It is easy to reproduce, just call exec_avp with sh script which has sleep 1 min.
Please find below part of configuration file where the exec_avp is used:
failure_route[HANDLE_FAILURE_ON_INCOMING_REQ] { if (t_is_canceled()) { exit; }
if (t_branch_timeout()) {
if (t_branch_replied()) {
// A local timeout after some provsional reply. xlog("L_WARN", "No final response on request $rm CSeq:$cs ($ci)!\n");
} else { // A local transaction timed out w/o any reply received. // In case incoming calls that means out Telephony doesn't reply.
xlog("L_ERR", "Failover on request $rm CSeq:$cs ($ci)!\n");
// Set current Telephony to inactive probbing state ds_mark_dst("IP");
// Checking next endpoint from the destination list if (!ds_next_dst()) { t_reply("503", "Service Unavailable"); xlog("L_CRIT","Failure route: All Telephony servers are invactive!\n");
if ($shv(is_zabbix_event_sent) == 0) { $shv(is_zabbix_event_sent) = 1; exec_avp("etc/kamailio/run_zabbix_sender.sh ecsp_no_telephony"); xlog("L_NOTICE","ecsp_no_telephony event is sent to zabbix\n"); }
exit; }
xlog("L_ERR", "Try to send to $rd:$rp ($ci)\n");
route(RELAY); } }
}