[ https://issues.apache.org/jira/browse/FLINK-9878?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16586571#comment-16586571 ]
Nico Kruber commented on FLINK-9878: ------------------------------------ Fixed via: - `release-1.5`: 9e421a438dd830c6be72e5f13f855e68a82aef21 (1.6 and master will get new forward-PRs) > IO worker threads BLOCKED on SSL Session Cache while CMS full gc > ---------------------------------------------------------------- > > Key: FLINK-9878 > URL: https://issues.apache.org/jira/browse/FLINK-9878 > Project: Flink > Issue Type: Bug > Components: Network > Affects Versions: 1.5.0, 1.5.1, 1.6.0 > Reporter: Nico Kruber > Assignee: Nico Kruber > Priority: Major > Labels: pull-request-available > Fix For: 1.6.1, 1.7.0, 1.5.4 > > > According to https://github.com/netty/netty/issues/832, there is a JDK issue > during garbage collection when the SSL session cache is not limited. We > should allow the user to configure this and further (advanced) SSL parameters > for fine-tuning to fix this and similar issues. In particular, the following > parameters should be configurable: > - SSL session cache size > - SSL session timeout > - SSL handshake timeout > - SSL close notify flush timeout -- This message was sent by Atlassian JIRA (v7.6.3#76005)