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flora karniav commented on FLINK-8414: -------------------------------------- Thank you for your reply, I am running the ConnectedComponents and PageRank algorithms from Gelly examples on two SNAP datasets: 1) https://snap.stanford.edu/data/egonets-Twitter.html - 81,306 vertices and 2,420,766 edges. 2) https://snap.stanford.edu/data/com-Youtube.html - 1,134,890 vertices and 2,987,624 edges. I also want to point out that I looked into CPU utilization when changing the parallelism level and it seems to grow as expected, however performance is still reduced. (I am sorry if I posted in an inappropriate section but thought of the issue bizarre enough to be configuration or bug-related.) > Gelly performance seriously decreases when using the suggested parallelism > configuration > ---------------------------------------------------------------------------------------- > > Key: FLINK-8414 > URL: https://issues.apache.org/jira/browse/FLINK-8414 > Project: Flink > Issue Type: Bug > Components: Configuration, Documentation, Gelly > Reporter: flora karniav > Priority: Minor > > I am running Gelly examples with different datasets in a cluster of 5 > machines (1 Jobmanager and 4 Taskmanagers) of 32 cores each. > The number of Slots parameter is set to 32 (as suggested) and the parallelism > to 128 (32 cores*4 taskmanagers). > I observe a vast performance degradation using these suggested settings than > setting parallelism.default to 16 for example were the same job completes at > ~60 seconds vs ~140 in the 128 parallelism case. > Is there something wrong in my configuration? Should I decrease parallelism > and -if so- will this inevitably decrease CPU utilization? > Another matter that may be related to this is the number of partitions of the > data. Is this somehow related to parallelism? How many partitions are created > in the case of parallelism.default=128? -- This message was sent by Atlassian JIRA (v6.4.14#64029)