Showing posts with label NameError. Show all posts

Saturday, June 15, 2013

SOA Retire Activate Composites

Why we need retire and activate composites?

Before you go for bouncing the SOA Suite Domain which contains SOA, ADF Clusters with multiple managed servers, where each Weblogic server hosted all the sessions which are in execution state on them must be persisted to a restore further when Servers back to RUNNING state. To make this possible we need to use the retire composites and then after RUNNING servers bring them back to activate state for service.

Here is a sample trail script where the SOA application composites management. Here you need to navigate to the wlst.sh or cmd path. To access SCA function you must start WLST from /common/bin. When trying to run the SOA WLST command from regular 'java weblogic.WLST' cannot execute the SCA functions. When you try to execute the sca_retireComposite() it could throw the 'NameError'. So the cause is started WLST from the wrong location, to avoid that our PATH is to change and run the script from the following path: $SOA_ORACLE_HOME/common/bin/wlst.sh will work on Unix/Linux environments. Similarly you choose for Windows environment instead of using executing the shell script you need to use 'call' in the batch script.

Here the major task we have proceeding with the following two functions.

Retire is to retire the composites .
Activate is to activate the composites.

loadProperties('/user/test/scripts/composites.properties')
def retireComposites(Soahost,port, username,password,scacompositename, ver):
        sca_retireComposite(Soahost, port, username, password, scacompositename, revision=ver, partition='default') 
def activateComposites(Soahost,port, username,password,scacompositename, ver):
        sca_activateComposite(Soahost, port, username, password, scacompositename, revision=ver, partition='default')
if __name__== "main":
        print "1.To retire composites"
        print "2.To activate composites"
        print "3.Exit from Menu"
        ch=input('Enter Your Choice: ')
        f=open('/user/test/scripts/composites.txt','r')
        if ch== 1 :
                for c in f:
                        c=c.rstrip('\n')
                        retireComposites(Soahost,port, username,password,c, ver)
        elif ch == 2 :
                for c in f:
                        c=c.rstrip('\n')
                        activateComposites(Soahost,port, username,password,c, ver)
        else:
                exit()
        f.close()

Here is the composite.txt sample, where you can specify your composites configured in the SOA partition. Which are usually visible on enterprise manager(em) console. Oracle must given a easy module for displaying the deployed SCA composites list. Anyway we have stored in a separate file as shown below. You have flexibility of changing the order when you use this composite.txt file.

B2B_BPEL_TEST_Sub_reccive
B2B_BPEL_TIBCO_PUB_invoke

The actual trouble started when we tried to use a separate composite.txt file. each line can be read and the value always having at the end an EOL ( \n ). To supress that escape sequance we have used python scring function rtrip function.

The regular properties file which is loaded on the fist line can be created as follows:

Soahost=localhost
port=8001
username=weblogic
password=welcome1
ver=1.0

Please share this with your friends and collegues, comment if you already tried or successfully implemented on your SOA environment.

Video References:

Iris Li demonstrates how to deploy a SOA composite application using the Oracle Enterprise Manager 11g

SOA Composites references :

Thursday, October 27, 2011

WLST Errors and Exceptions

When first time you started using WLST you might get many of these Python based WLST Errors. Here I had collected few of them which are very simple to handle them with care. Only thing you need to understand when what kind of errors raises, and what need to do to handle them. When there is error on your flow of WLST Script or prompt don't be panic, relax for a moment then after a while take a deep breath and focus on your error and map with one of the following and do the required workaround.

In Jython we have issubclass() to check superclass, subclass relation we can verify class relationship. You can find parent-child relationship with it. As per my understanding the Error hierarchy can be defined in WLST(Jython) as follows:

This WLST(Jython) Error tree I prepared and posted for your reference, so that you can make your script in perfect manner, here you can find what is going wrong why it is happen while working out your script.

try:
 # WLST code Block 
 # perform some tasks that may throw an exception
except ExceptionType, ExceptionVar:
 # WLST code or
 # perform some exception handling
finally:
    # perform tasks that must always be completed (Will be performed before the exception is # raised.)
else:
 # execute code that must always be invoked

The pass statement in WLST

While writing WLST scripts, there are some situations where you need ‘do nothing’ statement syntactically. That is provided by the pass statement. When you start working on Exception handling this statement will be the first experimenting statement for you.

WLST raise statement

In WLST raise is used to generate or invoke an exception condition. The syntax of this statement allows three comma separated expressions which are optional. If no expression is present, WLST attempt to re-raise the last exception that was raised. This raise statement we can use when we need exception handling with robust scripts. When you pass the expressions to the raise statement, the first two expressions are evaluated to get the objects. These objects are then used to determine the type and value of the exception. Omitted expressions are treated as None. The third expression could be used for traceback objects.

wls:/offline> try:
...     raise Exception('SituationalResponse')
...except Exception, e:
...     print e
...
java.lang.Exception: SituationalResponse

SyntaxError

This you cannot be handled with the try-except block, because it will be thrown when your syntax is not in properly arranged, that is in the statement missing indentation or improper arguments. SyntaxError could be raised when the script lines are given for parsing, it will do token by token parsing wherever the improper syntax given WLST Shell points with cap char under the token.

