Vivek Khera wrote:
> On Feb 22, 2006, at 12:28 PM, lkv wrote:
> 
>> I'm observing something odd, on the master I see a huge chunk of
>> st_lag_num_events (~190000) and on the same slave thats behind the
> 
> how big is sl_log_1 on the master? If it is > O(1M) then you're gonna  
> have a tough time catching up unless you have a *lot* of spare I/O  
> bandwidth.

Hi Vivek,

sl_log_1 and 2 were empty.
actually i fixed the problem thanks to a hint from Jan i found in the
archives:

http://article.gmane.org/gmane.comp.db.postgresql.slony1.general/1617

-- snip
Is there anything on the provider node that locks sl_event with and
access exclusive lock? Or is that providers (node 154) sl_event table
so bloated that 5 minutes to select some events is reasonable?
-- snip

my case was the latter. 5min were not enough.

the provider sl_event had a hugeeeee number of events and the select
from the node that was behind would take literally ages to read the
table, definitely more than 2x5 min. my solution here was to start a
local slon daemon on the provider node and wait for it to clear them,
it took about 2h to clear all 200k events in sl_event.

i also cleaned pg_listener.

i think here the problem was the kind-of-slow-link (15-30KB) which
sometimes could get quite saturated. now all looks good, but let see
for how long.

thanks,
l