How to start a Node Agent using scripting?

This is a tricky question.  The quick answer is that it can't be done using the typical wsadmin commands.  But it can be done by 'shelling out' from your python script to issue an operating system command.

My colleague and fellow wsadmin contributor Jose Luis provided this Q&A dialog...


1) Is it possible to start the Node agent using wsadmin scripting?

No.

You can not do any operations on a Node agent if it is down. A Node agent must be running in order to work with it.

2) Why don't wsadminlin.py methods such as 'startServer' and 'isServerRunning' work for Node agents?

The job of the node agent is to start and stop servers, and to monitor them.  Under the covers, the wsadmin startServer command asks a running node agent to start servers.  But the node agent can not start itself.  Therefore the 'startServer' command can not start a node agent.

However, method 'isServerRunning' does work on Node agents. It returns True if the node agent is running and False if it is down.

3) How do I start a Node agent that is not running?

Request for Feedback

Are you using wsadminlib.py?   Does it work well for you?

Would you like an update with some fixes and new methods?

Please send me a note.  I promise to keep your email private, no spam, no sharing.

Thanks

Python 'not callable' errors

Be careful not to heist the names of methods in wsadminlib.py...

The python language allows you to dynamically redefine a method to a variable, and vice-versa. This can be a nice feature if you do it intentionally. But it can be a nuisance to debug if unintentional. Here is a quick example:

First, define a method which returns the sum of two numbers:

ding@dingp:~$ python
Python 2.5.2 (r252:60911, Jan 20 2010, 21:48:48)
[GCC 4.2.4 (Ubuntu 4.2.4-1ubuntu3)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> def myMethod(i,j):
... return i+j
...
>>>

Pass in two numbers, set the return value to another variable, and it works as expected.

>>> k = myMethod(1,2)
>>> print k
3
>>>

But watch what happens next...

How to set custom properties in Global Security?

Use wsadminlib's method setCustomPropertyOnObject().

Here is the method signature. The parameters are straightforward:

setCustomPropertyOnObject(object_id, propname, propvalue)

The pydoc is pretty good too. If a property with this name does not exist, the method creates it. If one already exists, the method sets the new value.

Here is an example:

sid = getObjectsOfType('Security')[0]
setCustomPropertyOnObject(sid,'andy.propkey','andy.propvalue')
save()

We can then browse to the admin console and see the new custom property in the list.

Extra info:  We can also query the value of a custom property with this method.

getObjectCustomProperty(object_id, propname)