Ansible Handler and when condition - ansible

Question

I am trying to find a logic to check if the service is running, if Not Running, then start it. Below is the logic I have written, but for some reason the notify is not calling the handler?
---
- name: Executing the play to start the service
hosts: nodes
become: yes
gather_facts: False
tasks:
- name: Executing the Shell task to check the status of the wso2 instance
shell: myMsg=$(sudo service wso2esb status| grep Active | awk '{print $3}');if [[ $myMsg == "(dead)" ]]; then echo "Not Running";else echo "Running";fi
ignore_errors: yes
register: result
notify: handl
when: result.stdout == "Not Running" (I even tried 'changed_when', but the same error)
handlers:
- name: handl
service: name=wso2esb state=started
$ ansible-playbook -i inventories/hosts.sit start.yml -b -k
SSH password:
PLAY [Executing the play to start the wso2 service] ***********************************************
TASK [Executing the Shell task to check the status of the instance] *******************************
fatal: [mpstest01]: FAILED! => {"msg": "The conditional check 'result.stdout == \"Not Running\"' failed. The error was: error while evaluating conditional (result.stdout == \"Not Running\"): **'result' is undefined**\n\nThe error appears to have been in '/home/ansible1/start.yml': line 9, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n - name: Executing the Shell task to check the status of the instance\n ^ here\n"}
...ignoring
PLAY RECAP ****************************************************************************************
mpstest01 : ok=1 changed=0 unreachable=0 failed=0

Answer 1

That all seems unnecessary. You don't need to "check if the service is running, if Not Running, then start it"; that's exactly what the service module does. Just put the service module in a task, and don't bother with the handler:
- name: start service if it isn't already running
service: name=wso2esb state=started
Although I would prefer YAML syntax rather than the key=value syntax:
- name: start service if it isn't already running
service:
name: wso2esb
state: started
In any case, the service module will check if the service is running, and if not, it will start it.