HP P4522A - Traffic Management Server Sa8220 User Manual page 318

A P P E N D I X E
Problem
Client getting
timeout or "service
not found" errors
Round Robin Load
Balancing works
abnormally
306
HP Traffic Director Server Appliances User Guide
Possible Cause
Proxy servers inhibit use
of sticky src-ip option.
The client is on the same
subnet as server (SAP
mode only). This causes
the server to return the
response directly to the
client, bypassing the
SA8220 . The client
discards the response
since the destination is
that of the server and not
the SA8220 .
For OPR configurations,
the loopback adapter is
not configured on the
fulfillment server(s).
The directory and/or file
content of the fulfillment
servers defined under the
service is not identical.
New TCP connections,
not client sessions, are
assigned to fulfillment
servers in a round robin
fashion.
Solution
Some ISPs use proxy servers to load balance
client sessions. When the sticky src-ip option
is enabled and the client's session is switched to
another proxy server, the source IP address is
changed. This may cause the SA8220 to route
the request to a different server. The solution is
to use the "sticky cookie" option instead of
"sticky src-ip." In this mode, a cookie is sent to
the client to force use of the same server
regardless of the source IP.
Configure the client and server to reside on
different subnets.
For instructions on configuring the loopback
adapter on the server(s), please see "Set the
Loopback" in Appendix D.
Configure all the servers under the same
service with the same directory structure and
file content.
This is normal behavior. Multiple components
of a web page (such as HTML and GIFs)
require separate TCP connections. The
requests are assigned to the fulfillment servers
in round robin fashion, although it may not be
apparent from the browser.