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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