700 Mbit/s connection and squids

[Roberto Nibali]

Hello,

>    We would like to use LVS in a system where 700Mbit/s traffic is flowing
> through it. Concurrent connection number is about 420.000   . Our main
> purpose for using LVS is to direct 80. port requests into number of squid
> servers (~80 servers)
> I have read performance documents and I just wonder I can handle this much
> of traffic with a 2x3.2 Xeon  and 4GB of RAM of hardware or not . We are

Yes, it's enough.

> currenly using a so-called harware load balancer but its performance is not

Any specifics on this so-called hardware load balancer?

> satisfying.  Our traffic is increasing and it can be 1Gbit/s very soon. If

How is your current flow? Can you draw a sketch? How do you count your 
connections at this point? What is your definition of a connection with 
regard to the whole proxy mechanism. What's your average response time 
and your average hit/miss rate?

> you give me any directions about the hardware and tuning parameters for 
> this
> much of traffic, I will be so glad.

If you use LVS-DR and your squid caches have a moderate hit rate, the 
amount of RAM you'll need to load balance 420'000 connections is:

420000 x 128 x [RTTmin up to RTTmin+maxIdleTime] [bytes]

This means with 4GB and a standard 3/1GB split (your Xeon CPU is 32bit 
only with 64bit EMT) in the 2.6 kernel (I take it as 3000000000 Bytes), 
you will be able to serve half a million parallel connections, each 
connection lasting at most

3000000000/(500000*128) [secs] = 46.875 secs.

Is this good enough for you?

Best regards,
Roberto Nibali, ratz
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