Hi Daniel,
I've actually been spending a lot of time with the dispatcher readme to try to
figure this out. If there are restrictions in usage as you indicate, then it is
not documented.
>From the dispatcher readme:
ds_next_dst
Takes the next destination address from the corresponding XAVPs and sets the
dst_uri (outbound proxy address).
This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.
ds_select_dst
If the bit 2 in 'flags' parameter is set, the rest of the addresses from the
destination set are stored in XAVP list (limited with an optional 'limit'
parameter). You can use 'ds_next_dst()' to use next address in order to achieve
serial forking to all possible destinations.
This function can be used from REQUEST_ROUTE, FAILURE_ROUTE.
My issue is that I want to select from a new group of destinations only when a
particular failure status has been received, so I can't simply only call
ds_next_dst() in failure_route.
Anyways, the problem is not in the initial group selection, but rather in the
subsequent calls to ds_next_dst(). I changed the logic to how you recommended,
with ds_select_dst() being called only in request_route, and ds_next_dst() only
called by failure_route. The problem is exactly the same: ds_next_dst() starts
selecting destinations that are not in the group that was initially selected
with ds_select_dst().
You can see it happening here:
dispatcher [dispatch.c:2097]: ds_manage_routes(): set [2]
dispatcher [dispatch.c:2213]: ds_manage_routes(): using alg [8] hash [0]
dispatcher [dispatch.c:2260]: ds_manage_routes(): selected [8-2-0/0]
<sip:127.0.0.1:5072;transport=udp>
dispatcher [dispatch.c:2281]: ds_manage_routes(): using first entry [2/0]
dispatcher [dispatch.c:2057]: ds_select_dst_limit(): selected target
destinations: 1
<script>: REQUEST ROUTE: Relayed to [sip:127.0.0.1:5072;transport=udp] via
forced socket [udp:127.0.0.1:5074]
<script>: FAILURE ROUTE: 400 Bad Request, trying next available gateway...
<script>: FAILURE ROUTE: Selecting next destination from:
[grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
dispatcher [dispatch.c:2357]: ds_update_dst(): updating dst
dispatcher [dispatch.c:2373]: ds_update_dst(): updating dst with next record
dispatcher [dispatch.c:2403]: ds_update_dst(): using next dst uri
[sip:127.0.0.1:5072;transport=udp]
<script>: FAILURE ROUTE: Next destination selected:
[sip:127.0.0.1:5072;transport=udp] from
[grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
<script>: FAILURE ROUTE: 400 Bad Request, trying next available gateway...
<script>: FAILURE ROUTE: Selecting next destination from:
[grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
dispatcher [dispatch.c:2357]: ds_update_dst(): updating dst
dispatcher [dispatch.c:2373]: ds_update_dst(): updating dst with next record
dispatcher [dispatch.c:2403]: ds_update_dst(): using next dst uri
[sip:127.0.0.1:5071;transport=udp]
<script>: FAILURE ROUTE: Next destination selected:
[sip:127.0.0.1:5071;transport=udp] from
[grp=1;uri=sip:127.0.0.1:5071;transport=udp;]
It happens in this order:
1. Request_route ds_select_dst() selects group=2
destination=sip:127.0.0.1:5072;transport=udp
2. Failure_route ds_next_dst() selects group=2
destination=sip:127.0.0.1:5072;transport=udp (again?)
3. Failure_route ds_next_dst() selects group=1
destination=sip:127.0.0.1:5071;transport=udp
I don't understand what I'm doing incorrectly for it to select a destination
from group 1.
One thing that is standing out to me is the log line showing
"ds_select_dst_limit(): selected target destinations: 1" when ds_select_dst()
is called. Based on the readme for ds_select_dst(), all addresses from the
group are stored in the XAVP if bit 2 of the 'flags' parameter is set (which it
is) unless otherwise limited by the 'limit' parameter (it is not). However,
when I print out the XAVP with xavp_params_implode, the XAVP only ever contains
a single destination.
Thanks,
________________________________
From: Daniel-Constantin Mierla <mico...@gmail.com>
Sent: Wednesday, September 27, 2023 01:58
To: Kamailio (SER) - Users Mailing List <sr-users@lists.kamailio.org>
Cc: Geoff Goas <geoff.g...@interoptechnologies.com>
Subject: Re: [SR-Users] What is the expected behavior for dispatcher's
ds_next_dst?
Hello,
normally ds_select_dst() should be used inside request_route and
ds_next_dst() in the failure_route. As you do the former also in the
failure_route, you keep selecting the destination from the group and add
them to the list of possible next hops.
Look at the readme of dispatcher module, it has a complete sample config
how to use the two functions.
Cheers,
Daniel
On 26.09.23 22:02, geoff.goas--- via sr-users wrote:
> Hello,
>
> I have some questions about dispatcher's behavior. I noticed that when I
> first ds_select_dst() a specific dispatcher group ID, ds_next_dst() will
> cycle through the active destinations in that group. When it reaches the end
> of the destinations in the group, it does not return "false", instead it
> starts to return destinations that are not a part of that group, ie. those
> destinations which are listed prior to the selected group in the
> dispatcher.list file. Is this the expected behavior? I've observed it on
> kamailio 5.3 and 5.5 releases.
