Re: Review: DTrace probes (merged version)

Alvaro Herrera napsal(a):
> Zdenek Kotala wrote:
> 
>> 1) Naming convention:
>>
>>  - Some probes uses "*end", some "*done". It would be good to select one name.
>>  - I prefer to use clog instead of slru in probes name. clog is widely known.
> 
> But slru is also used in pg_subtrans and pg_multixact.  Which maybe
> says that we oughta have separate probes for these rather than a single
> one in slru.  Otherwise it's going to be difficult telling one from the
> other, yes?

Yeah, you are right, I missed that it is used in other part too. slru is OK

> 
>> Autovacuum_start probe is alone. I propose following probes for completeness:
>>
>> proc-autovacuum-start
>> proc-autovacuum-stop
>> proc-bgwriter-start
>> proc-bgwriter-stop
> 
> Separate proc-autovacuum-worker-start and proc-autovacuum-launcher-start,
> perhaps.  Not that I see any usefulness in tracking autovacuum launcher
> start and stop, but then if we're tracking bgwriter start and stop then
> it makes the same sense.

The advantage to track start and stop of procese is that you can stop the 
process in dtrace script at the beginning and for example attach debugger or for 
example start counting number of writes per process and so on.

>> proc-master-start
>> proc-master-stop
> 
> What's "master" here?

Main process - postmaster.

    Zdenek

-- 
Zdenek Kotala              Sun Microsystems
Prague, Czech Republic     http://sun.com/postgresql