Apache
/
druid
mirror of https://github.com/apache/druid.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Clean up Kinesis doc (#14529)

This commit is contained in:
Katya Macedo 2023-07-25 21:24:36 -05:00 committed by GitHub
parent 2dc3e94a9a
commit 4804630c78
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 374 additions and 338 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

709
docs/development/extensions-core/kinesis-ingestion.md
View File

@ -23,154 +23,258 @@ sidebar_label: "Amazon Kinesis"
~ under the License.
-->
When you enable the Kinesis indexing service, you can configure *supervisors* on the Overlord to manage the creation and lifetime of Kinesis indexing tasks. These indexing tasks read events using Kinesis' own shard and sequence number mechanism to guarantee exactly-once ingestion. The supervisor oversees the state of the indexing tasks to:
When you enable the Kinesis indexing service, you can configure supervisors on the Overlord to manage the creation and lifetime of Kinesis indexing tasks. These indexing tasks read events using Kinesis' own shard and sequence number mechanism to guarantee exactly-once ingestion. The supervisor oversees the state of the indexing tasks to coordinate handoffs, manage failures, and ensure that scalability and replication requirements are maintained.
- coordinate handoffs
- manage failures
- ensure that scalability and replication requirements are maintained.
This topic contains configuration reference information for the Kinesis indexing service supervisor for Apache Druid.
To use the Kinesis indexing service, load the `druid-kinesis-indexing-service` core Apache Druid extension (see
[Including Extensions](../../configuration/extensions.md#loading-extensions)).
## Setup
> Before you deploy the Kinesis extension to production, read the [Kinesis known issues](#kinesis-known-issues).
To use the Kinesis indexing service, you must first load the `druid-kinesis-indexing-service` core extension on both the Overlord and the Middle Manager. See [Loading extensions](../../configuration/extensions.md#loading-extensions) for more information.
Review the [Kinesis known issues](#kinesis-known-issues) before deploying the `druid-kinesis-indexing-service` extension to production.
## Submitting a Supervisor Spec
## Supervisor spec
To use the Kinesis indexing service, load the `druid-kinesis-indexing-service` extension on both the Overlord and the MiddleManagers. Druid starts a supervisor for a dataSource when you submit a supervisor spec. Submit your supervisor spec to the following endpoint:
The following table outlines the high-level configuration options for the Kinesis supervisor object.
See [Supervisor API](../../api-reference/supervisor-api.md) for more information.
`http://<OVERLORD_IP>:<OVERLORD_PORT>/druid/indexer/v1/supervisor`
|Property|Type|Description|Required|
|--------|----|-----------|--------|
|`type`|String|The supervisor type; this should always be `kinesis`.|Yes|
|`spec`|Object|The container object for the supervisor configuration.|Yes|
|`ioConfig`|Object|The [I/O configuration](#supervisor-io-configuration) object for configuring Kafka connection and I/O-related settings for the supervisor and indexing task.|Yes|
|`dataSchema`|Object|The schema used by the Kinesis indexing task during ingestion. See [`dataSchema`](../../ingestion/ingestion-spec.md#dataschema) for more information.|Yes|
|`tuningConfig`|Object|The [tuning configuration](#supervisor-tuning-configuration) object for configuring performance-related settings for the supervisor and indexing tasks.|No|
For example:
Druid starts a new supervisor when you define a supervisor spec.
To create a supervisor, send a `POST` request to the `/druid/indexer/v1/supervisor` endpoint.
Once created, the supervisor persists in the configured metadata database. There can only be a single supervisor per datasource, and submitting a second spec for the same datasource overwrites the previous one.
```sh
curl -X POST -H 'Content-Type: application/json' -d @supervisor-spec.json http://localhost:8090/druid/indexer/v1/supervisor
When an Overlord gains leadership, either by being started or as a result of another Overlord failing, it spawns
a supervisor for each supervisor spec in the metadata database. The supervisor then discovers running Kinesis indexing
tasks and attempts to adopt them if they are compatible with the supervisor's configuration. If they are not
compatible because they have a different ingestion spec or shard allocation, the tasks are killed and the
supervisor creates a new set of tasks. In this way, the supervisors persist across Overlord restarts and failovers.
The following example shows how to submit a supervisor spec for a stream with the name `KinesisStream`.
In this example, `http://SERVICE_IP:SERVICE_PORT` is a placeholder for the server address of deployment and the service port.
<!--DOCUSAURUS_CODE_TABS-->
<!--cURL-->
```shell
curl -X POST "http://SERVICE_IP:SERVICE_PORT/druid/indexer/v1/supervisor" \
-H "Content-Type: application/json" \
-d '{
"type": "kinesis",
"spec": {
"ioConfig": {
"type": "kinesis",
"stream": "KinesisStream",
"inputFormat": {
"type": "json"
},
"useEarliestSequenceNumber": true
},
"tuningConfig": {
"type": "kinesis"
},
"dataSchema": {
"dataSource": "KinesisStream",
"timestampSpec": {
"column": "timestamp",
"format": "iso"
},
"dimensionsSpec": {
"dimensions": [
"isRobot",
"channel",
"flags",
"isUnpatrolled",
"page",
"diffUrl",
{
"type": "long",
"name": "added"
},
"comment",
{
"type": "long",
"name": "commentLength"
},
"isNew",
"isMinor",
{
"type": "long",
"name": "delta"
},
"isAnonymous",
"user",
{
"type": "long",
"name": "deltaBucket"
},
{
"type": "long",
"name": "deleted"
},
"namespace",
"cityName",
"countryName",
"regionIsoCode",
"metroCode",
"countryIsoCode",
"regionName"
]
},
"granularitySpec": {
"queryGranularity": "none",
"rollup": false,
"segmentGranularity": "hour"
}
}
}
}'
```
<!--HTTP-->
```HTTP
POST /druid/indexer/v1/supervisor
HTTP/1.1
Host: http://SERVICE_IP:SERVICE_PORT
Content-Type: application/json
Where the file `supervisor-spec.json` contains a Kinesis supervisor spec:
```json
{
"type": "kinesis",
"spec": {
"ioConfig": {
"type": "kinesis",
"stream": "KinesisStream",
"inputFormat": {
"type": "json"
},
"useEarliestSequenceNumber": true
},
"tuningConfig": {
"type": "kinesis"
},
"dataSchema": {
"dataSource": "metrics-kinesis",
"dataSource": "KinesisStream",
"timestampSpec": {
"column": "timestamp",
"format": "auto"
"format": "iso"
},
"dimensionsSpec": {
"dimensions": [],
"dimensionExclusions": [
"timestamp",
"value"
]
"dimensionsSpec": {
"dimensions": [
"isRobot",
"channel",
"flags",
"isUnpatrolled",
"page",
"diffUrl",
{
"type": "long",
"name": "added"
},
"comment",
{
"type": "long",
"name": "commentLength"
},
"isNew",
"isMinor",
{
"type": "long",
"name": "delta"
},
"isAnonymous",
"user",
{
"type": "long",
"name": "deltaBucket"
},
{
"type": "long",
"name": "deleted"
},
"namespace",
"cityName",
"countryName",
"regionIsoCode",
"metroCode",
"countryIsoCode",
"regionName"
]
},
"metricsSpec": [
{
"name": "count",
"type": "count"
},
{
"name": "value_sum",
"fieldName": "value",
"type": "doubleSum"
},
{
"name": "value_min",
"fieldName": "value",
"type": "doubleMin"
},
{
"name": "value_max",
"fieldName": "value",
"type": "doubleMax"
}
],
"granularitySpec": {
"type": "uniform",
"segmentGranularity": "HOUR",
"queryGranularity": "NONE"
}
},
"ioConfig": {
"stream": "metrics",
"inputFormat": {
"type": "json"
},
"endpoint": "kinesis.us-east-1.amazonaws.com",
"taskCount": 1,
"replicas": 1,
"taskDuration": "PT1H"
},
"tuningConfig": {
"type": "kinesis",
"maxRowsPerSegment": 5000000
}
"granularitySpec": {
"queryGranularity": "none",
"rollup": false,
"segmentGranularity": "hour"
}
}
}
}
```
<!--END_DOCUSAURUS_CODE_TABS-->
## Supervisor Spec
## Supervisor I/O configuration
|Field|Description|Required|
|--------|-----------|---------|
|`type`|The supervisor type; this should always be `kinesis`.|yes|
|`spec`|Container object for the supervisor configuration.|yes|
|`dataSchema`|The schema that will be used by the Kinesis indexing task during ingestion. See [`dataSchema`](../../ingestion/ingestion-spec.md#dataschema).|yes|
|`ioConfig`|An [`ioConfig`](#ioconfig) object for configuring Kafka connection and I/O-related settings for the supervisor and indexing task.|yes|
|`tuningConfig`|A [`tuningConfig`](#tuningconfig) object for configuring performance-related settings for the supervisor and indexing tasks.|no|
The following table outlines the configuration options for `ioConfig`:
### `ioConfig`
|Property|Type|Description|Required|Default|
|--------|----|-----------|--------|-------|
|`stream`|String|The Kinesis stream to read.|Yes||
|`inputFormat`|Object|The [input format](../../ingestion/data-formats.md#input-format) to specify how to parse input data. See [Specify data format](#specify-data-format) for more information.|Yes||
|`endpoint`|String|The AWS Kinesis stream endpoint for a region. You can find a list of endpoints in the [AWS service endpoints](http://docs.aws.amazon.com/general/latest/gr/rande.html#ak_region) document.|No|`kinesis.us-east-1.amazonaws.com`|
|`replicas`|Integer|The number of replica sets, where 1 is a single set of tasks (no replication). Druid always assigns replicate tasks to different workers to provide resiliency against process failure.|No|1|
|`taskCount`|Integer|The maximum number of reading tasks in a replica set. Multiply `taskCount` and `replicas` to measure the maximum number of reading tasks. <br />The total number of tasks (reading and publishing) is higher than the maximum number of reading tasks. See [Capacity planning](#capacity-planning) for more details. When `taskCount > {numKinesisShards}`, the actual number of reading tasks is less than the `taskCount` value.|No|1|
