Performance Question in Large iRule

Not sure why switch -glob wouldn't do the trick:

switch -glob [string tolower [HTTP::uri]]{ 
  /abc/* -
  /bcd/* -
  ...
  /jkl/* { pool one }
  /klm/* -
  /lmn/* -
  ...
  /nop/* { pool two }
  /opq/* -
  /pqr/* -
  ...
  /rst/* { pool three }
}

Or if you're going to switch only on the first level directory, you could avoid -glob switch if you parse out just that value for comparison:

switch [getfield [string tolower [HTTP::uri]] / 2] { 
  abc -
  bcd -
  ...
  jkl { pool one }
  klm -
  lmn -
  ...
  nop { pool two }
  opq -
  pqr -
  ...
  rst { pool three }
}

Or you could use a class listing the first directory and pool with a findclass (maintaining the list in the class instead of the iRule is probably easier administratively.)

Class:

class VirtualHosts {
  abc one
  bcd one
  ...
  rst three
}

iRule snip:

set myPool [findclass [getfield [string tolower [HTTP::uri]] / 2] $::VirtualHosts " "]
if {$myPool != "" }{
  pool $myPool
}

HTH

/deb