Hi Kenan, You may check the stack trace and task-level flame graph [1] to investigate it.
[1] https://nightlies.apache.org/flink/flink-docs-release-1.17/docs/ops/debugging/flame_graphs/ Best, Zhanghao Chen ________________________________ 发件人: Kenan Kılıçtepe <kkilict...@gmail.com> 发送时间: 2023年9月26日 23:06 收件人: user <user@flink.apache.org> 主题: backpressure for just one subtask Hi, I have a job running with parallelism=24. I see that only one subtask is %100 busy and the others are %100 idle. When I checked the received message counts, I saw that they are almost identical. How can I figure out why this task causes backpressure and why only one subtask is %100 busy. Thanks Kenan