Async module taking down our server - sr-users

20 Jan 2015

Hi All

We are trying to use the async module to to delay sending a bye on
from one end of the call to the other.

We are using async_route(routename, seconds) to delay
the WITHINDLG route. The idea is that in the future we want to be
able to have our billing min duration enforced (though currently
we are having issues with the dialog module that we are discussing
in another thread).

After running this on our deploy servers, the delays before
sending on the byes get longer and longer, and then kamailio goes
down. Then the receive udp buffer fills up.

We tried it with both 4 and 400 async workers, and it made no
difference.

I am including a screen capture of the servers stats when this
happens taken from voip monitor.

Here are the relevant parts of the config:

...
loadmodule "async.so"
...
modparam("async", "workers", ASYNC_THREADS)
...
request_route {
...
route(DELAYED_BYE_STATIC);
...
route[DELAYED_BYE_STATIC] {
xlog("L_DEBUG","route DELAYED_BYE_STATIC");
#!ifdef WITH_DELAYED_BYE_STATIC
if (is_method("BYE")) {
xlog("L_DEBUG","route DELAYED_BYE_STATIC, from self \n");
#if (from_uri == myself) {
if ((allow_trusted() || allow_source_address()) && from_uri ==
myself) {
xlog("L_DEBUG","route DELAYED_BYE_STATIC, Bye detected, from self
\n");
send_reply("200", "OK");
xlog("L_DEBUG","route DELAYED_BYE_STATIC, sent 200 about to sleep
\n");
setflag(FLT_ACC); # do accounting ...
setflag(FLT_ACCFAILED); # ... even if the transaction fails
if (has_totag()) {
xlog("L_DEBUG","route DELAYED_BYE_STATIC, sleeping to
WITHINDLG_DELAYED \n");
async_route("WITHINDLG_DELAYED", MIN_DURATION);
} else {
xlog("L_DEBUG","route DELAYED_BYE_STATIC, sleeping to WITHINDLG \n");
async_route("WITHINDLG", MIN_DURATION);
}
xlog("L_DEBUG","route DELAYED_BYE_STATIC, slept\n");
exit;
}
}
#!endif
return;
}
...
route[WITHINDLG_DELAYED] {
xlog("L_DEBUG", "route WITHINDLG_DELAYED: triggered \n");
$avp(was_delayed) = 1;
route(WITHINDLG);
}
...
route[WITHINDLG] {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG triggered, request
method: $rm \n");
#!ifdef WITH_DISPATCHER
if(is_method("BYE|CANCEL")) {
xlog("L_DEBUG","route WITHINDLG:  cancel or bye detected, request
method: $rm \n");
#!ifdef WITH_DISPATCHER_LOAD_AWARE
xlog("L_DEBUG","route WITHINDLG: running ds_load_update, request
method: $rm \n");
ds_load_update();
#dlg_get ("$ci","$ft","$tt"); 
               #dlg_bye ("all");
        #!endif
}
#!endif

if (has_totag() || $avp(was_delayed) == 1) {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG has totag or
was_delayed: $avp(was_delayed)  \n");
# sequential request withing a dialog should
# take the path determined by record-routing
if (loose_route()) {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG has loose route \n");
route(DLGURI);
if (is_method("BYE")) {
xlog("L_DEBUG","route WITHINDLG: BYE detected");
setflag(FLT_ACC); # do accounting ...
setflag(FLT_ACCFAILED); # ... even if the transaction fails
xlog("L_DEBUG","route WITHINDLG: ACC flag set");
}
else if ( is_method("ACK") ) {
# ACK is forwarded statelessy
route(NATMANAGE);
}
else if ( is_method("NOTIFY") ) {
# Add Record-Route for in-dialog NOTIFY as per RFC 6665.
record_route();
}
xlog("L_DEBUG", "route WITHINDLG: will -- DLG RELAY 1\n");
route(RELAY);
} else {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG else \n");
if (is_method("SUBSCRIBE") && uri == myself) {
# in-dialog subscribe requests
route(PRESENCE);
exit;
}
if ( is_method("ACK") ) {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG is ack \n");
if ( t_check_trans() ) {
xlog("L_DEBUG", "route WITHINDLG: will -- DLG t_check_trans \n");
# no loose-route, but stateful ACK;
# must be an ACK after a 487
# or e.g. 404 from upstream server
xlog("L_DEBUG", "route WITHINDLG: will -- DLG RELAY 2\n");
route(RELAY);
exit;
} else {
# ACK without matching transaction ... ignore and discard
exit;
}
}
sl_send_reply("404","Not here");
}
exit;
}
}
...

Does any one know if this is a bug or a leak with in the async
module, or perhaps something I am doing in my config?

Thanks in advance for an assistance you can offer me.

All the best.

Will Ferrer
Switchsoft