pgbench: could not connect to server: Resource temporarily unavailable
Hi Everyone, I'm trying to run pgbench with various numbers of connections. However, my DB seems to be hitting some limit around 147-150 connections. I'd like to run with at least 500 and even up to 2000 if possible. I've already increased the max_connections, shared_buffers and kernel.shmmax. All by 20 times. What's limiting my DB from allowing more connections? This is a sample of the output I'm getting, which repeats the error 52 times (one for each failed connection) -bash-4.2$ pgbench -c 200 -j 200 -t 100 benchy ... connection to database "benchy" failed: could not connect to server: Resource temporarily unavailable Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"? transaction type: scaling factor: 50 query mode: simple number of clients: 200 number of threads: 200 number of transactions per client: 100 number of transactions actually processed: 14800/2 latency average = 165.577 ms tps = 1207.895829 (including connections establishing) tps = 1255.496312 (excluding connections establishing) Thanks, Kevin
Re: pgbench: could not connect to server: Resource temporarily unavailable
Kevin McKibbin writes: > What's limiting my DB from allowing more connections? > This is a sample of the output I'm getting, which repeats the error 52 > times (one for each failed connection) > -bash-4.2$ pgbench -c 200 -j 200 -t 100 benchy > ... > connection to database "benchy" failed: > could not connect to server: Resource temporarily unavailable > Is the server running locally and accepting > connections on Unix domain socket > "/var/run/postgresql/.s.PGSQL.5432"? This is apparently a client-side failure not a server-side failure (you could confirm that by seeing whether any corresponding failure shows up in the postmaster log). That means that the kernel wouldn't honor pgbench's attempt to open a connection, which implies you haven't provisioned enough networking resources to support the number of connections you want. Since you haven't mentioned what platform this is on, it's impossible to say more than that --- but it doesn't look like Postgres configuration settings are at issue at all. regards, tom lane
