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Posted to commits@druid.apache.org by GitBox <gi...@apache.org> on 2021/11/11 22:39:05 UTC
[GitHub] [druid] sthetland commented on a change in pull request #11912: Docs: Splits Kafka topic. Adds detailed example for kafka inputFormat
sthetland commented on a change in pull request #11912:
URL: https://github.com/apache/druid/pull/11912#discussion_r747849092
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -41,19 +46,22 @@ Additionally, you can set `isolation.level` to `read_uncommitted` in `consumerPr
If your Kafka cluster enables consumer-group based ACLs, you can set `group.id` in `consumerProperties` to override the default auto generated group id.
-## Submitting a Supervisor Spec
-
-To use the Kafka indexing service, load the `druid-kafka-indexing-service` extension on both the Overlord and the MiddleManagers. Druid starts a supervisor for a dataSource when you submit a supervisor spec. You can use the following endpoint:
+## Load the Kafka indexing service
-`http://<OVERLORD_IP>:<OVERLORD_PORT>/druid/indexer/v1/supervisor`
+To use the Kafka indexing service, load the `druid-kafka-indexing-service` extension on both the Overlord and the MiddleManagers. See [Loading extensions](../extensions.md#loading-extensions) for instructions on how to configure extensions.
-For example:
+## Define a supervisor spec
+Similar to the ingestion spec for batch ingestion, the supervisor spec configures the data ingestion for Kafka streaming ingestion. A supervisor spec has the following sections:
+- `dataSchema` to specify the Druid datasource name, primary timestamp, dimensions, metrics, transforms, and any necessary filters.
+- `ioConfig` to configure Druid to connect to Kafka how to parse the data. Kafka-specific connection details go in the `consumerProperties`. For more information, see the [Kafka supervisor reference](./kafka-supervisor-reference.md).
Review comment:
"..connect to Kafka _and_ how to parse the data"? Or to rewrite a bit more...
```suggestion
- `ioConfig` to configure Kafka connection settings and configure how Druid parses the data. Kafka-specific connection details go in the `consumerProperties`. For more information, see the [Kafka supervisor reference](./kafka-supervisor-reference.md).
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -41,19 +46,22 @@ Additionally, you can set `isolation.level` to `read_uncommitted` in `consumerPr
If your Kafka cluster enables consumer-group based ACLs, you can set `group.id` in `consumerProperties` to override the default auto generated group id.
-## Submitting a Supervisor Spec
-
-To use the Kafka indexing service, load the `druid-kafka-indexing-service` extension on both the Overlord and the MiddleManagers. Druid starts a supervisor for a dataSource when you submit a supervisor spec. You can use the following endpoint:
+## Load the Kafka indexing service
-`http://<OVERLORD_IP>:<OVERLORD_PORT>/druid/indexer/v1/supervisor`
+To use the Kafka indexing service, load the `druid-kafka-indexing-service` extension on both the Overlord and the MiddleManagers. See [Loading extensions](../extensions.md#loading-extensions) for instructions on how to configure extensions.
-For example:
+## Define a supervisor spec
+Similar to the ingestion spec for batch ingestion, the supervisor spec configures the data ingestion for Kafka streaming ingestion. A supervisor spec has the following sections:
+- `dataSchema` to specify the Druid datasource name, primary timestamp, dimensions, metrics, transforms, and any necessary filters.
+- `ioConfig` to configure Druid to connect to Kafka how to parse the data. Kafka-specific connection details go in the `consumerProperties`. For more information, see the [Kafka supervisor reference](./kafka-supervisor-reference.md).
+- `tuningConfig` to control various tuning parameters specific to each ingestion method.
+For a full description of all the fields and parameters in a Kafka supervisor spec, see the [Kafka supervisor reference](./kafka-supervisor-reference.md).
+For information on how to configure the input format, see [Data formats](../../ingestion/data-formats.md).
-```
-curl -X POST -H 'Content-Type: application/json' -d @supervisor-spec.json http://localhost:8090/druid/indexer/v1/supervisor
-```
+The following sections contain examples to help you get started with supervisor specs.
-Where the file `supervisor-spec.json` contains a Kafka supervisor spec:
+### JSON input format supervisor spec example
+The following example demonstrates a supervisor spec for Kafka that uses the `JSON` input format. In this case Druid parses the message contents from the value field which are in JSON format:
Review comment:
The "which" is ambiguous, at first read, as to whether it refers to the value field or the message contents (more likely due to the verb tense). Maybe either "...the value field, which is in JSON format" .. or:
```suggestion
The following example demonstrates a supervisor spec for Kafka that uses the `JSON` input format. In this case Druid parses the message contents in JSON format from the value field:
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -2,6 +2,7 @@
id: kafka-ingestion
title: "Apache Kafka ingestion"
sidebar_label: "Apache Kafka"
Review comment:
A small thing, but I'd suggest making the sidebar title to be the same as the page title here, just to make the distinction with the next two pages in the tree, which also start with "Apache Kafka"
```suggestion
sidebar_label: "Apache Kafka ingestion"
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -23,14 +24,18 @@ sidebar_label: "Apache Kafka"
~ under the License.
-->
-When you enable the Kafka indexing service, you can configure *supervisors* on the Overlord to manage the creation and lifetime of Kafka indexing tasks. These indexing tasks read events using Kafka's own partition and offset mechanism to guarantee exactly-once ingestion. The supervisor oversees the state of the indexing tasks to:
+When you enable the Kafka indexing service, you can configure supervisors on the Overlord to manage the creation and lifetime of Kafka indexing tasks.
+
+Kafka indexing tasks read events using Kafka's own partition and offset mechanism to guarantee exactly-once ingestion. The supervisor oversees the state of the indexing tasks to:
- coordinate handoffs
- manage failures
- ensure that scalability and replication requirements are maintained.
-To use the Kafka indexing service, load the `druid-kafka-indexing-service` core Apache Druid extension. See [Including Extensions](../../development/extensions.md#loading-extensions)).
-This topic covers the ingestion spec for Kafka. For a general `ingestionSpec` reference, see [Ingestion specs](../../ingestion/ingestion-spec.md). For a walk-through, check out the [Loading from Apache Kafka](../../tutorials/tutorial-kafka.md) tutorial.
+This topic covers how to submit a supervisor spec to ingest data from Kafka. See the following for more information:
+- For a reference of Kafka supervisor spec configuration options, see the [Kafka supervisor reference](./kafka-supervisor-reference.md).
+- For an operations reference information to help run and maintain Apache Kafka supervisors, see [Kafka supervisor operations](./kafka-supervisor-operations.md)
Review comment:
```suggestion
- For operations reference information to help run and maintain Apache Kafka supervisors, see [Kafka supervisor operations](./kafka-supervisor-operations.md).
```
##########
File path: docs/development/extensions-core/kafka-supervisor-reference.md
##########
@@ -0,0 +1,425 @@
+---
+id: kafka-supervisor-reference
+title: "Apache Kafka supervisor reference"
+sidebar_label: "Apache Kafka supervisor"
+description: "Refrence topic for Apache Kafka supervisors"
+---
+
+<!--
+ ~ Licensed to the Apache Software Foundation (ASF) under one
+ ~ or more contributor license agreements. See the NOTICE file
+ ~ distributed with this work for additional information
+ ~ regarding copyright ownership. The ASF licenses this file
+ ~ to you under the Apache License, Version 2.0 (the
+ ~ "License"); you may not use this file except in compliance
+ ~ with the License. You may obtain a copy of the License at
+ ~
+ ~ http://www.apache.org/licenses/LICENSE-2.0
+ ~
+ ~ Unless required by applicable law or agreed to in writing,
+ ~ software distributed under the License is distributed on an
+ ~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ ~ KIND, either express or implied. See the License for the
+ ~ specific language governing permissions and limitations
+ ~ under the License.
