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fanrui commented on FLINK-27530: -------------------------------- Hi [~godfreyhe] , as I understand, [~pnowojski] has written the release note in FLINK-26762 before, that is : {code:java} New concept of overdraft network buffers was introduced to mitigate effects of uninterruptible blocking a subtask thread during back pressure. Starting from 1.16.0 Flink subtask can request by default up to 5 extra (overdraft) buffers over the regular configured amount (you can read more about this in the documentation: https://nightlies.apache.org/flink/flink-docs-master/docs/deployment/memory/network_mem_tuning/#overdraft-buffers). This change can slightly increase memory consumption of the Flink Job. To restore the older behaviour you can set `taskmanager.network.memory.max-overdraft-buffers-per-gate` to zero.{code} In theory it has no negative effects, but it is helpful for Unaligned Checkpoints, and I'm not sure whether to introduce this feature in the Flink-1.16 Release note. > FLIP-227: Support overdraft buffer > ---------------------------------- > > Key: FLINK-27530 > URL: https://issues.apache.org/jira/browse/FLINK-27530 > Project: Flink > Issue Type: Improvement > Components: Runtime / Checkpointing, Runtime / Network > Reporter: fanrui > Assignee: fanrui > Priority: Major > Fix For: 1.16.0 > > > This is the umbrella issue for the feature of unaligned checkpoints. Refer to > the > [FLIP-227|https://cwiki.apache.org/confluence/display/FLINK/FLIP-227%3A+Support+overdraft+buffer] > for more details. -- This message was sent by Atlassian Jira (v8.20.10#820010)