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cherry pick #11630: Kafka Input Format for headers, key and payload parsing #52

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merged 1 commit into from
Oct 13, 2021

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@lokesh-lingarajan lokesh-lingarajan commented Oct 12, 2021

Notes:
This commit is a cherry pick of ad6609a from upstream (apache#11630).

Some conflicts had to be resolved related to docs.
Other than that the only change we need to handle is wrt to

public InputRowSchema(TimestampSpec timestampSpec, DimensionsSpec dimensionsSpec, List<String> metricNames)

changes were mainly in the file - KafkaInputFormatTest
From:ColumnsFilter.all()
To: Collections.emptyList()


Today we ingest a number of high cardinality metrics into Druid across dimensions. These metrics are rolled up on a per minute basis, and are very useful when looking at metrics on a partition or client basis. Events is another class of data that provides useful information about a particular incident/scenario inside a Kafka cluster. Events themselves are carried inside kafka payload, but nonetheless there are some very useful metadata that is carried in kafka headers that can serve as useful dimension for aggregation and in turn bringing better insights.

PR(apache#10730) introduced support of Kafka headers in InputFormats.

We still need an input format to parse out the headers and translate those into relevant columns in Druid. Until that’s implemented, none of the information available in the Kafka message headers would be exposed. So first there is a need to write an input format that can parse headers in any given format(provided we support the format) like we parse payloads today. Apart from headers there is also some useful information present in the key portion of the kafka record. We also need a way to expose the data present in the key as druid columns. We need a generic way to express at configuration time what attributes from headers, key and payload need to be ingested into druid. We need to keep the design generic enough so that users can specify different parsers for headers, key and payload.

This PR is designed to solve the above by providing wrapper around any existing input formats and merging the data into a single unified Druid row.

Lets look at a sample input format from the above discussion

"inputFormat":
{
"type": "kafka", // New input format type
"headerLabelPrefix": "kafka.header.", // Label prefix for header columns, this will avoid collusions while merging columns
"recordTimestampLabelPrefix": "kafka.", // Kafka record's timestamp is made available in case payload does not carry timestamp
"headerFormat": // Header parser specifying that values are of type string
{
"type": "string"
},
"valueFormat": // Value parser from json parsing
{
"type": "json",
"flattenSpec": {
"useFieldDiscovery": true,
"fields": [...]
}
},
"keyFormat": // Key parser also from json parsing
{
"type": "json"
}
}

Since we have independent sections for header, key and payload, it will enable parsing each section with its own parser, eg., headers coming in as string and payload as json.

KafkaInputFormat will be the uber class extending inputFormat interface and will be responsible for creating individual parsers for header, key and payload, blend the data resolving conflicts in columns and generating a single unified InputRow for Druid ingestion.

"headerFormat" will allow users to plug parser type for the header values and will add default header prefix as "kafka.header."(can be overridden) for attributes to avoid collision while merging attributes with payload.

Kafka payload parser will be responsible for parsing the Value portion of the Kafka record. This is where most of the data will come from and we should be able to plugin existing parser. One thing to note here is that if batching is performed, then the code is augmenting header and key values to every record in the batch.

Kafka key parser will handle parsing Key portion of the Kafka record and will ingest the Key with dimension name as "kafka.key".

This is the class that orchestrates sending the consumerRecord to each parser, retrieve rows, merge the columns into one final row for Druid consumption. KafkaInputformat should make sure to release the resources that gets allocated as a part of reader in CloseableIterator during normal and exception cases.

During conflicts in dimension/metrics names, the code will prefer dimension names from payload and ignore the dimension either from headers/key. This is done so that existing input formats can be easily migrated to this new format without worrying about losing information.

(cherry picked from commit ad6609a)

Fixes #XXXX.

Description

Fixed the bug ...

Renamed the class ...

Added a forbidden-apis entry ...


This PR has:

  • been self-reviewed.
  • added documentation for new or modified features or behaviors.
  • added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
  • added or updated version, license, or notice information in licenses.yaml
  • added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
  • added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
  • added integration tests.
  • been tested in a test Druid cluster.

Key changed/added classes in this PR
  • MyFoo
  • OurBar
  • TheirBaz

Today we ingest a number of high cardinality metrics into Druid across dimensions. These metrics are rolled up on a per minute basis, and are very useful when looking at metrics on a partition or client basis. Events is another class of data that provides useful information about a particular incident/scenario inside a Kafka cluster. Events themselves are carried inside kafka payload, but nonetheless there are some very useful metadata that is carried in kafka headers that can serve as useful dimension for aggregation and in turn bringing better insights.

PR(apache#10730) introduced support of Kafka headers in InputFormats.

