How to control pool selection in VS when you have more than one pool?

Hi msalah, what traffic you want to sent it to pool 1 and pool 2 ? is there any specific condition you required to sent the traffic to respective pools ?

Hi Maneesh,

I am trying to send HTTP traffic.

So for example if SERVER A hits the VIP at this stage has option to either use POOL-1 or POOL-2 for this instance it gets pushed to Pool 1 with 2 node NODE-A and NODE-B RR selects NODE-A responds all good.

If SERVER A hits the same VIP again it gets the same option to either use POOL-1 or POOL-2 but this time POOL-1 has NODE-A as down. I want this session to then keep using POOL 1 and use NODE-B rather than moving to POOL-2.

But if SERVER B attempts to connect with a new session it can use either POOL-1 or POOL-2

Is this possible?

Thanks

If i understand your need:

you want to load balance to 4 servers:

• Server1 (POOL1, NODE-A in your example)
• Server2 (POOL1, NODE-B in your example)
• Server3 (POOL2, NODE-A in your example)
• Server4 (POOL2, NODE-B in your example)

And you want the following behavior:

• If Server1 become unreachable, you want persistent sessions will be balanced to Server2
• If Server2 become unreachable, you want persistent sessions will be balanced to Server1
• If Server3 become unreachable, you want persistent sessions will be balanced to Server4
• If Server4 become unreachable, you want persistent sessions will be balanced to Server3

yes thats correct @Stanislas

Thank you

can this be done with iRules?

You can use :

• PERSIST_DOWN event which is raised if persistence pool member become unavailable.
• LB::persist command to get the previous member in persistence records
• pool member to select the new member

you do not need to create 2 pools but only one

Thanks @Stanislas is there a irule syntax to do this as well?

Hi Msalah,

I will back the reply of Stanislas, as explained by Stanislas you don't need to create two pools you can achieve this by one pool.

Regards,

i have found a way to do this....thank you again for all your help...

when CLIENT_ACCEPTED { set first-octet [expr {[getfield [IP::client_addr] "." 1]}] if { [$first-octet <=128] { set DC_LOCATION 1} elseif { set DC_LOCATION 2} if { $::DC_LOCATION == 1 } and ([active_members pool_1] >= 1){ pool pool_1 persist source_addr } elseif { $::DC_LOCATION == 2 } and ([active_members pool_2] >= 1) pool pool_2 persist source_addr } elseif { ([active_members pool_1] >= 1) pool pool_1 persist source_addr } elseif { ([active_members pool_2] >= 1) pool pool_2 persist source_addr } }

alternative way to do this....

when RULE_INIT { set ::NEXT_POOL 0 }

when CLIENT_ACCEPTED { if { $::NEXT_POOL == 0 } and ([active_members pool_1] >= 1){ pool pool_1 persist source_addr set ::NEXT_POOL 1 } else { pool pool_2 persist source_addr set ::NEXT_POOL 0 } }