Response times on an S670

[sbenson01]

Lately our S670 has been giving us problems with streaming video. We're a school district with 8,000 students and 1,000 staff. For a variety of reasons, we've recently seen a significant uptick in bandwidth requirements from students and staff. Some streaming media has started to suffer. Players won't load or take multiple browser refreshes before video starts to play.

I generated a System Status report from the S670 and I'm seeing numbers in the Response Times that look high to me, but I don't know what's normal. I'm seeing Average in the last hour: 602 and Average since proxy restart: 5,131.

Are those high numbers? If they are, what steps can I take to reduce those numbers? My Transactions per second are 792 maximum since proxy restart which was August 5, 2013.

Thanks,

Steve

[Vance Kwan]

Hi Steven,

Those average response times do not tell very much since some slower sites can skew the metrics.  There is nothing more accurate than just hopping being the proxy and surfing the web to confirm the speed.

792 requests per second for a S670 sounds very close to capacity.  What version of code are you on?  If you are on version 7.5.1 or higher, you can use the command 'rate' in the CLI to show the CPU utilization during your peak hours.  If it is reaching 90%+, that is not good.  The CPU output if you are not => version 7.5.1 will be inaccurate for judging performance.

-Vance

[sbenson01]

Hi Vance,

My current version is 7.5.0-833, so I'll need to upgrade. Would you recommend going to the latest available version of the code? If not, which version would you recommend?

So if we do the upgrade and find out that I'm driving the CPU over 90% during my peak periods, is my only recourse to add another S670 and load balance? We haven't budgeted for another S670, so I'll be looking for any reasonable alternative to the situation to hold me over until our next budget cycle

Thanks,

Steve

[Vance Kwan]

Steven,

Upgrading from 7.5.0 to 7.5.1 does not have any performance fixes.  If you hitting 90%+ during peak periods, configuration cost may be a factor.  But at 700+ requests per second, I want to speculate that your configuration cost is in line.  If you are reaching capacity, yes, it may be a good idea to add an additional appliance.

Since you are on version 7.5.0, which makes it a bit difficult for you to track the CPU utilization, I'd recommend you open a TAC case on this so that it can be investigated.

I suppose you can upgrade to version 7.5.1-201, or even 7.5.2-118 so you can get a more accurate RATE command if you'd prefer not to open a TAC case.

-Vance