You can use WLST to retrieve information that WebLogic Server instances produce to describe their run-time state. The following sections using WLST to get run-time information:
The Administration Server hosts the domain run-time hierarchy which provides access to any MBean on any server in the WebLogic domain. If the Administration Server is not running for a WebLogic domain, WLST can connect to individual Managed Servers to retrieve run-time data.
Accessing the run-time information for a WebLogic domain includes the following main steps:
Invoke WLST and connect to a running Administration Server instance. See Invoking WLST.
Navigate to the domain run-time MBean hierarchy by entering the domainRuntime command.
wls:/mydomain/serverConfig>domainRuntime()
The domainRuntime command places WLST at the root of the domain-wide run-time management objects, DomainRuntimeMBean.
Navigate to ServerRuntimes and then to the server instance which you are interested in monitoring.
wls:/mydomain/domainRuntime>cd('ServerRuntimes/myserver')
At the server instance, navigate to and interrogate run-time MBeans.
wls:/mydomain/domainRuntime/ServerRuntimes/myserver>cd('JVMRuntime/myserver')> wls:/mydomain/domainRuntime/ServerRuntimes/myserver/JVMRuntime/myserver>ls() -r-- AllProcessorsAverageLoad 0.0 -r-- Concurrent true -r-- FreeHeap 15050064 -r-- FreePhysicalMemory 900702208 -r-- GCHandlesCompaction true -r-- GcAlgorithm Dynamic GC currently running strategy: Nursery, parallel mark, parallel sweep -r-- Generational true -r-- HeapFreeCurrent 14742864 -r-- HeapFreePercent 5 -r-- HeapSizeCurrent 268435456 -r-- HeapSizeMax 268435456 -r-- Incremental false -r-- JVMDescription Oracle JRockit Java Virtual Machine -r-- JavaVMVendor BEA Systems, Inc. -r-- JavaVendor BEA Systems, Inc. -r-- JavaVersion 1.5.0 ...
The following sections provide example scripts for retrieving run-time information about WebLogic Server server instances and WebLogic domain resources.
The WLST online script in Example 8-1 navigates the domain run-time hierarchy and checks the status of a Managed Server every 5 seconds. It restarts the server if the server state changes from RUNNING to any other status. It assumes that WLST is connected to the WebLogic domain's Administration Server.
For information on how to run this script, see Invoking WLST.
Example 8-1 Monitoring Server State
# Node Manager needs to be running to run this script.
import thread
import time
def checkHealth(serverName):
while 1:
slBean = getSLCRT(serverName)
status = slBean.getState()
print 'Status of Managed Server is '+status
if status != "RUNNING":
print 'Starting server '+serverName
start(serverName, block="true")
time.sleep(5)
def getSLCRT(svrName):
domainRuntime()
slrBean = cmo.lookupServerLifecycleRuntime(svrName)
return slcBean
The WLST online script in Example 8-2 monitors the HJVMHeapSize for all running servers in a WebLogic domain; it checks the heap size every 3 minutes and prints a warning if the heap size is greater than a specified threshold. It assumes that the URL for the WebLogic domain's Administration Server is t3://localhost:7001.
For information on how to run this script, see Invoking WLST.
Example 8-2 Monitoring the JVM Heap Size
waitTime=300000
THRESHOLD=100000000
uname = "weblogic"
pwd = "welcome1"
url = "t3://localhost:7001"
def monitorJVMHeapSize():
connect(uname, pwd, url)
while 1:
serverNames = getRunningServerNames()
domainRuntime()
for name in serverNames:
print 'Now checking '+name.getName()
try:
cd("/ServerRuntimes/"+name.getName()+"/JVMRuntime/"+name.getName())
heapSize = cmo.getHeapSizeCurrent()
if heapSize > THRESHOLD:
# do whatever is neccessary, send alerts, send email etc
print 'WARNING: The HEAPSIZE is Greater than the Threshold'
else:
print heapSize
except WLSTException,e:
# this typically means the server is not active, just ignore
# pass
java.lang.Thread.sleep(1800000)
def getRunningServerNames():
# only returns the currently running servers in the domain
# return domainRuntimeService.getServerRuntimes()
if __name__== "main":
monitorJVMHeapSize()
if __name__== "main":
monitorJVMHeapSize()
Using WLST, you can configure a server instance's logging and message output.
To determine which log attributes can be configured, see "LogMBean" and "LogFileMBean" in the Oracle WebLogic Server MBean Reference. The reference also indicates valid values for each attribute.
The WLST online script in Example 8-3 sets attributes of LogMBean (which extends LogFileMBean). For information on how to run this script, see Invoking WLST.
Example 8-3 Configuring Logging
# Connect to the server
connect("weblogic","welcome1","t3://localhost:7001")
edit()
startEdit()
# set CMO to the server log config
cd("Servers/myserver/Log/myserver")
ls ()
# change LogMBean attributes
set("FileCount", 5)
set("FileMinSize", 400)
# list the current directory to confirm the new attribute values
ls ()
# save and activate the changes
save()
activate()
# all done...
exit()
The WebLogic Diagnostic Framework (WLDF) is a monitoring and diagnostic framework that can collect diagnostic data that servers and applications generate. You configure WLDF to collect the data and store it in various sources, including log records, data events, and harvested metrics. For more information, see Configuring and Using the Diagnostics Framework for Oracle WebLogic Server.
For example scripts that demonstrate using WLST to configure the WebLogic Diagnostic Framework, see "WebLogic Scripting Tool Examples" in Configuring and Using the Diagnostics Framework for Oracle WebLogic Server.
To view the collected diagnostics information using WLST, use one of the following commands to export the data from the WLDF repositories:
From WLST offline, use the exportDiagnosticData command (see "exportDiagnosticData" in WebLogic Scripting Tool Command Reference).
From WLST online, use the exportDiagnosticDataFromServer command (see "exportDiagnosticDataFromServer" in WebLogic Scripting Tool Command Reference)).