Dear Tom, Thanks for your fast approach. First of all, yes, queries seems to take more time to process and they are like queued up (you can even see inserts with status waiting on top/htop). I didn't know about that connection tip, and I will absolutely find a moment to add a pg_pooler to reduce the amount of active/idle connections shown at the database. I'm monitoring the pg_stat_activity table and when connections raise there's no query being processed that could block a table and cause the other queries to stack waiting. I'm checking pg_lock table too, with results to be determined yet. At least for the moment, it has spiked up once again (it's happening with more frequency). I was able to catch this log from I/O. These are 24 300Gb SAS disks on Raid 10 with hot spare. Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 42,00 136,00 96,00 136 96 avg-cpu: %user %nice %system %iowait %steal %idle 14,82 0,00 52,75 0,61 0,00 31,82 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 598,00 1764,00 15188,00 1764 15188 avg-cpu: %user %nice %system %iowait %steal %idle 17,79 0,00 82,19 0,01 0,00 0,01 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 230,00 28,00 6172,00 28 6172 avg-cpu: %user %nice %system %iowait %steal %idle 26,79 0,00 72,49 0,12 0,00 0,60 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 200,00 96,00 8364,00 96 8364 avg-cpu: %user %nice %system %iowait %steal %idle 17,88 0,00 81,95 0,01 0,00 0,15 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 87,00 48,00 4164,00 48 4164 avg-cpu: %user %nice %system %iowait %steal %idle 26,09 0,00 66,86 1,69 0,00 5,36 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 563,00 1932,00 9004,00 1932 9004 avg-cpu: %user %nice %system %iowait %steal %idle 19,30 0,00 80,38 0,10 0,00 0,21 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 159,00 348,00 5292,00 348 5292 avg-cpu: %user %nice %system %iowait %steal %idle 28,15 0,00 68,03 0,19 0,00 3,63 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 250,00 196,00 7388,00 196 7388 avg-cpu: %user %nice %system %iowait %steal %idle 11,03 0,00 38,68 0,14 0,00 50,16 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 294,00 1508,00 2916,00 1508 2916 Hope it helps. If you feel we should reduce shared_buffers, what would be a nice value? Thanks! -- View this message in context: http://postgresql.nabble.com/Sudden-connection-and-load-average-spikes-with-postgresql-9-3-tp5855895p5855900.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance