kafka dataflow template launch failed

Google Cloud Data Analytics
,
1

Hi,

I’m trying to ingest kafka topic from on-premises kafka cluster using the dataflow template. When trying to run the job, I get this error :

com.google.cloud.teleport.v2.common.UncaughtExceptionLogger - The template launch failed. java.lang.IllegalArgumentException: Please Provide --kafkaReadTopic at com.google.cloud.teleport.v2.templates.KafkaToBigQuery.run(KafkaToBigQuery.java:273) at com.google.cloud.teleport.v2.templates.KafkaToBigQuery.main(KafkaToBigQuery.java:236)

However, i’ve already mentioned the name of the topic in the parameters. Not sure what is causing the issue?

2

The error message you’re encountering indicates that the KafkaToBigQuery template in Dataflow requires the --kafkaReadTopic parameter. Although you’ve mentioned that this parameter has been included, the template is not recognizing it. This could be due to several reasons:

  1. Incorrect Parameter Syntax: Ensure you’re using the correct syntax: --kafkaReadTopic=<topic-name>. Double-check for any typos or formatting errors.

  2. Parameter Not Passed Correctly: Confirm that the --kafkaReadTopic parameter is actually being passed when running the job. Review your command or script to ensure its inclusion.

  3. Parameter Overwritten in Configuration: If you’re using a configuration file, check if the --kafkaReadTopic parameter is being inadvertently overwritten.

  4. Template Version Mismatch: Verify that you’re using the latest version of the KafkaToBigQuery template, as older versions might have issues with parameter parsing.

To further troubleshoot:

  • Review Environment Settings: Make sure all environmental variables and dependencies are correctly configured for your Dataflow job.

  • Consult Documentation: Refer to the official Dataflow documentation for specific instructions or notes regarding the KafkaToBigQuery template.

  • Check Parameter Format: Pay attention to the format of the parameters. In some cases, quotes may be needed around the parameter value.

  • Enable Detailed Logging: Turn on detailed logging for the Dataflow job to gain more insights into the job’s execution and potential points of failure.

  • Start with Minimal Configuration: Begin with a basic configuration and gradually add parameters. This approach can help isolate the cause of the issue.

  • Update Template Version: Ensure you’re using the most current version of the KafkaToBigQuery template.

3

Hi MS4446,

I’ve validated and the parameters syntax seems correct. Is it possible that the order of the arguments and parameters has an impact?

Also, looked at the job log info and the step before the error is mentioning this :

org.apache.beam.runners.dataflow.DataflowRunner - PipelineOptions.filesToStage was not specified. Defaulting to files from the classpath: will stage 3 files. Enable logging at DEBUG level to see which files will be staged.

Does this have any impact?

4

Hi @ainabaudelle ,

The order of arguments and parameters in a command line invocation can sometimes impact how they are interpreted, especially in complex systems like Dataflow. While many programs and scripts are designed to parse arguments in any order, some might require a specific sequence or have dependencies between parameters. It’s always a good practice to follow the order of parameters as documented or exemplified in official guides or templates.

Regarding the log message about PipelineOptions.filesToStage:

  • What It Means: This message indicates that Dataflow is defaulting to staging files from the classpath because the filesToStage option was not explicitly specified. This option is used to specify additional files to be made available to all workers executing a Dataflow job, such as JAR files containing custom code or dependencies.

  • Potential Impact: If your Dataflow job relies on specific files or dependencies that are not included in the classpath, not specifying them in filesToStage could lead to runtime errors or unexpected behavior. However, if all necessary files are already included in the classpath, this message might not indicate a problem.

  • Debugging Tip: If you suspect that missing files could be causing issues, you can enable DEBUG level logging to see which files are being staged. This can help you determine if any essential files are missing from the staging process.

  • Resolution: If you identify missing files, you can specify them in the filesToStage option. Alternatively, ensure that all necessary files are included in the classpath.

While the order of parameters can be important and should be verified against documentation, the message about filesToStage is more about the staging of files for the Dataflow job and may or may not be directly related to the issue with the --kafkaReadTopic parameter. It’s worth investigating both aspects to ensure your Dataflow job is configured correctly.

5

Thanks @ms4446 for your feedback. As you mentioned, i’m not sure the fileToStage is causing the error.

To help, i’ve included my command down below, hoping this helps identify the issue. Note I’m running the command from powershell.

gcloud dataflow flex-template run job_name --template-file-gcs-location gs://dataflow-templates-northamerica-northeast1/latest/flex/Kafka_to_BigQuery --parameters outputTableSpec=project-01:staging.strimzi_building,bootstrapServers=$listbootstrap,inputTopics=$kafkatopiclist,outputDeadletterTable=project-01:staging_error.strimzi_building_deadletter,kafkaReadTopics=$kafkatopiclist,javascriptTextTransformReloadIntervalMinutes=0,numStorageWriteApiStreams=0,stagingLocation=nso-staging/topic-name/staging,defaultWorkerLogLevel=DEBUG,serviceAccount=dataflow-service-producer-prod@project-01.iam.gserviceaccount.com,usePublicIps=false --region northamerica-northeast1 --worker-zone northamerica-northeast1-a --temp-location gs://nso-staging/topic_name/temp --service-account-email=dataflow-service-producer-prod@project-01.iam.gserviceaccount.com --disable-public-ips --subnetwork https://www.googleapis.com/compute/v1/projects/project-01/regions/northamerica-northeast1/subnetworks/snet-project-dataflow-01

6

@ainabaudelle ,

Based on the command you’ve provided for running the Google Cloud Dataflow job, there are a few observations and suggestions that might help identify the issue:

  • Parameter Naming: The error message you received earlier mentioned --kafkaReadTopic as the missing parameter, but in your command, you have used kafkaReadTopics=$kafkatopiclist. Ensure that the parameter name in the command matches exactly with what the template expects. It’s possible that the template is looking for kafkaReadTopic (singular) while you are providing kafkaReadTopics (plural).

  • Variable Expansion in PowerShell: You are using PowerShell variables ($listbootstrap and $kafkatopiclist) in your command. Ensure that these variables are correctly expanded and hold the expected values at the time of command execution. You can verify this by echoing the variables before running the command.

  • Correct Use of Template Parameters: Double-check that all the parameters you are passing are expected by the Kafka to BigQuery template. Any unnecessary or misspelled parameters might cause issues.

  • Quoting and Special Characters: In PowerShell, if your variables contain special characters, spaces, or are expected to expand to a list, ensure they are correctly quoted. For instance, if $kafkatopiclist expands to a list of topics, it might need to be enclosed in quotes.

  • Debugging: Since you have set defaultWorkerLogLevel=DEBUG, check the detailed logs for any additional clues about the error. Look for any messages that occur immediately before the error message for potential leads.

  • Template Version: Ensure that the template version you are using (latest/flex/Kafka_to_BigQuery) supports all the parameters you are using. Sometimes, template versions might have specific requirements or support different sets of parameters.

  • Documentation Review: Review the documentation for the Kafka to BigQuery template to ensure that all parameters are correctly used and that there are no additional required parameters that you might have missed.

  • Trial and Error: As a troubleshooting step, you might try simplifying the command to use only the essential parameters and then gradually add more parameters to isolate the issue.