+ -->
+This topic contains the reference Apache Kafka supervisor configuration for Apache Druid. The following table outlines the high level configuration options:
Review comment:
```suggestion
This topic contains configuration reference information for the Apache Kafka supervisor for Apache Druid. The following table outlines the high-level configuration options:
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -119,403 +127,142 @@ Where the file `supervisor-spec.json` contains a Kafka supervisor spec:
}
```
-## Supervisor Configuration
-
-|Field|Description|Required|
-|--------|-----------|---------|
-|`type`|Supervisor type. For Kafka streaming, set to `kafka`.|yes|
-|`spec`| Container object for the supervisor configuration. | yes |
-|`dataSchema`|Schema for the Kafka indexing task to use during ingestion.|yes|
-|`ioConfig`|A `KafkaSupervisorIOConfig` object to define the Kafka connection and I/O-related settings for the supervisor and indexing task. See [KafkaSupervisorIOConfig](#kafkasupervisorioconfig).|yes|
-|`tuningConfig`|A KafkaSupervisorTuningConfig object to define performance-related settings for the supervisor and indexing tasks. See [KafkaSupervisorTuningConfig](#kafkasupervisortuningconfig).|no|
-
-### KafkaSupervisorIOConfig
-
-|Field|Type|Description|Required|
-|-----|----|-----------|--------|
-|`topic`|String|The Kafka topic to read from. Must be a specific topic. Topic patterns are not supported.|yes|
-|`inputFormat`|Object|`inputFormat` to define input data parsing. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
-|`consumerProperties`|Map<String, Object>|A map of properties to pass to the Kafka consumer. See [More on consumer properties](#more-on-consumerproperties).|yes|
-|`pollTimeout`|Long|The length of time to wait for the Kafka consumer to poll records, in milliseconds|no (default == 100)|
-|`replicas`|Integer|The number of replica sets. "1" means a single set of tasks without replication. Druid always assigns replica tasks to different workers to provide resiliency against worker failure.|no (default == 1)|
-|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. The maximum number of reading tasks equals `taskCount * replicas`. Therefore, the total number of tasks, *reading* + *publishing*, is greater than this count. See [Capacity Planning](#capacity-planning) for more details. When `taskCount > {numKafkaPartitions}`, the actual number of reading tasks is less than the `taskCount` value.|no (default == 1)|
-|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing segments.|no (default == PT1H)|
-|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
-|`period`|ISO8601 Period|Frequency at which the supervisor executes its management logic. The supervisor also runs in response to certain events. For example task success, task failure, and tasks reaching their `taskDuration`. The `period` value specifies the maximum time between iterations.|no (default == PT30S)|
-|`useEarliestOffset`|Boolean|If a supervisor manages a dataSource for the first time, it obtains a set of starting offsets from Kafka. This flag determines whether it retrieves the earliest or latest offsets in Kafka. Under normal circumstances, subsequent tasks will start from where the previous segments ended. Therefore Druid only uses `useEarliestOffset` 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 the value is too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT30M)|
-|`lateMessageRejectionStartDateTime`|ISO8601 DateTime|Configure tasks to reject messages with timestamps earlier than this date time; for example if this is set to `2016-01-01T11:00Z` and the supervisor creates a task at *2016-01-01T12:00Z*, Druid drops messages with timestamps earlier than *2016-01-01T11:00Z*. This can 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 realtime and a nightly batch ingestion pipeline).|no (default == none)|
-|`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 realtime and a nightly batch ingestion pipeline). Please note that only one of `lateMessageRejectionPeriod` or `lateMessageRejectionStartDateTime` can be specified.|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)|
-|`autoScalerConfig`|Object|Defines auto scaling behavior for Kafka ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
-
-#### Task Autoscaler Properties
-
-> Note that Task AutoScaler is currently designated as experimental.
-
-| Property | Description | Required |
-| ------------- | ------------- | ------------- |
-| `enableTaskAutoScaler` | Enable or disable autoscaling. `false` or blank disables the `autoScaler` even when `autoScalerConfig` is not null| no (default == false) |
-| `taskCountMax` | Maximum number of ingestion tasks. Set `taskCountMax >= taskCountMin`. If `taskCountMax > {numKafkaPartitions}`, Druid only scales reading tasks up to the `{numKafkaPartitions}`. In this case `taskCountMax` is ignored. | yes |
-| `taskCountMin` | Minimum number of ingestion tasks. When you enable autoscaler, Druid ignores the value of taskCount in `IOConfig` and starts with the `taskCountMin` number of tasks.| yes |
-| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions. | no (default == 600000) |
-| `autoScalerStrategy` | The algorithm of `autoScaler`. Only supports `lagBased`. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
-
-##### Lag Based AutoScaler Strategy Related Properties
-| 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 after supervisor starts when first check scale logic. | no (default == 300000) |
-| `scaleActionPeriodMillis` | The frequency of checking whether to do scale action in millis | no (default == 60000) |
-| `scaleInStep` | How many tasks to reduce at a time | no (default == 1) |
-| `scaleOutStep` | How many tasks to add at a time | no (default == 2) |
-
-The following example demonstrates supervisor spec with `lagBased` autoScaler enabled:
-```json
+### Kafka input format supervisor spec example
+If you want to ingest data from other fields in addition to the Kafka message contents, you can use the `kafka` input format. The `kafka` input format lets you ingest:
+- the message key field.
+- message headers.
+- the Kafka message timestamp.
+
+> The Kafka inputFormat is currently designated as experimental.
+
+For example, consider the following structure for a message that represents an fictitious wiki edit in a development environment:
+- **Event headers**: {"environment": "development"}
+- **Event key**: {"key: "wiki-edit"}
+- **Event value**: \<JSON object with message contents of the change details\>
+- **Event timestamp**: "Nov. 10, 2021 at 14:06"
+
+When you use the `kafka` input format, you configure the way that Druid names the dimensions created from the Kafka message:
+- `headerLabelPrefix`: Supply a prefix to the Kafka headers to avoid any conflicts with named dimensions. The default is `kafka.header.`. Considering the header from the example, Druid maps the header to the following column: `kafka.header.enviornment`.
+- `timestampColumnName`:Supply a custom name for the Kafka timestamp in the Druid schema to avoid conflicts with other time columns. The default is `kafka.timestamp`.
+- `keyColumnName`: Supply the name for the Kafka key column in Druid. The default is `kafka.key`.
+Additionally, you must provide information about how Druid should parse the data in the Kafka message:
+- `headerFormat`: The default "string" decodes UTF8-encoded strings from the Kafka header. If you need another format, you can implement your own parser.
+- `keyFormat`: Takes a Druid `inputFormat` and uses the value for first key it finds. According to the example the value is "wiki-edit". It discards the key name in this case. If you store the key as a string, use the `CSV` input format. For example if you have simple string for the the key `wiki-edit`, you can use the following to parse the key:
Review comment:
```suggestion
- `keyFormat`: Takes a Druid `inputFormat` and uses the value for the first key it finds. According to the example the value is "wiki-edit". It discards the key name in this case. If you store the key as a string, use the `CSV` input format. For example, if you have simple string for the the key `wiki-edit`, you can use the following to parse the key:
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -119,403 +127,142 @@ Where the file `supervisor-spec.json` contains a Kafka supervisor spec:
}
```
-## Supervisor Configuration
-
-|Field|Description|Required|
-|--------|-----------|---------|
-|`type`|Supervisor type. For Kafka streaming, set to `kafka`.|yes|
-|`spec`| Container object for the supervisor configuration. | yes |
-|`dataSchema`|Schema for the Kafka indexing task to use during ingestion.|yes|
-|`ioConfig`|A `KafkaSupervisorIOConfig` object to define the Kafka connection and I/O-related settings for the supervisor and indexing task. See [KafkaSupervisorIOConfig](#kafkasupervisorioconfig).|yes|
-|`tuningConfig`|A KafkaSupervisorTuningConfig object to define performance-related settings for the supervisor and indexing tasks. See [KafkaSupervisorTuningConfig](#kafkasupervisortuningconfig).|no|
-
-### KafkaSupervisorIOConfig
-
-|Field|Type|Description|Required|
-|-----|----|-----------|--------|
-|`topic`|String|The Kafka topic to read from. Must be a specific topic. Topic patterns are not supported.|yes|
-|`inputFormat`|Object|`inputFormat` to define input data parsing. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
-|`consumerProperties`|Map<String, Object>|A map of properties to pass to the Kafka consumer. See [More on consumer properties](#more-on-consumerproperties).|yes|
-|`pollTimeout`|Long|The length of time to wait for the Kafka consumer to poll records, in milliseconds|no (default == 100)|
-|`replicas`|Integer|The number of replica sets. "1" means a single set of tasks without replication. Druid always assigns replica tasks to different workers to provide resiliency against worker failure.|no (default == 1)|
-|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. The maximum number of reading tasks equals `taskCount * replicas`. Therefore, the total number of tasks, *reading* + *publishing*, is greater than this count. See [Capacity Planning](#capacity-planning) for more details. When `taskCount > {numKafkaPartitions}`, the actual number of reading tasks is less than the `taskCount` value.|no (default == 1)|
-|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing segments.|no (default == PT1H)|
-|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
-|`period`|ISO8601 Period|Frequency at which the supervisor executes its management logic. The supervisor also runs in response to certain events. For example task success, task failure, and tasks reaching their `taskDuration`. The `period` value specifies the maximum time between iterations.|no (default == PT30S)|
-|`useEarliestOffset`|Boolean|If a supervisor manages a dataSource for the first time, it obtains a set of starting offsets from Kafka. This flag determines whether it retrieves the earliest or latest offsets in Kafka. Under normal circumstances, subsequent tasks will start from where the previous segments ended. Therefore Druid only uses `useEarliestOffset` 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 the value is too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT30M)|
-|`lateMessageRejectionStartDateTime`|ISO8601 DateTime|Configure tasks to reject messages with timestamps earlier than this date time; for example if this is set to `2016-01-01T11:00Z` and the supervisor creates a task at *2016-01-01T12:00Z*, Druid drops messages with timestamps earlier than *2016-01-01T11:00Z*. This can 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 realtime and a nightly batch ingestion pipeline).|no (default == none)|
-|`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 realtime and a nightly batch ingestion pipeline). Please note that only one of `lateMessageRejectionPeriod` or `lateMessageRejectionStartDateTime` can be specified.|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)|
-|`autoScalerConfig`|Object|Defines auto scaling behavior for Kafka ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
-
-#### Task Autoscaler Properties
-
-> Note that Task AutoScaler is currently designated as experimental.
-
-| Property | Description | Required |
-| ------------- | ------------- | ------------- |
-| `enableTaskAutoScaler` | Enable or disable autoscaling. `false` or blank disables the `autoScaler` even when `autoScalerConfig` is not null| no (default == false) |
-| `taskCountMax` | Maximum number of ingestion tasks. Set `taskCountMax >= taskCountMin`. If `taskCountMax > {numKafkaPartitions}`, Druid only scales reading tasks up to the `{numKafkaPartitions}`. In this case `taskCountMax` is ignored. | yes |
-| `taskCountMin` | Minimum number of ingestion tasks. When you enable autoscaler, Druid ignores the value of taskCount in `IOConfig` and starts with the `taskCountMin` number of tasks.| yes |
-| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions. | no (default == 600000) |
-| `autoScalerStrategy` | The algorithm of `autoScaler`. Only supports `lagBased`. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
-
-##### Lag Based AutoScaler Strategy Related Properties
-| 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 after supervisor starts when first check scale logic. | no (default == 300000) |
-| `scaleActionPeriodMillis` | The frequency of checking whether to do scale action in millis | no (default == 60000) |
-| `scaleInStep` | How many tasks to reduce at a time | no (default == 1) |
-| `scaleOutStep` | How many tasks to add at a time | no (default == 2) |
-
-The following example demonstrates supervisor spec with `lagBased` autoScaler enabled:
-```json
+### Kafka input format supervisor spec example
+If you want to ingest data from other fields in addition to the Kafka message contents, you can use the `kafka` input format. The `kafka` input format lets you ingest:
+- the message key field.
+- message headers.
+- the Kafka message timestamp.
+
+> The Kafka inputFormat is currently designated as experimental.
+
+For example, consider the following structure for a message that represents an fictitious wiki edit in a development environment:
+- **Event headers**: {"environment": "development"}
+- **Event key**: {"key: "wiki-edit"}
+- **Event value**: \<JSON object with message contents of the change details\>
+- **Event timestamp**: "Nov. 10, 2021 at 14:06"
+
+When you use the `kafka` input format, you configure the way that Druid names the dimensions created from the Kafka message:
+- `headerLabelPrefix`: Supply a prefix to the Kafka headers to avoid any conflicts with named dimensions. The default is `kafka.header.`. Considering the header from the example, Druid maps the header to the following column: `kafka.header.enviornment`.
+- `timestampColumnName`:Supply a custom name for the Kafka timestamp in the Druid schema to avoid conflicts with other time columns. The default is `kafka.timestamp`.
Review comment:
```suggestion
- `timestampColumnName`: Supply a custom name for the Kafka timestamp in the Druid schema to avoid conflicts with other time columns. The default is `kafka.timestamp`.
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -119,403 +127,142 @@ Where the file `supervisor-spec.json` contains a Kafka supervisor spec:
}
```
-## Supervisor Configuration
-
-|Field|Description|Required|
-|--------|-----------|---------|
-|`type`|Supervisor type. For Kafka streaming, set to `kafka`.|yes|
-|`spec`| Container object for the supervisor configuration. | yes |
-|`dataSchema`|Schema for the Kafka indexing task to use during ingestion.|yes|
-|`ioConfig`|A `KafkaSupervisorIOConfig` object to define the Kafka connection and I/O-related settings for the supervisor and indexing task. See [KafkaSupervisorIOConfig](#kafkasupervisorioconfig).|yes|
-|`tuningConfig`|A KafkaSupervisorTuningConfig object to define performance-related settings for the supervisor and indexing tasks. See [KafkaSupervisorTuningConfig](#kafkasupervisortuningconfig).|no|
-
-### KafkaSupervisorIOConfig
-
-|Field|Type|Description|Required|
-|-----|----|-----------|--------|
-|`topic`|String|The Kafka topic to read from. Must be a specific topic. Topic patterns are not supported.|yes|
-|`inputFormat`|Object|`inputFormat` to define input data parsing. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
-|`consumerProperties`|Map<String, Object>|A map of properties to pass to the Kafka consumer. See [More on consumer properties](#more-on-consumerproperties).|yes|
-|`pollTimeout`|Long|The length of time to wait for the Kafka consumer to poll records, in milliseconds|no (default == 100)|
-|`replicas`|Integer|The number of replica sets. "1" means a single set of tasks without replication. Druid always assigns replica tasks to different workers to provide resiliency against worker failure.|no (default == 1)|
-|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. The maximum number of reading tasks equals `taskCount * replicas`. Therefore, the total number of tasks, *reading* + *publishing*, is greater than this count. See [Capacity Planning](#capacity-planning) for more details. When `taskCount > {numKafkaPartitions}`, the actual number of reading tasks is less than the `taskCount` value.|no (default == 1)|
-|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing segments.|no (default == PT1H)|
-|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
-|`period`|ISO8601 Period|Frequency at which the supervisor executes its management logic. The supervisor also runs in response to certain events. For example task success, task failure, and tasks reaching their `taskDuration`. The `period` value specifies the maximum time between iterations.|no (default == PT30S)|
-|`useEarliestOffset`|Boolean|If a supervisor manages a dataSource for the first time, it obtains a set of starting offsets from Kafka. This flag determines whether it retrieves the earliest or latest offsets in Kafka. Under normal circumstances, subsequent tasks will start from where the previous segments ended. Therefore Druid only uses `useEarliestOffset` 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 the value is too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT30M)|
-|`lateMessageRejectionStartDateTime`|ISO8601 DateTime|Configure tasks to reject messages with timestamps earlier than this date time; for example if this is set to `2016-01-01T11:00Z` and the supervisor creates a task at *2016-01-01T12:00Z*, Druid drops messages with timestamps earlier than *2016-01-01T11:00Z*. This can 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 realtime and a nightly batch ingestion pipeline).|no (default == none)|
-|`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 realtime and a nightly batch ingestion pipeline). Please note that only one of `lateMessageRejectionPeriod` or `lateMessageRejectionStartDateTime` can be specified.|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)|
-|`autoScalerConfig`|Object|Defines auto scaling behavior for Kafka ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
-
-#### Task Autoscaler Properties
-
-> Note that Task AutoScaler is currently designated as experimental.
