HP Traffic Director sa7220 - Manual (Page 27)

C H A P T E R 2 Sticky Options
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Sticky Options Some services operate best if all requests from a specific client during
a single session are directed to the same fulfillment server. For
example, if the server maintains a local database of client activity or
context (shopping cart, registration info, navigation history, etc.), it is
important that subsequent client requests go to the server with these
database records. The SA8220's “sticky” options allow this to occur.
Sticky is available in the two modes shown below.
Sticky source IP for SSL uses the SSL session ID for stickiness
instead of the source IP of the client.
Both HTTP and HTTPS services can be RICH. However, incoming
RICH SSL connections will always be decrypted and sent on to the
fulfillment servers in clear text. Sticky cookie must be used when the
clients need to remain stuck to the same server between HTTPS and
HTTP.
There is no sticky cookie requirement for HTTPS traffic.
Each brokered service can be configured with sticky cookie, sticky
IP, or no sticky option enabled. When a sticky option is configured,
all client requests (identified according to the enabled sticky mode)
during a session are routed to the same fulfillment server. When the
sticky option is disabled, the SA8220 determines the best fulfillment
server for each client request and directs them accordingly.
Mode Description
Source IP
address
(“src-ip”) Requests from a given IP address are directed to a
single server.
Cookie The requesting browser is given a cookie, which
subsequently identifies it as a unique requestor to
be directed to a single server. This method uniquely
identifies the client even if the request passes
through a proxy server. RICH service is required.