This PR fixes an issue when using 'auto' encoded LONG typed columns and the 'vectorized' query engine. These columns use a delta based bit-packing mechanism, and errors in the vectorized reader would cause it to incorrectly read column values for some bit sizes (1 through 32 bits). This is a regression caused by #11004, which added the optimized readers to improve performance, so impacts Druid versions 0.22.0+.
While writing the test I finally got sad enough about IndexSpec not having a "builder", so I made one, and switched all the things to use it. Apologies for the noise in this bug fix PR, the only real changes are in VSizeLongSerde, and the tests that have been modified to cover the buggy behavior, VSizeLongSerdeTest and ExpressionVectorSelectorsTest. Everything else is just cleanup of IndexSpec usage.
* Make LoggingEmitter more useful
* Skip code coverage for facade classes
* fix spellcheck
* code review
* fix dependency
* logging.md
* fix checkstyle
* Add back jacoco version to main pom
Hadoop 2 often causes red security scans on Druid distribution because of the dependencies it brings. We want to move away from Hadoop 2 and provide Hadoop 3 distribution available. Switch druid to building with Hadoop 3 by default. Druid will still be compatible with Hadoop 2 and users can build hadoop-2 compatible distribution using hadoop2 profile.
* Compaction: Block input specs not aligned with segmentGranularity.
When input intervals are not aligned with segmentGranularity, data may be
overshadowed if it lies in the space between the input intervals and the
output segmentGranularity.
In MSQ REPLACE, this is a validation error. IMO the same behavior makes
sense for compaction tasks. In case anyone was depending on the ability
to compact nonaligned intervals, a configuration parameter
allowNonAlignedInterval is provided. I don't expect it to be used much.
* Remove unused.
* ITCompactionTaskTest uses non-aligned intervals.
* return task status reported by peon
* Write TaskStatus to file in AbstractTask.cleanUp
* Get TaskStatus from task log
* Fix merge conflicts in AbstractTaskTest
* Add unit tests for TaskLogPusher, TaskLogStreamer, NoopTaskLogs to satisfy code coverage
* Add license headerss
* Fix style
* Remove unknown exception declarations
* Allow for Log4J to be configured for peons but still ensure console logging is enforced
This change will allow for log4j to be configured for peons but require console logging is still
configured for them to ensure peon logs are saved to deep storage.
Also fixed the test ConsoleLoggingEnforcementTest to use a valid appender for the non console
Config as the previous config was incorrect and would never return a logger.
* fix checkstyle
* add warning to logger when it overwrites all loggers to be console
* optimize calls for altering logging config for ConsoleLoggingEnforcementConfigurationFactory
add getName to the druid logger class
* update docs, and error message
* edit docs to be more clear
* fix checkstyle issues
* CI fixes - LoggerTest code coverage and fix spelling issue for logging docs
### Description
This pr fixes a few bugs found with the inputSource security feature.
1. `KillUnusedSegmentsTask` previously had no definition for the `getInputSourceResources`, which caused an unsupportedOperationException to be thrown when this task type was submitted with the inputSource security feature enabled. This task type should not require any input source specific resources, so returning an empty set for this task type now.
2. Fixed a bug where when the input source type security feature is enabled, all of the input source type specific resources used where authenticated against:
`{"resource": {"name": "EXTERNAL", "type": "{INPUT_SOURCE_TYPE}"}, "action": "READ"}`
When they should be instead authenticated against:
`{"resource": {"name": "{INPUT_SOURCE_TYPE}", "type": "EXTERNAL"}, "action": "READ"}`
3. fixed bug where supervisor tasks were not authenticated against the specific input source types used, if input source security feature was enabled.
*
Adds new run time parameter druid.indexer.task.tmpStorageBytesPerTask. This sets a limit for the amount of temporary storage disk space used by tasks. This limit is currently only respected by MSQ tasks.
* Removes query context parameters intermediateSuperSorterStorageMaxLocalBytes and composedIntermediateSuperSorterStorageEnabled. Composed intermediate super sorter (which was enabled by composedIntermediateSuperSorterStorageEnabled) is now enabled automatically if durableShuffleStorage is set to true. intermediateSuperSorterStorageMaxLocalBytes is calculated from the limit set by the run time parameter druid.indexer.task.tmpStorageBytesPerTask.
* Make the tasks run with only a single directory
There was a change that tried to get indexing to run on multiple disks
It made a bunch of changes to how tasks run, effectively hiding the
"safe" directory for tasks to write files into from the task code itself
making it extremely difficult to do anything correctly inside of a task.