-
-| Property | Description | Required |
-| ------------- | ------------- | ------------- |
-| `enableTaskAutoScaler` | Enable or disable autoscaling. `false` or blank disables the `autoScaler` even when `autoScalerConfig` is not null| no (default == false) |
-| `taskCountMax` | Maximum number of ingestion tasks. Set `taskCountMax >= taskCountMin`. If `taskCountMax > {numKafkaPartitions}`, Druid only scales reading tasks up to the `{numKafkaPartitions}`. In this case `taskCountMax` is ignored. | yes |
-| `taskCountMin` | Minimum number of ingestion tasks. When you enable autoscaler, Druid ignores the value of taskCount in `IOConfig` and starts with the `taskCountMin` number of tasks.| yes |
-| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions. | no (default == 600000) |
-| `autoScalerStrategy` | The algorithm of `autoScaler`. Only supports `lagBased`. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
-
-##### Lag Based AutoScaler Strategy Related Properties
-| 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 after supervisor starts when first check scale logic. | no (default == 300000) |
-| `scaleActionPeriodMillis` | The frequency of checking whether to do scale action in millis | no (default == 60000) |
-| `scaleInStep` | How many tasks to reduce at a time | no (default == 1) |
-| `scaleOutStep` | How many tasks to add at a time | no (default == 2) |
-
-The following example demonstrates supervisor spec with `lagBased` autoScaler enabled:
-```json
+### Kafka input format supervisor spec example
+If you want to ingest data from other fields in addition to the Kafka message contents, you can use the `kafka` input format. The `kafka` input format lets you ingest:
+- the message key field.
+- message headers.
+- the Kafka message timestamp.
+
+> The Kafka inputFormat is currently designated as experimental.
+
+For example, consider the following structure for a message that represents an fictitious wiki edit in a development environment:
+- **Event headers**: {"environment": "development"}
+- **Event key**: {"key: "wiki-edit"}
+- **Event value**: \<JSON object with message contents of the change details\>
+- **Event timestamp**: "Nov. 10, 2021 at 14:06"
+
+When you use the `kafka` input format, you configure the way that Druid names the dimensions created from the Kafka message:
+- `headerLabelPrefix`: Supply a prefix to the Kafka headers to avoid any conflicts with named dimensions. The default is `kafka.header.`. Considering the header from the example, Druid maps the header to the following column: `kafka.header.enviornment`.
+- `timestampColumnName`:Supply a custom name for the Kafka timestamp in the Druid schema to avoid conflicts with other time columns. The default is `kafka.timestamp`.
+- `keyColumnName`: Supply the name for the Kafka key column in Druid. The default is `kafka.key`.
+Additionally, you must provide information about how Druid should parse the data in the Kafka message:
+- `headerFormat`: The default "string" decodes UTF8-encoded strings from the Kafka header. If you need another format, you can implement your own parser.
+- `keyFormat`: Takes a Druid `inputFormat` and uses the value for first key it finds. According to the example the value is "wiki-edit". It discards the key name in this case. If you store the key as a string, use the `CSV` input format. For example if you have simple string for the the key `wiki-edit`, you can use the following to parse the key:
+ ```
+ "keyFormat": {
+ "type": "csv",
+ "hasHeaderRow": false,
+ "findColumnsFromHeader": false,
+ "columns": ["key"]
+ }
+ ```
+- `valueFormat`: Define how to parse the message contents. You can use any of the Druid input formats that work for Kafka.
+
+For more information on data formats, see [Data formats](../../ingestion/data-formats.md).
+
+Finally, add the Kafka message columns to the `dimensionsSpec`. For the key and timestamp, you can use the dimension names you defined for `keyColumnName` and `timestampColumnName`. For header dimensions, supply the append the header key to the `headerLabelPrefix`. For example `kafka.header.environment`.
+
+The following supervisor spec demonstrates how to ingest the Kafka header, key, and timestamp into Druid dimensions:
+```
{
- "type": "kafka",
- "spec": {
- "dataSchema": {
- ...
+ "type": "kafka",
+ "spec": {
+ "ioConfig": {
+ "type": "kafka",
+ "consumerProperties": {
+ "bootstrap.servers": "localhost:9092"
},
- "ioConfig": {
- "topic": "metrics",
- "inputFormat": {
- "type": "json"
- },
- "consumerProperties": {
- "bootstrap.servers": "localhost:9092"
+ "topic": "wiki-edits",
+ "inputFormat": {
+ "type": "kafka",
+ "headerLabelPrefix": "kafka.header.",
+ "timestampColumnName": "kafka.timestamp",
+ "keyColumnName": "kafka.key",
+ "headerFormat": {
+ "type": "string"
+ },
+ "keyFormat": {
+ "type": "json"
+ },
+ "valueFormat": {
+ "type": "json"
+ },
+ "findColumnsFromHeader": false
+ },
+ "useEarliestOffset": true
+ },
+ "tuningConfig": {
+ "type": "kafka"
+ },
+ "dataSchema": {
+ "dataSource": "wikiticker",
+ "timestampSpec": {
+ "column": "timestamp",
+ "format": "posix"
+ },
+ "dimensionsSpec": {
+ "dimensions": [
+ {
+ "type": "string",
+ "name": "kafka.key"
},
- "autoScalerConfig": {
- "enableTaskAutoScaler": true,
- "taskCountMax": 6,
- "taskCountMin": 2,
- "minTriggerScaleActionFrequencyMillis": 600000,
- "autoScalerStrategy": "lagBased",
- "lagCollectionIntervalMillis": 30000,
- "lagCollectionRangeMillis": 600000,
- "scaleOutThreshold": 6000000,
- "triggerScaleOutFractionThreshold": 0.3,
- "scaleInThreshold": 1000000,
- "triggerScaleInFractionThreshold": 0.9,
- "scaleActionStartDelayMillis": 300000,
- "scaleActionPeriodMillis": 60000,
- "scaleInStep": 1,
- "scaleOutStep": 2
- },
- "taskCount":1,
- "replicas":1,
- "taskDuration":"PT1H"
+ {
+ "type": "string",
+ "name": "kafka.timestamp"
+ },
+ {
+ "type": "string",
+ "name": "kafka.header.environment"
+ },
+ "$schema",
+ {
+ "type": "long",
+ "name": "id"
+ },
+ "type",
+ {
+ "type": "long",
+ "name": "namespace"
+ },
+ "title",
+ "comment",
+ "user",]
+ ]
},
- "tuningConfig":{
- ...
