Repeated JGroups Flow Control (FC) Warning Messages and threads waiting in FC
Issue
-
Warning messages like these appear in
log/server.log
or the console:WARN [org.jgroups.protocols.FC] Received two credit requests from 127.0.0.2:64842 without any intervening messages; sending 1999689 credits WARN [org.jgroups.protocols.FC] Received two credit requests from 127.0.0.2:64842 without any intervening messages; sending 1999093 credits WARN [org.jgroups.protocols.FC] Received two credit requests from 127.0.0.2:64842 without any intervening messages; sending 2000000 credits
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The following WARN messages are appearing non-stop in the log file over a long period
WARN [org.jgroups.protocols.FC] Received two credit requests from 192.168.10.11:55200 without any intervening messages; sending 1986459 credits
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JBoss is slow and we see request threads stalling in replication activity and JGroups FlowControl:
"ajp-/127.0.0.1:8009-1" daemon prio=10 tid=0x00007f82f40bf800 nid=0x7a2a in Object.wait() [0x00007f82cddd9000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000b6794e60> (a org.jgroups.protocols.FlowControl$Credit)
at org.jgroups.protocols.FlowControl$Credit.decrementIfEnoughCredits(FlowControl.java:553)
- locked <0x00000000b6794e60> (a org.jgroups.protocols.FlowControl$Credit)
at org.jgroups.protocols.UFC.handleDownMessage(UFC.java:114)
Environment
- Red Hat JBoss Enterprise Application Platform (EAP)
- 4.2.x
- 4.3.x
- 5.x
- 6.x
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