This change reverts those changes inside of the tasks and makes it so that
only the task runners are the ones that make decisions about which
mount points should be used for storing task-related files.
It adds the config druid.worker.baseTaskDirs which can be used by the
task runners to know which directories they should schedule tasks inside of.
The TaskConfig remains the authoritative source of configuration for where
and how an individual task should be operating.
changes:
* adds support for boolean inputs to the classic long dimension indexer, which plays nice with LONG being the semi official boolean type in Druid, and even nicer when druid.expressions.useStrictBooleans is set to true, since the sampler when using the new 'auto' schema when 'useSchemaDiscovery' is specified on the dimensions spec will call the type out as LONG
* fix bugs with sampler response and new schema discovery stuff incorrectly using classic 'json' type for the logical schema instead of the new 'auto' type
Fixes#13837.
### Description
This change allows for input source type security in the native task layer.
To enable this feature, the user must set the following property to true:
`druid.auth.enableInputSourceSecurity=true`
The default value for this property is false, which will continue the existing functionality of needing authorization to write to the respective datasource.
When this config is enabled, the users will be required to be authorized for the following resource action, in addition to write permission on the respective datasource.
`new ResourceAction(new Resource(ResourceType.EXTERNAL, {INPUT_SOURCE_TYPE}, Action.READ`
where `{INPUT_SOURCE_TYPE}` is the type of the input source being used;, http, inline, s3, etc..
Only tasks that provide a non-default implementation of the `getInputSourceResources` method can be submitted when config `druid.auth.enableInputSourceSecurity=true` is set. Otherwise, a 400 error will be thrown.
changes:
* introduce ColumnFormat to separate physical storage format from logical type. ColumnFormat is now used instead of ColumnCapabilities to get column handlers for segment creation
* introduce new 'auto' type indexer and merger which produces a new common nested format of columns, which is the next logical iteration of the nested column stuff. Essentially this is an automatic type column indexer that produces the most appropriate column for the given inputs, making either STRING, ARRAY<STRING>, LONG, ARRAY<LONG>, DOUBLE, ARRAY<DOUBLE>, or COMPLEX<json>.
* revert NestedDataColumnIndexer, NestedDataColumnMerger, NestedDataColumnSerializer to their version pre #13803 behavior (v4) for backwards compatibility
* fix a bug in RoaringBitmapSerdeFactory if anything actually ever wrote out an empty bitmap using toBytes and then later tried to read it (the nerve!)
Changes:
- Set `useRoundRobinSegmentAssignment` in coordinator dynamic config to `true` by default.
- Set `batchSegmentAllocation` in `TaskLockConfig` (used in Overlord runtime properties) to `true` by default.
* Lower default maxRowsInMemory for realtime ingestion.
The thinking here is that for best ingestion throughput, we want
intermediate persists to be as big as possible without using up all
available memory. So, we rely mainly on maxBytesInMemory. The default
maxRowsInMemory (1 million) is really just a safety: in case we have
a large number of very small rows, we don't want to get overwhelmed
by per-row overheads.
However, maximum ingestion throughput isn't necessarily the primary
goal for realtime ingestion. Query performance is also important. And
because query performance is not as good on the in-memory dataset, it's
helpful to keep it from growing too large. 150k seems like a reasonable
balance here. It means that for a typical 5 million row segment, we
won't trigger more than 33 persists due to this limit, which is a
reasonable number of persists.
* Update tests.
* Update server/src/main/java/org/apache/druid/segment/indexing/RealtimeTuningConfig.java
Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>
* Fix test.
* Fix link.
---------
Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>
* As a follow up to #13893, this PR improves the comments added along with examples for the code, as well as adds handling for an edge case where the generated tombstone boundaries were overshooting the bounds of MIN_TIME (or MAX_TIME).
* Improve memory efficiency of WrappedRoaringBitmap.
Two changes:
1) Use an int[] for sizes 4 or below.
2) Remove the boolean compressRunOnSerialization. Doesn't save much
space, but it does save a little, and it isn't adding a ton of value
to have it be configurable. It was originally configurable in case
anything broke when enabling it, but it's been a while and nothing
has broken.
* Slight adjustment.
* Adjust for inspection.
* Updates.
* Update snaps.
* Update test.
* Adjust test.
* Fix snaps.
