Technical data

Brocade ServerIron ADX Advanced Server Load Balancing Guide 95
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Cache persistence using URL hashing
2
The contents and operation of the offset-value is the same as described in “Parsing using the
“pattern string” only”.
With this command, the third step is for the system to parse the URL string up-to a character
defined by the value of the delimiter-string variable. The delimiter string is used to define the end
pattern after finding the substring. If the rest of URL string has multiple delimiter strings, only the
first one will be used. If the delimiter-string is not found, or the value of the delimiter-string variable
is empty, the system will look to the end of the host string to define the string used for hashing.
Parsing using the “pattern string” with a specified string length
The following example identifies a pattern string to perform hashing on with an offset of “0” and a
length of “8”.
NOTE
Because hash-persist action is a secondary action, you must add a forward action as shown in the
following example, before adding a hash-persist action.
ServerIronADX(config)#csw-policy p1
ServerIronADX(config-csw-p1)#match r1 forward 1
ServerIronADX(config-csw-p1)#match r1 hash-persist url search-host “www.” offset
0 length 5
Syntax: [no] hash-persist url search-url pattern-string offset offset-value length length
The contents of the pattern-string variable is the same as described in “Parsing using the “pattern
string” only”.
The contents and operation of the offset-value is the same as described in “Parsing using the
“pattern string” only”.
With this command, the third step is for the system to parse the URL string up-to the number of
characters defined by the value of the length variable. The value of the length variable must be
greater than 0 (zero). If the value of the length variable extends beyond the length of the host
string, the system will look to the end of the host string to define the string used for hashing.
Examples for parsing on the host string of the URL
In the following example, the client tries to connect to Brocade at the following URL.
http://www.brocade.com
Table 8 displays the contents of the stings used for hashing if the pattern-string variable is set to
“example3.com” and the offset value is set to “0” depending on the method used. The methods
and commands required are described as follows.
Parsing using the “pattern string” only
ServerIronADX(config)#csw-policy p1
ServerIronADX(config-csw-p1)#match r1 forward 1
ServerIronADX(config-csw-p1)#match r1 hash-persist url search-host “www.” offset
0
Parsing using the “pattern string” with a delimiter
ServerIronADX(config)#csw-policy p1
ServerIronADX(config-csw-p1)#match r1 forward 1
ServerIronADX(config-csw-p1)#match r1 hash-persist url search-host “www.” offset
0 delimiter “.”