warning 'fork/exec /bin/sh: too many open files'

The config file try to get CPU info from  multiple server.

```
    sample: ssh <name>@<ip>   "ps --no-headers -A -o  %cpu  | awk '{ s+=\$1 } END {print s}'"
```

It's sometimes display ok, and some time there is warning display as below

```
SAMPLING FAILURE
fork/exec /bin/sh: too many open files
```



