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New Member

LD-416 Overloaded By Simultaneous Connections?

Hello all,

We have a LD-416 running software version 4.2.4. The LD is setup to balance port 80 connections to seven real servers behind one virtual IP.

Lately, we have had an issue where if enough simultaneous connections hit the virtual IP address, the LD fails to distribute them. Our web server logs are showing one or two out of the seven carrying the brunt of the simultaneous connections. It is never the same two servers during any such instance.

When this occurs, we'll often see large (hundreds) unchanging connection numbers to each server according to "show real" where our normal load is between 20-40. Checking the monitoring on our web servers, they aren't registering anything beyond the normal connections. What is really troubling is that if we reset web services on the web servers during this time, the individual servers never show as failed like they do during normal operation.

Mind you, the traffic is valid traffic. It is coming from people opening a link in a newsletter we have sent. The page they are viewing is not very intensive, so the web servers should be able to handle the load, were it being properly distributed. However, near as we can determine, it seems that the Local Director is crumbling under the sudden load.

Is there a limit to the number of simultaneous connections an LD-416 can process? Is there anything in the settings I can tweak to help it along?

Regards,

Robert Kropiewnicki

3 REPLIES
Cisco Employee

Re: LD-416 Overloaded By Simultaneous Connections?

try the command 'predictor leastconn'

Gilles.

New Member

Re: LD-416 Overloaded By Simultaneous Connections?

According to the results of 'show predictor', it is already set to leastconn.

Virtual Machine(s) Predictor Slowstart

www.structuredweb.com:80:0:tcp leastconns roundrobin

Regards,

Robert Kropiewnicki

Cisco Employee

Re: LD-416 Overloaded By Simultaneous Connections?

then give a try to another predictor like weighted or loaded.

Just to see if we get the same behavior all the time.

Gilles.

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