Using reselect method to keep http session persistence

Question

Hi,I have two http servers behind a specific VIP, i'm using cookie method for persistency which working fine,The problem I have is that when one of the my pool members goes down, the users who were logined on this pool member thrown out and have to log in again.Can I use the RESELECT method in ActionOnDown section of my pool to avoid this problem?if yes, shall i disable port/address translation on my virtual server?thanks

petewhite · Answer

I agree with Mike - this is not about connections to servers, it is at the HTTP level. In short, you need a common authentication mechanism across backend servers, or use APM to handle the authentication and passthrough the user credentials to the server. You may find that federation such as SAML or OAuth gives a near-seamless solution ( to re-authenticate, the client would be redirected to the IdP and assuming they have a valid session then be redirected back immediately ).
This requires some architectural thought - we in F5 Professional Services do this sort of thing all the time, it might be worth looking into that if you want to discuss it further.

mohamed_salah_ · Answer

Hello Nimbostratus,what is the current Virtual server and backend server IP/port&nbsp; ?

レザ · Answer

Hello 🙂Both virtual server and pool members are on same subnet, and service port is 80 (HTTP)for example:Virtual Server is: 192.168.23.254Server1: 192.168.23.180Server2: 192.168.23.181&nbsp;

nikoolayy1 · Answer

Better read the article for this feature https://support.f5.com/csp/article/K15095 as it has good description for this feature:
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This option is only appropriate for:

Virtual servers with address and port translation disabled
Note: This is the default for network&nbsp;virtual servers, such as wildcard IP Forwarding virtual servers.

Transparent pool members, such as firewalls, routers, proxy servers, and cache servers
Note: Transparent devices can forward packets to destinations without regard for the state of the connection.

UDP virtual serversImportant:&nbsp;Because this setting does not re-establish&nbsp;TLS&nbsp;or any other stateful&nbsp;protocol, you should not use it in a reverse-proxy deployment where pool members are stateful endpoints.
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mohamed_salah_ · Answer

Hello,you are right, you need to disable both translation to use this option based on the below article.Reselect option is only appropriate for:Virtual servers with address and port translation disabledTransparent pool members, such as firewalls, routers, proxy servers, and cache servershttps://support.f5.com/csp/article/K15095It actually doesn't matter for the port translation. But regarding the address translaiton, the service will stop working because the address must be translated to the pool member.&nbsp;So based on this, unfortunately, i think you will not be able to use the reselect option.

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Using reselect method to keep http session persistence

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