Hello, We upgraded from Ubuntu 11.04 to Ubuntu 12.04 and almost immediately obeserved increased CPU usage and significantly higher load average on our database server. At the time we were on Postgres 9.0.5. We decided to upgrade to Postgres 9.2 to see if that resolves the issue, but unfortunately it did not. Just for illustration purposes, below are a few links to cpu and load graphs pre and post upgrade. https://s3.amazonaws.com/iqtell.ops/Load+Average+Post+Upgrade.png https://s3.amazonaws.com/iqtell.ops/Load+Average+Pre+Upgrade.png https://s3.amazonaws.com/iqtell.ops/Server+CPU+Post+Upgrade.png https://s3.amazonaws.com/iqtell.ops/Server+CPU+Pre+Upgrade.png We also tried tweaking kernel parameters as mentioned here - http://www.postgresql.org/message-id/50E4AAB1.9040902@xxxxxxxxxxxxxxxx, but have not seen any improvement. Any advice on how to trace what could be causing the change in CPU usage and load average is appreciated. Our postgres version is: PostgreSQL 9.2.2 on x86_64-unknown-linux-gnu, compiled by gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 64-bit OS: Linux ip-10-189-175-25 3.2.0-37-virtual #58-Ubuntu SMP Thu Jan 24 15:48:03 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux Hardware (this an Amazon Ec2 High memory quadruple extra large instance): 8 core Intel(R) Xeon(R) CPU E5-2665 0 @ 2.40GHz 68 GB RAM RAID10 with 8 drives using xfs Drives are EBS with provisioned IOPS, with 1000 iops each Postgres Configuration: archive_command = rsync -a %p slave:/var/lib/postgresql/replication_load/%f archive_mode = on checkpoint_completion_target = 0.9 checkpoint_segments = 64 checkpoint_timeout = 30min default_text_search_config = pg_catalog.english external_pid_file = /var/run/postgresql/9.2-main.pid lc_messages = en_US.UTF-8 lc_monetary = en_US.UTF-8 lc_numeric = en_US.UTF-8 lc_time = en_US.UTF-8 listen_addresses = * log_checkpoints=on log_destination=stderr log_line_prefix = %t [%p]: [%l-1] log_min_duration_statement =500 max_connections=300 max_stack_depth=2MB max_wal_senders=5 shared_buffers=4GB synchronous_commit=off unix_socket_directory=/var/run/postgresql wal_keep_segments=128 wal_level=hot_standby work_mem=8MB Thanks, Dan |
