ACE backup-server and sticky

[danilo-dicesare]

Hi all,

a question:

     if a configure a serverfarm with backup-server

serverfarm host S_Das

  rserver DAS1

    backup-rserver DAS1_1

    inservice

  rserver DAS_1

    inservice standby

  rserver DAS2

    backup-rserver DAS2_1

    inservice

  rserver DAS_1

    inservice standby

sticky ip-netmask 255.255.255.255 address both SF_DAS

  timeout 10

  replicate sticky

  serverfarm S_Das

and rserver DAS1 goes down what will be behaviour of sticky and balancing?

New connection wel'll go towards DAS2 or a tricky and clever sticky take precedence? (i mean persistence on DAS1_1 that is my backup server..)

tnx

Das

[Pablo]

Hi Danilo,

If your primary rserver goes down the sticky entries associated with that server will be automatically flushed from the sticky table so that

all new incoming connections will be diverted to your backup rserver.

In case that primary rserver comes back then:

- Existing connections on backup keep accessing backup.

- For new connection requests ACE looks up sticky entries, if there's already an entry for backup server the connections is sent to the standby rserver.

- If a new client request (connection) doesn't match any sticky entry for backup rserver ACE forwards this request to primary.

In case that you want to use the primary rserver for all the connections after coming back to operational state then the backup option would be configured like this:

rserver Primary

ip address 10.10.10.2

  inservice

rserver Standby

ip address 10.10.10.3

  inservice

serverfarm host Primary

  rserver Primary

    inservice

serverfarm host Standby

  rserver Standby

    inservice

policy-map type loadbalance http first-match slb
class class-default
serverfarm Primary backup Standby

HTH

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