Strange behavior with $shtinc - sr-users

31 May 2018

Let me preface this with the statement that as best I can tell from docs and code, this
function is supposed to be 100% atomic and this shouldn't be able to happen.  I also
have not found anything in the module's github commit logs that would indicate this
behavior has changed from previous versions.

That being said, I appear to have run into an oddity where intermittently I'm getting
2 slots being put in the same entry, which results in trying to parse the output for
graphing and reporting not working quite right.  The mechanism I'm using is a very
simple counter mechanism to record statistics about calls.  As an example, I am using the
following mechanism:

$var(z) = $shtinc(callstats=>$avp(realm),cps_exceeded);
or
$var(z) = $shtinc(callstats=>$avp(realm),sessions_exceeded);

This typically results in something like this:

{
        entry: 4335
        size: 1
        slot: {
                {
                        name: realm1,total_requests
                        value: 2365034
                        type: int
                }
        }
}
{
        entry: 4532
        size: 1
        slot: {
                {
                        name: realm2,cps_exceeded
                        value: 30
                        type: int
                }
        }
}
And so on...  However, one or more of them sometimes end up like this:

{
        entry: 4646
        size: 2
        slot: {
                {
                        name: realm1,total_requests
                        value: 15958026
                        type: int
                }
                {
                        name: realm2,cps_exceeded
                        value: 6432103
                        type: int
                }
        }
}

Thanks in advance for your help and/or suggestions!

Brooks Bridges | Engineering Manager
O1 Communications
4359 Town Center Boulevard, Suite 217
El Dorado Hills, California 95762
office: 916.235.2097 | main: 888.444.1111, Option 2
email: bbridges@o1.com<mailto:bbridges@o1.com> | web:
www.o1.com<http://www.o1.com/>