css11506 question - balance leastconn

[julxu]

Hi

I have one vip configured as:

content firstproxy-443

  vip address 10.2.3.4

  protocol tcp

  port 443

  blance leastconn

  add service firstproxy-srv1-443

  add service secdproxy-srv2-443

  active

I expect the both server has roughly same load, and the fact is one server has got most traffic and onather server only an half load.

Could any one advice me:

    - base on what condition the css11506 select one server not another?

    - for what possible reason the css11506 perfer one than another?

I have monitoring the servers by show server xxx. and I do find that one server get more session than another one.

Any comments will be appreciated

Thanks in advance

Julxu

[Kanwaljeet Singh]

Hi Julxu,

Least connection means that whichever server has least connection would get the next connection. The load depends upon the session persistence too. If server A has 10 and server B has 15, let's say server A users , 5 of them decide to close the connection but none on server B. Now you have server A 5 connections and server B has 15. Next connection coming will go to server A. But there can be mismatch in the number of active connections.

Regards,

Kanwal

[julxu]

Thanks Kanwalsi

for this case, my client want the performance same on both server, I should change to balance weightedrr, am I right?

Please advice

Thousands thanks

Julxu

[Kanwaljeet Singh]

Hi Julxu,

In theory round robin should work fine but in real world you will never have exact numbers on both servers. Weighted should be should when you know that one server can handle more connection than the other and you explicitly tell the CSS to send more towards it. Normally least connection should be okay. I don't see any reason for CSS to send  more load to one server always. Does your customer see one SAME server getting more connections always? How much is the difference here? Also, note that once the connection is sent to one server, all the traffic coming from that same IP would be sent to the same server since it will match the flow(unless the flow is cleared  due to client closing the connection or timed out. I think in your case customer has IP based sticky. Can you double check that? It might be a possibility there is lot of connections coming from one IP address and always going to the same server.

Regards,

Kanwal

Note: Please mark if you find answers helpful.

[julxu]

Kanwal

the information I get from client is one machine has 12 conections/sec, and another one get 90 connections/sec.

my configuration is:

content server1-443

vip address xxxx...

protocol tcp

port 443

blance leastconn

add service server1

add service server2

advance-balance stricy-srcip

active

the configuration same on two css11506s. not only one,  they are dns round robin. is this setting will cause problem also?

Please advice

Julxu

I have two css11506 configure for them

[julxu]

another thing, is possible the advanced-balance sticky-srcip cause this issue?

[Kanwaljeet Singh]

Hi Julxu,

How does he know that he is getting 12 connections/sec on one and 90 on another? Can you check show flows? With least connection algorithm, the server with less connections will get the connections mostly. So if one server has less connections, it will get more connections per second. Now if the traffic coming matches the existing flows, then they will go back to the same server.

Can you get me the output of "show service <service name> summary"? Please do it for both the servers. I need to see how many connections are there.

Can  you also get complete show flows output as well?

Regards,

Kanwal

[julxu]

Kanwal

thanks for the reply. attached output of command. please check.

Many Thanks for the help

Julxu