On 10/23/06, Andrew Sullivan <[EMAIL PROTECTED]> wrote: > On Sat, Oct 21, 2006 at 02:08:48PM -0300, Andrew And wrote: > > I am using Slony with 4 slaves, and I look that my CPU in master has with > > 25% - 40 % busy when slony is active (UP). When I stop Slony the CPU is less > > than 8% busy in Master. > > It sounds like your replication tables need some attention. 40% busy > suggests to me that the system is doing a lot of sorting that it > shouldn't need to do, which tells me you may have some stats tuning > or vacuuming needed. But. . .
Is that strictly CPU or is it an amalgamated measurement? I'd be quite surprised to see that level of usage just for CPU. > > I will need to use 80 slaves in 2 months, then I am nervous with this. > > . . .have you tested such a scenario? 80 replicas is a _lot_. > There is a non-zero overhead per replica. My guess is that 80 is > going to be a really significant burden. I'd consider doing > something with cascaded replicas as well, but even so, it may be more > than is practical. Slony does support log shipped replication. You may find that this helps you to support such a very large number of subscribers. > > My master is CPU Intel Pentium 4 (3.20GHz) with 1 Gb RAM. > > And you can be sure that that machine is nowhere near enough for 80 > replicas. I'd have at least an 8-way system for that kind of load. I'd go further to suggest that you might want to consider testing a plaform other than classic Intel. FSB is likely to be a bottleneck in this scenario. Drew _______________________________________________ Slony1-general mailing list [email protected] http://gborg.postgresql.org/mailman/listinfo/slony1-general
