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[GitHub] [incubator-druid] ccaominh commented on a change in pull request
#8153: Add more warning to the doc for resetOffsetAutomatically
ccaominh commented on a change in pull request #8153: Add more warning to the doc for resetOffsetAutomatically
URL: https://github.com/apache/incubator-druid/pull/8153#discussion_r306998756
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File path: docs/content/development/extensions-core/kafka-ingestion.md
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@@ -130,31 +130,31 @@ A sample supervisor spec is shown below:
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|Whether to reset the consumer offset if the next offset that it is trying to fetch is less than the earliest available offset for that particular partition. The consumer offset will be reset to either the earliest or latest offset depending on `useEarliestOffset` property of `KafkaSupervisorIOConfig` (see below). This situation typically occurs when messages in Kafka are no longer available for consumption and therefore won't be ingested into Druid. If set to false then ingestion for that particular partition will halt and manual intervention is required to correct the situation, please see `Reset Supervisor` API below.|no (default == false)|
-|`workerThreads`|Integer|The number of threads that will be used by the supervisor for asynchronous operations.|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.|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/reports.html). Overridden if `reportParseExceptions` is set.|no, default == 0|
+| 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 | This option _MUST_ not be set if you don't want to ignore missing data from Kafka. Once this is set, the supervisor _automatically_ resets the consumer offset for each Kafka partitions whenever the next offset it's trying to fetch is less than the earliest available offset in Kafka. The consumer offset will be reset to either the earliest or latest offset available in Kafka depending on `useEarliestOffset` property of `KafkaSupervisorIOConfig`. Please note that this could lead _data loss_ (when `useEarliestOffset` = false) or _data duplicate_ (when `useEarliestOffset` = true). The missing offsets in Kafka typically occurs when messages in Kafka are no longer available for consumption and therefore won’t be ingested into Druid. If set to false then ingestion for that particular partition will halt and manual intervention is required to correct the situation, please see [Reset Supervisor API](../../operations/api-reference.html#supervisors). | no (default == false) |
Review comment:
Typos:
- for each Kafka partitions -> for each Kafka partition
- depending on `useEarliestOffset` -> depending on the `useEarliestOffset`
- could lead _data loss_ -> could lead to _data loss_
- missing offsets in Kafka typically occurs -> missing offsets in Kafka typically occur
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