We still need an input format to parse out the headers and translate those into relevant columns in Druid. Until that’s implemented, none of the information available in the Kafka message headers would be exposed. So first there is a need to write an input format that can parse headers in any given format(provided we support the format) like we parse payloads today. Apart from headers there is also some useful information present in the key portion of the kafka record. We also need a way to expose the data present in the key as druid columns. We need a generic way to express at configuration time what attributes from headers, key and payload need to be ingested into druid. We need to keep the design generic enough so that users can specify different parsers for headers, key and payload.

This PR is designed to solve the above by providing wrapper around any existing input formats and merging the data into a single unified Druid row.

Lets look at a sample input format from the above discussion

"inputFormat":
{
    "type": "kafka",     // New input format type
    "headerLabelPrefix": "kafka.header.",   // Label prefix for header columns, this will avoid collusions while merging columns
    "recordTimestampLabelPrefix": "kafka.",  // Kafka record's timestamp is made available in case payload does not carry timestamp
    "headerFormat":  // Header parser specifying that values are of type string
    {
        "type": "string"
    },
    "valueFormat": // Value parser from json parsing
    {
        "type": "json",
        "flattenSpec": {
          "useFieldDiscovery": true,
          "fields": [...]
        }
    },
    "keyFormat":  // Key parser also from json parsing
    {
        "type": "json"
    }
}

Since we have independent sections for header, key and payload, it will enable parsing each section with its own parser, eg., headers coming in as string and payload as json.

KafkaInputFormat will be the uber class extending inputFormat interface and will be responsible for creating individual parsers for header, key and payload, blend the data resolving conflicts in columns and generating a single unified InputRow for Druid ingestion.

"headerFormat" will allow users to plug parser type for the header values and will add default header prefix as "kafka.header."(can be overridden) for attributes to avoid collision while merging attributes with payload.

Kafka payload parser will be responsible for parsing the Value portion of the Kafka record. This is where most of the data will come from and we should be able to plugin existing parser. One thing to note here is that if batching is performed, then the code is augmenting header and key values to every record in the batch.

Kafka key parser will handle parsing Key portion of the Kafka record and will ingest the Key with dimension name as "kafka.key".

This is the class that orchestrates sending the consumerRecord to each parser, retrieve rows, merge the columns into one final row for Druid consumption. KafkaInputformat should make sure to release the resources that gets allocated as a part of reader in CloseableIterator<InputRow> during normal and exception cases.

During conflicts in dimension/metrics names, the code will prefer dimension names from payload and ignore the dimension either from headers/key. This is done so that existing input formats can be easily migrated to this new format without worrying about losing information.

(cherry picked from commit ad6609a)
@lokesh-lingarajan
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tested the changes locally on my laptop.

@lokesh-lingarajan lokesh-lingarajan changed the title Kafka Input Format for headers, key and payload parsing (#11630) - Upstream pull Kafka Input Format for headers, key and payload parsing (#11630) - Upstream pull (cherry pick - ad6609a606c0ca945c6aa57f1b7c40593ba29f80) Oct 12, 2021
@xvrl xvrl changed the title Kafka Input Format for headers, key and payload parsing (#11630) - Upstream pull (cherry pick - ad6609a606c0ca945c6aa57f1b7c40593ba29f80) cherry pick apache/druid#11630: Kafka Input Format for headers, key and payload parsing Oct 12, 2021
@xvrl xvrl changed the title cherry pick apache/druid#11630: Kafka Input Format for headers, key and payload parsing cherry pick #11630: Kafka Input Format for headers, key and payload parsing Oct 12, 2021
@xvrl xvrl merged commit f01023d into 0.21.0-confluent Oct 13, 2021
@xvrl xvrl deleted the conf-kif branch October 13, 2021 18:19
harinirajendran pushed a commit that referenced this pull request Feb 23, 2022
…load parsing (apache#11630) (#52)

Today we ingest a number of high cardinality metrics into Druid across dimensions. These metrics are rolled up on a per minute basis, and are very useful when looking at metrics on a partition or client basis. Events is another class of data that provides useful information about a particular incident/scenario inside a Kafka cluster. Events themselves are carried inside kafka payload, but nonetheless there are some very useful metadata that is carried in kafka headers that can serve as useful dimension for aggregation and in turn bringing better insights.

PR(apache#10730) introduced support of Kafka headers in InputFormats.

We still need an input format to parse out the headers and translate those into relevant columns in Druid. Until that’s implemented, none of the information available in the Kafka message headers would be exposed. So first there is a need to write an input format that can parse headers in any given format(provided we support the format) like we parse payloads today. Apart from headers there is also some useful information present in the key portion of the kafka record. We also need a way to expose the data present in the key as druid columns. We need a generic way to express at configuration time what attributes from headers, key and payload need to be ingested into druid. We need to keep the design generic enough so that users can specify different parsers for headers, key and payload.