|`taskDuration`|ISO 8601 period|The length of time before tasks stop reading and begin publishing their segments.|No|PT1H|
|`startDelay`|ISO 8601 period|The period to wait before the supervisor starts managing tasks.|No|PT5S|
|`period`|ISO 8601 period|Determines how often the supervisor executes its management logic. Note that the supervisor also runs in response to certain events, such as tasks succeeding, failing, and reaching their task duration, so this value specifies the maximum time between iterations.|No|PT30S|
|`useEarliestSequenceNumber`|Boolean|If a supervisor is managing a datasource for the first time, it obtains a set of starting sequence numbers from Kinesis. This flag determines whether a supervisor retrieves the earliest or latest sequence numbers in Kinesis. Under normal circumstances, subsequent tasks start from where the previous segments ended so this flag is only used on the first run.|No|`false`|
|`completionTimeout`|ISO 8601 period|The length of time to wait before Druid declares a publishing task has failed and terminates it. If this is set too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|No|PT6H|
|`lateMessageRejectionPeriod`|ISO 8601 period|Configure tasks to reject messages with timestamps earlier than this period before the task is created. For example, if `lateMessageRejectionPeriod` is set to `PT1H` and the supervisor creates a task at `2016-01-01T12:00Z`, messages with timestamps earlier than `2016-01-01T11:00Z` are dropped. This may help prevent concurrency issues if your data stream has late messages and you have multiple pipelines that need to operate on the same segments, such as a streaming and a nightly batch ingestion pipeline.|No||
|`earlyMessageRejectionPeriod`|ISO 8601 period|Configure tasks to reject messages with timestamps later than this period after the task reached its `taskDuration`. For example, if `earlyMessageRejectionPeriod` is set to `PT1H`, the `taskDuration` is set to `PT1H` and the supervisor creates a task at `2016-01-01T12:00Z`. Messages with timestamps later than `2016-01-01T14:00Z` are dropped. **Note:** Tasks sometimes run past their task duration, for example, in cases of supervisor failover. Setting `earlyMessageRejectionPeriod` too low may cause messages to be dropped unexpectedly whenever a task runs past its originally configured task duration.|No||
|`recordsPerFetch`|Integer|The number of records to request per call to fetch records from Kinesis.|No| See [Determine fetch settings](#determine-fetch-settings) for defaults.|
|`fetchDelayMillis`|Integer|Time in milliseconds to wait between subsequent calls to fetch records from Kinesis. See [Determine fetch settings](#determine-fetch-settings).|No|0|
|`awsAssumedRoleArn`|String|The AWS assumed role to use for additional permissions.|No||
|`awsExternalId`|String|The AWS external ID to use for additional permissions.|No||
|`deaggregate`|Boolean|Whether to use the deaggregate function of the Kinesis Client Library (KCL).|No||
|`autoScalerConfig`|Object|Defines autoscaling behavior for Kinesis ingest tasks. See [Task autoscaler properties](#task-autoscaler-properties) for more information.|No|null|
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|`stream`|String|The Kinesis stream to read.|yes|
|`inputFormat`|Object|[`inputFormat`](../../ingestion/data-formats.md#input-format) to specify how to parse input data. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
|`endpoint`|String|The AWS Kinesis stream endpoint for a region. You can find a list of endpoints [here](http://docs.aws.amazon.com/general/latest/gr/rande.html#ak_region).|no (default == kinesis.us-east-1.amazonaws.com)|
|`replicas`|Integer|The number of replica sets, where 1 means a single set of tasks (no replication). Replica tasks will always be assigned to different workers to provide resiliency against process failure.|no (default == 1)|
|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. This means that the maximum number of reading tasks will be `taskCount * replicas` and the total number of tasks (*reading* + *publishing*) will be higher than this. See [Capacity Planning](#capacity-planning) below for more details. The number of reading tasks will be less than `taskCount` if `taskCount > {numKinesisShards}`.|no (default == 1)|
|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing their segment.|no (default == PT1H)|
|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
|`period`|ISO8601 Period|How often the supervisor will execute its management logic. Note that the supervisor will also run in response to certain events (such as tasks succeeding, failing, and reaching their taskDuration) so this value specifies the maximum time between iterations.|no (default == PT30S)|
|`useEarliestSequenceNumber`|Boolean|If a supervisor is managing a dataSource for the first time, it will obtain a set of starting sequence numbers from Kinesis. This flag determines whether it retrieves the earliest or latest sequence numbers in Kinesis. Under normal circumstances, subsequent tasks will start from where the previous segments ended so this flag will only be used on first run.|no (default == false)|
|`completionTimeout`|ISO8601 Period|The length of time to wait before declaring a publishing task as failed and terminating it. If this is set too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT6H)|
|`lateMessageRejectionPeriod`|ISO8601 Period|Configure tasks to reject messages with timestamps earlier than this period before the task was created; for example if this is set to `PT1H` and the supervisor creates a task at *2016-01-01T12:00Z*, messages with timestamps earlier than *2016-01-01T11:00Z* will be dropped. This may help prevent concurrency issues if your data stream has late messages and you have multiple pipelines that need to operate on the same segments (e.g. a streaming and a nightly batch ingestion pipeline).|no (default == none)|
|`earlyMessageRejectionPeriod`|ISO8601 Period|Configure tasks to reject messages with timestamps later than this period after the task reached its taskDuration; for example if this is set to `PT1H`, the taskDuration is set to `PT1H` and the supervisor creates a task at *2016-01-01T12:00Z*. Messages with timestamps later than *2016-01-01T14:00Z* will be dropped. **Note:** Tasks sometimes run past their task duration, for example, in cases of supervisor failover. Setting `earlyMessageRejectionPeriod` too low may cause messages to be dropped unexpectedly whenever a task runs past its originally configured task duration.|no (default == none)|
|`recordsPerFetch`|Integer|The number of records to request per call to fetch records from Kinesis. See [Determining fetch settings](#determining-fetch-settings).|no (see [Determining fetch settings](#determining-fetch-settings) for defaults)|
|`fetchDelayMillis`|Integer|Time in milliseconds to wait between subsequent calls to fetch records from Kinesis. See [Determining fetch settings](#determining-fetch-settings).|no (default == 0)|
|`awsAssumedRoleArn`|String|The AWS assumed role to use for additional permissions.|no|
|`awsExternalId`|String|The AWS external id to use for additional permissions.|no|
|`deaggregate`|Boolean|Whether to use the de-aggregate function of the KCL. See below for details.|no|
|`autoScalerConfig`|Object|Defines auto scaling behavior for Kinesis ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
### Task autoscaler properties
#### Task Autoscaler Properties
The following table outlines the configuration options for `autoScalerConfig`:
| Property | Description | Required |
| ------------- | ------------- | ------------- |
| `enableTaskAutoScaler` | Enable or disable the auto scaler. When false or absent, Druid disables the `autoScaler` even when `autoScalerConfig` is not null.| no (default == false) |
| `taskCountMax` | Maximum number of Kinesis ingestion tasks. Must be greater than or equal to `taskCountMin`. If greater than `{numKinesisShards}`, the maximum number of reading tasks is `{numKinesisShards}` and `taskCountMax` is ignored. | yes |
| `taskCountMin` | Minimum number of Kinesis ingestion tasks. When you enable the auto scaler, Druid ignores the value of taskCount in `IOConfig` and uses`taskCountMin` for the initial number of tasks to launch.| yes |
| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions | no (default == 600000) |
| `autoScalerStrategy` | The algorithm of `autoScaler`. ONLY `lagBased` is supported for now. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
|Property|Description|Required|Default|
|--------|-----------|--------|-------|
|`enableTaskAutoScaler`|Enables the auto scaler. If not specified, Druid disables the auto scaler even when `autoScalerConfig` is not null.|No|`false`|
|`taskCountMax`|Maximum number of Kinesis ingestion tasks. Must be greater than or equal to `taskCountMin`. If greater than `{numKinesisShards}`, Druid sets the maximum number of reading tasks to `{numKinesisShards}` and ignores `taskCountMax`.|Yes||
|`taskCountMin`|Minimum number of Kinesis ingestion tasks. When you enable the auto scaler, Druid ignores the value of `taskCount` in `IOConfig` and uses `taskCountMin` for the initial number of tasks to launch.|Yes||
|`minTriggerScaleActionFrequencyMillis`|Minimum time interval between two scale actions.| No|600000|
|`autoScalerStrategy`|The algorithm of `autoScaler`. Druid only supports the `lagBased` strategy. See [Lag based autoscaler strategy related properties](#lag-based-autoscaler-strategy-related-properties) for more information.|No|Defaults to `lagBased`.|
##### Lag Based AutoScaler Strategy Related Properties
### Lag based autoscaler strategy related properties
The Kinesis indexing service reports lag metrics measured in time milliseconds rather than message count which is used by Kafka.
