Configuration Rules

Flink Job Parameter Configuration Specifications

The following table describes the rules for configuring Flink job parameters.

**Table 1** Parameter configuration specifications
Parameter	Mandatory	Description	Recommended Value
-c	Yes	Main class name	Set this parameter as you need.
-ynm	Yes	Flink YARN job name	Set this parameter as you need.
execution.checkpointing.interval	Yes	Interval for triggering a checkpoint, which can be added using -yD. The unit is ms.	60000
execution.checkpointing.timeout	Yes	Checkpoint timeout interval. You can run the -yD command to add a checkpoint timeout interval. The default value is 30 minutes.	30min
parallelism.default	No	Job parallelism. For example, to add the job parallelism for the join operator, use -yD. The default value is 1.	Set this parameter based on the site requirements.
table.exec.state.ttl	Yes	TTL (join ttl) of Flink state, which can be added using -yD. The default value is 0.	Set this parameter based on the site requirements.

Checkpoint Interval Should Be Longer Than the Checkpoint Execution Duration

The checkpoint execution duration depends on checkpoint data volume. The larger the data volume, the longer the execution duration.

Checkpoint Timeout Duration Should Be Longer Than the Checkpoint Interval

The checkpoint interval indicates the interval for triggering a checkpoint. If the execution duration is longer than the checkpoint timeout interval, the job fails.

If CDC is used, changelog needs to be enabled for Hudi table read and write.

To ensure Flink calculation accuracy when CDC is used, retain +I, +U, -U, and -D in Hudi tables. Changelog must be enabled when data is written to or read from the same Hudi table.

Parent topic: Flink on Hudi

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