This PR is designed to solve the above by providing wrapper around any existing input formats and merging the data into a single unified Druid row.

Lets look at a sample input format from the above discussion

"inputFormat":
{
    "type": "kafka",     // New input format type
    "headerLabelPrefix": "kafka.header.",   // Label prefix for header columns, this will avoid collusions while merging columns
    "recordTimestampLabelPrefix": "kafka.",  // Kafka record's timestamp is made available in case payload does not carry timestamp
    "headerFormat":  // Header parser specifying that values are of type string
    {
        "type": "string"
    },
    "valueFormat": // Value parser from json parsing
    {
        "type": "json",
        "flattenSpec": {
          "useFieldDiscovery": true,
          "fields": [...]
        }
    },
    "keyFormat":  // Key parser also from json parsing
    {
        "type": "json"
    }
}

Since we have independent sections for header, key and payload, it will enable parsing each section with its own parser, eg., headers coming in as string and payload as json.

KafkaInputFormat will be the uber class extending inputFormat interface and will be responsible for creating individual parsers for header, key and payload, blend the data resolving conflicts in columns and generating a single unified InputRow for Druid ingestion.

"headerFormat" will allow users to plug parser type for the header values and will add default header prefix as "kafka.header."(can be overridden) for attributes to avoid collision while merging attributes with payload.

Kafka payload parser will be responsible for parsing the Value portion of the Kafka record. This is where most of the data will come from and we should be able to plugin existing parser. One thing to note here is that if batching is performed, then the code is augmenting header and key values to every record in the batch.

Kafka key parser will handle parsing Key portion of the Kafka record and will ingest the Key with dimension name as "kafka.key".

This is the class that orchestrates sending the consumerRecord to each parser, retrieve rows, merge the columns into one final row for Druid consumption. KafkaInputformat should make sure to release the resources that gets allocated as a part of reader in CloseableIterator<InputRow> during normal and exception cases.

During conflicts in dimension/metrics names, the code will prefer dimension names from payload and ignore the dimension either from headers/key. This is done so that existing input formats can be easily migrated to this new format without worrying about losing information.

(cherry picked from commit ad6609a)
kkonstantine pushed a commit that referenced this pull request Sep 1, 2022
…load parsing (apache#11630) (#52)

Today we ingest a number of high cardinality metrics into Druid across dimensions. These metrics are rolled up on a per minute basis, and are very useful when looking at metrics on a partition or client basis. Events is another class of data that provides useful information about a particular incident/scenario inside a Kafka cluster. Events themselves are carried inside kafka payload, but nonetheless there are some very useful metadata that is carried in kafka headers that can serve as useful dimension for aggregation and in turn bringing better insights.

PR(apache#10730) introduced support of Kafka headers in InputFormats.

We still need an input format to parse out the headers and translate those into relevant columns in Druid. Until that’s implemented, none of the information available in the Kafka message headers would be exposed. So first there is a need to write an input format that can parse headers in any given format(provided we support the format) like we parse payloads today. Apart from headers there is also some useful information present in the key portion of the kafka record. We also need a way to expose the data present in the key as druid columns. We need a generic way to express at configuration time what attributes from headers, key and payload need to be ingested into druid. We need to keep the design generic enough so that users can specify different parsers for headers, key and payload.

This PR is designed to solve the above by providing wrapper around any existing input formats and merging the data into a single unified Druid row.

Lets look at a sample input format from the above discussion

"inputFormat":
{
    "type": "kafka",     // New input format type
    "headerLabelPrefix": "kafka.header.",   // Label prefix for header columns, this will avoid collusions while merging columns
    "recordTimestampLabelPrefix": "kafka.",  // Kafka record's timestamp is made available in case payload does not carry timestamp
    "headerFormat":  // Header parser specifying that values are of type string
    {
        "type": "string"
    },
    "valueFormat": // Value parser from json parsing
    {
        "type": "json",
        "flattenSpec": {
          "useFieldDiscovery": true,
          "fields": [...]
        }
    },
    "keyFormat":  // Key parser also from json parsing
    {
        "type": "json"
    }
}

Since we have independent sections for header, key and payload, it will enable parsing each section with its own parser, eg., headers coming in as string and payload as json.

KafkaInputFormat will be the uber class extending inputFormat interface and will be responsible for creating individual parsers for header, key and payload, blend the data resolving conflicts in columns and generating a single unified InputRow for Druid ingestion.

