Create a Weblogic dynamic server cluster using WLST
March 20, 2014
Continuing my little series of posts on using wlst, how to create a domain and how to add a machine the below will set up a dynamic server cluster. This is a new feature for Weblogic 12C 12.1.2.
You can find more details on the dynamic cluster here. In brief it allows you to grow and shrink the number of available managed servers, with each managed server based on a template.
if __name__ == '__main__':
from wlstModule import *
connect('weblogic', 'weblogic1', 't3://myhost.mydomain.ie:7001')
edit()
startEdit()
dynamicServerTemplate = cmo.createServerTemplate('my-server-template')
dynamicServerTemplate.setAcceptBacklog(2000)
dynamicServerTemplate.setAutoRestart(true)
dynamicServerTemplate.setRestartMax(1)
dynamicServerTemplate.setStartupTimeout(600)
dynamicServerTemplate.setAutoKillIfFailed(true)
dynamicServerTemplate.getOverloadProtection().setFailureAction('force-shutdown')
dynamicServerTemplate.getOverloadProtection().setPanicAction('system-exit')
# Set whatever settings best suit the memory on the system and what you what to do with this server
#I believe MaxPermSize should be half the max heap
#The urandom is covered in another post
dynamicServerTemplate.getServerStart().setArguments(
'-Xmx2048m -Xms2048m -XX:+UseG1GC -XX:MaxPermSize=1024m -Djava.security.egd=file:///dev/./urandom')
dynamicServerTemplate.getLog().setFileName('${serverName}_%yyyy%_%MM%_%dd%_%hhmm%.log')
dynamicServerTemplate.getLog().setRotationType('byTime')
dynamicServerTemplate.getLog().setRedirectStderrToServerLogEnabled(true)
dynamicServerTemplate.getLog().setRedirectStdoutToServerLogEnabled(true)
dynamicServerTemplate.getWebServer().getWebServerLog().setFileName('${serverName}_access_%yyyy%_%MM%_%dd%_%hhmm%.log')
dynamicServerTemplate.getWebServer().getWebServerLog().setRotationType('byTime')
dynCluster = cmo.createCluster('my-cluster')
dynCluster.getOverloadProtection().setFailureAction('force-shutdown')
dynCluster.getOverloadProtection().setPanicAction('system-exit')
dynServers = dynCluster.getDynamicServers()
dynServers.setMaximumDynamicServerCount(1)
dynServers.setServerTemplate(dynamicServerTemplate)
dynServers.setServerNamePrefix('my-server-')
dynServers.setCalculatedMachineNames(true)
dynServers.setCalculatedListenPorts(true)
activate(block="true")
exit() One thing worth mentioning a bit more is the log file names.
As the servers an dynamically created based on the prefix, in this case my-server-1, my-server-2, etc… you can use a variable made available by Weblogic ${serverName} which will have this dynamically created name.
The filepattern can be of your choosing and is used when the log files are rotated, the pattern replaced with the actual date values.
So for example the logs for my-server—1 would be
my-server-1_yyyy_MM_dd_hhmm.log
Bit of an eye full, but when rotated the old one becomes
my-server-1_2014_03_20_0000.log
Which I find better than the sequence number which is the default
