hll.md
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
* Add a new metric query/segments/count that is not emitted by default
* docs
* test the default implementation of the metric
* fix spelling error in docs
* document the fact that query retries will result in additional metric emissions
* update using recommended text from @jihoonson
* fix doc
* address comments
* Update docs/configuration/index.md
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
This PR splits current SegmentLoader into SegmentLoader and SegmentCacheManager.
SegmentLoader - this class is responsible for building the segment object but does not expose any methods for downloading, cache space management, etc. Default implementation delegates the download operations to SegmentCacheManager and only contains the logic for building segments once downloaded. . This class will be used in SegmentManager to construct Segment objects.
SegmentCacheManager - this class manages the segment cache on the local disk. It fetches the segment files to the local disk, can clean up the cache, and in the future, support reserve and release on cache space. [See https://github.com/Make SegmentLoader extensible and customizable #11398]. This class will be used in ingestion tasks such as compaction, re-indexing where segment files need to be downloaded locally.
* compaction/status API retains status for datasources that no longer existed causing in-memory used to grow unbounded
* compaction/status API retains status for datasources that no longer existed causing in-memory used to grow unbounded
* compaction/status API retains status for datasources that no longer existed causing in-memory used to grow unbounded
* fix test
* fix test
* Bound memory in native batch ingest create segments
* Move BatchAppenderatorDriverTest to indexing service... note that we had to put the sink back in sinks in mergeandpush since the persistent data needs to be dropped and the sink is required for that
* Remove sinks from memory and clean up intermediate persists dirs manually after sink has been merged
* Changed name from RealtimeAppenderator to StreamAppenderator
* Style
* Incorporating tests from StreamAppenderatorTest
* Keep totalRows and cleanup code
* Added missing dep
* Fix unit test
* Checkstyle
* allowIncrementalPersists should always be true for batch
* Added sinks metadata
* clear sinks metadata when closing appenderator
* Style + minor edits to log msgs
* Update sinks metadata & totalRows when dropping a sink (segment)
* Remove max
* Intelli-j check
* Keep a count of hydrants persisted by sink for sanity check before merge
* Move out sanity
* Add previous hydrant count to sink metadata
* Remove redundant field from SinkMetadata
* Remove unneeded functions
* Cleanup unused code
* Removed unused code
* Remove unused field
* Exclude it from jacoco because it is very hard to get branch coverage
* Remove segment announcement and some other minor cleanup
* Add fallback flag
* Minor code cleanup
* Checkstyle
* Code review changes
* Update batchMemoryMappedIndex name
* Code review comments
* Exclude class from coverage, will include again when packaging gets fixed
* Moved test classes to server module
* More BatchAppenderator cleanup
* Fix bug in wrong counting of totalHydrants plus minor cleanup in add
* Removed left over comments
* Have BatchAppenderator follow the Appenderator contract for push & getSegments
* Fix LGTM violations
* Review comments
* Add stats after push is done
* Code review comments (cleanup, remove rest of synchronization constructs in batch appenderator, reneame feature flag,
remove real time flag stuff from stream appenderator, etc.)
* Update javadocs
* Add thread safety notice to BatchAppenderator
* Further cleanup config
* More config cleanup
* Avro union support
* Document new union support
* Add support for AvroStreamInputFormat and fix checkstyle
* Extend multi-member union test schema and format
* Some additional docs and add Enums to spelling
* Rename explodeUnions -> extractUnions
* explode -> extract
* ByType
* Correct spelling error
* add single input string expression dimension vector selector and better expression planning
* better
* fixes
* oops
* rework how vector processor factories choose string processors, fix to be less aggressive about vectorizing
* oops
* javadocs, renaming
* more javadocs
* benchmarks
* use string expression vector processor with vector size 1 instead of expr.eval
* better logging
* javadocs, surprising number of the the
* more
* simplify
* Create /opt/data to fix permission problem
* eliminate symlink to avoid compatibility problem on AWS Fargate
* Add a workaround section
* Update instruction for named volume
* Use named volume in docker-compose
* Revert some doc change
* Resolve review comments
With this change, Druid will only support ZooKeeper 3.5.x and later.
