HP P4522A - Traffic Management Server Sa8220 User Manual page 92

C H A P T E R 4
NOTE: The "*" and "!"
are allowed in
expressions, but they can
only exist at the
beginning or end of the
expression. Also, a
positive expression is
required after a not (!)
expression, otherwise the
(!) expression has no
effect.
80
HP Traffic Director Server Appliances User Guide
• HTTP Error Detection: When HTTP Error Detection is
enabled, requests that generate HTTP errors 401-405 and 500-
503 are rerouted, transparently to the client, to the next available
server. When disabled, these errors are sent back to the
requesting client.
• RICH Expression List: Expressions allow the SA8220 to parse
requests at the levels of path name, file type, and filename and
direct them to the appropriate server. Expressions can include
wildcards. To define an expression list, type a series of
expressions separated by the semicolon character into the RICH
Expression List: field according to the following usage:
Valid expressions include the following:
• File type expressions, such as *.gif, or */index.html
• Path expressions, such as /home/*, or /home/images/*, or /home/
images/a*
• Unique file expressions, such as /index.html
• Wildcard expression, such as *
• The negation operator (!), e.g., !*.gif, or !*/index.html
Invalid expressions include the following:
• Text on either side of the asterisk, e.g., /index*.gif
• Expressions containing more than one asterisk, e.g., /index*.*
• Expressions containing one or more spaces or the dollar sign ($)
character