Users Guide

Cluster Constraints | Clustering
OMNM 6.5.3 Installation Guide 111
MySQL’s online support suggests that you can create as many as 10,000 connections depending on
the amount of RAM available: “Linux should be able to support at 500 to 1000 simultaneous
connections routinely and as many as 10,000 connections if you have many gigabytes of RAM
available and the workload from each is low or the response time target undemanding.”
Oracle Database Connections
You may need more connections for Oracle since it can recursively consume database connections
internally. Refer to the following for more about this:
http://tech.e2sn.com/oracle/oracle-internals-
and-architecture/recursive-sessions-and-ora-00018-maximum-number-of-sessions-exceeded
Notifying Users of Lost Database Connection
In the owareapps\installedprops\installed.properties file, you can configure the
application server to send e-mail when it loses connection to the database. Here are the properties
to insert:
redcell.smtp.host=mail_server.com
redcell.smtp.authentication.enabled=true
redcell.smtp.authentication.username=[e-mail]
redcell.smtp.authentication.password=password
redcell.smtp.recipients=[e-mail]
redcell.smtp.subject.message=Lost DB connection ### optional
redcell.smtp.message=Call 911!!!! ### optional
The contents specified above are examples.
Disabling Multicast
Disabling Multicast for a Standalone Server
Multicast is enabled to facilitate communication between servers in distributed, multi-server
installations. If your system is a standalone server, it may be useful to disable this feature to reduce
performance delay. Follow these steps to disable multicast.
1 Stop appserver.
2 Add the property oware.unicast=true to installed.properties file located in .../dorado/
owareapps/installprops/lib directory
3 Locate .../oware/jboss/server/oware/deploy/cluster/jgroups-channelfactory.sar/META-INF/
jgroups-channelfactory-stacks.xml
4 In the TCP section (you can search by <stack name="tcp"), comment this portion:
<!--Alternative 1: multicast-based automatic discovery.-->
<MPING timeout="3000"
num_initial_members="3"
mcast_addr="${jboss.partition.udpGroup:230.11.11.11}"
mcast_port="${jgroups.tcp.mping_mcast_port:45700}"
ip_ttl="${jgroups.udp.ip_ttl:2}"/>