On 28 November 2016 at 18:46, Jakub Hrozek <jhrozek@redhat.com> wrote:
On Mon, Nov 28, 2016 at 02:45:59PM +1100, Lachlan Musicman wrote:
> I'm on Centos 7.2 and thought I'd try this to see how it works. Instead of
> nice output I got and error. Have I done something wrong?
>
> [root@linux systemtap]# stap id_perf.stp
> ERROR: empty aggregate near identifier 'print' at id_perf.stp:68:5

Ah, sorry, this is a silly bug in the script. In your case, id returned
data from the cache (as you can see the time id ran was only 3ms) so
there were no writable transactions done and the script ended up
dereferencing an empty aggregate that normally saves the transaction
times.

I've opened a PR on github to fix the script, but runnning sss_cache
before you run the script next time should give 'better' results.


Yes, that worked - thanks.

cheers
L.


------
The most dangerous phrase in the language is, "We've always done it this way."

- Grace Hopper