* Use TaskConfig to get task dir in KubernetesTaskRunner
* Use the first path specified in baseTaskDirPaths instead of deprecated baseTaskDirPath
* Use getBaseTaskDirPaths in generate command
The FiniteFirehoseFactory and InputRowParser classes were deprecated in 0.17.0 (#8823) in favor of InputSource & InputFormat. This PR removes the FiniteFirehoseFactory and all its implementations along with classes solely used by them like Fetcher (Used by PrefetchableTextFilesFirehoseFactory). Refactors classes including tests using FiniteFirehoseFactory to use InputSource instead.
Removing InputRowParser may not be as trivial as many classes that aren't deprecated depends on it (with no alternatives), like EventReceiverFirehoseFactory. Hence FirehoseFactory, EventReceiverFirehoseFactory, and Firehose are marked deprecated.
*When running REPLACE queries, the segments which contain no data are dropped (marked as unused). This PR aims to generate tombstones in place of segments which contain no data to mark their deletion, as is the behavior with the native ingestion.
This will cause InsertCannotReplaceExistingSegmentFault to be removed since it was generated if the interval to be marked unused didn't fully overlap one of the existing segments to replace.
If the intermediate handoff period is less than the task duration and there is no new data in the input topic, task will continuously checkpoint the same offsets again and again. This PR fixes that bug by resetting the checkpoint time even when the task receives the same end offset request again.
* merge druid-core, extendedset, and druid-hll into druid-processing to simplify everything
* fix poms and license stuff
* mockito is evil
* allow reset of JvmUtils RuntimeInfo if tests used static injection to override
* Allow users to add additional metadata to ingestion metrics
When submitting an ingestion spec, users may pass a map of metadata
in the ingestion spec config that will be added to ingestion metrics.
This will make it possible for operators to tag metrics with other
metadata that doesn't necessarily line up with the existing tags
like taskId.
Druid clusters that ingest these metrics can take advantage of the
nested data columns feature to process this additional metadata.
* rename to tags
* docs
* tests
* fix test
* make code cov happy
* checkstyle
* discover nested columns when using nested column indexer for schemaless
* move useNestedColumnIndexerForSchemaDiscovery from AppendableIndexSpec to DimensionsSpec
* Kinesis: More robust default fetch settings.
1) Default recordsPerFetch and recordBufferSize based on available memory
rather than using hardcoded numbers. For this, we need an estimate
of record size. Use 10 KB for regular records and 1 MB for aggregated
records. With 1 GB heaps, 2 processors per task, and nonaggregated
records, recordBufferSize comes out to the same as the old
default (10000), and recordsPerFetch comes out slightly lower (1250
instead of 4000).
2) Default maxRecordsPerPoll based on whether records are aggregated
or not (100 if not aggregated, 1 if aggregated). Prior default was 100.
3) Default fetchThreads based on processors divided by task count on
Indexers, rather than overall processor count.
4) Additionally clean up the serialized JSON a bit by adding various
JsonInclude annotations.
* Updates for tests.
* Additional important verify.
* single typed "root" only nested columns now mimic "regular" columns of those types
* incremental index can now use nested column indexer instead of string indexer for discovered columns
* Support Framing for Window Aggregations
This adds support for framing over ROWS
for window aggregations.
Still not implemented as yet:
1. RANGE frames
2. Multiple different frames in the same query
3. Frames on last/first functions
This commit adds a new class `InputStats` to track the total bytes processed by a task.
The field `processedBytes` is published in task reports along with other row stats.
Major changes:
- Add class `InputStats` to track processed bytes
- Add method `InputSourceReader.read(InputStats)` to read input rows while counting bytes.
> Since we need to count the bytes, we could not just have a wrapper around `InputSourceReader` or `InputEntityReader` (the way `CountableInputSourceReader` does) because the `InputSourceReader` only deals with `InputRow`s and the byte information is already lost.
- Classic batch: Use the new `InputSourceReader.read(inputStats)` in `AbstractBatchIndexTask`
- Streaming: Increment `processedBytes` in `StreamChunkParser`. This does not use the new `InputSourceReader.read(inputStats)` method.
- Extend `InputStats` with `RowIngestionMeters` so that bytes can be exposed in task reports
Other changes:
- Update tests to verify the value of `processedBytes`
- Rename `MutableRowIngestionMeters` to `SimpleRowIngestionMeters` and remove duplicate class
- Replace `CacheTestSegmentCacheManager` with `NoopSegmentCacheManager`
- Refactor `KafkaIndexTaskTest` and `KinesisIndexTaskTest`
Refactor DataSource to have a getAnalysis method()
This removes various parts of the code where while loops and instanceof
checks were being used to walk through the structure of DataSource objects
in order to build a DataSourceAnalysis. Instead we just ask the DataSource
for its analysis and allow the stack to rebuild whatever structure existed.