- }
+ "granularitySpec": {
+ "queryGranularity": "none",
+ "rollup": false,
+ "segmentGranularity": "day"
+ }
}
+ },
+ "tuningConfig": {
+ "type": "kafka"
+ }
}
```
-
-#### More on consumerProperties
-
-Consumer properties must contain a property `bootstrap.servers` with a list of Kafka brokers in the form: `<BROKER_1>:<PORT_1>,<BROKER_2>:<PORT_2>,...`.
-By default, `isolation.level` is set to `read_committed`. If you use older versions of Kafka servers without transactions support or don't want Druid to consume only committed transactions, set `isolation.level` to `read_uncommitted`.
-
-In some cases, you may need to fetch consumer properties at runtime. For example, when `bootstrap.servers` is not known upfront, or is not static. To enable SSL connections, you must provide passwords for `keystore`, `truststore` and `key` secretly. You can provide configurations at runtime with a dynamic config provider implementation like the environment variable config provider that comes with Druid. For more information, see [DynamicConfigProvider](../../operations/dynamic-config-provider.md).
-
-For example, if you are using SASL and SSL with Kafka, set the following environment variables for the Druid user on the machines running the Overlord and the Peon services:
-
-```
-export KAFKA_JAAS_CONFIG="org.apache.kafka.common.security.plain.PlainLoginModule required username='admin_user' password='admin_password';"
-export SSL_KEY_PASSWORD=mysecretkeypassword
-export SSL_KEYSTORE_PASSWORD=mysecretkeystorepassword
-export SSL_TRUSTSTORE_PASSWORD=mysecrettruststorepassword
-```
-
-```
- "druid.dynamic.config.provider": {
- "type": "environment",
- "variables": {
- "sasl.jaas.config": "KAFKA_JAAS_CONFIG"
- "ssl.key.password": "SSL_KEY_PASSWORD",
- "ssl.keystore.password": "SSL_KEYSTORE_PASSWORD",
- "ssl.truststore.password": "SSL_TRUSTSTORE_PASSWORD"
- }
- }
- }
+After Druid ingests the data, you can query the Kafka message columns as follows:
+```unix
+SELECT
+ "kafka.header.environment",
+ "kafka.key",
+ "kafka.timestamp"
+FROM "wikiticker"
+
+kafka.header.environment kafka.key kafka.timestamp
+development wiki-edit 1636399229823
```
-Verify that you've changed the values for all configurations to match your own environment. You can use the environment variable config provider syntax in the **Consumer properties** field on the **Connect tab** in the **Load Data** UI in the Druid console. When connecting to Kafka, Druid replaces the environment variables with their corresponding values.
-
-Note: You can provide SSL connections with [Password Provider](../../operations/password-provider.md) interface to define the `keystore`, `truststore`, and `key`, but this feature is deprecated.
-
-#### Specifying data format
-
-Kafka 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 Kafka indexing service unless you need a format only supported by the legacy `parser`.
-
-Supported `inputFormat`s include:
-- `csv`
-- `delimited`
-- `json`
-- `kafka`
-- `avro_stream`
-- `protobuf`
-
-For more information, see [Data formats](../../ingestion/data-formats.md). You can also read [`thrift`](../extensions-contrib/thrift.md) formats using `parser`.
+For more information, see [`kafka` data format](../../ingestion/data-formats.md#kafka).
+## Submit a Supervisor Spec
-<a name="tuningconfig"></a>
+Druid starts a supervisor for a dataSource when you submit a supervisor spec. You can use the Druid Load Data console or you can submit a supervisor spec to the following following endpoint:
Review comment:
```suggestion
Druid starts a supervisor for a dataSource when you submit a supervisor spec. You can use the data loader in the Druid console or you can submit a supervisor spec to the following endpoint:
```
##########
File path: docs/development/extensions-core/kafka-ingestion.md
##########
@@ -119,403 +127,142 @@ Where the file `supervisor-spec.json` contains a Kafka supervisor spec:
}
```
-## Supervisor Configuration
-
-|Field|Description|Required|
-|--------|-----------|---------|
-|`type`|Supervisor type. For Kafka streaming, set to `kafka`.|yes|
-|`spec`| Container object for the supervisor configuration. | yes |
-|`dataSchema`|Schema for the Kafka indexing task to use during ingestion.|yes|
-|`ioConfig`|A `KafkaSupervisorIOConfig` object to define the Kafka connection and I/O-related settings for the supervisor and indexing task. See [KafkaSupervisorIOConfig](#kafkasupervisorioconfig).|yes|
-|`tuningConfig`|A KafkaSupervisorTuningConfig object to define performance-related settings for the supervisor and indexing tasks. See [KafkaSupervisorTuningConfig](#kafkasupervisortuningconfig).|no|
-
-### KafkaSupervisorIOConfig
-
-|Field|Type|Description|Required|
-|-----|----|-----------|--------|
-|`topic`|String|The Kafka topic to read from. Must be a specific topic. Topic patterns are not supported.|yes|
-|`inputFormat`|Object|`inputFormat` to define input data parsing. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
-|`consumerProperties`|Map<String, Object>|A map of properties to pass to the Kafka consumer. See [More on consumer properties](#more-on-consumerproperties).|yes|
-|`pollTimeout`|Long|The length of time to wait for the Kafka consumer to poll records, in milliseconds|no (default == 100)|
-|`replicas`|Integer|The number of replica sets. "1" means a single set of tasks without replication. Druid always assigns replica tasks to different workers to provide resiliency against worker failure.|no (default == 1)|
-|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. The maximum number of reading tasks equals `taskCount * replicas`. Therefore, the total number of tasks, *reading* + *publishing*, is greater than this count. See [Capacity Planning](#capacity-planning) for more details. When `taskCount > {numKafkaPartitions}`, the actual number of reading tasks is less than the `taskCount` value.|no (default == 1)|
-|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing segments.|no (default == PT1H)|
-|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
-|`period`|ISO8601 Period|Frequency at which the supervisor executes its management logic. The supervisor also runs in response to certain events. For example task success, task failure, and tasks reaching their `taskDuration`. The `period` value specifies the maximum time between iterations.|no (default == PT30S)|
-|`useEarliestOffset`|Boolean|If a supervisor manages a dataSource for the first time, it obtains a set of starting offsets from Kafka. This flag determines whether it retrieves the earliest or latest offsets in Kafka. Under normal circumstances, subsequent tasks will start from where the previous segments ended. Therefore Druid only uses `useEarliestOffset` 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 the value is too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT30M)|
-|`lateMessageRejectionStartDateTime`|ISO8601 DateTime|Configure tasks to reject messages with timestamps earlier than this date time; for example if this is set to `2016-01-01T11:00Z` and the supervisor creates a task at *2016-01-01T12:00Z*, Druid drops messages with timestamps earlier than *2016-01-01T11:00Z*. This can 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 realtime and a nightly batch ingestion pipeline).|no (default == none)|
-|`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 realtime and a nightly batch ingestion pipeline). Please note that only one of `lateMessageRejectionPeriod` or `lateMessageRejectionStartDateTime` can be specified.|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)|
-|`autoScalerConfig`|Object|Defines auto scaling behavior for Kafka ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
-
-#### Task Autoscaler Properties
-
-> Note that Task AutoScaler is currently designated as experimental.
