Re: Blocked on system high

Steve Coates · ‎03-06-2007

I am trying to determine if I have a bottleneck someplace in the system. Using glance I see that I have a 25-44% blocked on system. I do not have any real blocking on I/O. I need some help understanding this.

Also CPU is at 100% and load average is running 2.5 (4 CPU PARISC 8700+)

Court Campbell · ‎03-06-2007

The real question is if any users are complaining. Just because you have high CPU utilization doesn't necessarily mean you have a bottleneck. It's tough to make any real assessments unless you have a baseline to compare to. If this is not normal you might want to see what has changed on the system recently. Are more users on the system? Did you add a new service? You might use glance to see what processes are using the most CPU and move from there.

"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"

Steve Coates · ‎03-06-2007

The problem is a .net application that accesses the Oracle DB on this box. They have very slow response times from the .net app a couple hours a day. Since the users and DBA's can see the CPU they are blaming the UNIX machine for the slowdown.

I am trying to see if there is anything on the UNIX side that could be causing the problems and the blocking on system is the only thing I see that looks odd to me.

Court Campbell · ‎03-06-2007

Is the server doing any paging? Open the memory report in glance and see if you have any page outs.

"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"

Steve Coates · ‎03-06-2007

No paging at all.

Court Campbell · ‎03-06-2007

what process(es) show the highest cpu utilization in glance?

"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"

Steve Coates · ‎03-06-2007

the top processes are all oracle related

Court Campbell · ‎03-06-2007

Sorry for all the questions. Does there seem to be any other bottlenecks? Is there a lot of disk i/o? What is the size of the SGA? The more info you can provide the better.

"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"

Steve Coates · ‎03-06-2007

The issues is I can not see anything else going on. Disk's look good. avque less than one , avwait andavserv 3.5 or under most of the time.

plenty of free memory, not sure of the SGA size.

Steve Coates · ‎03-06-2007

the system blocked may be a wild goose chase. the light blub went offf and I looked at another system (same configuration) and it is doing nothing (95% CPU idle) and the blocked on system is 65%. Could this be telling me that the system is burning unused cycles and they are showing as being blocked on system?

Court Campbell · ‎03-06-2007

It could come down to badly tuned sql. The DBAs and the developers are always going to try and blame the system. I have an oracle database that running and show the system blocking at 22.4% but am not seeing the same issues. Can the DBAs give you any info? Can you post your output from kmtune? what is your dmesg/syslog output?

"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"

Steve Coates · ‎03-06-2007

here is output from kmtune. The BDA's can not really see anything but I need to talk to them more.