David Kerr <dmk@xxxxxxxxxxxxxx> writes: > I'm running pgbench with a fairly large # of clients and getting this error in my PG log file. > LOG: could not send data to client: Broken pipe That error suggests that pgbench dropped the connection. You might be running into some bug or internal limitation in pgbench. Did you check to make sure pgbench isn't crashing? > (I had to modify the pgbench.c file to make it go that high, i changed: > MAXCLIENTS = 2048 Hm, you can't just arbitrarily change that number; it has to be less than whatever number of open files select(2) supports. A look on my Fedora 13 box suggests that 1024 is the limit there; I'm not sure which Red Hat variant you're using but I suspect it might have the same limit. As of the 9.0 release, it's possible to run pgbench in a "multi thread" mode, and if you forced the subprocess rather than thread model it looks like the select() limit would be per subprocess rather than global. So I think you could get above the FD_SETSIZE limit with a bit of hacking if you were using 9.0's pgbench. No chance with 8.3 though. (This suggests BTW that we might want to expose the thread-versus-fork choice in a slightly more user-controllable fashion, rather than assuming that threads are always better.) regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
