Incorrect balancing using two pools based on cookies.

sorry colleagues, the description was cutted.

The problem is in incorrect balancing within two server pools. It works fine for 1 pool and goes unpredictabe for another. We have have two rules, 1 - defined pool 2 - check cookie and insert persistant record for server - cookie pair.

It works fine untill we've switch off one of the servers from the second pool. If so - all sessions comes to one server of the pilot pool, instead of balancing over 6 others virtual severs. I've put the existing rule in Preformatted code.

Maybe there are some predefine patterns and best practice for iRules we can use for that configuration ?

WBR, Dmitry.

when HTTP_REQUEST 
{
set need_cookie 0
set pinned_to_pilot 0
set pilot_region 0
set remove_bIPs_cookie 0
set do_not_persist 0

if { [HTTP::cookie exists "bIPs"] } 
{
         LB::detach
}
if { [HTTP::cookie exists "bIPs"] } 

{
set cookie_bIPs [HTTP::cookie value "bIPs"]
switch -- $cookie_bIPs
     {
       "564844779" { 
         set pinned_to_pilot 1
      }
       "-538018688" { 
         set pinned_to_pilot 1
        }
       "-1461105642"{ 
         set pinned_to_pilot 1
        }
       "836771244"{ 
         set pinned_to_pilot 1
        }
       "1189555514"{ 
         set pinned_to_pilot 1
        }
       "-662456167"{ 
         set pinned_to_pilot 1
        }
       "-1350268913" { 
         set pinned_to_pilot 1
        }
     }
   }
if { [HTTP::cookie exists "MVID_CITY_ID"] } 

 {
     set cookie_local [HTTP::cookie value "MVID_CITY_ID"]
     if { [class match $cookie_local equals ATG_PILOT_COOKIE_GROUP] } 
        {
          set pilot_region 1
        }
   }

set bIPs_crc_num ""
if {[HTTP::query] contains "o.bIPs"}
  {
      set bIPs_crc_num [URI::query [HTTP::uri] "o.bIPs"]
  }

switch -glob [HTTP::host]
  {

    "*mvl.ru" 
      {
        set domain "[www.mvl.ru"](//www.mvl.ru);
      } 
  }

if 
   { 
        not ([HTTP::path] starts_with "/assets/") 
    and not ([HTTP::path] starts_with "/media/")
    and not ([HTTP::path] starts_with "/errors/holdingPage.html")
    and not ([HTTP::path] starts_with "/sitemap.xml")
    and not ([HTTP::path] starts_with "/robots.txt")
    and not ([HTTP::path] starts_with "/sitemaps")
    and not ([HTTP::path] starts_with "/affiliates_unloads/")
    and not ([HTTP::path] starts_with "/favicon.ico") 
    } 
{
    if { ([HTTP::cookie value "bIPs"] ne "") }
    {
      if { not ($pinned_to_pilot) and not ($pilot_region) } 
       {
        persist uie [HTTP::cookie value "bIPs"]
        set need_cookie 0
       }
      elseif { ($pinned_to_pilot) and ($pilot_region) } 
       {
        persist uie [HTTP::cookie value "bIPs"]
        set need_cookie 0
       }
      else 
      { 
        set need_cookie 1
        set do_not_persist 1
      }
    } 
    else 
    {
        set need_cookie 1
    }

    if { ($bIPs_crc_num ne "") } 
    {
        persist uie [HTTP::cookie value "bIPs"]
    }
    `

    }
    }

    when LB_SELECTED 
    {
       if { 
            not ([HTTP::path] starts_with "/assets/") 
        and not ([HTTP::path] starts_with "/media/")
        and not ([HTTP::path] starts_with "/errors/holdingPage.html")
        and not ([HTTP::path] starts_with "/sitemap.xml")
        and not ([HTTP::path] starts_with "/robots.txt")
        and not ([HTTP::path] starts_with "/sitemaps")
        and not ([HTTP::path] starts_with "/affiliates_unloads/")
        and not ([HTTP::path] starts_with "/favicon.ico") 
          } 
        {

    

`if { ([HTTP::cookie value "bIPs"] ne "") and not ($do_not_persist)  } 
      {
         persist uie [HTTP::cookie value "bIPs"]
      }
    }

set do_not_persist 0
}

when PERSIST_DOWN 
{
    set need_cookie 1
    set do_not_persist 1
}

when HTTP_RESPONSE 
{
   set pool_is_dynamic 0
  if { ([LB::server pool] ==  "/Common/atg-ps-prod_tcp80") or ([LB::server pool] ==  "/Common/atg-pilot-pool")} 
   {
      set pool_is_dynamic 1 

      HTTP::cookie insert name "bIPs" value [crc32 [IP::server_addr]] path "/" domain $domain version 1
      HTTP::cookie httponly bIPs enable 

   }
   if { ($need_cookie) and ($pool_is_dynamic) } 
   {
      catch { persist add uie [crc32 [IP::server_addr]] }
   }
}