Unlike the Kafka indexing service, Kinesis reports lag metrics measured in time difference in milliseconds between the current sequence number and latest sequence number, rather than message count.
| Property | Description | Required |
| ------------- | ------------- | ------------- |
| `lagCollectionIntervalMillis` | Period of lag points collection. | no (default == 30000) |
| `lagCollectionRangeMillis` | The total time window of lag collection, Use with `lagCollectionIntervalMillis`，it means that in the recent `lagCollectionRangeMillis`, collect lag metric points every `lagCollectionIntervalMillis`. | no (default == 600000) |
| `scaleOutThreshold` | The Threshold of scale out action | no (default == 6000000) |
| `triggerScaleOutFractionThreshold` | If `triggerScaleOutFractionThreshold` percent of lag points are higher than `scaleOutThreshold`, then do scale out action. | no (default == 0.3) |
| `scaleInThreshold` | The Threshold of scale in action | no (default == 1000000) |
| `triggerScaleInFractionThreshold` | If `triggerScaleInFractionThreshold` percent of lag points are lower than `scaleOutThreshold`, then do scale in action. | no (default == 0.9) |
| `scaleActionStartDelayMillis` | Number of milliseconds to delay after the supervisor starts before the first scale logic check. | no (default == 300000) |
| `scaleActionPeriodMillis` | Frequency in milliseconds to check if a scale action is triggered | no (default == 60000) |
| `scaleInStep` | Number of tasks to reduce at a time when scaling down | no (default == 1) |
| `scaleOutStep` | Number of tasks to add at a time when scaling out | no (default == 2) |
The following table outlines the configuration options for `autoScalerStrategy`:
The following example demonstrates a supervisor spec with `lagBased` autoScaler enabled:
|Property|Description|Required|Default|
|--------|-----------|--------|-------|
|`lagCollectionIntervalMillis`|The time period during which Druid collects lag metric points.|No|30000|
|`lagCollectionRangeMillis`|The total time window of lag collection. Use with `lagCollectionIntervalMillis` to specify the intervals at which to collect lag metric points.|No|600000|
|`scaleOutThreshold`|The threshold of scale out action. |No|6000000|
|`triggerScaleOutFractionThreshold`|Enables scale out action if `triggerScaleOutFractionThreshold` percent of lag points is higher than `scaleOutThreshold`.|No|0.3|
|`scaleInThreshold`|The threshold of scale in action.|No|1000000|
|`triggerScaleInFractionThreshold`|Enables scale in action if `triggerScaleInFractionThreshold` percent of lag points is lower than `scaleOutThreshold`.|No|0.9|
|`scaleActionStartDelayMillis`|The number of milliseconds to delay after the supervisor starts before the first scale logic check.|No|300000|
|`scaleActionPeriodMillis`|The frequency in milliseconds to check if a scale action is triggered.|No|60000|
|`scaleInStep`|The number of tasks to reduce at once when scaling down.|No|1|
|`scaleOutStep`|The number of tasks to add at once when scaling out.|No|2|
The following example shows a supervisor spec with `lagBased` auto scaler enabled.
<details>
<summary>Click to view the example</summary>
```json
{
@ -249,10 +353,12 @@ The following example demonstrates a supervisor spec with `lagBased` autoScaler
}
```
#### Specifying data format
</details>
Kinesis indexing service supports both [`inputFormat`](../../ingestion/data-formats.md#input-format) and [`parser`](../../ingestion/data-formats.md#parser) to specify the data format.
Use the `inputFormat` to specify the data format for Kinesis indexing service unless you need a format only supported by the legacy `parser`.
### Specify data format
The Kinesis indexing service supports both [`inputFormat`](../../ingestion/data-formats.md#input-format) and [`parser`](../../ingestion/data-formats.md#parser) to specify the data format.
Use the `inputFormat` to specify the data format for the Kinesis indexing service unless you need a format only supported by the legacy `parser`.
Supported values for `inputFormat` include:
@ -265,104 +371,85 @@ Supported values for `inputFormat` include:
For more information, see [Data formats](../../ingestion/data-formats.md). You can also read [`thrift`](../extensions-contrib/thrift.md) formats using `parser`.
<a name="tuningconfig"></a>
## Supervisor tuning configuration
### `tuningConfig`
The `tuningConfig` object is optional. If you don't specify the `tuningConfig` object, Druid uses the default configuration settings.
The `tuningConfig` is optional. If no `tuningConfig` is specified, default parameters are used.
The following table outlines the configuration options for `tuningConfig`:
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|`type`| String|The indexing task type, this should always be `kinesis`.|yes|
|`maxRowsInMemory`|Integer|The number of rows to aggregate before persisting. This number is the post-aggregation rows, so it is not equivalent to the number of input events, but the number of aggregated rows that those events result in. This is used to manage the required JVM heap size. Maximum heap memory usage for indexing scales with `maxRowsInMemory * (2 + maxPendingPersists)`.|no (default == 150000)|
|`maxBytesInMemory`|Long| The number of bytes to aggregate in heap memory before persisting. This is based on a rough estimate of memory usage and not actual usage. Normally, this is computed internally and user does not need to set it. The maximum heap memory usage for indexing is `maxBytesInMemory * (2 + maxPendingPersists)`.|no (default == One-sixth of max JVM memory)|
|`maxRowsPerSegment`|Integer|The number of rows to aggregate into a segment; this number is post-aggregation rows. Handoff will happen either if `maxRowsPerSegment` or `maxTotalRows` is hit or every `intermediateHandoffPeriod`, whichever happens earlier.|no (default == 5000000)|
|`maxTotalRows`|Long|The number of rows to aggregate across all segments; this number is post-aggregation rows. Handoff will happen either if `maxRowsPerSegment` or `maxTotalRows` is hit or every `intermediateHandoffPeriod`, whichever happens earlier.|no (default == unlimited)|
|`intermediatePersistPeriod`|ISO8601 Period|The period that determines the rate at which intermediate persists occur.|no (default == PT10M)|
|`maxPendingPersists`|Integer|Maximum number of persists that can be pending but not started. If this limit would be exceeded by a new intermediate persist, ingestion will block until the currently-running persist finishes. Maximum heap memory usage for indexing scales with `maxRowsInMemory * (2 + maxPendingPersists)`.|no (default == 0, meaning one persist can be running concurrently with ingestion, and none can be queued up)|
|`indexSpec`|Object|Tune how data is indexed. See [IndexSpec](#indexspec) for more information.|no|
|`indexSpecForIntermediatePersists`|Object|Defines segment storage format options to be used at indexing time for intermediate persisted temporary segments. This can be used to disable dimension/metric compression on intermediate segments to reduce memory required for final merging. However, disabling compression on intermediate segments might increase page cache use while they are used before getting merged into final segment published, see [IndexSpec](#indexspec) for possible values.| no (default = same as `indexSpec`)|
|`reportParseExceptions`|Boolean|If true, exceptions encountered during parsing will be thrown and will halt ingestion; if false, unparseable rows and fields will be skipped.|no (default == false)|
|`handoffConditionTimeout`|Long| Number of milliseconds to wait for segment handoff. Set to a value >= 0, where 0 means to wait indefinitely.| no (default == 900000 [15 minutes])|
|`resetOffsetAutomatically`|Boolean|Controls behavior when Druid needs to read Kinesis messages that are no longer available.<br/><br/>If false, the exception bubbles up, causing tasks to fail and ingestion to halt. If this occurs, manual intervention is required to correct the situation, potentially using the [Reset Supervisor API](../../api-reference/supervisor-api.md). This mode is useful for production, since it highlights issues with ingestion.<br/><br/>If true, Druid automatically resets to the earliest or latest sequence number available in Kinesis, based on the value of the `useEarliestSequenceNumber` property (earliest if true, latest if false). Note that this can lead to data being *DROPPED* (if `useEarliestSequenceNumber` is false) or *DUPLICATED* (if `useEarliestSequenceNumber` is true) without your knowledge. Druid will log messages indicating that a reset has occurred without interrupting ingestion. This mode is useful for non-production situations since it enables Druid to recover from problems automatically, even if they lead to quiet dropping or duplicating of data.|no (default == false)|
|`skipSequenceNumberAvailabilityCheck`|Boolean|Whether to enable checking if the current sequence number is still available in a particular Kinesis shard. If set to false, the indexing task will attempt to reset the current sequence number (or not), depending on the value of `resetOffsetAutomatically`.|no (default == false)|