-
-| Property | Description | Required |
-| ------------- | ------------- | ------------- |
-| `enableTaskAutoScaler` | Enable or disable autoscaling. `false` or blank disables the `autoScaler` even when `autoScalerConfig` is not null| no (default == false) |
-| `taskCountMax` | Maximum number of ingestion tasks. Set `taskCountMax >= taskCountMin`. If `taskCountMax > {numKafkaPartitions}`, Druid only scales reading tasks up to the `{numKafkaPartitions}`. In this case `taskCountMax` is ignored. | yes |
-| `taskCountMin` | Minimum number of ingestion tasks. When you enable autoscaler, Druid ignores the value of taskCount in `IOConfig` and starts with the `taskCountMin` number of tasks.| yes |
-| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions. | no (default == 600000) |
-| `autoScalerStrategy` | The algorithm of `autoScaler`. Only supports `lagBased`. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
-
-##### Lag Based AutoScaler Strategy Related Properties
-| 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 after supervisor starts when first check scale logic. | no (default == 300000) |
-| `scaleActionPeriodMillis` | The frequency of checking whether to do scale action in millis | no (default == 60000) |
-| `scaleInStep` | How many tasks to reduce at a time | no (default == 1) |
-| `scaleOutStep` | How many tasks to add at a time | no (default == 2) |
-
-The following example demonstrates supervisor spec with `lagBased` autoScaler enabled:
-```json
+### Kafka input format supervisor spec example
+If you want to ingest data from other fields in addition to the Kafka message contents, you can use the `kafka` input format. The `kafka` input format lets you ingest:
+- the message key field.
+- message headers.
+- the Kafka message timestamp.
+
+> The Kafka inputFormat is currently designated as experimental.
+
+For example, consider the following structure for a message that represents an fictitious wiki edit in a development environment:
+- **Event headers**: {"environment": "development"}
+- **Event key**: {"key: "wiki-edit"}
+- **Event value**: \<JSON object with message contents of the change details\>
+- **Event timestamp**: "Nov. 10, 2021 at 14:06"
+
+When you use the `kafka` input format, you configure the way that Druid names the dimensions created from the Kafka message:
+- `headerLabelPrefix`: Supply a prefix to the Kafka headers to avoid any conflicts with named dimensions. The default is `kafka.header.`. Considering the header from the example, Druid maps the header to the following column: `kafka.header.enviornment`.
+- `timestampColumnName`:Supply a custom name for the Kafka timestamp in the Druid schema to avoid conflicts with other time columns. The default is `kafka.timestamp`.
+- `keyColumnName`: Supply the name for the Kafka key column in Druid. The default is `kafka.key`.
+Additionally, you must provide information about how Druid should parse the data in the Kafka message:
+- `headerFormat`: The default "string" decodes UTF8-encoded strings from the Kafka header. If you need another format, you can implement your own parser.
+- `keyFormat`: Takes a Druid `inputFormat` and uses the value for first key it finds. According to the example the value is "wiki-edit". It discards the key name in this case. If you store the key as a string, use the `CSV` input format. For example if you have simple string for the the key `wiki-edit`, you can use the following to parse the key:
+ ```
+ "keyFormat": {
+ "type": "csv",
+ "hasHeaderRow": false,
+ "findColumnsFromHeader": false,
+ "columns": ["key"]
+ }
+ ```
+- `valueFormat`: Define how to parse the message contents. You can use any of the Druid input formats that work for Kafka.
+
+For more information on data formats, see [Data formats](../../ingestion/data-formats.md).
+
+Finally, add the Kafka message columns to the `dimensionsSpec`. For the key and timestamp, you can use the dimension names you defined for `keyColumnName` and `timestampColumnName`. For header dimensions, supply the append the header key to the `headerLabelPrefix`. For example `kafka.header.environment`.
+
+The following supervisor spec demonstrates how to ingest the Kafka header, key, and timestamp into Druid dimensions:
+```
{
- "type": "kafka",
- "spec": {
- "dataSchema": {
- ...
+ "type": "kafka",
+ "spec": {
+ "ioConfig": {
+ "type": "kafka",
+ "consumerProperties": {
+ "bootstrap.servers": "localhost:9092"
},
- "ioConfig": {
- "topic": "metrics",
- "inputFormat": {
- "type": "json"
- },
- "consumerProperties": {
- "bootstrap.servers": "localhost:9092"
+ "topic": "wiki-edits",
+ "inputFormat": {
+ "type": "kafka",
+ "headerLabelPrefix": "kafka.header.",
+ "timestampColumnName": "kafka.timestamp",
+ "keyColumnName": "kafka.key",
+ "headerFormat": {
+ "type": "string"
+ },
+ "keyFormat": {
+ "type": "json"
+ },
+ "valueFormat": {
+ "type": "json"
+ },
+ "findColumnsFromHeader": false
+ },
+ "useEarliestOffset": true
+ },
+ "tuningConfig": {
+ "type": "kafka"
+ },
+ "dataSchema": {
+ "dataSource": "wikiticker",
+ "timestampSpec": {
+ "column": "timestamp",
+ "format": "posix"
+ },
+ "dimensionsSpec": {
+ "dimensions": [
+ {
+ "type": "string",
+ "name": "kafka.key"
},
- "autoScalerConfig": {
- "enableTaskAutoScaler": true,
- "taskCountMax": 6,
- "taskCountMin": 2,
- "minTriggerScaleActionFrequencyMillis": 600000,
- "autoScalerStrategy": "lagBased",
- "lagCollectionIntervalMillis": 30000,
- "lagCollectionRangeMillis": 600000,
- "scaleOutThreshold": 6000000,
- "triggerScaleOutFractionThreshold": 0.3,
- "scaleInThreshold": 1000000,
- "triggerScaleInFractionThreshold": 0.9,
- "scaleActionStartDelayMillis": 300000,
- "scaleActionPeriodMillis": 60000,
- "scaleInStep": 1,
- "scaleOutStep": 2
- },
- "taskCount":1,
- "replicas":1,
- "taskDuration":"PT1H"
+ {
+ "type": "string",
+ "name": "kafka.timestamp"
+ },
+ {
+ "type": "string",
+ "name": "kafka.header.environment"
+ },
+ "$schema",
+ {
+ "type": "long",
+ "name": "id"
+ },
+ "type",
+ {
+ "type": "long",
+ "name": "namespace"
+ },
+ "title",
+ "comment",
+ "user",]
+ ]
},
- "tuningConfig":{
- ...
- }
+ "granularitySpec": {
+ "queryGranularity": "none",
+ "rollup": false,
+ "segmentGranularity": "day"
+ }
}
+ },
+ "tuningConfig": {
+ "type": "kafka"
+ }
}
```
-
-#### More on consumerProperties
-
-Consumer properties must contain a property `bootstrap.servers` with a list of Kafka brokers in the form: `<BROKER_1>:<PORT_1>,<BROKER_2>:<PORT_2>,...`.
-By default, `isolation.level` is set to `read_committed`. If you use older versions of Kafka servers without transactions support or don't want Druid to consume only committed transactions, set `isolation.level` to `read_uncommitted`.
-
-In some cases, you may need to fetch consumer properties at runtime. For example, when `bootstrap.servers` is not known upfront, or is not static. To enable SSL connections, you must provide passwords for `keystore`, `truststore` and `key` secretly. You can provide configurations at runtime with a dynamic config provider implementation like the environment variable config provider that comes with Druid. For more information, see [DynamicConfigProvider](../../operations/dynamic-config-provider.md).
