RE: N/w Bottleneck Check using tnsping under Tran. Load ... Basic Qs
From: Tanel Poder <tanel.poder.003@xxxxxxx>
To: VIVEK_SHARMA@xxxxxxxxxxx, oracle-l@xxxxxxxxxxxxx
Date: Sun, 01 Jun 2008 13:16:29 +0800
Hi,
It takes at most ~1.475MB of data in your servers network stack send buffers
to cause a 118ms jump in reply time ( 100Mbit / 8 * 0.118 = 1.475 MB ).
In practice this number is probably lower.
You can run netstat in HP-UX couple of times and calculate how many bytes
worth of TCP packets are sent out:
netstat -f inet -p tcp
And this command (depending on your OS version) should show a statistic
called "outbound queue length". If this is constantly high (tens of
thousands packets I'd say) then there's a network bandwidth issue, also if
"outbound discards" is non-zero then there's definitely some problem in
network transmission.
/usr/sbin/lanadmin -g mibstats
Solutions? IF the commands above show a bandwidth bottleneck (high
utilization and long outbound queues) then get higher bandwidth network
interfaces or multiple network interfaces. Otherwise the problem is
somewhere else.
One specific case may be that the NIC interrupt handler is bound to a
specific CPU but can't get onto CPU enough due an Oracle process running
there with the SCHED_NOAGE bit which keeps the process on CPU until it
voluntarily yields it. But that's just a guess, I suspect that your issue is
just in the low-throughput NIC.
--
Regards,
Tanel Poder
http://blog.tanelpoder.com <http://blog.tanelpoder.com/>
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of VIVEK_SHARMA
Sent: Saturday, May 31, 2008 12:35
To: Tanel Poder; oracle-l@xxxxxxxxxxxxx
Subject: RE: N/w Bottleneck Check using tnsping under Tran. Load ... Basic
Qs
YES Tanel. ping is also giving a similar increased Timing of about 118 ms
under Peak Load.
Cheers
_____
From: Tanel Poder [mailto:tanel.poder.003@xxxxxxx]
Sent: Saturday, May 31, 2008 8:53 AM
Does plain Unix ping also experience similar latency increase?
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of VIVEK_SHARMA
Sent: Saturday, May 31, 2008 03:52
To: Tanel Poder; oracle-l@xxxxxxxxxxxxx
Thanks V much Tanel for responding, as always.
CPU Usage of BOTH DB & APP Servers is about 30 % only at Peak Load when
tnsping is giving a Timing of 118 ms. Hence do Not expect any CPU runqueue.