"headerFormat" will allow users to plug parser type for the header values and will add default header prefix as "kafka.header."(can be overridden) for attributes to avoid collision while merging attributes with payload.

Kafka payload parser will be responsible for parsing the Value portion of the Kafka record. This is where most of the data will come from and we should be able to plugin existing parser. One thing to note here is that if batching is performed, then the code is augmenting header and key values to every record in the batch.

Kafka key parser will handle parsing Key portion of the Kafka record and will ingest the Key with dimension name as "kafka.key".

This is the class that orchestrates sending the consumerRecord to each parser, retrieve rows, merge the columns into one final row for Druid consumption. KafkaInputformat should make sure to release the resources that gets allocated as a part of reader in CloseableIterator<InputRow> during normal and exception cases.

During conflicts in dimension/metrics names, the code will prefer dimension names from payload and ignore the dimension either from headers/key. This is done so that existing input formats can be easily migrated to this new format without worrying about losing information.

(cherry picked from commit ad6609a)
kkonstantine pushed a commit that referenced this pull request Sep 1, 2022
…load parsing (apache#11630) (#52)

Today we ingest a number of high cardinality metrics into Druid across dimensions. These metrics are rolled up on a per minute basis, and are very useful when looking at metrics on a partition or client basis. Events is another class of data that provides useful information about a particular incident/scenario inside a Kafka cluster. Events themselves are carried inside kafka payload, but nonetheless there are some very useful metadata that is carried in kafka headers that can serve as useful dimension for aggregation and in turn bringing better insights.

PR(apache#10730) introduced support of Kafka headers in InputFormats.

We still need an input format to parse out the headers and translate those into relevant columns in Druid. Until that’s implemented, none of the information available in the Kafka message headers would be exposed. So first there is a need to write an input format that can parse headers in any given format(provided we support the format) like we parse payloads today. Apart from headers there is also some useful information present in the key portion of the kafka record. We also need a way to expose the data present in the key as druid columns. We need a generic way to express at configuration time what attributes from headers, key and payload need to be ingested into druid. We need to keep the design generic enough so that users can specify different parsers for headers, key and payload.

This PR is designed to solve the above by providing wrapper around any existing input formats and merging the data into a single unified Druid row.

Lets look at a sample input format from the above discussion

"inputFormat":
{
    "type": "kafka",     // New input format type
    "headerLabelPrefix": "kafka.header.",   // Label prefix for header columns, this will avoid collusions while merging columns
    "recordTimestampLabelPrefix": "kafka.",  // Kafka record's timestamp is made available in case payload does not carry timestamp
    "headerFormat":  // Header parser specifying that values are of type string
    {
        "type": "string"
    },
    "valueFormat": // Value parser from json parsing
    {
        "type": "json",
        "flattenSpec": {
          "useFieldDiscovery": true,
          "fields": [...]
        }
    },
    "keyFormat":  // Key parser also from json parsing
    {
        "type": "json"
    }
}

Since we have independent sections for header, key and payload, it will enable parsing each section with its own parser, eg., headers coming in as string and payload as json.

KafkaInputFormat will be the uber class extending inputFormat interface and will be responsible for creating individual parsers for header, key and payload, blend the data resolving conflicts in columns and generating a single unified InputRow for Druid ingestion.

"headerFormat" will allow users to plug parser type for the header values and will add default header prefix as "kafka.header."(can be overridden) for attributes to avoid collision while merging attributes with payload.

Kafka payload parser will be responsible for parsing the Value portion of the Kafka record. This is where most of the data will come from and we should be able to plugin existing parser. One thing to note here is that if batching is performed, then the code is augmenting header and key values to every record in the batch.

Kafka key parser will handle parsing Key portion of the Kafka record and will ingest the Key with dimension name as "kafka.key".

This is the class that orchestrates sending the consumerRecord to each parser, retrieve rows, merge the columns into one final row for Druid consumption. KafkaInputformat should make sure to release the resources that gets allocated as a part of reader in CloseableIterator<InputRow> during normal and exception cases.

During conflicts in dimension/metrics names, the code will prefer dimension names from payload and ignore the dimension either from headers/key. This is done so that existing input formats can be easily migrated to this new format without worrying about losing information.

(cherry picked from commit ad6609a)
pagrawal10 added a commit that referenced this pull request Sep 23, 2024
…er (#49) (#226)

* feat: add the number of merge buffers used for druid emitter (#49)

Signed-off-by: TessaIO <[email protected]>
Co-authored-by: TessaIO <[email protected]>

* Update setMetric (#51)

* Improve metrics emit (#52)

* Fix checkstyle (#53)

---------

Signed-off-by: TessaIO <[email protected]>
Co-authored-by: TessaIO <[email protected]>
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