topic Re: Extreme Outbound Queue Length in Operating System - HP-UX

Extreme Outbound Queue Length

UNIXTEK — Mon, 06 Dec 2010 11:53:16 GMT

Hi

We have an rx8640 that have an extreme outbound queue length:

tsiv@whisky|pts/12:/home/tsiv$ while : ; do lanadmin -g mibstats 5| grep "Outbound Queue Length" ; sleep 5 ; done
Outbound Queue Length = 27
Outbound Queue Length = 87
Outbound Queue Length = 33
Outbound Queue Length = 8
Outbound Queue Length = 24
Outbound Queue Length = 17
Outbound Queue Length = 17
Outbound Queue Length = 8
Outbound Queue Length = 123
Outbound Queue Length = 14
Outbound Queue Length = 32
Outbound Queue Length = 11
Outbound Queue Length = 21
Outbound Queue Length = 4
Outbound Queue Length = 41
Outbound Queue Length = 20
Outbound Queue Length = 18
Outbound Queue Length = 6
Outbound Queue Length = 60
Outbound Queue Length = 71
Outbound Queue Length = 41
Outbound Queue Length = 56
Outbound Queue Length = 13

But this is a 10GB interface and the interface does not seem saturated.

Any ideas on the cause? This is a highly loaded machine in every sense.

Re: Extreme Outbound Queue Length

Steven E. Protter — Mon, 06 Dec 2010 12:28:39 GMT

Shalom,

Use lanadmin -x ##
replace the ## with the numeric part of lan## and lets see what connect speed this NIC is getting.

Use lanscan to find the active lan port for this card.

Frequently this issue is due to switch or other system configuration not permitting good speed.

I would also like to know a little about the switch environment, the OS and update level and such to put together a more clear set of recommendations.

I would ask the network people to check the switch for errors.

SEP

Re: Extreme Outbound Queue Length

rick jones — Mon, 06 Dec 2010 23:51:45 GMT

There are two (perhaps three) possible 10GbE NICs in an rx8640 - which do you have installed?

FWIW, a NIC can have at least two limits - one is a bandwidth limit - as in megabits per second or whatever units you might prefer. Another is a packet per second limit. Can you include some statistics to show the bites/bytes per second and packets per second through the interface?

For outbound, the NIC can only pull packets from the host as fast as they can be DMA'd from the host, so there is a chance that the NIC isn't the bottleneck - still want to see the model of NIC being used though.