FrankChen021 commented on a change in pull request #11240: URL: https://github.com/apache/druid/pull/11240#discussion_r659146121
########## File path: docs/development/extensions-contrib/rocketmq-ingestion.md ########## @@ -0,0 +1,414 @@ +--- +id: rocketmq-ingestion +title: "Apache RocketMQ ingestion" +sidebar_label: "Apache RocketMQ" +--- + +<!-- + ~ 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. + --> + + +The `RocketMQ` indexing service enables the configuration of *supervisors* on the Overlord, which facilitate ingestion from +`RocketMQ` by managing the creation and lifetime of `RocketMQ` indexing tasks. These indexing tasks read events using `RocketMQ's` own +message queue and offset mechanism and are therefore able to provide guarantees of exactly-once ingestion. Message queue is defined unique by +broker name and `queueID`, and message is in ordered stored in one message queue. +The supervisor oversees the state of the indexing tasks to coordinate handoffs, +manage failures, and ensure that the scalability and replication requirements are maintained. + +This service is provided in the `druid-rocketmq-indexing-service` contrib Apache Druid extension (see +[Including Extensions](../../development/extensions.md#loading-extensions)). + +## Tutorial + +This page contains reference documentation for `Apache RocketMQ-based` ingestion. + +## Submitting a Supervisor Spec + +The `RocketMQ` indexing service requires that the `druid-rocketmq-indexing-service` extension be loaded on both the Overlord and the +MiddleManagers. A supervisor for a dataSource is started by submitting a supervisor spec via HTTP POST to +`http://<OVERLORD_IP>:<OVERLORD_PORT>/druid/indexer/v1/supervisor`, for example: + +``` +curl -X POST -H 'Content-Type: application/json' -d @supervisor-spec.json http://localhost:8090/druid/indexer/v1/supervisor +``` + +A sample supervisor spec is shown below: + +```json +{ + "type": "rocketmq", + "dataSchema": { + "dataSource": "metrics-rocketmq", + "timestampSpec": { + "column": "timestamp", + "format": "auto" + }, + "dimensionsSpec": { + "dimensions": [], + "dimensionExclusions": [ + "timestamp", + "value" + ] + }, + "metricsSpec": [ + { + "name": "count", + "type": "count" + }, + { + "name": "value_sum", + "fieldName": "value", + "type": "doubleSum" + }, + { + "name": "value_min", + "fieldName": "value", + "type": "doubleMin" + }, + { + "name": "value_max", + "fieldName": "value", + "type": "doubleMax" + } + ], + "granularitySpec": { + "type": "uniform", + "segmentGranularity": "HOUR", + "queryGranularity": "NONE" + } + }, + "ioConfig": { + "topic": "metrics", + "inputFormat": { + "type": "json" + }, + "consumerProperties": { + "nameserver.url": "localhost:9876" + }, + "taskCount": 1, + "replicas": 1, + "taskDuration": "PT1H" + }, + "tuningConfig": { + "type": "rocketmq", + "maxRowsPerSegment": 5000000 + } +} +``` + +## Supervisor Configuration + +|Field|Description|Required| +|--------|-----------|---------| +|`type`|The supervisor type, this should always be `rocketmq`.|yes| +|`dataSchema`|The schema that will be used by the `RocketMQ` indexing task during ingestion. See [`dataSchema`](../../ingestion/index.md#dataschema) for details.|yes| +|`ioConfig`|A `RocketMQSupervisorIOConfig` object for configuring `RocketMQ` connection and I/O-related settings for the supervisor and indexing task. See [`RocketMQSupervisorIOConfig`](#rocketmqsupervisorioconfig) below.|yes| +|`tuningConfig`|A `RocketMQSupervisorTuningConfig` object for configuring performance-related settings for the supervisor and indexing tasks. See [`RocketMQSupervisorTuningConfig`](#rocketmqsupervisortuningconfig) below.|no| + +### `RocketMQSupervisorIOConfig` + +|Field|Type|Description|Required| +|-----|----|-----------|--------| +|`topic`|String|The `RocketMQ` topic to read from. This must be a specific topic as topic patterns are not supported.|yes| +|`inputFormat`|Object|[`inputFormat`](../../ingestion/data-formats.md#input-format) to specify how to parse input data. See [the below section](#specifying-data-format) for details about specifying the input format.