* Zero-copy local deep storage.
This is useful for local deep storage, since it reduces disk usage and
makes Historicals able to load segments instantaneously.
Two changes:
1) Introduce "druid.storage.zip" parameter for local storage, which defaults
to false. This changes default behavior from writing an index.zip to writing
a regular directory. This is safe to do even during a rolling update, because
the older code actually already handled unzipped directories being present
on local deep storage.
2) In LocalDataSegmentPuller and LocalDataSegmentPusher, use hard links
instead of copies when possible. (Generally this is possible when the
source and destination directory are on the same filesystem.)
Changes:
- Limit max batch size in `SegmentAllocationQueue` to 500
- Rename `batchAllocationMaxWaitTime` to `batchAllocationWaitTime` since the actual
wait time may exceed this configured value.
- Replace usage of `SegmentInsertAction` in `TaskToolbox` with `SegmentTransactionalInsertAction`
In a cluster with a large number of streaming tasks (~1000), SegmentAllocateActions
on the overlord can often take very long intervals of time to finish thus causing spikes
in the `task/action/run/time`. This may result in lag building up while a task waits for a
segment to get allocated.
The root causes are:
- large number of metadata calls made to the segments and pending segments tables
- `giant` lock held in `TaskLockbox.tryLock()` to acquire task locks and allocate segments
Since the contention typically arises when several tasks of the same datasource try
to allocate segments for the same interval/granularity, the allocation run times can be
improved by batching the requests together.
Changes
- Add flags
- `druid.indexer.tasklock.batchSegmentAllocation` (default `false`)
- `druid.indexer.tasklock.batchAllocationMaxWaitTime` (in millis) (default `1000`)
- Add methods `canPerformAsync` and `performAsync` to `TaskAction`
- Submit each allocate action to a `SegmentAllocationQueue`, and add to correct batch
- Process batch after `batchAllocationMaxWaitTime`
- Acquire `giant` lock just once per batch in `TaskLockbox`
- Reduce metadata calls by batching statements together and updating query filters
- Except for batching, retain the whole behaviour (order of steps, retries, etc.)
- Respond to leadership changes and fail items in queue when not leader
- Emit batch and request level metrics
* fixes BlockLayoutColumnarLongs close method to nullify internal buffer.
* fixes other BlockLayoutColumnar supplier close methods to nullify internal buffers.
* fix spotbugs
Main changes:
1) Convert SeekableStreamIndexTaskClient to an interface, move old code
to SeekableStreamIndexTaskClientSyncImpl, and add new implementation
SeekableStreamIndexTaskClientAsyncImpl that uses ServiceClient.
2) Add "chatAsync" parameter to seekable stream supervisors that causes
the supervisor to use an async task client.
3) In SeekableStreamSupervisor.discoverTasks, adjust logic to avoid making
blocking RPC calls in workerExec threads.
4) In SeekableStreamSupervisor generally, switch from Futures.successfulAsList
to FutureUtils.coalesce, so we can better capture the errors that occurred
with contacting individual tasks.
Other, related changes:
1) Add ServiceRetryPolicy.retryNotAvailable, which controls whether
ServiceClient retries unavailable services. Useful since we do not
want to retry calls unavailable tasks within the service client. (The
supervisor does its own higher-level retries.)
2) Add FutureUtils.transformAsync, a more lambda friendly version of
Futures.transform(f, AsyncFunction).
3) Add FutureUtils.coalesce. Similar to Futures.successfulAsList, but
returns Either instead of using null on error.
4) Add JacksonUtils.readValue overloads for JavaType and TypeReference.
Currently, a shared lock is acquired only when all other locks are also shared locks.
This commit updates the behaviour and acquires a shared lock only if all locks
of equal or higher priority are either shared locks or are already revoked.
The lock type of locks with lower priority does not matter as they can be revoked.
Eliminates two common sources of noise with Kafka supervisors that have
large numbers of tasks and partitions:
1) Log the report at DEBUG rather than INFO level at each run cycle.
It can get quite large, and can be retrieved via API when needed.
2) Use log4j2.xml to quiet down the org.apache.kafka.clients.consumer.internals
package. Avoids a log message per-partition per-minute as part of seeking
to the latest offset in the reporting thread. In the tasks, where this
sort of logging might be more useful, we have another log message with
the same information: "Seeking partition[%s] to[%s]".