In order to support Java 15 we need to switch to ZK 3.5.x client libraries and drop support for ZK 3.4.x
(see #10780 for the detailed reasons)
* remove ZooKeeper 3.4.x compatibility
* exclude additional ZK 3.5.x netty dependencies to ensure we use our version
* keep ZooKeeper version used for integration tests in sync with client library version
* remove the need to specify ZK version at runtime for docker
* add support to run integration tests with JDK 15
* build and run unit tests with Java 15 in travis
* Avoid mapping hydrants in create segments phase for native ingestion
* Drop queriable indices after a given sink is fully merged
* Do not drop memory mappings for realtime ingestion
* Style fixes
* Renamed to match use case better
* Rollback memoization code and use the real time flag instead
* Null ptr fix in FireHydrant toString plus adjustments to memory pressure tracking calculations
* Style
* Log some count stats
* Make sure sinks size is obtained at the right time
* BatchAppenderator unit test
* Fix comment typos
* Renamed methods to make them more readable
* Move persisted metadata from FireHydrant class to AppenderatorImpl. Removed superfluous differences and fix comment typo. Removed custom comparator
* Missing dependency
* Make persisted hydrant metadata map concurrent and better reflect the fact that keys are Java references. Maintain persisted metadata when dropping/closing segments.
* Replaced concurrent variables with normal ones
* Added batchMemoryMappedIndex "fallback" flag with default "false". Set this to "true" make code fallback to previous code path.
* Style fix.
* Added note to new setting in doc, using Iterables.size (and removing a dependency), and fixing a typo in a comment.
* Forgot to commit this edited documentation message
* SQL timeseries no longer skip empty buckets with all granularity
* add comment, fix tests
* the ol switcheroo
* revert unintended change
* docs and more tests
* style
* make checkstyle happy
* docs fixes and more tests
* add docs, tests for array_agg
* fixes
* oops
* doc stuffs
* fix compile, match doc style
* allow user to set group.id for Kafka ingestion task
* fix test coverage by removing deprecated code and add doc
* fix typo
* Update docs/development/extensions-core/kafka-ingestion.md
Co-authored-by: frank chen <frankchen@apache.org>
Co-authored-by: frank chen <frankchen@apache.org>
* Update datasource.md
Change "table" to "datasource" in join discussion: This means that all datasources
other than the leftmost "base" table must fit in memory.
According to docs on datasources, "datasource" is the more general term, and a table is a kind of datasource. In the context here, then, "datasource" is applicable.
* left-hand table -> left-hand datasource
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
Co-authored-by: sthetland <steve.hetland@imply.io>
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
Fixed a syntax error in "prefix" lines in docs/ingestion/native-batch.md
S3 requires a trailing slash for directory like structures, so this updates the examples to include the trailing slashes.
* lay the groundwork for throttling replicant loads per RunRules execution
* Add dynamic coordinator config to control new replicant threshold.
* remove redundant line
* add some unit tests
* fix checkstyle error
* add documentation for new dynamic config
* improve docs and logs
* Alter how null is handled for new config. If null, manually set as default
* ARRAY_AGG sql aggregator function
* add javadoc
* spelling
* review stuff, return null instead of empty when nil input
* review stuff
* Update sql.md
* use type inference for finalize, refactor some things
* Add feature to automatically remove rules based on retention period
* Add feature to automatically remove rules based on retention period
* address comments
* add experimental expression aggregator
* add test
* fix lgtm
* fix test
* adjust test
* use not null constant
* array_set_concat docs
* add equals and hashcode and tostring
* fix it
* spelling
* do multi-value magic for expression agg, more javadocs, tests
* formatting
* fix inspection
* more better
* nullable
The main one is updating datasources.md to talk about SQL. (It still said
that table unions are not supported in SQL.) Also, this doc update adds
some clarifying details on limitations.
