53 lines
1.3 KiB
Markdown
53 lines
1.3 KiB
Markdown
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# Kafka - openCypher clause
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One must be able to specify the following when importing data from Kafka:
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* Kafka URI
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* Transform [script](transform.md) URI
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Kafka endpoint is the URI of the leader broker and it is required for data
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[extractor](extractor.md).
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Minimum required syntax looks like:
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```opencypher
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CREATE STREAM kafka_stream AS LOAD DATA KAFKA '127.0.0.1/topic' WITH TRANSFORM
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'127.0.0.1/transform.py';
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```
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The `CREATE STREAM` clause happens in a transaction.
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The full openCypher clause for creating a stream is:
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```opencypher
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CREATE STREAM stream_name AS
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LOAD DATA KAFKA 'URI'
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WITH TRANSFORM 'URI'
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[BATCH INTERVAL milliseconds]
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```
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The `WITH TRANSFORM` parameter should contain a URI of the transform script.
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The `BATCH_INTERVAL` parameter defines the time interval in milliseconds
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that defines the time between two successive stream importing operations.
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The `DROP` clause deletes a stream:
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```opencypher
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DROP STREAM stream_name;
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```
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The `SHOW` clause enables you to see all configured streams:
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```opencypher
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SHOW STREAMS;
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```
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You can also start/stop streams with the `START` and `STOP` clauses:
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```opencypher
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START STREAM stream_name [LIMIT count BATCHES];
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STOP STREAM stream_name;
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```
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There are also convenience clauses to start and stop all streams:
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```opencypher
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START ALL STREAMS;
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STOP ALL STREAMS;
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```
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