Flooding "not found in retransmission table" in server log too much in cluster and making application slow.

[dheeraj.mishra]

We have Wildfly 11.0.0 Final version - 24 JVMs cluster using multicast and observing below error too much in server.log and it is making application slower. attaching logs for your reference.

2020-02-02 02:22:07,839 WARN [org.jboss.as.clustering.jgroups.protocol.NAKACK2] (thread-1) JGRP000041: sol120_7433: message sol120_7403::1425 not found in retransmission table

[pferraro]

You probably need to disable use_mcast_xmit (which was inadvertently enabled in some older WF versions).

e.g.

<stack name="...">

  <transport type="UDP" ... />

  <!-- ... -->

  <protocol type="pbcast.NAKACK2">

    <property name="use_mcast_xmit_req">false</property>

  </protocol>

  <!-- ... -->

</stack>

[dheeraj.mishra]

Thanks Paul!

I tried this option but no luck!

I changed all standalone.xml file with below parameter and tried. still i see the error and slowness. one thing which I observed that still i see use_mcast_xmit value true in Jconsole JMX.

<protocol type="pbcast.NAKACK2">

    <property name="use_mcast_xmit">false</property>

  </protocol>

[pferraro]

My apologies, the property to disable should be "use_mcast_xmit_req".

[dheeraj.mishra]

Thanks Paul for your response!

i tried to configure parameters like below but still I see value is true in Jconsole. did i miss anything?

            <stacks>

                <stack name="udp">

                    <transport type="UDP" socket-binding="jgroups-udp"/>

                    <protocol type="PING"/>

                    <protocol type="MERGE3"/>

                    <protocol type="FD_SOCK"/>

                    <protocol type="FD_ALL"/>

                    <protocol type="VERIFY_SUSPECT"/>

                    <protocol type="pbcast.NAKACK2">

                      <property name="use_mcast_xmit">false</property>

                      <property name="use_mcast_xmit_req">false</property>

                    </protocol>

                    <protocol type="UNICAST3"/>

                    <protocol type="pbcast.STABLE"/>

                    <protocol type="pbcast.GMS"/>

                    <protocol type="UFC"/>

                    <protocol type="MFC"/>

                    <protocol type="FRAG2"/>

                </stack>

            </stacks>

[pferraro]

I fear the only workaround options are:

1. Use the legacy protocol configuration for NAKACK2, i.e. <protocol type="org.jgroups.protocols.pbcast.NAKACK2"/>
2. Cherry pick this fix and rebuild: WFLY-9473 Custom NAKACK2 automatically enables use_mcast_xmit/use_mca… · wildfly/wildfly@106ed30 · GitHub
3. Disable multicast for UDP (i.e. use a socket binding that does not supply a multicast address).
4. Upgrade to a more recent version of WildFly.

[dheeraj.mishra]

Thanks much Paul! it is working now with option 1 change. now we dont see any re-transmission related WARN/ERROR in log.

thanks again.