|`workerThreads`|Integer|The number of threads that the supervisor uses to handle requests/responses for worker tasks, along with any other internal asynchronous operation.|no (default == min(10, taskCount))|
|`chatAsync`|Boolean| If true, the supervisor uses asynchronous communication with indexing tasks and ignores the `chatThreads` parameter. If false, the supervisor uses synchronous communication in a thread pool of size `chatThreads`.| no (default == true)|
|`chatThreads`|Integer| The number of threads that will be used for communicating with indexing tasks. Ignored if `chatAsync` is `true` (the default).| no (default == min(10, taskCount * replicas))|
|`chatRetries`|Integer|The number of times HTTP requests to indexing tasks will be retried before considering tasks unresponsive.| no (default == 8)|
|`httpTimeout`|ISO8601 Period|How long to wait for a HTTP response from an indexing task.|no (default == PT10S)|
|`shutdownTimeout`|ISO8601 Period|How long to wait for the supervisor to attempt a graceful shutdown of tasks before exiting.|no (default == PT80S)|
|`recordBufferSize`|Integer|Size of the buffer (number of events) used between the Kinesis fetch threads and the main ingestion thread.|no (see [Determining fetch settings](#determining-fetch-settings) for defaults)|
|`recordBufferOfferTimeout`|Integer|Length of time in milliseconds to wait for space to become available in the buffer before timing out.| no (default == 5000)|
|`recordBufferFullWait`|Integer|Length of time in milliseconds to wait for the buffer to drain before attempting to fetch records from Kinesis again.|no (default == 5000)|
|`fetchThreads`|Integer|Size of the pool of threads fetching data from Kinesis. There is no benefit in having more threads than Kinesis shards.|no (default == procs * 2, where `procs` is the number of processors available to the task)|
|`segmentWriteOutMediumFactory`|Object|Segment write-out medium to use when creating segments. See below for more information.|no (not specified by default, the value from `druid.peon.defaultSegmentWriteOutMediumFactory.type` is used)|
|`intermediateHandoffPeriod`|ISO8601 Period|How often the tasks should hand off segments. Handoff will happen either if `maxRowsPerSegment` or `maxTotalRows` is hit or every `intermediateHandoffPeriod`, whichever happens earlier.| no (default == P2147483647D)|
|`logParseExceptions`|Boolean|If true, log an error message when a parsing exception occurs, containing information about the row where the error occurred.|no, default == false|
|`maxParseExceptions`|Integer|The maximum number of parse exceptions that can occur before the task halts ingestion and fails. Overridden if `reportParseExceptions` is set.|no, unlimited default|
|`maxSavedParseExceptions`|Integer|When a parse exception occurs, Druid can keep track of the most recent parse exceptions. "maxSavedParseExceptions" limits how many exception instances will be saved. These saved exceptions will be made available after the task finishes in the [task completion report](../../ingestion/tasks.md#task-reports). Overridden if `reportParseExceptions` is set.|no, default == 0|
|`maxRecordsPerPoll`|Integer|The maximum number of records/events to be fetched from buffer per poll. The actual maximum will be `Max(maxRecordsPerPoll, Max(bufferSize, 1))`|no (see [Determining fetch settings](#determining-fetch-settings) for defaults)|
|`repartitionTransitionDuration`|ISO8601 period|When shards are split or merged, the supervisor recomputes shard to task group mappings. The supervisor also signals any running tasks created under the old mappings to stop early at (current time + `repartitionTransitionDuration`). Stopping the tasks early allows Druid to begin reading from the new shards more quickly. The repartition transition wait time controlled by this property gives the stream additional time to write records to the new shards after the split or merge, which helps avoid issues with [empty shard handling](https://github.com/apache/druid/issues/7600).|no, (default == PT2M)|
|`offsetFetchPeriod`|ISO8601 period|How often the supervisor queries Kinesis and the indexing tasks to fetch current offsets and calculate lag. If the user-specified value is below the minimum value (`PT5S`), the supervisor ignores the value and uses the minimum value instead.|no (default == PT30S, min == PT5S)|
|`useListShards`|Boolean|Indicates if `listShards` API of AWS Kinesis SDK can be used to prevent `LimitExceededException` during ingestion. Please note that the necessary `IAM` permissions must be set for this to work.|no (default == false)|
|Property|Type|Description|Required|Default|
|--------|----|-----------|--------|-------|
|`type`|String|The indexing task type. This should always be `kinesis`.|Yes||
|`maxRowsInMemory`|Integer|The number of rows to aggregate before persisting. This number represents the post-aggregation rows. It is not equivalent to the number of input events, but the resulting number of aggregated rows. Druid uses `maxRowsInMemory` to manage the required JVM heap size. The maximum heap memory usage for indexing scales is `maxRowsInMemory * (2 + maxPendingPersists)`.|No|100000|
|`maxBytesInMemory`|Long| The number of bytes to aggregate in heap memory before persisting. This is based on a rough estimate of memory usage and not actual usage. Normally, this is computed internally. The maximum heap memory usage for indexing is `maxBytesInMemory * (2 + maxPendingPersists)`.|No|One-sixth of max JVM memory|
|`skipBytesInMemoryOverheadCheck`|Boolean|The calculation of `maxBytesInMemory` takes into account overhead objects created during ingestion and each intermediate persist. To exclude the bytes of these overhead objects from the `maxBytesInMemory` check, set `skipBytesInMemoryOverheadCheck` to `true`.|No|`false`|
|`maxRowsPerSegment`|Integer|The number of rows to aggregate into a segment; this number represents the post-aggregation rows. Handoff occurs when `maxRowsPerSegment` or `maxTotalRows` is reached or every `intermediateHandoffPeriod`, whichever happens first.|No|5000000|
|`maxTotalRows`|Long|The number of rows to aggregate across all segments; this number represents the post-aggregation rows. Handoff occurs when `maxRowsPerSegment` or `maxTotalRows` is reached or every `intermediateHandoffPeriod`, whichever happens first.|No|unlimited|
|`intermediateHandoffPeriod`|ISO 8601 period|The period that determines how often tasks hand off segments. Handoff occurs if `maxRowsPerSegment` or `maxTotalRows` is reached or every `intermediateHandoffPeriod`, whichever happens first.|No|P2147483647D|
|`intermediatePersistPeriod`|ISO 8601 period|The period that determines the rate at which intermediate persists occur.|No|PT10M|
|`maxPendingPersists`|Integer|Maximum number of persists that can be pending but not started. If a new intermediate persist exceeds this limit, Druid blocks ingestion until the currently running persist finishes. One persist can be running concurrently with ingestion, and none can be queued up. The maximum heap memory usage for indexing scales is `maxRowsInMemory * (2 + maxPendingPersists)`.|No|0|
|`indexSpec`|Object|Defines how Druid indexes the data. See [IndexSpec](#indexspec) for more information.|No||
|`indexSpecForIntermediatePersists`|Object|Defines segment storage format options to use at indexing time for intermediate persisted temporary segments. You can use `indexSpecForIntermediatePersists` to disable dimension/metric compression on intermediate segments to reduce memory required for final merging. However, disabling compression on intermediate segments might increase page cache use while they are used before getting merged into final segment published. See [IndexSpec](#indexspec) for possible values.|No|Same as `indexSpec`|
|`reportParseExceptions`|Boolean|If `true`, Druid throws exceptions encountered during parsing causing ingestion to halt. If `false`, Druid skips unparseable rows and fields.|No|`false`|
|`handoffConditionTimeout`|Long|Number of milliseconds to wait for segment handoff. Set to a value >= 0, where 0 means to wait indefinitely.|No|0|
|`resetOffsetAutomatically`|Boolean|Controls behavior when Druid needs to read Kinesis messages that are no longer available.<br/>If `false`, the exception bubbles up causing tasks to fail and ingestion to halt. If this occurs, manual intervention is required to correct the situation, potentially using the [Reset Supervisor API](../../api-reference/supervisor-api.md). This mode is useful for production, since it highlights issues with ingestion.<br/>If `true`, Druid automatically resets to the earliest or latest sequence number available in Kinesis, based on the value of the `useEarliestSequenceNumber` property (earliest if `true`, latest if `false`). Note that this can lead to dropping data (if `useEarliestSequenceNumber` is `false`) or duplicating data (if `useEarliestSequenceNumber` is `true`) without your knowledge. Druid logs messages indicating that a reset has occurred without interrupting ingestion. This mode is useful for non-production situations since it enables Druid to recover from problems automatically, even if they lead to quiet dropping or duplicating of data.|No|`false`|
