Get hands-on experience with 20+ free Google Cloud products and $300 in free credit for new customers.

Hi guys I am getting this error runing dataflow with flex-template

Workflow failed. Causes: S30:Read TransferResultDetails from MySQL/Create.Values/Impulse+Read TransferResultDetails from MySQL/Create.Values/MapElements/Map/ParMultiDo(Anonymous)+Read TransferResultDetails from MySQL/JdbcIO.ReadAll/ParDo(Read)/ParMultiDo(Read)+Read TransferResultDetails from MySQL/JdbcIO.ReadAll/JdbcIO.Reparallelize/Consume/ParDo(Anonymous)/ParMultiDo(Anonymous)+Read TransferResultDetails from MySQL/JdbcIO.ReadAll/JdbcIO.Reparallelize/View.AsIterable/MapElements/Map/ParMultiDo(Anonymous) failed., The job failed because a work item has failed 4 times. Look in previous log entries for the cause of each one of the 4 failures. If the logs only contain generic timeout errors related to accessing external resources, such as MongoDB, verify that the worker service account has permission to access the resource's subnetwork. For more information, see https://cloud.google.com/dataflow/docs/guides/common-errors. The work item was attempted on these workers: Root cause: SDK disconnect. Worker ID: transfermigration-2024061-06131334-5v8q-harness-9g3c, Root cause: SDK disconnect. Worker ID: transfermigration-2024061-06131334-5v8q-harness-9g3c, Root cause: SDK disconnect. Worker ID: transfermigration-2024061-06131334-5v8q-harness-9g3c, Root cause: SDK disconnect. Worker ID: transfermigration-2024061-06131334-5v8q-harness-9g3c

 

 

Error message from worker: SDK harness sdk-0-0 disconnected. This usually means that the process running the pipeline code has crashed. Inspect the Worker Logs and the Diagnostics tab to determine the cause of the crash.
0 2 1,355
2 REPLIES 2

This Dataflow error message indicates that the worker processes responsible for running your pipeline have crashed repeatedly, leading to job failure. This signifies a disruption in the communication between the worker process (running your pipeline code) and the Dataflow service, often due to a crash. The error indicates that a specific work item failed multiple times, likely related to reading data from a MySQL database. While the immediate cause is "SDK disconnect," the underlying issue leading to the crash needs further investigation. Here are some troubleshooting steps you can take:

  1. Check Worker Logs:

    • Navigate to the Dataflow job's Worker Logs tab in the Google Cloud Console.
    • Look for error messages, stack traces, or exceptions around the time of the crash. Common issues include:
      • Out of memory errors (OOM)
      • Dependency conflicts
      • Problems with MySQL connection or data
  2. Check Diagnostics Tab:

    • Review the Diagnostics tab for resource utilization (CPU, memory, disk).
    • Look for spikes or anomalies that could have caused the worker to crash.
  3. Verify MySQL Connectivity and Credentials:

    • Ensure that the Dataflow worker service account has the necessary permissions to access your MySQL database.
    • Double-check connection parameters (host, port, username, password) in your Dataflow code.
  4. Review Dataflow Code:

    • Examine the portion of your code that reads from the MySQL database (specifically the JdbcIO.ReadAll operation).
    • Check for potential issues such as:
      • Incorrect queries or data types
      • Inefficient data processing
      • Handling large datasets
  5. Increase Worker Resources:

    • If the worker logs indicate memory or CPU issues, try increasing the worker machine type (e.g., from n1-standard-1 to n1-standard-2).
  6. Consider Batching or Windowing:

    • If handling large volumes of data from MySQL, implement batching or windowing in your pipeline to process data in smaller chunks.

Additional Tips

  • Retry Logic: Incorporate retry mechanisms to handle transient errors when connecting to MySQL.
  • Isolate the Issue: Create a simplified Dataflow pipeline that only reads from MySQL to determine if the problem lies solely in database interaction.
  • Community Resources: Search for similar issues on Stack Overflow and the Google Cloud Community forums.

Example Code Snippet (Checking for Errors)

pipeline
    .apply("Read from MySQL", JdbcIO.<KV<Integer, String>>read()
        .withDataSourceConfiguration(JdbcIO.DataSourceConfiguration.create("com.mysql.cj.jdbc.Driver", "jdbc:mysql://your-database-host:3306/your-database-name")
            .withUsername("your-username")
            .withPassword("your-password"))
        .withQuery("select id, name from your_table")
        .withCoder(KvCoder.of(BigEndianIntegerCoder.of(), StringUtf8Coder.of()))
        .withRowMapper(new JdbcIO.RowMapper<KV<Integer, String>>() {
            @Override
            public KV<Integer, String> mapRow(ResultSet resultSet) throws Exception {
                // Handle errors gracefully here, e.g., log exceptions
                return KV.of(resultSet.getInt("id"), resultSet.getString("name"));
            }
        }))
    // ... rest of your pipeline

Additional Considerations:

  • Environment Setup: Ensure your Dataflow environment and dependencies are compatible with your Flex-Template.
  • Flex-Template Debugging: When debugging Flex-Templates, ensure the Docker container has the necessary resources and configurations.

Hello,

Thank you for your engagement regarding this issue. We haven’t heard back from you regarding this issue for sometime now. Hence, I'm going to close this issue which will no longer be monitored. However, if you have any new issues, Please don’t hesitate to create a new issue . We will be happy to assist you on the same.

Regards,

Jai Ade