On Tue, Apr 30, 2013 at 8:28 AM, Andrew Hastie <andrew@xxxxxxxxxxx> wrote:
I'm currently working on a project porting an application from RedHat Linux on Intel onto IBM zLinux. Our application requires PostgreSQL at version 9.n, so the PostgreSQL binaries have been built using the standard build tools from source. Everything appears run correctly. However as part of performance testing, our IBM and Linux SysProgs have been "poking around" using strace and have reported the following (which they think is an error condition) when hooking up to the postmaster processes:-
read(3, 0x3ffff875ee0, 16) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=6, events=POLLIN}], 2, 200) = 0 (Timeout)
read(3, 0x3ffff875ee0, 16) = -1 EAGAIN (Resource temporarily unavailable)
poll([{fd=3, events=POLLIN}, {fd=6, events=POLLIN}], 2, 10000) = 0 (Timeout)
... repeated many times
That does not look like the postmaster process. It looks like probably the background writer process.
It is normal, and doesn't explain high CPU utilization.
Cheers,
Jeff
