Process not running alerts - exact and regex matching
The process not running alerts allow you to be alerted when a certain process or service stops running. By default the alert will perform an exact match of the process name you supply against the process list, however it can also match based on a regular expression you enter.
Exact matching
Enter the full name of the process including any parameters. As you type any matches will be displayed so you can quickly click to auto complete the field. The matches will be drawn from the processes running on the server today (although it may not necessarily be which processes are running right now).
Since it is an exact match, only one of these processes can be selected to be matched, even though they are similar. You should use regular expression matching (explained below) to match all in a single alert.
Regular expression matching
You can specify a Perl Compatible Regular Expression (PCRE) to use as the match pattern so you can easily match multiple processes which may have different parameters.
All regular expressions start and end with a forward-slash / which is what Server Density uses to detect that a regular expression is being used. When it is detected the UI will update to show this and the auto complete box will show what your expression matches in real time against the process list. Any errors will also be displayed.
Nobody likes writing regexes so here a few examples that should cover most situations. The Python documentation also has a good intro guide. In all the examples below we are matching against several processes running called /sbin/mingetty which have parameters after them ttyn where n is a number from 1 to 6.
/(.*)mingetty/- will match anything beforemingetty/(.*)mingetty(.*)/- will match anything before and aftermingetty/(.*)mingetty(\stty)[1-3]/- will match the first 3 processes but not the last 3. Here(.*)matches/sbin/at the start,mingettyis specified and then any whitespace character followed bytty(\smatches the whitespace character). Finally the numbers 1 to 3 (i.e. 1, 2 and 3) are matched.