>
> My dispatcher.list:
>
> # Group 1
> 1 sip:127.0.0.1:5071;transport=udp 8 0
> # Group 2
> 2 sip:127.0.0.1:5072;transport=udp 8 0
> # Group 3
> 3 sip:127.0.0.1:7010;transport=udp 8 0
> 3 sip:127.0.0.1:7011;transport=udp 8 0
> 3 sip:127.0.0.1:7012;transport=udp 8 0
> # Group 4
> 4 sip:127.0.0.1:5071;transport=udp 8 0
> 4 sip:127.0.0.1:5072;transport=udp 8 0
>
> I have the following in failure_route (excerpt):
>
> $var(dsFoundDestination) = 0;
>
> if (t_any_replied())
> {
> xavp_params_implode("_dsdst_",
> "$var(dsDestinations)");
> xlog("L_INFO", "FAILURE ROUTE: Already have
> replies on this transaction. Selecting next destination from:
> [$var(dsDestinations)]");
> if (ds_next_dst())
> {
> xavp_params_implode("_dsdst_",
> "$var(dsDestinations)");
> xlog("L_INFO", "FAILURE ROUTE: Next
> destination selected: [$du] from [$var(dsDestinations)]");
> $var(dsFoundDestination) = 1;
> }
> }
> else if (ds_select_dst("3", "8")) // Dispatcher Group
> 3
> {
> xlog("L_INFO", "FAILURE ROUTE: Did not find any
> replies on this transaction. Selected destination: [$du]");
> $var(dsFoundDestination) = 1;
> }
> if ($var(dsFoundDestination))
> {
> $var(logString) = "FAILURE ROUTE: Relayed to [" +
> $du + "]";
> if (t_relay())
> {
> xlog("L_INFO", "$var(logString)");
> }
> }
>
> Produces the following logs:
>
> FAILURE ROUTE: Did not find any replies on this transaction. Selected
> destination: [sip:127.0.0.1:7012;transport=udp]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:7012;transport=udp]
> FAILURE ROUTE: Already have replies on this transaction. Selecting next
> destination from: [grp=3;uri=sip:127.0.0.1:7012;transport=udp;]
> FAILURE ROUTE: Next destination selected: [sip:127.0.0.1:7011;transport=udp]
> from [grp=3;uri=sip:127.0.0.1:7011;transport=udp;]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:7011;transport=udp]
> FAILURE ROUTE: Already have replies on this transaction. Selecting next
> destination from: [grp=3;uri=sip:127.0.0.1:7011;transport=udp;]
> FAILURE ROUTE: Next destination selected: [sip:127.0.0.1:7010;transport=udp]
> from [grp=3;uri=sip:127.0.0.1:7010;transport=udp;]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:7010;transport=udp]
> FAILURE ROUTE: Already have replies on this transaction. Selecting next
> destination from: [grp=3;uri=sip:127.0.0.1:7010;transport=udp;]
> FAILURE ROUTE: Next destination selected: [sip:127.0.0.1:5072;transport=udp]
> from [grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:5072;transport=udp]
> FAILURE ROUTE: Already have replies on this transaction. Selecting next
> destination from: [grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
> FAILURE ROUTE: Next destination selected: [sip:127.0.0.1:5072;transport=udp]
> from [grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:5072;transport=udp]
> FAILURE ROUTE: Already have replies on this transaction. Selecting next
> destination from: [grp=2;uri=sip:127.0.0.1:5072;transport=udp;]
> FAILURE ROUTE: Next destination selected: [sip:127.0.0.1:5071;transport=udp]
> from [grp=1;uri=sip:127.0.0.1:5071;transport=udp;]
> FAILURE ROUTE: Relayed to [sip:127.0.0.1:5071;transport=udp]
>
> I want to stop the loop once there are no more active destinations in group
> 3. Is the solution simply to check that the selected destination is part of
> the desired group and stop processing if it is not?
>
> Thanks for your time.
> __________________________________________________________
> Kamailio - Users Mailing List - Non Commercial Discussions
> To unsubscribe send an email to sr-users-le...@lists.kamailio.org
> Important: keep the mailing list in the recipients, do not reply only to the
> sender!
> Edit mailing list options or unsubscribe:
--
Daniel-Constantin Mierla (@ asipto.com)
twitter.com/miconda -- linkedin.com/in/miconda
Kamailio Consultancy - Training Services -- asipto.com
Kamailio World Conference - kamailioworld.com
CAUTION: This email originated from outside of the organization. Do not click
links or open attachments unless you recognize the sender and know the content
is safe.
__________________________________________________________
Kamailio - Users Mailing List - Non Commercial Discussions
To unsubscribe send an email to sr-users-le...@lists.kamailio.org
Important: keep the mailing list in the recipients, do not reply only to the
sender!
Edit mailing list options or unsubscribe:
