Baohe Zhang created SPARK-34779: ----------------------------------- Summary: ExecutoMetricsPoller should keep stage entry in stageTCMP until a heartbeat occurs Key: SPARK-34779 URL: https://issues.apache.org/jira/browse/SPARK-34779 Project: Spark Issue Type: Improvement Components: Spark Core Affects Versions: 3.1.1, 3.1.0, 3.0.2, 3.0.1, 3.0.0 Reporter: Baohe Zhang
The current implementation of ExecutoMetricsPoller uses task count in each stage to decide whether to keep a stage entry or not. In the case of the executor only has 1 core, it may have these issues: # Peak metrics missing (due to stage entry being removed within a heartbeat interval) # Unnecessary and frequent hashmap entry removal and insertion. Assuming an executor with 1 core has 2 tasks (task1 and task2, both belong to stage (0,0)) to execute in a heartbeat interval, the workflow in current ExecutorMetricsPoller implementation would be: 1. task1 start -> stage (0, 0) entry created in stageTCMP, task count increment to1 2. 1st poll() -> update peak metrics of stage (0, 0) 3. task1 end -> stage (0, 0) task count decrement to 0, stage (0, 0) entry removed, peak metrics lost. 4. task2 start -> stage (0, 0) entry created in stageTCMP, task count increment to1 5. 2nd poll() -> update peak metrics of stage (0, 0) 6. task2 end -> stage (0, 0) task count decrement to 0, stage (0, 0) entry removed, peak metrics lost 7. heartbeat() -> empty or inaccurate peak metrics for stage(0,0) reported. We can fix the issue by keeping entries with task count = 0 in stageTCMP map until a heartbeat occurs. At the heartbeat, after reporting the peak metrics for each stage, we scan each stage in stageTCMP and remove entries with task count = 0. After the fix, the workflow would be: 1. task1 start -> stage (0, 0) entry created in stageTCMP, task count increment to1 2. 1st poll() -> update peak metrics of stage (0, 0) 3. task1 end -> stage (0, 0) task count decrement to 0,but the entry (0,0) still remain. 4. task2 start -> task count of stage (0,0) increment to1 5. 2nd poll() -> update peak metrics of stage (0, 0) 6. task2 end -> stage (0, 0) task count decrement to 0,but the entry (0,0) still remain. 7. heartbeat() -> accurate peak metrics for stage (0, 0) reported. Remove entry for stage (0,0) in stageTCMP because its task count is 0. How to verify the behavior? Submit a job with a custom polling interval (e.g., 2s) and spark.executor.cores=1 and check the debug logs of ExecutoMetricsPoller. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org