16-Jan-2023 06:50
Hi,
I have a question about connections to the pool memebers.
In the event of the failure of one of the pool memebers the connections will be established on the available member.
When the failed member comes back online can the connections be transfered back to that member so that the load is balanced again?
Solved! Go to Solution.
18-Jan-2023 07:09
Thanks guys!
Basically there is no option to transfer already established connections to the new pool member.
16-Jan-2023 07:19 - edited 16-Jan-2023 07:21
it depends on the load-balancing method you use.
You probably want the least-connections method. But the connections are not transferred back. New connections will be sent to the member that has the least number of current connections in the pool
here are the methods:
https://support.f5.com/csp/article/K42275060
16-Jan-2023 11:37
F5 will reap all connections about this pool member if your pool member is monitor down and it will reset the connection for both sides client and server. The connections will be re-established with the available pool member as a new independent connection. When failed member comes back online, F5 do not send the all client traffic immediately instead will send new connections gradually.
16-Jan-2023 18:01 - edited 16-Jan-2023 18:02
Hi,
Traffic is forwarded to the available server for new connections only.
but, If used persistence profile, It not come back Client connection when have persist and connection table.
@Seçkin1983 said
'F5 do not send the all client traffic immediately instead will send new connections gradually'
--> options is 'Slow Ramp Time '
Slow Ramp Time
Specifies the duration during which the system sends less traffic to a newly-enabled pool member. The amount of traffic is based on the ratio of how long the pool member has been available compared to the slow ramp time, in seconds. Once the pool member has been online for a time greater than the slow ramp time, the pool member receives a full proportion of the incoming traffic. Slow ramp time is particularly useful for the least connections load balancing mode
Setting this to a nonzero value can cause unexpected Priority Group behavior, such as load balancing to a low-priority member even with enough high-priority servers.
17-Jan-2023 03:58
Hi guys, thanks for the quick reply.
As I suspected, only the new connections will be sent to the newly available server. We have Least Connections (Member) for the Load Balancing Method.
@Hooni_L if I understand you correctly the connections will not be transfered the the available member if persistance profile is used?
17-Jan-2023 04:01
if monitor down happens, all connections including persisted and existing will be resetted on both sides client and server connected.
17-Jan-2023 17:07
I known if you need transfer the available member when persist enable and going down pool member, you setting 'action on service down value reject' on pool.
Action on service down Reject
Send a deny to the client and server when the connection table exists and the pool member goes down.
18-Jan-2023 00:19 - edited 18-Jan-2023 00:19
you might want to use Reselect on the pool Action on Service down. But it applies only in certain scenarios.
Read about it first. Otherwise, the Reject option looks to be better.
Have a look here:
18-Jan-2023 07:09
Thanks guys!
Basically there is no option to transfer already established connections to the new pool member.