Hi All,
Just wondering, has anyone else experienced the behaviour described below, where messages are still routed to a gateway that is in Active-Probing state? From my understanding of the docs, when a destination is in probing state, it should not be used in the destination selection. I can see that Kamailio does set the state from AX to AP (Active to Active-Probing) when a timeout occurs, and a "kamctl dispatcher dump" does show that the state has changed to AP, however, sip trace to the destination still shows messages being routed to the destination that is in AP mode.
Just checking if anyone else is seeing this behaviour as well.
Thanks
On 24/10/2011 16:30, Asgaroth wrote:OK, did a few more tests but have come accross something, which I am not sure is intended behaviour.
When setting a destingation as probing in failure route (due to timeout), the destination still gets used in destination selection.
# ./kamailio -V
version: kamailio 3.3.0-dev0 (i386/linux) 25bedc
flags: STATS: Off, USE_IPV6, USE_TCP, USE_TLS, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, DBG_QM_MALLOC, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES
ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144, MAX_LISTEN 16, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 4MB
poll method support: poll, epoll_lt, epoll_et, sigio_rt, select.
id: 25bedc
compiled on 09:18:41 Oct 21 2011 with gcc 4.1.2
Dispatcher module parameters (in testing) are as follows (SBC_PING_FROM is #defined previously):
modparam("dispatcher", "flags", 2)
modparam("dispatcher", "dst_avp", "$avp(AVP_DST)")
modparam("dispatcher", "grp_avp", "$avp(AVP_GRP)")
modparam("dispatcher", "cnt_avp", "$avp(AVP_CNT)")
modparam("dispatcher", "ds_ping_method", "OPTIONS")
modparam("dispatcher", "ds_ping_from", SBC_PING_FROM)
modparam("dispatcher", "ds_ping_interval", 10)
modparam("dispatcher", "ds_probing_threshhold", 1)
modparam("dispatcher", "ds_probing_mode", 0)
Main routing logic has following snippet to select destination (hash table selects dispatcher setid based on request domain):
if(!ds_select_dst("$sht(which_sbc=>$rd)", "0")) {
sl_send_reply("500", "No destination available");
xlog("route[MAIN] : $rm : No destinations available for $rd");
exit;
}
Failure route has following logic to select next destination based on timout/failure of destination:
if (t_branch_timeout() && !t_branch_replied())
{
xlog("route[TO_SBC] : $rm : timeout and no reply ($si:$sp->$Ri:$Rp->$du)\n");
xlog("route[TO_SBC] : $rm : setting $du to probing state");
ds_mark_dst("p");
if(ds_next_dst())
{
xlog("route[TO_SBC] : $rm : next destination select ($du)\n");
t_on_failure("TO_SBC");
t_relay();
exit;
} else {
send_reply("500", "No destination available");
xlog("route[TO_SBC] : $rm : No destinations available for $rd");
exit;
}
}
According to 3.2 module docs for dispatcher, when a destination is set into probing state, it will not be used by ds_select_dst:
----
4.6.
ds_mark_dst("s")Mark the last used address from destination set as inactive ("i"/"I"/"0"), active ("a"/"A"/"1") or probing ("p"/"P"/"2"). With this function, an automatic detection of failed gateways can be implemented. When an address is marked as inactive or probing, it will be ignored by 'ds_select_dst' and 'ds_select_domain'.
possible parameters:
"i", "I" or "0" - the last destination should be set to inactive and will be ignored in future requests.
"a", "A" or "1" - the last destination should be set to active and the error-counter should set to "0".
"p", "P" or "2" - the last destination will be set to probing. Note: You will need to call this function "threshhold"-times, before it will be actually set to probing.
This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.
---
What happens here, for me, is:
[1] Gateway is in Active mode (state: AX).
[2] Request comes in and times out, destination is set to Active/Probing (state: AP)
[3] Another request comes in and it selects gateway that is in AP mode, times out, and then selects next dst in list.
[4] Another request comes in and it selects gateway that is in AP mode, times out, and then selects next dst in list.
.
.
NOTE: The requests selecting the AP mode gateway may not be right after each other (algorythm used is hash over callid) but I have stripped those out in above steps. If I'm not mistaked, if 2 destination in a set, and 1 destination is marked as AP, then remaining destination should always be selected as destination to send to. The destination marked AP (active-probing) should not be selected while in probing state.
When the gateway is set into AP mode at step [2], then, according to docs, any new request coming in should not have the gateway selected as it is marked as being in probing state.
Is this the intended behaviour or am I missing something in the documentation, or is it a bug?
Thanks
[...]
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