* add protobuf inputformat
* repair pom
* alter intermediateRow to type of Dynamicmessage
* add document
* refine test
* fix document
* add protoBytesDecoder
* refine document and add ser test
* add hash
* add schema registry ser test
Co-authored-by: yuanyi <yuanyi@freewheel.tv>
* add miss API references for coordinator
* add miss API references for coordinator
* add miss API references for coordinator
Co-authored-by: yuezhang <yuezhang@freewheel.tv>
* Add ability to wait for segment availability for batch jobs
* IT updates
* fix queries in legacy hadoop IT
* Fix broken indexing integration tests
* address an lgtm flag
* spell checker still flagging for hadoop doc. adding under that file header too
* fix compaction IT
* Updates to wait for availability method
* improve unit testing for patch
* fix bad indentation
* refactor waitForSegmentAvailability
* Fixes based off of review comments
* cleanup to get compile after merging with master
* fix failing test after previous logic update
* add back code that must have gotten deleted during conflict resolution
* update some logging code
* fixes to get compilation working after merge with master
* reset interrupt flag in catch block after code review pointed it out
* small changes following self-review
* fixup some issues brought on by merge with master
* small changes after review
* cleanup a little bit after merge with master
* Fix potential resource leak in AbstractBatchIndexTask
* syntax fix
* Add a Compcation TuningConfig type
* add docs stipulating the lack of support by Compaction tasks for the new config
* Fixup compilation errors after merge with master
* Remove erreneous newline
* Add paramter to loadstatus API to compute underdeplication against cluster view
This change adds a query parameter `computeUsingClusterView` to loadstatus apis
that if specified have the coordinator compute undereplication for segments based
on the number of services available within cluster that the segment can be replicated
on, instead of the configured replication count configured in load rule. A default
load rule is created in all clusters that specified that all segments should be
replicated 2 times. As replicas are forced to be on separate nodes in the cluster,
this causes the loadstatus api to report that there are under-replicated segments
when there is only 1 data server in the cluster. In this case, calling loadstatus
api without this new query parameter will always result in a response indicating
under-replication of segments
* * fix exception mapper
* * Address review comments
* * update external API docs
* Apply suggestions from code review
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* * update more external docs
* * update javadoc
* Apply suggestions from code review
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* request logs through kafka emitter
* travis fixes
* review comments
* kafka emitter unit test
* new line
* travis checks
* checkstyle fix
* count request lost when request topic is null
* DruidInputSource: Fix issues in column projection, timestamp handling.
DruidInputSource, DruidSegmentReader changes:
1) Remove "dimensions" and "metrics". They are not necessary, because we
can compute which columns we need to read based on what is going to
be used by the timestamp, transform, dimensions, and metrics.
2) Start using ColumnsFilter (see below) to decide which columns we need
to read.
3) Actually respect the "timestampSpec". Previously, it was ignored, and
the timestamp of the returned InputRows was set to the `__time` column
of the input datasource.
(1) and (2) together fix a bug in which the DruidInputSource would not
properly read columns that are used as inputs to a transformSpec.
(3) fixes a bug where the timestampSpec would be ignored if you attempted
to set the column to something other than `__time`.
(1) and (3) are breaking changes.
Web console changes:
1) Remove "Dimensions" and "Metrics" from the Druid input source.
2) Set timestampSpec to `{"column": "__time", "format": "millis"}` for
compatibility with the new behavior.
Other changes:
1) Add ColumnsFilter, a new class that allows input readers to determine
which columns they need to read. Currently, it's only used by the
DruidInputSource, but it could be used by other columnar input sources
in the future.
2) Add a ColumnsFilter to InputRowSchema.
3) Remove the metric names from InputRowSchema (they were unused).
4) Add InputRowSchemas.fromDataSchema method that computes the proper
ColumnsFilter for given timestamp, dimensions, transform, and metrics.
5) Add "getRequiredColumns" method to TransformSpec to support the above.
* Various fixups.
* Uncomment incorrectly commented lines.
* Move TransformSpecTest to the proper module.
* Add druid.indexer.task.ignoreTimestampSpecForDruidInputSource setting.
