Extreme Networks Px Series Switch User Manual


 
Px Series Application Switch Installation and Configuration Guide 6-11
Persistence Modes
Unlike self-identifying cookie persistence and hashed cookie persistence, learned cookie
persistence does not require the website administrator to make any changes to the
website. Learned cookie persistence is a best-effort persistence mode that creates a
short-term stickiness between the client and the web server.
Figure 6-4 illustrates learned cookie persistence mode.
Figure 6-4: Learned cookie persistence mode
The following transactions occur in Figure 6-4:
The website administrator configures the Px series application switch to use learned
cookie persistence mode, and configures the name of the cookie to be tracked.
The client at IP address 65.11.11.11 transmits its first TCP request (A) to
www.buystuff.com at its publicly-known VIP address, 64.1.1.7.
The Px series application switch responds (B) on behalf of 64.1.1.7, and the three-way
TCP handshake is established between the client and the Px series application
switch.
Using its configured load balancing policy, the Px series application switch selects
one of the web server. In this example, server 3 at IP address 10.1.1.3.
WS_004
Client
65.11.11.11
Cookie:
sessionID=37654
Server 1
10.1.1.1
Server 2
10.1.1.2
Server 3
10.1.1.3
64.1.1.7
www.buystuff.com
A
C
D
B
E
E
F
F