On Mon, Jun 14, 2010 at 2:25 PM, Hernan Saltiel <[email protected]> wrote: > > > On Mon, Jun 14, 2010 at 5:01 PM, Scott Marlowe <[email protected]> > wrote: >> >> On Mon, Jun 14, 2010 at 9:56 AM, Dhaval Jaiswal >> <[email protected]> wrote: >> > >> > I am working on PostgreSQL 8.0.2. with slony I. >> > >> > Whenever there is a update, insert, delete happened on primary it will >> > take >> > some time to replicate the same on slave. We came to know about this >> > using >> > sl_status table, where its lagging time showing 1 hr or 2 hrs. However, >> > sl_confirm table shows last replicated events is before 5 mins. >> > We have also seen there is vacuum analyze running on replications >> > schema. >> >> Happens to me when there's too much IO for my hardware (which is quite >> a bit on my hardware). > > > How can I meassure how much is too much use of my hardware when Slony is in > place? > I can meassure the CPU, memory, disk IO, and network use, but how much is > needed in order to let Slony work well? > Is there any way to calculate this on a transaction number and size basis?
size isn't so much important as how much disk io you're using, and whether or not that's too much is very dependent on your hardware. I find that when iostat -xd /dev/sd? 60 consistently shows 100% utilization, slony starts to fall behind. Load testing / benchmarking your system will tell you how many requests / second of your typical load it takes to hit that. Once you hit that load, the only solution is faster hardware, or reducing load, often by optimizing your code. _______________________________________________ Slony1-general mailing list [email protected] http://lists.slony.info/mailman/listinfo/slony1-general