* Fix.
* Fix build.
* Checkstyle.
* Misc fixes.
* Fix test.
* Move config.
* Fix imports.
* Fixup.
* Fix ShuffleResourceTest.
* Add import.
* Smarter exclusions.
* Fixes based on tests.
Also, add TIME_COLUMN constant in the web console.
* Adjustments for tests.
* Reorder test data.
* Update docs.
* Update docs to say Druid 0.22.0 instead of 0.21.0.
* Fix test.
* Fix ITAutoCompactionTest.
* Changes from review & from merging.
* first pass compaction refactor. includes updated behavior for queryGranularity. removes duplicated doc
* fix links, typos, some reorganization
* fix spelling. TBD still there for work in progress
* updates tutorial examples, adds more clarification around compaction use cases
* add granularity spec to automatic compaction config
* final edits
* spelling fixes
* apply suggestions from review
* upadtes from review
* last edits
* move note
* clarify null
* fix links & spelling
* latest review
* edits to auto-compaction config
* add back rollup
* fix links & spelling
* Update compaction.md
add granularityspec to example
* prometheus-emitter
* use existing jetty server to expose prometheus collection endpoint
* unused variables
* better variable names
* removed unused dependencies
* more metric definitions
* reorganize
* use prometheus HTTPServer instead of hooking into Jetty server
* temporary empty help string
* temporary non-empty help. fix incorrect dimension value in JSON (also updated statsd json)
* added full help text. added metric conversion factor for timers that are not using seconds. Correct metric dimension name in documentation
* added documentation for prometheus emitter
* safety for invalid labelNames
* fix travis checks
* Unit test and better sanitization of metrics names and label values
* add precondition to check namespace against regex
* use precompiled regex
* remove static imports. fix metric types
* better docs. fix possible NPE in PrometheusEmitterConfig. Guard against multiple calls to PrometheusEmitter.start()
* Update regex for label-value replacements to allow internal numeric values. Additional tests
* Adds missing license header
updates website/.spelling to add words used in prometheus-emitter docs.
updates docs/operations/metrics.md to correct the spelling of
bufferPoolName
* fixes version in extensions-contrib/prometheus-emitter
* fix style guide errors
* update import ordering
* add another word to website/.spelling
* remove unthrown declared exception
* remove unused import
* Pushgateway strategy for metrics
* typo
* Format fix and nullable strategy
* Update pom file for prometheus-emitter
* code review comments. Counter to gauge for cache metrics, periodical task to pushGateway
* Syntax fix
* Dimension label regex include numeric character back, fix previous commit
* bump prometheus-emitter pom dev version
* Remove scheduled task inside poen that push metrics
* Fix checkstyle
* Unit test coverage
* Unit test coverage
* Spelling
* Doc fix
* spelling
Co-authored-by: Michael Schiff <michael.schiff@tubemogul.com>
Co-authored-by: Michael Schiff <schiff.michael@gmail.com>
Co-authored-by: Tianxin Zhao <tianxin.zhao@tubemogul.com>
Co-authored-by: Tianxin Zhao <tizhao@adobe.com>
* Allow only HTTP and HTTPS protocols for the HTTP inputSource
* rename
* Update core/src/main/java/org/apache/druid/data/input/impl/HttpInputSource.java
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
* fix http firehose and update doc
* HDFS inputSource
* add configs for allowed protocols
* fix checkstyle and doc
* more checkstyle
* remove stale doc
* remove more doc
* Apply doc suggestions from code review
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* update hdfs address in docs
* fix test
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* druid task auto scale based on kafka lag
* fix kafkaSupervisorIOConfig and KinesisSupervisorIOConfig
* druid task auto scale based on kafka lag
* fix kafkaSupervisorIOConfig and KinesisSupervisorIOConfig
* test dynamic auto scale done
* auto scale tasks tested on prd cluster
* auto scale tasks tested on prd cluster
* modify code style to solve 29055.10 29055.9 29055.17 29055.18 29055.19 29055.20
* rename test fiel function
* change codes and add docs based on capistrant reviewed
* midify test docs
* modify docs
* modify docs
* modify docs
* merge from master
* Extract the autoScale logic out of SeekableStreamSupervisor to minimize putting more stuff inside there && Make autoscaling algorithm configurable and scalable.