-
-For example, if you are using SASL and SSL with Kafka, set the following environment variables for the Druid user on the machines running the Overlord and the Peon services:
-
-```
-export KAFKA_JAAS_CONFIG="org.apache.kafka.common.security.plain.PlainLoginModule required username='admin_user' password='admin_password';"
-export SSL_KEY_PASSWORD=mysecretkeypassword
-export SSL_KEYSTORE_PASSWORD=mysecretkeystorepassword
-export SSL_TRUSTSTORE_PASSWORD=mysecrettruststorepassword
-```
-
-```
- "druid.dynamic.config.provider": {
- "type": "environment",
- "variables": {
- "sasl.jaas.config": "KAFKA_JAAS_CONFIG"
- "ssl.key.password": "SSL_KEY_PASSWORD",
- "ssl.keystore.password": "SSL_KEYSTORE_PASSWORD",
- "ssl.truststore.password": "SSL_TRUSTSTORE_PASSWORD"
- }
- }
- }
+After Druid ingests the data, you can query the Kafka message columns as follows:
+```unix
+SELECT
+ "kafka.header.environment",
+ "kafka.key",
+ "kafka.timestamp"
+FROM "wikiticker"
+
+kafka.header.environment kafka.key kafka.timestamp
+development wiki-edit 1636399229823
```
-Verify that you've changed the values for all configurations to match your own environment. You can use the environment variable config provider syntax in the **Consumer properties** field on the **Connect tab** in the **Load Data** UI in the Druid console. When connecting to Kafka, Druid replaces the environment variables with their corresponding values.
-
-Note: You can provide SSL connections with [Password Provider](../../operations/password-provider.md) interface to define the `keystore`, `truststore`, and `key`, but this feature is deprecated.
-
-#### Specifying data format
-
-Kafka 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 Kafka indexing service unless you need a format only supported by the legacy `parser`.
-
-Supported `inputFormat`s include:
-- `csv`
-- `delimited`
-- `json`
-- `kafka`
-- `avro_stream`
-- `protobuf`
-
-For more information, see [Data formats](../../ingestion/data-formats.md). You can also read [`thrift`](../extensions-contrib/thrift.md) formats using `parser`.
+For more information, see [`kafka` data format](../../ingestion/data-formats.md#kafka).
+## Submit a Supervisor Spec
Review comment:
```suggestion
## Submit a supervisor spec
```
##########
File path: docs/development/extensions-core/kafka-supervisor-reference.md
##########
@@ -0,0 +1,425 @@
+---
+id: kafka-supervisor-reference
+title: "Apache Kafka supervisor reference"
+sidebar_label: "Apache Kafka supervisor"
+description: "Refrence topic for Apache Kafka supervisors"
+---
+
+<!--
+ ~ Licensed to the Apache Software Foundation (ASF) under one
+ ~ or more contributor license agreements. See the NOTICE file
+ ~ distributed with this work for additional information
+ ~ regarding copyright ownership. The ASF licenses this file
+ ~ to you under the Apache License, Version 2.0 (the
+ ~ "License"); you may not use this file except in compliance
+ ~ with the License. You may obtain a copy of the License at
+ ~
+ ~ http://www.apache.org/licenses/LICENSE-2.0
+ ~
+ ~ Unless required by applicable law or agreed to in writing,
+ ~ software distributed under the License is distributed on an
+ ~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ ~ KIND, either express or implied. See the License for the
+ ~ specific language governing permissions and limitations
+ ~ under the License.
+ -->
+This topic contains the reference Apache Kafka supervisor configuration for Apache Druid. The following table outlines the high level configuration options:
+
+|Field|Description|Required|
+|--------|-----------|---------|
+|`type`|Supervisor type. For Kafka streaming, set to `kafka`.|yes|
+|`spec`| Container object for the supervisor configuration. | yes |
+|`dataSchema`|Schema for the Kafka indexing task to use during ingestion.|yes|
+|`ioConfig`|A `KafkaSupervisorIOConfig` object to define the Kafka connection and I/O-related settings for the supervisor and indexing task. See [KafkaSupervisorIOConfig](#kafkasupervisorioconfig).|yes|
+|`tuningConfig`|A KafkaSupervisorTuningConfig object to define performance-related settings for the supervisor and indexing tasks. See [KafkaSupervisorTuningConfig](#kafkasupervisortuningconfig).|no|
+
+## KafkaSupervisorIOConfig
+
+|Field|Type|Description|Required|
+|-----|----|-----------|--------|
+|`topic`|String|The Kafka topic to read from. Must be a specific topic. Topic patterns are not supported.|yes|
+|`inputFormat`|Object|`inputFormat` to define input data parsing. See [Specifying data format](#specifying-data-format) for details about specifying the input format.|yes|
+|`consumerProperties`|Map<String, Object>|A map of properties to pass to the Kafka consumer. See [More on consumer properties](#more-on-consumerproperties).|yes|
+|`pollTimeout`|Long|The length of time to wait for the Kafka consumer to poll records, in milliseconds|no (default == 100)|
+|`replicas`|Integer|The number of replica sets. "1" means a single set of tasks without replication. Druid always assigns replica tasks to different workers to provide resiliency against worker failure.|no (default == 1)|
+|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. The maximum number of reading tasks equals `taskCount * replicas`. Therefore, the total number of tasks, *reading* + *publishing*, is greater than this count. See [Capacity Planning](#capacity-planning) for more details. When `taskCount > {numKafkaPartitions}`, the actual number of reading tasks is less than the `taskCount` value.|no (default == 1)|
+|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing segments.|no (default == PT1H)|
+|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == PT5S)|
+|`period`|ISO8601 Period|Frequency at which the supervisor executes its management logic. The supervisor also runs in response to certain events. For example task success, task failure, and tasks reaching their `taskDuration`. The `period` value specifies the maximum time between iterations.|no (default == PT30S)|
+|`useEarliestOffset`|Boolean|If a supervisor manages a dataSource for the first time, it obtains a set of starting offsets from Kafka. This flag determines whether it retrieves the earliest or latest offsets in Kafka. Under normal circumstances, subsequent tasks will start from where the previous segments ended. Therefore Druid only uses `useEarliestOffset` 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 the value is too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == PT30M)|
+|`lateMessageRejectionStartDateTime`|ISO8601 DateTime|Configure tasks to reject messages with timestamps earlier than this date time; for example if this is set to `2016-01-01T11:00Z` and the supervisor creates a task at *2016-01-01T12:00Z*, Druid drops messages with timestamps earlier than *2016-01-01T11:00Z*. This can 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 realtime and a nightly batch ingestion pipeline).|no (default == none)|
+|`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 realtime and a nightly batch ingestion pipeline). Please note that only one of `lateMessageRejectionPeriod` or `lateMessageRejectionStartDateTime` can be specified.|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)|
+|`autoScalerConfig`|Object|Defines auto scaling behavior for Kafka ingest tasks. See [Tasks Autoscaler Properties](#task-autoscaler-properties).|no (default == null)|
+
+## Task Autoscaler Properties
+
+> Note that Task AutoScaler is currently designated as experimental.
