This is what I have for an iRule to implement when all members of a pool are not available due to maintenance or unplanned outage when HTTP_REQUEST { if { [active_members EXAMPLETEST_POOL] == 0 } { HTTP::redirect "http://209.196.27.42/" } } Now this is for one pool, we have over 10 pools. Is there a way to re-write this so the same iRule can be applied to each virtual server? Or do I need to create a separate iRule for each pool? Lastly, the re-direct is going to one server serving the web page. This has to be mapped to a public IP at the firewall with the non-nat'd IP as the virtual server for that web server. Then a DNS record created for that public IP address. Is this the typical practice for a sorry server? Are there any steps I can take to mitigate any risks if any in my present setup? Thanks,

You can use [LB::server pool] to get the currently selected pool instead of hardcoding it in the iRule. Your network config for the sorry VS seems standard. Aaron

Aaron, thanks, so you are saying instead of [active_members ] you would use [active_members LB:::server pool]?

Hi dmenardSABA, I think that what Hoolio is saying is that you don't have to hard code the pool name in the iRule. If you use [LB::server pool] that it will use the default pool assigned to the Virtual Server. when HTTP_REQUEST { if { [active_members [LB::server pool]] == 0 } { HTTP::redirect "http://209.196.27.42/" } }

Thanks to you both. I'll give that a try with that change. Regarding the standard practice for a sorry server I am still open to knowing what other are doing? Thanks again, Dave

I would say that there is no best practice. There is only "what best fits your situation". I use a combination of redirects for custom content vanity splash and sorry pages and iRules. Here is a basic example: when HTTP_RESPONSE { HTTP::respond 200 content "Site unavailable System Maintenance NOTICE: This site is down for maintenance. " }

Irule for redirect when all pool members down, need one for each pool? and what is the standard practice for sorry server?

20 Replies

Techgeeeg
Nimbostratus
Jun 15, 2013
Hi Kevin,

I think something got missed out in this irule? can u repost again.

Regards,
nitass
Employee
Jun 17, 2013
I think something got missed out in this irule?i understand what missing is html code which is sent to client when pool is down.
DushyantSingh_1
Nimbostratus
Jun 15, 2015
Hello Everyone,

I am new to F5. I have got a task to make a Strict failover VIP for my client. Referring to your sample irule

when HTTP_REQUEST { if { [active_members [LB::server pool]] == 0 } { HTTP::redirect "http://209.196.27.42/" } }

Please help me understand the meaning of ---HTTP::redirect "http://209.196.27.42/"--- part. When the members of pool in condition is down it will take the VIP down then how would it resolve the redirection. Per my understanding, which I know is wrong, there is no mention of new Pool.
- Shiva14
  Nimbostratus
  Jun 16, 2015
  Hi Dushyant, the above example is when your pool members (i.e all backend servers are down ) are not available then redirect all the request to other destination , destination might be other vip or some other source ip. I understand your concern i.e when pools are down how does vip will take traffic and process the irule . When Vip is down mean its doesn't mean that it will not do tcp handshake it will still accept the connections but the decision will be made basing on your config on your vip how to process those request . Thanks , Shiva
- DushyantSingh_1
  Nimbostratus
  Jun 16, 2015
  Thanks for your answer. Could you share any link for irule keywords and tutorials.
- DushyantSingh_1
  Nimbostratus
  Nov 03, 2015
  Thanks Shiva. I have another query one of my client has set up sorry page on different ports. for instance port 80 and 443. Could you help me understand how to make conditional sorry page availability.
juhiverma17_320
Nimbostratus
May 09, 2017
I have a query here. The irules works when your default pool is down. I.e it displays sorry page for the main URL. I've many L7 URI pools in my application, So the requirement is that for every URI also it should display the sorry page.

i.e if the main URL is https://abc.apple.com and it has a L7 URI for /payment which which has different set of nodes.

I want the even https://abc.apple.com/payment should also display the sorry page when the URI pool is down.

Can someone suggest what should be the "if" condition, to take in account all pools of an application?
- Vijay_E
  Cirrus
  May 09, 2017
  You can try something like:
  
  when LB_SELECTED { if { [active_members [LB::server pool]] == 0 } { HTTP::respond 200 content " " } }

shamsar_340408

Nimbostratus

Jan 03, 2018

Hello Everyone,

    I have a request on the same scenario, where the pool members are down, can it be redirected to another pool? Trying to achieve same redirection to sorry pages which is hosted on two nodes.

Village_Idiot
Nimbostratus
Jan 17, 2018
Shamsar,

Yes, you can try something like this:

when HTTP_REQUEST { if { [active_members [LB::server pool]] == 0 } { pool pool-name-here } }

Forum Discussion

Irule for redirect when all pool members down, need one for each pool? and what is the standard practice for sorry server?

20 Replies

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