* fix ci failed
* revert msic.xml
* add uts to test autoscaler create && scale out/in and kafka ingest with scale enable
* add more uts
* fix inner class check
* add IT for kafka ingestion with autoscaler
* add new IT in groups=kafka-index named testKafkaIndexDataWithWithAutoscaler
* review change
* code review
* remove unused imports
* fix NLP
* fix docs and UTs
* revert misc.xml
* use jackson to build autoScaleConfig with default values
* add uts
* use jackson to init AutoScalerConfig in IOConfig instead of Map<>
* autoscalerConfig interface and provide a defaultAutoScalerConfig
* modify uts
* modify docs
* fix checkstyle
* revert misc.xml
* modify uts
* reviewed code change
* reviewed code change
* code reviewed
* code review
* log changed
* do StringUtils.encodeForFormat when create allocationExec
* code review && limit taskCountMax to partitionNumbers
* modify docs
* code review
Co-authored-by: yuezhang <yuezhang@freewheel.tv>
* Clarify docs
* Apply suggestions from code review
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* Add config and header support for confluent schema registry. (porting code from https://github.com/apache/druid/pull/9096)
* Add Eclipse Public License 2.0 to license check
* Update licenses.yaml, revert changes to check-licenses.py and dependencies for integration-tests
* Add spelling exception and remove unused dependency
* Use non-deprecated getSchemaById() and remove duplicated license entry
* Update docs/ingestion/data-formats.md
Co-authored-by: Clint Wylie <cjwylie@gmail.com>
* Added check for schema being null, as per Confluent code
* Missing imports and whitespace
* Updated unit tests with AvroSchema
Co-authored-by: Sergio Spinatelli <sergio.spinatelli.extern@7-tv.de>
Co-authored-by: Sergio Spinatelli <sergio.spinatelli.extern@joyn.de>
Co-authored-by: Clint Wylie <cjwylie@gmail.com>
* clarify security requirements around HTTPInputSource
* explicitly mention write/datasource in best practices. clarify that the ingestion task is the risk
* Update docs/operations/security-overview.md
Co-authored-by: Suneet Saldanha <suneet@apache.org>
Co-authored-by: Suneet Saldanha <suneet@apache.org>
* Improve Druid ldap auth documentation
Improved the ldap auth docs by clarifying that the object classes and
attributes noted are specific to Microsoft Active Directory, and could
be different depending on the specific ldap server being used. Also
emphasized the importance of the memberOf field and noted that the
step about adding users to roles is only needed in certain circumstances.
* * add another note
* Apply suggestions from code review
Co-authored-by: sthetland <steve.hetland@imply.io>
* * simplify
* * Address review comments
Co-authored-by: sthetland <steve.hetland@imply.io>
* add druid jdbc handler config for minimum number of rows per frame
* javadocs and docs adjustments
* spelling
* adjust docs per review with minor tweaks
* adjust more
* add offsetFetchPeriod to kinesis ingestion doc
* Remove jackson dependencies from extensions
* Use fixed delay for lag collection
* Metrics reset after finishing processing
* comments
* Broaden the list of exceptions to retry for
* Unit tests
* Add more tests
* Refactoring
* re-order metrics
* Doc suggestions
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* Add tests
Co-authored-by: Charles Smith <38529548+techdocsmith@users.noreply.github.com>
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* fix checkstyle
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* fix test
* fix test
* add log
* Fix byte calculation for maxBytesInMemory to take into account of Sink/Hydrant Object overhead
* address comments
* fix checkstyle
* fix checkstyle
* add config to skip overhead memory calculation
* add test for the skipBytesInMemoryOverheadCheck config
* add docs
* fix checkstyle
* fix checkstyle
* fix spelling
* address comments
* fix travis
* address comments