iRule Switch Statement default pool

You have some syntax problems with your iRule, namely unbalanced closing braces and an empty else statement. I've fixed those below.

when CLIENT_ACCEPTED {
  set default_pool prod_default3_pool
  set inbound_temp_pool prod_temp3_pool
}

when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::uri]] {
    "/foo*" {
      drop
    }
    "/bar*" {
      pool bar_pool
      persist cookie insert "barsession"  "1d 00:00:00"
    }
    default {
      pool $default_pool
      if { [HTTP::cookie exists "TEMP"] } {
        pool $inbound_temp_pool
      }
    }
  }  
}

In a switch statement, the 'default' option handles anything that haven't matched one of the configured comparisons. In your rule, that means any request with a URI not beginning with /foo or /bar will fall to the default case and end up assigned to the pool specified by $default_pool...except when the request contains the HTTP cookie "TEMP", in which case, the connection is assigned to the pool specified by $inbound_temp_pool.

As written, your rule is setting the variables default_pool and inbound_temp_pool on each new connection, which is probably not needed. You might want to move that variable assignment out to the RULE_INIT event, or even get rid of the assignment entirely and directly name the pools.