Hi all,
i have a Tomcat application with PostgreSQL 8.1.4 running which
performs about 10000 inserts/deletes every 2-4 minutes and updates on
a database and after some hours of loadtesting the top output says
0.0% idle, 6-7% system load, load average 32, 31, 28 and there are
many exceptions at statement execution like:
An I/O error occured while sending to the backend.
There are 10-15 postmaster processes running which use all the CPU power.
A restart of tomcat and then postgresql results in the same situation.
Some postgres processes are in DELETE waiting or SELECT waiting.
VACUUM runs through in just about 1-2 seconds and is run via cron
every minute and reports that the fsm setting are high enough.
The situation just gets better if tomcat is stopped and postgresql is
restarted -> 90%idle
The tomcat application talks to another application on the server
which uses much CPU cycles at startup of tomcat and my observation is
that after this startup with 0.0% idle, PostgreSQL can't recover from
this situation.
Dual Xeon Server
machines (Dell PowerEdge 2850) using Heartbeat1. Each server has only
one harddisk, no RAID configuration is used.
- Each Cluster has 4 drbd Devices, one for the PostgreSQL data
- Two of these clusters are using the same PostgreSQL installation to
share the data, the database can be moved from one cluster to the
other in case of failure
- OS: Debian Sarge with postgresql 8.1.4
- Two cronjobs are configured to perform a "vacuumdb --all"
every 1 minute and a "vacuumdb --all--analyze" every 23
minutes
- There are 3 applications using the PostgreSQL installation, each
with their own database.
- The main application is based on Tomcat 4.1-30 partly a
Web-Application, partly a terminal login protocol based on http and
XML, so the database access is of course done using JDBC
- A cronjob is configured to perform a pg_dump of the main database
every 4 hours
Any ideas are welcome.
thx,
Peter