|`skipSequenceNumberAvailabilityCheck`|Boolean|Whether to enable checking if the current sequence number is still available in a particular Kinesis shard. If `false`, the indexing task attempts to reset the current sequence number, depending on the value of `resetOffsetAutomatically`.|No|`false`|
|`workerThreads`|Integer|The number of threads that the supervisor uses to handle requests/responses for worker tasks, along with any other internal asynchronous operation.|No| `min(10, taskCount)`|
|`chatAsync`|Boolean| If `true`, the supervisor uses asynchronous communication with indexing tasks and ignores the `chatThreads` parameter. If `false`, the supervisor uses synchronous communication in a thread pool of size `chatThreads`.|No| `true`|
|`chatThreads`|Integer|The number of threads Druid uses to communicate with indexing tasks. Druid ignores this setting if `chatAsync` is `true`.|No|`min(10, taskCount * replicas)`|
|`chatRetries`|Integer|The number of times Druid retries HTTP requests to indexing tasks before considering tasks unresponsive.|No|8|
|`httpTimeout`|ISO 8601 period|The period of time to wait for a HTTP response from an indexing task.|No|PT10S|
|`shutdownTimeout`|ISO 8601 period|The period of time to wait for the supervisor to attempt a graceful shutdown of tasks before exiting.|No|PT80S|
|`recordBufferSize`|Integer|The size of the buffer (number of events) Druid uses between the Kinesis fetch threads and the main ingestion thread.|No|See [Determine fetch settings](#determine-fetch-settings) for defaults.|
|`recordBufferOfferTimeout`|Integer|The number of milliseconds to wait for space to become available in the buffer before timing out.|No|5000|
|`recordBufferFullWait`|Integer|The number of milliseconds to wait for the buffer to drain before Druid attempts to fetch records from Kinesis again.|No|5000|
|`fetchThreads`|Integer|The size of the pool of threads fetching data from Kinesis. There is no benefit in having more threads than Kinesis shards.|No| `procs * 2`, where `procs` is the number of processors available to the task.|
|`segmentWriteOutMediumFactory`|Object|The segment write-out medium to use when creating segments See [Additional Peon configuration: SegmentWriteOutMediumFactory](../../configuration/index.md#segmentwriteoutmediumfactory) for explanation and available options.|No|If not specified, Druid uses the value from `druid.peon.defaultSegmentWriteOutMediumFactory.type`.|
|`logParseExceptions`|Boolean|If `true`, Druid logs an error message when a parsing exception occurs, containing information about the row where the error occurred.|No|`false`|
|`maxParseExceptions`|Integer|The maximum number of parse exceptions that can occur before the task halts ingestion and fails. Overridden if `reportParseExceptions` is set.|No|unlimited|
|`maxSavedParseExceptions`|Integer|When a parse exception occurs, Druid keeps track of the most recent parse exceptions. `maxSavedParseExceptions` limits the number of saved exception instances. These saved exceptions are available after the task finishes in the [task completion report](../../ingestion/tasks.md#task-reports). Overridden if `reportParseExceptions` is set.|No|0|
|`maxRecordsPerPoll`|Integer|The maximum number of records to be fetched from buffer per poll. The actual maximum will be `Max(maxRecordsPerPoll, Max(bufferSize, 1))`.|No| See [Determine fetch settings](#determine-fetch-settings) for defaults.|
|`repartitionTransitionDuration`|ISO 8601 period|When shards are split or merged, the supervisor recomputes shard to task group mappings. The supervisor also signals any running tasks created under the old mappings to stop early at current time + `repartitionTransitionDuration`. Stopping the tasks early allows Druid to begin reading from the new shards more quickly. The repartition transition wait time controlled by this property gives the stream additional time to write records to the new shards after the split or merge, which helps avoid issues with [empty shard handling](https://github.com/apache/druid/issues/7600).|No|PT2M|
|`offsetFetchPeriod`|ISO 8601 period|Determines how often the supervisor queries Kinesis and the indexing tasks to fetch current offsets and calculate lag. If the user-specified value is below the minimum value of PT5S, the supervisor ignores the value and uses the minimum value instead.|No|PT30S|
|`useListShards`|Boolean|Indicates if `listShards` API of AWS Kinesis SDK can be used to prevent `LimitExceededException` during ingestion. You must set the necessary `IAM` permissions.|No|`false`|
#### IndexSpec
### IndexSpec
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|bitmap|Object|Compression format for bitmap indexes. Should be a JSON object. See [Bitmap types](#bitmap-types) below for options.|no (defaults to Roaring)|
|dimensionCompression|String|Compression format for dimension columns. Choose from `LZ4`, `LZF`, or `uncompressed`.|no (default == `LZ4`)|
|metricCompression|String|Compression format for primitive type metric columns. Choose from `LZ4`, `LZF`, `uncompressed`, or `none`.|no (default == `LZ4`)|
|longEncoding|String|Encoding format for metric and dimension columns with type long. Choose from `auto` or `longs`. `auto` encodes the values using sequence number or lookup table depending on column cardinality, and store them with variable size. `longs` stores the value as is with 8 bytes each.|no (default == `longs`)|
The following table outlines the configuration options for `indexSpec`:
##### Bitmap types
For Roaring bitmaps:
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|`type`|String|Must be `roaring`.|yes|
For Concise bitmaps:
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|`type`|String|Must be `concise`.|yes|
#### SegmentWriteOutMediumFactory
|Field|Type|Description|Required|
|-----|----|-----------|--------|
|`type`|String|See [Additional Peon Configuration: SegmentWriteOutMediumFactory](../../configuration/index.md#segmentwriteoutmediumfactory) for explanation and available options.|yes|
|Property|Type|Description|Required|Default|
|--------|----|-----------|--------|-------|
|`bitmap`|Object|Compression format for bitmap indexes. Druid supports roaring and concise bitmap types.|No|Roaring|
|`dimensionCompression`|String|Compression format for dimension columns. Choose from `LZ4`, `LZF`, or `uncompressed`.|No|`LZ4`|
|`metricCompression`|String|Compression format for primitive type metric columns. Choose from `LZ4`, `LZF`, `uncompressed`, or `none`.|No|`LZ4`|
|`longEncoding`|String|Encoding format for metric and dimension columns with type long. Choose from `auto` or `longs`. `auto` encodes the values using sequence number or lookup table depending on column cardinality and stores them with variable sizes. `longs` stores the value as is with 8 bytes each.|No|`longs`|
## Operations
This section describes how some supervisor APIs work in Kinesis Indexing Service.
For all supervisor APIs, check [Supervisor API reference](../../api-reference/supervisor-api.md).
This section describes how to use the [Supervisor API](../../api-reference/supervisor-api.md) with the Kinesis indexing service.
### AWS Authentication
### AWS authentication
To authenticate with AWS, you must provide your AWS access key and AWS secret key via `runtime.properties`, for example:
To authenticate with AWS, you must provide your AWS access key and AWS secret key using `runtime.properties`, for example:
```text
-Ddruid.kinesis.accessKey=123 -Ddruid.kinesis.secretKey=456
druid.kinesis.accessKey=AKIAWxxxxxxxxxx4NCKS
druid.kinesis.secretKey=Jbytxxxxxxxxxxx2+555
```
The AWS access key ID and secret access key are used for Kinesis API requests. If this is not provided, the service will
look for credentials set in environment variables, via [Web Identity Token](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_providers_oidc.html), in the default profile configuration file, and from the EC2 instance
profile provider (in this order).
Druid uses the AWS access key and AWS secret key to authenticate Kinesis API requests. If not provided, the service looks for credentials set in environment variables, via [Web Identity Token](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_providers_oidc.html), in the default profile configuration file, and from the EC2 instance profile provider (in this order).
To ingest data from Kinesis, ensure that the policy attached to your IAM role contains the necessary permissions.
The required permissions depend on the value of `useListShards`.
If the `useListShards` flag is set to `true`, you need following permissions:
- `ListStreams`: required to list your data streams
- `Get*`: required for `GetShardIterator`
- `GetRecords`: required to get data records from a data stream's shard
- `ListShards` : required to get the shards for a stream of interest
- `ListStreams` to list your data streams.
- `Get*` required for `GetShardIterator`.
- `GetRecords` to get data records from a data stream's shard.
- `ListShards` to get the shards for a stream of interest.
**Example policy**
The following is an example policy:
```json
[
@ -381,12 +468,12 @@ If the `useListShards` flag is set to `true`, you need following permissions:
If the `useListShards` flag is set to `false`, you need following permissions:
- `ListStreams`: required to list your data streams
- `Get*`: required for `GetShardIterator`
- `GetRecords`: required to get data records from a data stream's shard
- `DescribeStream`: required to describe the specified data stream
- `ListStreams` to list your data streams.
- `Get*` required for `GetShardIterator`.
- `GetRecords` to get data records from a data stream's shard.
- `DescribeStream` to describe the specified data stream.
**Example policy**
The following is an example policy:
```json
[
@ -408,128 +495,106 @@ If the `useListShards` flag is set to `false`, you need following permissions:
]
```
### Getting Supervisor Status Report
### Get supervisor status report
`GET /druid/indexer/v1/supervisor/<supervisorId>/status` returns a snapshot report of the current state of the tasks
managed by the given supervisor. This includes the latest sequence numbers as reported by Kinesis. Unlike the Kafka
Indexing Service, Kinesis reports lag metrics measured in time difference in milliseconds between the current sequence number and latest sequence number, rather than message count.
To retrieve the current status report for a single supervisor, send a `GET` request to the `/druid/indexer/v1/supervisor/:supervisorId/status` endpoint.
The status report also contains the supervisor's state and a list of recently thrown exceptions (reported as
`recentErrors`, whose max size can be controlled using the `druid.supervisor.maxStoredExceptionEvents` configuration).
There are two fields related to the supervisor's state - `state` and `detailedState`. The `state` field will always be
one of a small number of generic states that apply to any type of supervisor, while the `detailedState` field
will contain a more descriptive, implementation-specific state that may provide more insight into the supervisor's
activities than the generic `state` field.
The report contains the state of the supervisor tasks, the latest sequence numbers, and an array of recently thrown exceptions reported as `recentErrors`. You can control the maximum size of the exceptions using the `druid.supervisor.maxStoredExceptionEvents` configuration.
The list of possible `state` values are: [`PENDING`, `RUNNING`, `SUSPENDED`, `STOPPING`, `UNHEALTHY_SUPERVISOR`, `UNHEALTHY_TASKS`]
The two properties related to the supervisor's state are `state` and `detailedState`. The `state` property contains a small number of generic states that apply to any type of supervisor, while the `detailedState` property contains a more descriptive, implementation-specific state that may provide more insight into the supervisor's activities.
The list of `detailedState` values and their corresponding `state` mapping is as follows:
Possible `state` values are `PENDING`, `RUNNING`, `SUSPENDED`, `STOPPING`, `UNHEALTHY_SUPERVISOR`, and `UNHEALTHY_TASKS`.
|Detailed State|Corresponding State|Description|
The following table lists `detailedState` values and their corresponding `state` mapping:
|Detailed state|Corresponding state|Description|
|--------------|-------------------|-----------|
|UNHEALTHY_SUPERVISOR|UNHEALTHY_SUPERVISOR|The supervisor has encountered errors on the past `druid.supervisor.unhealthinessThreshold` iterations|
|UNHEALTHY_TASKS|UNHEALTHY_TASKS|The last `druid.supervisor.taskUnhealthinessThreshold` tasks have all failed|
|UNABLE_TO_CONNECT_TO_STREAM|UNHEALTHY_SUPERVISOR|The supervisor is encountering connectivity issues with Kinesis and has not successfully connected in the past|
|LOST_CONTACT_WITH_STREAM|UNHEALTHY_SUPERVISOR|The supervisor is encountering connectivity issues with Kinesis but has successfully connected in the past|
|PENDING (first iteration only)|PENDING|The supervisor has been initialized and hasn't started connecting to the stream|
|CONNECTING_TO_STREAM (first iteration only)|RUNNING|The supervisor is trying to connect to the stream and update partition data|
|DISCOVERING_INITIAL_TASKS (first iteration only)|RUNNING|The supervisor is discovering already-running tasks|
|CREATING_TASKS (first iteration only)|RUNNING|The supervisor is creating tasks and discovering state|
|RUNNING|RUNNING|The supervisor has started tasks and is waiting for taskDuration to elapse|
|SUSPENDED|SUSPENDED|The supervisor has been suspended|
|STOPPING|STOPPING|The supervisor is stopping|
|`UNHEALTHY_SUPERVISOR`|`UNHEALTHY_SUPERVISOR`|The supervisor encountered errors on previous `druid.supervisor.unhealthinessThreshold` iterations.|
|`UNHEALTHY_TASKS`|`UNHEALTHY_TASKS`|The last `druid.supervisor.taskUnhealthinessThreshold` tasks all failed.|
|`UNABLE_TO_CONNECT_TO_STREAM`|`UNHEALTHY_SUPERVISOR`|The supervisor is encountering connectivity issues with Kinesis and has not successfully connected in the past.|
|`LOST_CONTACT_WITH_STREAM`|`UNHEALTHY_SUPERVISOR`|The supervisor is encountering connectivity issues with Kinesis but has successfully connected in the past.|
|`PENDING` (first iteration only)|`PENDING`|The supervisor has been initialized but hasn't started connecting to the stream.|
|`CONNECTING_TO_STREAM` (first iteration only)|`RUNNING`|The supervisor is trying to connect to the stream and update partition data.|
|`DISCOVERING_INITIAL_TASKS` (first iteration only)|`RUNNING`|The supervisor is discovering already-running tasks.|
|`CREATING_TASKS` (first iteration only)|`RUNNING`|The supervisor is creating tasks and discovering state.|
|`RUNNING`|`RUNNING`|The supervisor has started tasks and is waiting for `taskDuration` to elapse.|
|`SUSPENDED`|`SUSPENDED`|The supervisor is suspended.|
|`STOPPING`|`STOPPING`|The supervisor is stopping.|
On each iteration of the supervisor's run loop, the supervisor completes the following tasks in sequence:
1) Fetch the list of shards from Kinesis and determine the starting sequence number for each shard (either based on the
last processed sequence number if continuing, or starting from the beginning or ending of the stream if this is a new stream).
2) Discover any running indexing tasks that are writing to the supervisor's datasource and adopt them if they match
the supervisor's configuration, else signal them to stop.
3) Send a status request to each supervised task to update our view of the state of the tasks under our supervision.
4) Handle tasks that have exceeded `taskDuration` and should transition from the reading to publishing state.
5) Handle tasks that have finished publishing and signal redundant replica tasks to stop.
6) Handle tasks that have failed and clean up the supervisor's internal state.
7) Compare the list of healthy tasks to the requested `taskCount` and `replicas` configurations and create additional tasks if required.
1. Fetch the list of shards from Kinesis and determine the starting sequence number for each shard (either based on the last processed sequence number if continuing, or starting from the beginning or ending of the stream if this is a new stream).
2. Discover any running indexing tasks that are writing to the supervisor's datasource and adopt them if they match the supervisor's configuration, else signal them to stop.
3. Send a status request to each supervised task to update the view of the state of the tasks under supervision.
4. Handle tasks that have exceeded `taskDuration` and should transition from the reading to publishing state.
5. Handle tasks that have finished publishing and signal redundant replica tasks to stop.
6. Handle tasks that have failed and clean up the supervisor's internal state.
7. Compare the list of healthy tasks to the requested `taskCount` and `replicas` configurations and create additional tasks if required.
The `detailedState` field will show additional values (those marked with "first iteration only") the first time the
The `detailedState` property shows additional values (marked with "first iteration only" in the preceding table) the first time the
supervisor executes this run loop after startup or after resuming from a suspension. This is intended to surface
initialization-type issues, where the supervisor is unable to reach a stable state (perhaps because it can't connect to
Kinesis, it can't read from the stream, or it can't communicate with existing tasks). Once the supervisor is stable -
that is, once it has completed a full execution without encountering any issues - `detailedState` will show a `RUNNING`
initialization-type issues, where the supervisor is unable to reach a stable state. For example, if the supervisor cannot connect to
Kinesis, if it's unable to read from the stream, or cannot communicate with existing tasks. Once the supervisor is stable;
that is, once it has completed a full execution without encountering any issues, `detailedState` will show a `RUNNING`
state until it is stopped, suspended, or hits a failure threshold and transitions to an unhealthy state.
### Updating Existing Supervisors
### Update existing supervisors
`POST /druid/indexer/v1/supervisor` can be used to update existing supervisor spec.
Calling this endpoint when there is already an existing supervisor for the same dataSource will cause:
To update an existing supervisor spec, send a `POST` request to the `/druid/indexer/v1/supervisor` endpoint.
- The running supervisor to signal its managed tasks to stop reading and begin publishing.
- The running supervisor to exit.
- A new supervisor to be created using the configuration provided in the request body. This supervisor will retain the
existing publishing tasks and will create new tasks starting at the sequence numbers the publishing tasks ended on.
