Hi,
For default values of frequency (=500) and dropTime (=3000) in cluster
installation with TOMEE 7.0.7 (uses Tomcat 8.5.50.0) using JDK 12 or above
only, many memberDisappeared messages are logged on all nodes of the
cluster (almost for every 2 minutes). This is occuring even when the system
is idle. In the JDK 12 environment, on increasing the dropTime to 10000, we
identified that they are scarcely generated. The exact same setup works
without any problem when configured with JDK 11.
We also reproduced this issue on Tomcat-only (v8.5.54 and v8.5.50) cluster
setup using Oracle JDK 12.0.2 (64-bit, java version "12.0.2" 2019-07-16)
and JDK14 (64-bit, java version "14" 2020-03-17).
*Cluster setup details:*
1) *Nodes Configurations:*
Count : 2
Resources : 1-cpu 2.29 GHZ, 1-core and 4 GB RAM.
2)* Server.xml Configuration:*
a) We used the default cluster settings as per Tomcat 8.5 docs (
https://tomcat.apache.org/tomcat-8.5-doc/cluster-howto.html) using
asynchronous replication mode.
b) Also for non-default channelSendOptions:
<Cluster
className="org.apache.catalina.ha.tcp.SimpleTcpCluster"
channelSendOptions="6">
In both instances, we reproduced the issue.
Please note that were able to* consistently reproduce the issue with 1-cpu
nodes with default dropTime value*. However, we are unable to reproduce it
with increased cpu resources (cpu count >= 2) or higher dropTime (>= 8500
ms).
We would like to ascertain, if this is an environment issue and is caused
by 1-cpu configured nodes?
P.S - This was filed in bugzilla,
https://bz.apache.org/bugzilla/show_bug.cgi?id=64312
Best Regards,
Mahathi Vavilala
