Service XAPI is unresponsive:

Step 1: First, you need to find out process PID (process id)

Use ps command or pidof command to find out process ID (PID). 

Or

 service xapi status will also give the output

Step #2: kill process using PID (process id)

Above command tell you PID xapi process. Now kill process using this PID:

# kill <pid>

OR

# kill -9 <PID>

Where -9 is special Kill signal, which will kill the process forcefully.