When you call this endpoint on an existing supervisor for the same datasource, the running supervisor signals its tasks to stop reading and begin publishing their segments, exiting itself. Druid then uses the provided configuration from the request body to create a new supervisor with a new set of tasks that start reading from the sequence numbers, where the previous now-publishing tasks left off, but using the updated schema.
In this way, configuration changes can be applied without requiring any pause in ingestion.
Seamless schema migrations can thus be achieved by simply submitting the new schema using this endpoint.
You can achieve seamless schema migrations by submitting the new schema using the `/druid/indexer/v1/supervisor` endpoint.
### Suspending and Resuming Supervisors
### Suspend and resume a supervisor
You can suspend and resume a supervisor using `POST /druid/indexer/v1/supervisor/<supervisorId>/suspend` and `POST /druid/indexer/v1/supervisor/<supervisorId>/resume`, respectively.
To suspend a supervisor, send a `POST` request to the `/druid/indexer/v1/supervisor/:supervisorId/suspend` endpoint.
Suspending a supervisor does not prevent it from operating and emitting logs and metrics. It ensures that no indexing tasks are running until the supervisor resumes.
Note that the supervisor itself will still be operating and emitting logs and metrics,
it will just ensure that no indexing tasks are running until the supervisor is resumed.
To resume a supervisor, send a `POST` request to the `/druid/indexer/v1/supervisor/:supervisorId/resume` endpoint.
### Resetting Supervisors
### Reset a supervisor
The `POST /druid/indexer/v1/supervisor/<supervisorId>/reset` operation clears stored
sequence numbers, causing the supervisor to start reading from either the earliest or
The supervisor must be running for this endpoint to be available
To reset a supervisor, send a `POST` request to the `/druid/indexer/v1/supervisor/:supervisorId/reset` endpoint. This endpoint clears stored
sequence numbers, prompting the supervisor to start reading from either the earliest or the
latest sequence numbers in Kinesis (depending on the value of `useEarliestSequenceNumber`).
After clearing stored sequence numbers, the supervisor kills and recreates active tasks,
so that tasks begin reading from valid sequence numbers.
Use care when using this operation! Resetting the supervisor may cause Kinesis messages
to be skipped or read twice, resulting in missing or duplicate data.
This endpoint is useful when you need to recover from a stopped state due to missing sequence numbers in Kinesis.
Use this endpoint with caution as it may result in skipped messages, leading to data loss or duplicate data.
The reason for using this operation is to recover from a state in which the supervisor
ceases operating due to missing sequence numbers. The indexing service keeps track of the latest
The indexing service keeps track of the latest
persisted sequence number to provide exactly-once ingestion guarantees across
tasks.
Subsequent tasks must start reading from where the previous task completed
for the generated segments to be accepted. If the messages at the expected starting sequence numbers are
no longer available in Kinesis (typically because the message retention period has elapsed or the topic was
removed and re-created) the supervisor will refuse to start and in-flight tasks will fail. This operation
enables you to recover from this condition.
removed and re-created) the supervisor will refuse to start and in-flight tasks will fail. This endpoint enables you to recover from this condition.
Note that the supervisor must be running for this endpoint to be available.
### Terminate a supervisor
### Terminating Supervisors
To terminate a supervisor and its associated indexing tasks, send a `POST` request to the `/druid/indexer/v1/supervisor/:supervisorId/terminate` endpoint.
This places a tombstone marker in the database to prevent the supervisor from being reloaded on a restart and then gracefully
shuts down the currently running supervisor.
The tasks stop reading and begin publishing their segments immediately.
The call returns after all tasks have been signaled to stop but before the tasks finish publishing their segments.
The `POST /druid/indexer/v1/supervisor/<supervisorId>/terminate` operation terminates a supervisor and causes
all associated indexing tasks managed by this supervisor to immediately stop and begin
publishing their segments. This supervisor will still exist in the metadata store and its history may be retrieved
with the supervisor history API, but will not be listed in the 'get supervisors' API response nor can its configuration
or status report be retrieved. The only way this supervisor can start again is by submitting a functioning supervisor
spec to the create API.
The terminated supervisor continues exists in the metadata store and its history can be retrieved.
The only way to restart a terminated supervisor is by submitting a functioning supervisor spec to `/druid/indexer/v1/supervisor`.
### Capacity Planning
## Capacity planning
Kinesis indexing tasks run on MiddleManagers and are thus limited by the resources available in the MiddleManager
cluster. In particular, you should make sure that you have sufficient worker capacity (configured using the
`druid.worker.capacity` property) to handle the configuration in the supervisor spec. Note that worker capacity is
shared across all types of indexing tasks, so you should plan your worker capacity to handle your total indexing load
(e.g. batch processing, streaming tasks, merging tasks, etc.). If your workers run out of capacity, Kinesis indexing tasks
will queue and wait for the next available worker. This may cause queries to return partial results but will not result
in data loss (assuming the tasks run before Kinesis purges those sequence numbers).
Kinesis indexing tasks run on Middle Managers and are limited by the resources available in the Middle Manager cluster. In particular, you should make sure that you have sufficient worker capacity, configured using the
`druid.worker.capacity` property, to handle the configuration in the supervisor spec. Note that worker capacity is
shared across all types of indexing tasks, so you should plan your worker capacity to handle your total indexing load, such as batch processing, streaming tasks, and merging tasks. If your workers run out of capacity, Kinesis indexing tasks queue and wait for the next available worker. This may cause queries to return partial results but will not result in data loss, assuming the tasks run before Kinesis purges those sequence numbers.
A running task will normally be in one of two states: *reading* or *publishing*. A task will remain in reading state for
`taskDuration`, at which point it will transition to publishing state. A task will remain in publishing state for as long
as it takes to generate segments, push segments to deep storage, and have them be loaded and served by a Historical process
(or until `completionTimeout` elapses).
A running task can be in one of two states: reading or publishing. A task remains in reading state for the period defined in `taskDuration`, at which point it transitions to publishing state. A task remains in publishing state for as long as it takes to generate segments, push segments to deep storage, and have them loaded and served by a Historical process or until `completionTimeout` elapses.
The number of reading tasks is controlled by `replicas` and `taskCount`. In general, there will be `replicas * taskCount`
reading tasks, the exception being if taskCount > {numKinesisShards} in which case {numKinesisShards} tasks will
be used instead. When `taskDuration` elapses, these tasks will transition to publishing state and `replicas * taskCount`
new reading tasks will be created. Therefore, to allow for reading tasks and publishing tasks to run concurrently, there
should be a minimum capacity of:
The number of reading tasks is controlled by `replicas` and `taskCount`. In general, there are `replicas * taskCount` reading tasks. An exception occurs if `taskCount > {numKinesisShards}`, in which case Druid uses `{numKinesisShards}` tasks. When `taskDuration` elapses, these tasks transition to publishing state and `replicas * taskCount` new reading tasks are created. To allow for reading tasks and publishing tasks to run concurrently, there should be a minimum capacity of:
```text
workerCapacity = 2 * replicas * taskCount
@ -537,59 +602,29 @@ workerCapacity = 2 * replicas * taskCount
This value is for the ideal situation in which there is at most one set of tasks publishing while another set is reading.
In some circumstances, it is possible to have multiple sets of tasks publishing simultaneously. This would happen if the
time-to-publish (generate segment, push to deep storage, loaded on Historical) > `taskDuration`. This is a valid
scenario (correctness-wise) but requires additional worker capacity to support. In general, it is a good idea to have
`taskDuration` be large enough that the previous set of tasks finishes publishing before the current set begins.
time-to-publish (generate segment, push to deep storage, load on Historical) is greater than `taskDuration`. This is a valid and correct scenario but requires additional worker capacity to support. In general, it is a good idea to have `taskDuration` be large enough that the previous set of tasks finishes publishing before the current set begins.
### Supervisor Persistence
## Shards and segment handoff
When a supervisor spec is submitted via the `POST /druid/indexer/v1/supervisor` endpoint, it is persisted in the
configured metadata database. There can only be a single supervisor per dataSource, and submitting a second spec for
the same dataSource will overwrite the previous one.
Each Kinesis indexing task writes the events it consumes from Kinesis shards into a single segment for the segment granularity interval until it reaches one of the following limits: `maxRowsPerSegment`, `maxTotalRows`, or `intermediateHandoffPeriod`.
At this point, the task creates a new shard for this segment granularity to contain subsequent events.
When an Overlord gains leadership, either by being started or as a result of another Overlord failing, it will spawn
a supervisor for each supervisor spec in the metadata database. The supervisor will then discover running Kinesis indexing
tasks and will attempt to adopt them if they are compatible with the supervisor's configuration. If they are not
compatible because they have a different ingestion spec or shard allocation, the tasks will be killed and the
supervisor will create a new set of tasks. In this way, the supervisors are persistent across Overlord restarts and
fail-overs.
