https://community.cloudera.com/t5/Support-Questions/NiFi-node-keeps-disconnecting-from-the-cluster/m-p/191890#M153969 <P>Your FGC is not very high at only 4. </P><P>Do you still have issues if you restart your cluster with all components in a stopped state?</P><P>This would at least show that your issue is dataflow related.</P><P>To start with all components stopped, edit the nifi.properties file on all nodes and change the following property to "false"</P><PRE>nifi.flowcontroller.autoResumeState=true</PRE><P>Once you cluster is back up and you can access the UI, check for anywhere in your stopped flow where you have queued data (look at largest queues first). </P><P>Start these flows first and look at impact they are having on GC and Heap memory usage.</P><P>Another possibility is that you are are oversubscribing to your available resources.</P><P>Use the "top" command to observer impact on your system's resources (Namely CPU).</P><P>Make sure you have not allocated to many concurrent tasks to your individual processors.</P><P>Make sure you have not set your "max timer driven thread count" and "max event driven thread count" values to high. These values should be set to 2-4 times the number of cores you have in one node. (fro example if you have a 4 node cluster and each node in your cluster has 16 cores, the max values set should be between 32 and 64 (max 2-4 times 16 cores).</P><P>Thanks,</P><P>Matt</P> Wed, 31 May 2017 00:21:08 GMT MattWho 2017-05-31T00:21:08Z