Hi everyone,
I have JBoss 3.2.3 in production over two servers. I've been having intermittent cache invalidation problems ever since we deployed. An example is an update to an entity bean in Server A is occasionally not reflected in Server B.
The situation improved when we optimized the application so that it is lightly loaded (less than 50% utilization). However, it still occurred a couple of times a week.
Thinking it might be the network switch swallowing multicast packets, I tried to solve the problem by switching to TCP for the transport layer of JGroups but it did not work.
Two days ago, I added Apache to Server A to do load balancing to Server A and B using mod_jk. The cache invalidation problem has suddenly ballooned and I get 10 or more problem instances per day. (The workaround I use to survive temporarily is to flush the specific entity bean cache when it occurs).
It would be a tremendous help if someone could help me identify some steps I could take to either diagnose the problem or solve it? Many thanks in advance!
My JGroups configuration is below.
Thanks,
Aris
<TCP start_port="7800" bind_addr="10.20.0.18"/>
<TCPPING initial_hosts="10.20.0.18[7800],10.20.0.17[7800]"
port_range="5" up_thread="true" down_thread="true"
num_initial_members="2" timeout="5000"/>
<MERGE2 min_interval="5000" max_interval="10000" />
<FD shun="true" up_thread="true" down_thread="true"
timeout="2500" max_tries="5" />
<VERIFY_SUSPECT timeout="3000" num_msgs="3"
up_thread="true" down_thread="true" />
<pbcast.NAKACK gc_lag="50" retransmit_timeout="300,600,1200,2400,4800"
up_thread="true" down_thread="true" />
<pbcast.STABLE desired_avg_gossip="20000"
up_thread="true" down_thread="true" />
<pbcast.GMS join_timeout="5000" join_retry_timeout="2000"
shun="true" print_local_addr="true" />
<pbcast.STATE_TRANSFER up_thread="true" down_thread="true" />