|yes| +|`consumerProperties`|Map<String, Object>|A map of properties to be passed to the `RocketMQ` consumer. See [next section](#more-on-consumerproperties) for more information.|yes| +|`pollTimeout`|Long|The length of time to wait for the `RocketMQ` consumer to poll records, in milliseconds|no (default == 100)| +|`replicas`|Integer|The number of replica sets, where 1 means a single set of tasks (no replication). Replica tasks will always be assigned to different workers to provide resiliency against process failure.|no (default == 1)| +|`taskCount`|Integer|The maximum number of *reading* tasks in a *replica set*. This means that the maximum number of reading tasks will be `taskCount * replicas` and the total number of tasks (*reading* + *publishing*) will be higher than this. See [Capacity Planning](#capacity-planning) below for more details. The number of reading tasks will be less than `taskCount` if `taskCount > {numRocketMQMessageQueues}`.|no (default == 1)| +|`taskDuration`|ISO8601 Period|The length of time before tasks stop reading and begin publishing their segment.|no (default == `PT1H`)| +|`startDelay`|ISO8601 Period|The period to wait before the supervisor starts managing tasks.|no (default == `PT5S`)| +|`period`|ISO8601 Period|How often the supervisor will execute its management logic. Note that the supervisor will also run in response to certain events (such as tasks succeeding, failing, and reaching their `taskDuration`) so this value specifies the maximum time between iterations.|no (default == `PT30S`)| +|`useEarliestOffset`|Boolean|If a supervisor is managing a dataSource for the first time, it will obtain a set of starting offsets from `RocketMQ`. This flag determines whether it retrieves the earliest or latest offsets in `RocketMQ`. Under normal circumstances, subsequent tasks will start from where the previous segments ended so this flag will only be used on first run.|no (default == false)| +|`completionTimeout`|ISO8601 Period|The length of time to wait before declaring a publishing task as failed and terminating it. If this is set too low, your tasks may never publish. The publishing clock for a task begins roughly after `taskDuration` elapses.|no (default == `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`*, 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).|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)| + +#### More on consumerProperties + +Now `consumerProperties` only support one property. This must contain a property `nameserver.url` with a list of `RocketMQ` name servers in the form: `<NAMESREV_1>:<PORT_1>;<NAMESREV_2>:<PORT_2>;...`. + +#### Specifying data format + +`RocketMQ` indexing service supports both [`inputFormat`](../../ingestion/data-formats.md#input-format) and [`parser`](../../ingestion/data-formats.md#parser) to specify the data format. +The `inputFormat` is a new and recommended way to specify the data format for `RocketMQ` indexing service, +but unfortunately, it doesn't support all data formats supported by the legacy `parser`. +(They will be supported in the future.) + +The supported `inputFormat`s include [`csv`](../../ingestion/data-formats.md#csv), +[`delimited`](../../ingestion/data-formats.md#tsv-delimited), and [`json`](../../ingestion/data-formats.md#json). +You can also read [`avro_stream`](../../ingestion/data-formats.md#avro-stream-parser), +[`protobuf`](../../ingestion/data-formats.md#protobuf-parser), +and [`thrift`](../extensions-contrib/thrift.md) formats using `parser`. + +<a name="tuningconfig"></a> + +### `RocketMQSupervisorTuningConfig` + +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 `rocketmq`. | 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 `RocketMQ` 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 `RocketMQ`, 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 in gestion 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. | no (default == false) | Review comment: I don't see TaskRunner of this extension resets offset automatically. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
