Hello,
Hope you are doing great!
I would like to know if it is supported to mirror persistence between 2 DC’s across 2 Traffic Groups, each one is Active on a DC.
DC 1 Active on TG1
DC 2 Active on TG2
Client established connection on DC1, if it reconnected in DC2 traffic should be rerouted to DC1 backend. (There’s no application level session synchronization)
Any suggestions would be appreciated!
Thank you.
Regards!
Hello @AmineZAKARIA
My question is how a user could end up to a different DC? Is there a GSLB in front?
You could try cookie persistence.
Not sure if the built in cookie persistence mechanism will work in this case. But with an irule you could inject a custom cookie an use it later to make load balance decisions. Of course your client should always send the cookie.
Hello @Injeyan_Kostas
Yes there’s GSLB.
Cookie persistence did work, but using source address persistence is not working even with match across option, not sure if there’s a way to share persistence between TG except for cookie persistence.
Regards!
Cookie persistense is much more clear option for me in such case.
As for source address persistence and match across option, did you select match across virual servers? Also are you sure clients reach both traffic groups with their original source IP and there is no SNAT somewhere between?
Hello @Injeyan_Kostas
Yes i did use the match across virtual server and of course i am mirroring the persistence info, both VSs assigned with the same persistence profile.
Also are you sure clients reach both DC BIG-IPs with their original source IP and there is no SNAT somewhere between?
Yes using the same source ip address and persistence records create a new persistence record in TG2.
Regards!
As far as I am aware persistence records are not tide to Traffic Group, but again cookie cookie persistence seems more reliable in this case
That’s how the persist table looks like after failover to DC2.
Btw i have enabled cache array instead of record based, and the source persistence kept pointing to the same backend server as i wanted.
Regards!
gslb handles dns request not application layer, e.g. http request.
if you setup gslb persistence properly, the client’s dns request will get same ip in dns response when it asks gslb dc1 or gslb dc2.
I know, but in case ISP on DC1 went down here the DNS persistence will be flushed, And the objectif i should keep serving the app level from the same backend server even from Ltm of DC2 going through back DCI.
Regards!
Would you mind sharing a diagram of your set-up? How does the DNS function here? What is the WideIP or DNS LB method? How many BIG-IPs are being monitored? Is it using the built-in BIG-IP monitor? I am curious to see how the re-connected traffic lands on DC2.