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zhang commented on FLINK-33355: ------------------------------- [~yunta] I know that modifying the max parallelism is not possible, but I only changed the parallelism by using the parameter {*}parallelism.default{*}. In my tests, reducing it from n to m (where m < n and m > 1) is feasible. However, reducing it to 1 results in the aforementioned error. Nevertheless, I have a requirement to reduce the parallelism of a Flink process from n to 1. > can't reduce the parallelism from 'n' to '1' when recovering through a > savepoint. > --------------------------------------------------------------------------------- > > Key: FLINK-33355 > URL: https://issues.apache.org/jira/browse/FLINK-33355 > Project: Flink > Issue Type: Bug > Components: API / Core > Environment: flink 1.17.1 > Reporter: zhang > Priority: Major > > If the program includes operators with window, it is not possible to reduce > the parallelism of the operators from n to 1 when restarting from a > savepoint, and it will result in an error: > {code:java} > //IllegalStateException: Failed to rollback to checkpoint/savepoint > Checkpoint Metadata. Max parallelism mismatch between checkpoint/savepoint > state and new program. Cannot map operator 0e059b9f403cf6f35592ab773c9408d4 > with max parallelism 128 to new program with max parallelism 1. This > indicates that the program has been changed in a non-compatible way after the > checkpoint/savepoint. {code} -- This message was sent by Atlassian Jira (v8.20.10#820010)