The Kinesis indexing task also performs incremental hand-offs so that the segments created by the task are not held up until the task duration is over.
When the task reaches one of the `maxRowsPerSegment`, `maxTotalRows`, or `intermediateHandoffPeriod` limits, it hands off all the segments and creates a new set of segments for further events. This allows the task to run for longer durations
without accumulating old segments locally on Middle Manager processes.
A supervisor is stopped via the `POST /druid/indexer/v1/supervisor/<supervisorId>/terminate` endpoint. This places a
tombstone marker in the database (to prevent the supervisor from being reloaded on a restart) and then gracefully
shuts down the currently running supervisor. When a supervisor is shut down in this way, it will instruct its
managed tasks to stop reading. The tasks will begin publishing their segments immediately. The call to the shutdown
endpoint will return after all tasks have been signalled to stop but before the tasks finish publishing their segments.
The Kinesis indexing service may still produce some small segments.
For example, consider the following scenario:
### Schema/Configuration Changes
- Task duration is 4 hours
- Segment granularity is set to an HOUR
- The supervisor was started at 9:10
Schema and configuration changes are handled by submitting the new supervisor spec via the same
`POST /druid/indexer/v1/supervisor` endpoint used to initially create the supervisor. The Overlord will initiate a
graceful shutdown of the existing supervisor which will cause the tasks being managed by that supervisor to stop reading
and begin publishing their segments. A new supervisor will then be started which will create a new set of tasks that
will start reading from the sequence numbers where the previous now-publishing tasks left off, but using the updated schema.
In this way, configuration changes can be applied without requiring any pause in ingestion.
After 4 hours at 13:10, Druid starts a new set of tasks. The events for the interval 13:00 - 14:00 may be split across existing tasks and the new set of tasks which could result in small segments. To merge them together into new segments of an ideal size (in the range of ~500-700 MB per segment), you can schedule re-indexing tasks, optionally with a different segment granularity.
### Deployment Notes
For more detail, see [Segment size optimization](../../operations/segment-optimization.md).
#### On the Subject of Segments
Each Kinesis Indexing Task puts events consumed from Kinesis Shards assigned to it in a single segment for each segment
granular interval until maxRowsPerSegment, maxTotalRows or intermediateHandoffPeriod limit is reached. At this point, a new shard
for this segment granularity is created for further events. Kinesis Indexing Task also does incremental hand-offs which
means that all the segments created by a task will not be held up till the task duration is over. As soon as maxRowsPerSegment,
maxTotalRows or intermediateHandoffPeriod limit is hit, all the segments held by the task at that point in time will be handed-off
and new set of segments will be created for further events. This means that the task can run for longer durations of time
without accumulating old segments locally on Middle Manager processes, and it is encouraged to do so.
Kinesis Indexing Service may still produce some small segments. Let's say the task duration is 4 hours, segment granularity
is set to an HOUR and Supervisor was started at 9:10. Then after 4 hours at 13:10, the new set of tasks will be started and
events for the interval 13:00 - 14:00 may be split across the previous and the new set of tasks. If you see it becoming a problem then
one can schedule re-indexing tasks be run to merge segments together into new segments of an ideal size (in the range of ~500-700 MB per segment).
Details on how to optimize the segment size can be found on [Segment size optimization](../../operations/segment-optimization.md).
There is also ongoing work to support automatic segment compaction of sharded segments as well as compaction not requiring
Hadoop (see [here](https://github.com/apache/druid/pull/5102)).
### Determining Fetch Settings
## Determine fetch settings
Kinesis indexing tasks fetch records using `fetchThreads` threads.
If `fetchThreads` is higher than the number of Kinesis shards, the excess threads are unused.
@ -598,7 +633,7 @@ of `fetchDelayMillis`.
The records fetched by each thread are pushed into a shared queue of size `recordBufferSize`.
The main runner thread for each task polls up to `maxRecordsPerPoll` records from the queue at once.
When using Kinesis Producer Library's aggregation feature (i.e. when [`deaggregate`](#deaggregation) is set),
When using Kinesis Producer Library's aggregation feature, that is when [`deaggregate`](#deaggregation) is set,
each of these parameters refers to aggregated records rather than individual records.
The default values for these parameters are:
@ -620,7 +655,7 @@ Kinesis places the following restrictions on calls to fetch records:
- Each shard can read up to 2 MB per second.
- The maximum size of data that GetRecords can return is 10 MB.
If the above limits are exceeded, Kinesis throws ProvisionedThroughputExceededException errors. If this happens, Druid
If the above limits are exceeded, Kinesis throws `ProvisionedThroughputExceededException` errors. If this happens, Druid
Kinesis tasks pause by `fetchDelayMillis` or 3 seconds, whichever is larger, and then attempt the call again.
In most cases, the default settings for fetch parameters are sufficient to achieve good performance without excessive
@ -638,21 +673,21 @@ To enable this feature, set `deaggregate` to true in your `ioConfig` when submit
## Resharding
When changing the shard count for a Kinesis stream, there will be a window of time around the resharding operation with early shutdown of Kinesis ingestion tasks and possible task failures.
When changing the shard count for a Kinesis stream, there is a window of time around the resharding operation with early shutdown of Kinesis ingestion tasks and possible task failures.
The early shutdowns and task failures are expected. They occur because the supervisor updates the shard to task group mappings as shards are closed and fully read. This ensures that tasks are not running
with an assignment of closed shards that have been fully read and balances distribution of active shards across tasks.
This window with early task shutdowns and possible task failures will conclude when:
This window with early task shutdowns and possible task failures concludes when:
- All closed shards have been fully read and the Kinesis ingestion tasks have published the data from those shards, committing the "closed" state to metadata storage
- Any remaining tasks that had inactive shards in the assignment have been shutdown (these tasks would have been created before the closed shards were completely drained)
- All closed shards have been fully read and the Kinesis ingestion tasks have published the data from those shards, committing the "closed" state to metadata storage.
- Any remaining tasks that had inactive shards in the assignment have been shut down. These tasks would have been created before the closed shards were completely drained.
## Kinesis known issues
Before you deploy the Kinesis extension to production, consider the following known issues:
- Avoid implementing more than one Kinesis supervisor that read from the same Kinesis stream for ingestion. Kinesis has a per-shard read throughput limit and having multiple supervisors on the same stream can reduce available read throughput for an individual Supervisor's tasks. Additionally, multiple Supervisors ingesting to the same Druid Datasource can cause increased contention for locks on the Datasource.
- Avoid implementing more than one Kinesis supervisor that reads from the same Kinesis stream for ingestion. Kinesis has a per-shard read throughput limit and having multiple supervisors on the same stream can reduce available read throughput for an individual supervisor's tasks. Multiple supervisors ingesting to the same Druid datasource can also cause increased contention for locks on the datasource.
- The only way to change the stream reset policy is to submit a new ingestion spec and set up a new supervisor.
- If ingestion tasks get stuck, the supervisor does not automatically recover. You should monitor ingestion tasks and investigate if your ingestion falls behind.
- A Kinesis supervisor can sometimes compare the checkpoint offset to retention window of the stream to see if it has fallen behind. These checks fetch the earliest sequence number for Kinesis which can result in `IteratorAgeMilliseconds` becoming very high in AWS CloudWatch.

2
docs/ingestion/ingestion-spec.md
View File

@ -485,7 +485,7 @@ is:
|skipBytesInMemoryOverheadCheck|The calculation of maxBytesInMemory takes into account overhead objects created during ingestion and each intermediate persist. Setting this to true can exclude the bytes of these overhead objects from maxBytesInMemory check.|false|
|indexSpec|Defines segment storage format options to use at indexing time.|See [`indexSpec`](#indexspec) for more information.|
|indexSpecForIntermediatePersists|Defines segment storage format options to use at indexing time for intermediate persisted temporary segments.|See [`indexSpec`](#indexspec) for more information.|
|Other properties|Each ingestion method has its own list of additional tuning properties. See the documentation for each method for a full list: [Kafka indexing service](../development/extensions-core/kafka-supervisor-reference.md#tuningconfig), [Kinesis indexing service](../development/extensions-core/kinesis-ingestion.md#tuningconfig), [Native batch](native-batch.md#tuningconfig), and [Hadoop-based](hadoop.md#tuningconfig).||
|Other properties|Each ingestion method has its own list of additional tuning properties. See the documentation for each method for a full list: [Kafka indexing service](../development/extensions-core/kafka-supervisor-reference.md#tuningconfig), [Kinesis indexing service](../development/extensions-core/kinesis-ingestion.md#supervisor-tuning-configuration), [Native batch](native-batch.md#tuningconfig), and [Hadoop-based](hadoop.md#tuningconfig).||
### `indexSpec`

1
website/.spelling
View File

@ -310,6 +310,7 @@ enum
expectedType
expr
failover
failovers
featureSpec
findColumnsFromHeader
filenames