Now let us see the sample indentation issue that raises the Syntax Error.

wls:/offline>; try:
...connect('system','weblogic103','t3://adminhost:adminport')
Traceback (innermost last):
(no code object)
at line 0
File
"", line 2
connect('system','weblogic103','t3://adminhost:adminport')
^
SyntaxError: invalid syntax

Another option for Syntax Error
This Error I have observed when I tried to migrate the WebLogic domain with createDomain() command.

wls:/offline/wdomain>createDomain('/home/backup/olddomain.jar', '/home/otherusr/domains/newdomain',’system', 'weblogic103')
Traceback (innermost last):
  (no code object) at line 0
  File "", line 1
        createDomain('/home/backup/olddomain.jar', '/home/otherusr/domains/newdomain',?system', 'weblogic103')
                                                                                                          ^
SyntaxError: Lexical error at line 1, column 99.  Encountered: "\ufffd" (65533), after : ""

This "Lexical error" got due to the copying from the webpage which has single quotes in different unicode value. When I retype the single quotes it was resolved.

Here in the above sample after issuing try block starting we must use a tab or 4 spaces before connect() command. When it found that is not
having proper indentation it raised the SyntaxError.

NameError

When the name used to do something like print or use in some other expression without assigning the value before it was defined then WLST will raises NameError. When first time scripting most of the time user encounters this unknowingly.

The following example might give you an idea how to resolve your issue.

wls:/offline> var1=100
wls:/offline> var3=var1+var2
Traceback (innermost last):
  File "", line 1, in ?

You can handle this kind of error with our try-except block

wls:/offline> try: var3=var1+var2
...except NameError, e:
...     print "Please check there is: ", sys.exc_info()[0], sys.exc_info()[1]
...
Please check there is:  exceptions.NameError var2

The beauty of handling your Exception/Error more transparent and easy to understand with sys.exc_info() list.

KeyError

This error can be raised by the WLST while using the dictionary objects or map objects accessed with non-matching key.

wls:/offline> urls['b']
Traceback (innermost last):
File
"", line 1, in ?
KeyError: b

ValueError

The ValueError is raised by the WLST shell when there is a inappropriate element is accessed in a list or a variable, that is such as the value specified for searching in the list with index() method. Removing the element which is not really exists in the list.

wls:/offline> L.index('web2')
Traceback (innermost last):
File
"<console>", line 1, in ?
ValueError: list.index(x): x not in list

I was working on thread and JVM monitoring script, encountered with the ValueError in different way. After storing the ThreadPool values, JVM values into local variables I was using C type of formatting to display the data in a row of Table. Some of the attribute values are Long integers, some of them plain integers some of them are strings.

 cd('/ServerRuntimes/'+ svr +'/ThreadPoolRuntime/ThreadPoolRuntime')
 thtot=`get('ExecuteThreadTotalCount')`
 thid= `get('ExecuteThreadIdleCount')`
 hog= `get('HoggingThreadCount')`
 sbth= `get('StandbyThreadCount')`
 cr =`get('CompletedRequestCount')`
 pr =`get('PendingUserRequestCount')`
 ql =`get('QueueLength')`
 th= `get('Throughput')`
 
 cd('/ServerRuntimes/'+svr+'/JVMRuntime/'+svr)
        freejvm = long(get('HeapFreeCurrent'))/(1024*1024)
        totaljvm = long(get('HeapSizeCurrent'))/(1024*1024)
        usedjvm = (totaljvm - freejvm)

When I ran with all numbered values with format as %5d it was shouted as follows:

ValueError: unsupported format character ' ' (0x20) at index 23

Don't know what attribute requires which format ... Initially to resolve this display without any format for all attributes values from the MBean.

print svr, thtot, thid, hog, sbth, cr, pr, ql, th, hs, totaljvm, freejvm, usedjvm

But still ValueError was exists, when I updated with formatter it was stuck with CompletedRequestCount that was not integer type, it is actually Long integer type and that was causing the Error. So, changed the format for that attribute it resolved one issue. Now the issue with different index number came... I have an idea that, if I found all the attributes and their data types then it will be easy to fix the right format for each. I tried the following way

print type(thtot),type(thid), type(hog), type(sbth), type(cr), type(pr), type(ql), type(th),type(freejvm), type(totaljvm), type(usedjvm)

formatted accordingly the ValueError is resolved.

print '%14s %10s %5s %5s %5s %5s %8s %5s %5s %8s %5dMB %5dMB %5dMB' %  (svr, hs, thtot, thid, hog, sbth, cr, pr, ql, th, totaljvm, freejvm, usedjvm)

So now you can take care of Values of variables for your WLST code before use them for any operation!!

AttributeError

You might be on MBean tree where there is no such attribute defined and you tried to access it then WLST Shell raises AttributeError. Let us see an Example you can easily understand.

wls:/demodom/serverConfig> cmo.State()
Traceback (innermost last):
  File "", line 1, in ?
AttributeError: State

IndexError

The IndexError will be raised by the WLST shell, when thelist object is accessed with a out of range index value.

Let us see the example a list is defined with 5 elements

wls:/offline> L['app1', 'app2', 'app3', 'app4', 'web1']

when it is accessed with out of range index value say 7 then you get the IndexError.

wls:/offline> L[7]
Traceback (innermost last):
File
"<console>", line 1, in ?
IndexError: index out of range: 7

TypeError

The basic python object types int, str assignments or expressions or print statements with
concatenation does not allows you, raises the TypeError.

wls:/offline> print 'Number of servers:', 5
Number of servers: 5
 
wls:/offline>print 'Number of servers:'+ 5
Traceback (innermost last):
File
"<console>", line 1, in ?
TypeError: cannot concatenate 'str' and 'int' objects

Thanks for reading this post, Give your feedback in comments. cheers!!

Good References:

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