+
+| Property | Description | Required |
+| ------------- | ------------- | ------------- |
+| `enableTaskAutoScaler` | Enable or disable autoscaling. `false` or blank disables the `autoScaler` even when `autoScalerConfig` is not null| no (default == false) |
+| `taskCountMax` | Maximum number of ingestion tasks. Set `taskCountMax >= taskCountMin`. If `taskCountMax > {numKafkaPartitions}`, Druid only scales reading tasks up to the `{numKafkaPartitions}`. In this case `taskCountMax` is ignored. | yes |
+| `taskCountMin` | Minimum number of ingestion tasks. When you enable autoscaler, Druid ignores the value of taskCount in `IOConfig` and starts with the `taskCountMin` number of tasks.| yes |
+| `minTriggerScaleActionFrequencyMillis` | Minimum time interval between two scale actions. | no (default == 600000) |
+| `autoScalerStrategy` | The algorithm of `autoScaler`. Only supports `lagBased`. See [Lag Based AutoScaler Strategy Related Properties](#lag-based-autoscaler-strategy-related-properties) for details.| no (default == `lagBased`) |
+
+## Lag Based AutoScaler Strategy Related Properties
+| 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 after supervisor starts when first check scale logic. | no (default == 300000) |
+| `scaleActionPeriodMillis` | The frequency of checking whether to do scale action in millis | no (default == 60000) |
+| `scaleInStep` | How many tasks to reduce at a time | no (default == 1) |
+| `scaleOutStep` | How many tasks to add at a time | no (default == 2) |
+
+The following example demonstrates supervisor spec with `lagBased` autoScaler enabled:
+```json
+{
+ "type": "kafka",
+ "spec": {
+ "dataSchema": {
+ ...
+ },
+ "ioConfig": {
+ "topic": "metrics",
+ "inputFormat": {
+ "type": "json"
+ },
+ "consumerProperties": {
+ "bootstrap.servers": "localhost:9092"
+ },
+ "autoScalerConfig": {
+ "enableTaskAutoScaler": true,
+ "taskCountMax": 6,
+ "taskCountMin": 2,
+ "minTriggerScaleActionFrequencyMillis": 600000,
+ "autoScalerStrategy": "lagBased",
+ "lagCollectionIntervalMillis": 30000,
+ "lagCollectionRangeMillis": 600000,
+ "scaleOutThreshold": 6000000,
+ "triggerScaleOutFractionThreshold": 0.3,
+ "scaleInThreshold": 1000000,
+ "triggerScaleInFractionThreshold": 0.9,
+ "scaleActionStartDelayMillis": 300000,
+ "scaleActionPeriodMillis": 60000,
+ "scaleInStep": 1,
+ "scaleOutStep": 2
+ },
+ "taskCount":1,
+ "replicas":1,
+ "taskDuration":"PT1H"
+ },
+ "tuningConfig":{
+ ...
+ }
+ }
+}
+```
+
+## More on consumerProperties
+
+Consumer properties must contain a property `bootstrap.servers` with a list of Kafka brokers in the form: `<BROKER_1>:<PORT_1>,<BROKER_2>:<PORT_2>,...`.
+By default, `isolation.level` is set to `read_committed`. If you use older versions of Kafka servers without transactions support or don't want Druid to consume only committed transactions, set `isolation.level` to `read_uncommitted`.
+
+In some cases, you may need to fetch consumer properties at runtime. For example, when `bootstrap.servers` is not known upfront, or is not static. To enable SSL connections, you must provide passwords for `keystore`, `truststore` and `key` secretly. You can provide configurations at runtime with a dynamic config provider implementation like the environment variable config provider that comes with Druid. For more information, see [DynamicConfigProvider](../../operations/dynamic-config-provider.md).
+
+For example, if you are using SASL and SSL with Kafka, set the following environment variables for the Druid user on the machines running the Overlord and the Peon services:
+
+```
+export KAFKA_JAAS_CONFIG="org.apache.kafka.common.security.plain.PlainLoginModule required username='admin_user' password='admin_password';"
+export SSL_KEY_PASSWORD=mysecretkeypassword
+export SSL_KEYSTORE_PASSWORD=mysecretkeystorepassword
+export SSL_TRUSTSTORE_PASSWORD=mysecrettruststorepassword
+```
+
+```
+ "druid.dynamic.config.provider": {
+ "type": "environment",
+ "variables": {
+ "sasl.jaas.config": "KAFKA_JAAS_CONFIG"
+ "ssl.key.password": "SSL_KEY_PASSWORD",
+ "ssl.keystore.password": "SSL_KEYSTORE_PASSWORD",
+ "ssl.truststore.password": "SSL_TRUSTSTORE_PASSWORD"
+ }
+ }
+ }
+```
+Verify that you've changed the values for all configurations to match your own environment. You can use the environment variable config provider syntax in the **Consumer properties** field on the **Connect tab** in the **Load Data** UI in the Druid console. When connecting to Kafka, Druid replaces the environment variables with their corresponding values.
+
+Note: You can provide SSL connections with [Password Provider](../../operations/password-provider.md) interface to define the `keystore`, `truststore`, and `key`, but this feature is deprecated.
+
+## Specifying data format
+
+Kafka 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 Kafka indexing service unless you need a format only supported by the legacy `parser`.
+
+Supported `inputFormat`s include:
+- `csv`
+- `delimited`
+- `json`
+- `kafka`
+- `avro_stream`
+- `protobuf`
+
+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>
+
+## KafkaSupervisorTuningConfig
+
+The tuningConfig is optional and default parameters will be used if no tuningConfig is specified.
+
+| Field | Type | Description | Required |
+|-----------------------------------|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------|
+| `type` | String | The indexing task type, this should always be `kafka`. | 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). Normally user does not need to set this, but depending on the nature of data, if rows are short in terms of bytes, user may not want to store a million rows in memory and this value should be set. | no (default == 1000000) |
+| `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`| | 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 | *DEPRECATED*. If true, exceptions encountered during parsing will be thrown and will halt ingestion; if false, unparseable rows and fields will be skipped. Setting `reportParseExceptions` to true will override existing configurations for `maxParseExceptions` and `maxSavedParseExceptions`, setting `maxParseExceptions` to 0 and limiting `maxSavedParseExceptions` to no more than 1. | no (default == false) |
+| `handoffConditionTimeout` | Long | Milliseconds to wait for segment handoff. It must be >= 0, where 0 means to wait forever. | no (default == 0) |
+| `resetOffsetAutomatically` | Boolean | Controls behavior when Druid needs to read Kafka messages that are no longer available (i.e. when OffsetOutOfRangeException is encountered).<br/><br/>If false, the exception will bubble up, which will cause your tasks to fail and ingestion to halt. If this occurs, manual intervention is required to correct the situation; potentially using the [Reset Supervisor API](../../operations/api-reference.md#supervisors). This mode is useful for production, since it will make you aware of issues with ingestion.<br/><br/>If true, Druid will automatically reset to the earlier or latest offset available in Kafka, based on the value of the `useEarliestOffset` property (earliest if true, latest if false). Please note that this can lead to data being _DROPPED_ (if `useEarliestOffset` is false) or _DUPLICATED_ (if `useEarliestOffset` is true) without your knowledge. Messages will be logged indicating that a reset has occurred, but ingestion will
continue. This mode is useful for non-production situations, since it will make Druid attempt to recover from problems automatically, even if they lead to quiet dropping or duplicating of data.<br/><br/>This feature behaves similarly to the Kafka `auto.offset.reset` consumer property. | 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)) |
+| `chatThreads` | Integer | The number of threads that will be used for communicating with indexing tasks. | 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) |
+| `offsetFetchPeriod` | ISO8601 Period | How often the supervisor queries Kafka 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) |
+| `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#reports). Overridden if `reportParseExceptions` is set. | no, default == 0 |
+
+#### 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 offset 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`)|
+
+##### Bitmap types
+
+For Roaring bitmaps:
+
+|Field|Type|Description|Required|
+|-----|----|-----------|--------|
+|`type`|String|Must be `roaring`.|yes|
+|`compressRunOnSerialization`|Boolean|Use a run-length encoding where it is estimated as more space efficient.|no (default == `true`)|
+
+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|
+
+## Operations
Review comment:
It looks like this "Operations" section through to the end is a duplicate of what on the new page, kafka-supervisor-operations.md, and can come out?
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