Hi devs: We(release managers of flink 1.20) wanna update one performance regresses to the flink dev mail list.
# Background: The performance of serializerHeavyString starts regress since April 3, and we created FLINK-35040[1] to follow it. In brief: - The performance only regresses for jdk 11, and Java 8 and Java 17 are fine. - The regression reason is upgrading commons-io version from 2.11.0 to 2.15.1 - This upgrading is done in FLINK-34955[2]. - The performance can be recovered after reverting the commons-io version to 2.11.0 You can get more details from FLINK-35040[1]. # Problem We try to generate the flame graph (wall mode) to analyze why upgrading the commons-io version affects the performance. These flamegraphs can be found in FLINK-35040[1]. (Many thanks to Zakelly for generating these flamegraphs from the benchmark server). Unfortunately, we cannot find any code of commons-io dependency is called. Also, we try to analyze if any other dependencies are changed during upgrading commons-io version. The result is no, other dependencies are totally the same. # Request After the above analysis, we cannot find why the performance of serializerHeavyString starts to regress for jdk11. We are looking forward to hearing valuable suggestions from the Flink community. Thanks everyone in advance. Note: 1. I cannot reproduce the regression on my Mac with jdk11, and we suspect this regression may be caused by the benchmark environment. 2. We will accept this regression if the issue still cannot be solved. [1] https://issues.apache.org/jira/browse/FLINK-35040 [2] https://issues.apache.org/jira/browse/FLINK-34955 Best, Weijie, Ufuk, Robert and Rui