* SeekableStreamSupervisor: Don't enqueue duplicate notices.
Similar goal to #12018, but more aggressive. Don't enqueue a notice at
all if it is equal to one currently in the queue.
* Adjustments from review.
* Update indexing-service/src/test/java/org/apache/druid/indexing/overlord/supervisor/NoticesQueueTest.java
Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>
Co-authored-by: Kashif Faraz <kashif.faraz@gmail.com>
Changes:
- Add a metric for partition-wise kafka/kinesis lag for streaming ingestion.
- Emit lag metrics for streaming ingestion when supervisor is not suspended and state is in {RUNNING, IDLE, UNHEALTHY_TASKS, UNHEALTHY_SUPERVISOR}
- Document metrics
* Compaction: Fetch segments one at a time on main task; skip when possible.
Compact tasks include the ability to fetch existing segments and determine
reasonable defaults for granularitySpec, dimensionsSpec, and metricsSpec.
This is a useful feature that makes compact tasks work well even when the
user running the compaction does not have a clear idea of what they want
the compacted segments to be like.
However, this comes at a cost: it takes time, and disk space, to do all
of these fetches. This patch improves the situation in two ways:
1) When segments do need to be fetched, download them one at a time and
delete them when we're done. This still takes time, but minimizes the
required disk space.
2) Don't fetch segments on the main compact task when they aren't needed.
If the user provides a full granularitySpec, dimensionsSpec, and
metricsSpec, we can skip it.
* Adjustments.
* Changes from code review.
* Fix logic for determining rollup.
* Support for middle manager less druid, tasks launch as k8s jobs
* Fixing forking task runner test
* Test cleanup, dependency cleanup, intellij inspections cleanup
* Changes per PR review
Add configuration option to disable http/https proxy for the k8s client
Update the docs to provide more detail about sidecar support
* Removing un-needed log lines
* Small changes per PR review
* Upon task completion we callback to the overlord to update the status / locaiton, for slower k8s clusters, this reduces locking time significantly
* Merge conflict fix
* Fixing tests and docs
* update tiny-cluster.yaml
changed `enableTaskLevelLogPush` to `encapsulatedTask`
* Apply suggestions from code review
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
* Minor changes per PR request
* Cleanup, adding test to AbstractTask
* Add comment in peon.sh
* Bumping code coverage
* More tests to make code coverage happy
* Doh a duplicate dependnecy
* Integration test setup is weird for k8s, will do this in a different PR
* Reverting back all integration test changes, will do in anotbher PR
* use StringUtils.base64 instead of Base64
* Jdk is nasty, if i compress in jdk 11 in jdk 17 the decompressed result is different
Co-authored-by: Rahul Gidwani <r_gidwani@apple.com>
Co-authored-by: Abhishek Agarwal <1477457+abhishekagarwal87@users.noreply.github.com>
In clusters with a large number of segments, the duty `MarkAsUnusedOvershadowedSegments`
can take a long very long time to finish. This is because of the costly invocation of
`timeline.isOvershadowed` which is done for every used segment in every coordinator run.
Changes
- Use `DataSourceSnapshot.getOvershadowedSegments` to get all overshadowed segments
- Iterate over this set instead of all used segments to identify segments that can be marked as unused
- Mark segments as unused in the DB in batches rather than one at a time
- Refactor: Add class `SegmentTimeline` for ease of use and readability while using a
`VersionedIntervalTimeline` of segments.
* Remove basePersistDirectory from tuning configs.
Since the removal of CliRealtime, it serves no purpose, since it is
always overridden in production using withBasePersistDirectory given
some subdirectory of the task work directory.
Removing this from the tuning config has a benefit beyond removing
no-longer-needed logic: it also avoids the side effect of empty
"druid-realtime-persist" directories getting created in the systemwide
temp directory.
* Test adjustments to appropriately set basePersistDirectory.
* Remove unused import.
* Fix RATC constructor.
Overlord leader election can sometimes fail due to task lock re-acquisition issues.
This commit solves the issue by failing such tasks and clearing all their locks.
This commit fixes issues with delayed supervisor termination during certain transient states.
Tasks can be created during supervisor termination and left behind since the cleanup may
not consider these newly added tasks.
#12178 added a lock for the entire process of task creation to prevent such dangling tasks.
But it also introduced a deadlock scenario as follows:
- An invocation of `runInternal` is in progress.
