iRule with JSESSIONID including the server id with jvmRoute

I wrote this one a while ago (there is room for improvement with the array access):

when RULE_INIT {
    array set static::srvid_node {
        node1 172.29.32.160
        node2 172.29.32.161
        node3 172.29.32.162
        node4 172.29.32.163
    }
    set static::debug_map_srvid 1
}
when HTTP_REQUEST {
    set original_request "[IP::client_addr]:[HTTP::method]:[HTTP::uri]:HTTP/[HTTP::version]"
    if {([HTTP::cookie exists JSESSIONID])} {
        set session_id [HTTP::cookie value JSESSIONID]
        set node_id [getfield ${session_id} . 2]
        set node_ip [getfield [array get static::srvid_node ${node_id}] " " 2]
        if {(${node_ip} ne "")} {
            if {(${static::debug_map_srvid} > 0)} { log local0. "info: valid header-cookie JSESSIONID found (${session_id}) in request (${original_request}); mapping to ${node_ip}" }
        } else {
            log local0. "error: broken header-cookie JSESSIONID found (${session_id}) in request (${original_request}); balancing to default pool ([LB::server pool])"
            pool [LB::server pool]
            return
        }
    } elseif {([findstr [HTTP::path] JSESSIONID 11] ne "")} {
        set session_id [findstr [HTTP::path] JSESSIONID 11]
        set node_id [getfield ${session_id} . 2]
        set node_ip [getfield [array get static::srvid_node ${node_id}] " " 2]
        if {(${node_ip} ne "") and (${static::debug_map_srvid} > 0)} {
            log local0. "info: valid url-cookie JSESSIONID found (${session_id}) in request (${original_request}); mapping to ${node_ip}"
        } else {
            log local0. "error: broken url-cookie JSESSIONID found (${session_id}) in request (${original_request}); balancing to default pool ([LB::server pool])"
            pool [LB::server pool]
            return
        }
    } else {
        if {(${static::debug_map_srvid} > 0)} { log local0. "info: no addressed node found in request (${original_request}); balancing to default pool ([LB::server pool])" }
        pool [LB::server pool]
        return
    }
    if {([LB::status pool [LB::server pool] member ${node_ip} 80] equals "down")} {
        log local0. "warning: addressed node (${node_ip}) in request (${original_request}) is unavailable; sending 503"
        HTTP::respond 503 noserver Server "test service" Connection Close Date "[clock format [clock seconds] -format {%a, %b %d %Y %H:%M:%S %Z} -gmt 1]"
        return
    } else {
        pool [LB::server pool] member ${node_ip}:80
        return
    }
}

when HTTP_RESPONSE {
    if {([HTTP::cookie exists JSESSIONID]) and ($static::debug_map_srvid > 0) and ([info exists original_request])} {
         log local0. "info: response cookie JSESSIONID ([HTTP::cookie value JSESSIONID]) found in response for request (${original_request})"
    }
}

when LB_FAILED {
    # Ausloesung des Events bei Nichtverfuegbarkeit innerhalb Monitoring Timeout
    if {${static::debug_map_srvid} > 0} {
         log local0. "error: selected server not available (${node_ip}:80) for request (${original_request}); sending 503"
    }
    HTTP::respond 503 noserver Server "test service" Connection Close Date "[clock format [clock seconds] -format {%a, %b %d %Y %H:%M:%S %Z} -gmt 1]"
    return
}