Forum Discussion
NimbostratusConnection limit per node and source IP persistence conflict; who wins?
I have a pool of 5 web server nodes. The maximum connection count of each web server is set to maximum of 100. Also the VIP persistence is set to source IP.
Now suppose the are a few hundred clients behind the same public NAT. They call end up on the same web server, node A, due to the persistence rule. What happens when the 101st user from that same public NAT makes a connection?
-Will they connect to node A due to persistence rule?
-Will they forward to a different node, node B, due to the maximum limit rule?
-Or will they not be able to establish a connection at all due to conflicting rules?
6 Replies
Hannes_RappNow suppose the are a few hundred clients behind the same public NAT. They call end up on the same web server, node A, due to the persistence rule. What happens when the 101st user from that same public NAT makes a connection?Depends on a number of things
- Status of
setting (Persistence Profile)Override Connection Limit
Assuming this is enabled, 101th connection will go to node A
When disabled, the persistence record will be discarded and connection will go to another node (load-balancing occurs) - If
setting is disabled and no other pool members are available, TCP-RST will be sent to client which results in a generic "Connection Has Been Reset" web-browser errorOverride Connection Limit
Regards,
- tickermcse76_16See next comment....
- Status of
Hannes_Rapp_162Nacreous
Now suppose the are a few hundred clients behind the same public NAT. They call end up on the same web server, node A, due to the persistence rule. What happens when the 101st user from that same public NAT makes a connection?Depends on a number of things
- Status of
setting (Persistence Profile)Override Connection Limit
Assuming this is enabled, 101th connection will go to node A
When disabled, the persistence record will be discarded and connection will go to another node (load-balancing occurs) - If
setting is disabled and no other pool members are available, TCP-RST will be sent to client which results in a generic "Connection Has Been Reset" web-browser errorOverride Connection Limit
Regards,
- tickermcse76_16See next comment....
- Status of
- tickermcse76_16
•Status of Override Connection Limit setting (Persistence Profile)
When disabled, the persistence record will be discarded and connection will go to another node (load-balancing occurs)
Assuming Override is disabled, the F5 will be able to keep track of client to node session/socket information, correct? Client session data is currently on the web server (though in the process of migrating off).
- Hannes_RappBigIP identifies client connection as IP:SRC-PORT combination, not just the IP address. Therefore, all 100 connections, despite coming from the same IP are seen as unique connections from different clients. Each client will end up having a dedicated connection record. They won't share the client-side connection.