- A `stop` request comes, acquires `stateChangeLock` and submit a `ShutdownNotice`
- `runInternal` keeps waiting to acquire the `stateChangeLock`
- `ShutdownNotice` remains stuck in the notice queue because `runInternal` is still running
- After some timeout, the supervisor goes through a forced termination
Fix:
* `SeekableStreamSupervisor.runInternal` - do not try to acquire lock if supervisor is already stopping
* `SupervisorStateManager.maybeSetState` - do not allow transitions from STOPPING state
* Fixing RACE in HTTP remote task Runner
* Changes in the interface
* Updating documentation
* Adding test cases to SwitchingTaskLogStreamer
* Adding more tests
* Fix serialization in TaskReportFileWriters.
For some reason, serializing a Map<String, TaskReport> would omit the
"type" field. Explicitly sending each value through the ObjectMapper
fixes this, because the type information does not get lost.
* Fixes for static analysis.
* Fix race in TaskQueue.notifyStatus.
It was possible for manageInternal to relaunch a task while it was
being cleaned up, due to a race that happens when notifyStatus is
called to clean up a successful task:
1) In a critical section, notifyStatus removes the task from "tasks".
2) Outside a critical section, notifyStatus calls taskRunner.shutdown
to let the task runner know it can clear out its data structures.
3) In a critical section, syncFromStorage adds the task back to "tasks",
because it is still present in metadata storage.
4) In a critical section, manageInternalCritical notices that the task
is in "tasks" and is not running in the taskRunner, so it launches
it again.
5) In a (different) critical section, notifyStatus updates the metadata
store to set the task status to SUCCESS.
6) The task continues running even though it should not be.
The possibility for this race was introduced in #12099, which shrunk
the critical section in notifyStatus. Prior to that patch, a single
critical section encompassed (1), (2), and (5), so the ordering above
was not possible.
This patch does the following:
1) Fixes the race by adding a recentlyCompletedTasks set that prevents
the main management loop from doing anything with tasks that are
currently being cleaned up.
2) Switches the order of the critical sections in notifyStatus, so
metadata store updates happen first. This is useful in case of
server failures: it ensures that if the Overlord fails in the midst
of notifyStatus, then completed-task statuses are still available in
ZK or on MMs for the next Overlord. (Those are cleaned up by
taskRunner.shutdown, which formerly ran first.) This isn't related
to the race described above, but is fixed opportunistically as part
of the same patch.
3) Changes the "tasks" list to a map. Many operations require retrieval
or removal of individual tasks; those are now O(1) instead of O(N)
in the number of running tasks.
4) Changes various log messages to use task ID instead of full task
payload, to make the logs more readable.
* Fix format string.
* Update comment.
Kinesis ingestion requires all shards to have at least 1 record at the required position in druid.
Even if this is satisified initially, resharding the stream can lead to empty intermediate shards. A significant delay in writing to newly created shards was also problematic.
Kinesis shard sequence numbers are big integers. Introduce two more custom sequence tokens UNREAD_TRIM_HORIZON and UNREAD_LATEST to indicate that a shard has not been read from and that it needs to be read from the start or the end respectively.
These values can be used to avoid the need to read at least one record to obtain a sequence number for ingesting a newly discovered shard.
If a record cannot be obtained immediately, use a marker to obtain the relevant shardIterator and use this shardIterator to obtain a valid sequence number. As long as a valid sequence number is not obtained, continue storing the token as the offset.
These tokens (UNREAD_TRIM_HORIZON and UNREAD_LATEST) are logically ordered to be earlier than any valid sequence number.
However, the ordering requires a few subtle changes to the existing mechanism for record sequence validation:
The sequence availability check ensures that the current offset is before the earliest available sequence in the shard. However, current token being an UNREAD token indicates that any sequence number in the shard is valid (despite the ordering)
Kinesis sequence numbers are inclusive i.e if current sequence == end sequence, there are more records left to read.
However, the equality check is exclusive when dealing with UNREAD tokens.
AmatyaAvadhanula
Clint Wylie
Suneet Saldanha
Tejaswini Bandlamudi
Gian Merlino
Nicholas Lippis
TSFenwick
zachjsh
Adarsh Sanjeev
Rohan Garg
imply-cheddar
Karan Kumar
kaijianding
Kashif Faraz
Laksh Singla
Abhishek Agarwal
Paul Rogers
Churro
Maytas Monsereenusorn
somu-imply
Jonathan Wei
Herb Brewer