problem with dispatcher load balancing - sr-users

9 Jun 2015


      I'm trying to set up kamailio dispatcher to distribute calls to 2 asterisk
servers. So far, the failover case seems ok, but I cannot get the
dispatcher to distribute load. All calls are going to the last destination
entry in the dispatcher table even if I have set the maxload attributes.
I'm using algorithm 10 for load distribution. The number of calls sent to
one asterisk is well above the maxload. Hope someone more experienced in
dispatcher can review my config and give me some recommendations. Thanks in
advance.
Here is the content of dispatcher table in postgresql db.
select * from dispatcher;
 id | setid |    destination     | flags | priority |           attrs
    | description
----+-------+--------------------+-------+----------+---------------------------+-------------
  1 |     1 | sip:10.0.1.31:5061 |     0 |        0 |
duid=asterisk1;maxload=25 | Asterisk1
  2 |     1 | sip:10.0.1.33:5061 |     0 |        0 |
duid=asterisk2;maxload=25 | Asterisk2
(2 rows)
Here are the dispatcher sections in kamailio.cfg.
# ----- dispatcher params -----
#!ifdef WITH_DISPATCHER
modparam("dispatcher", "db_url", DBASTURL)
modparam("dispatcher", "table_name", "dispatcher")
modparam("dispatcher", "force_dst", 1).
# If flag 2 is set, then failover support is enabled.
modparam("dispatcher", "flags", 3)
# the last address in destination set is used as a final option to send the
request to
modparam("dispatcher", "use_default", 1)
# load balancing fail over
modparam("dispatcher", "dst_avp", "$avp(dsdst)")
modparam("dispatcher", "grp_avp", "$avp(dsgrp)")
modparam("dispatcher", "cnt_avp", "$avp(dscnt)")
modparam("dispatcher", "dstid_avp", "$avp(dsdstid)")
modparam("dispatcher", "attrs_avp", "$avp(dsattrs)")
# PVs for hashing
modparam("dispatcher", "hash_pvar", "$fU@$ci")
# PVs to store results when calling ds_is_from_list
modparam("dispatcher", "setid_pvname", "$var(setid)")
modparam("dispatcher", "attrs_pvname", "$var(attrs)")
# method to probe the gateways
modparam("dispatcher", "ds_ping_method", "OPTIONS")
modparam("dispatcher", "ds_ping_from", "sip:dispatcher@localhost")
modparam("dispatcher", "ds_ping_interval", 30)
modparam("dispatcher", "ds_probing_threshhold", 10)
modparam("dispatcher", "ds_ping_reply_codes",
"class=2;code=403;code=404;code=484;code=488;class=3")
modparam("dispatcher", "ds_probing_mode", 1)
# size of hash table storing data for call load dispatching, power of two
modparam("dispatcher", "ds_hash_size", 10)
# expiration time in seconds to remove the load on a destination if no BYE
was received
modparam("dispatcher", "ds_hash_expire", 3600)
# expiration time in seconds to remove the load on a destination if no 200
OK for INVITE was received
# and state updated with ds_load_update
modparam("dispatcher", "ds_hash_initexpire", 60)
modparam("dispatcher", "ds_hash_check_interval", 30)
#!endif
route[WITHINDLG] {
if (has_totag()) {
# sequential request withing a dialog should
# take the path determined by record-routing
#!ifdef WITH_DISPATCHER
if(is_method("BYE|CANCEL") && ds_is_from_list("1", "3"))
ds_load_update();
#!endif
......
       }
}
route[FROMASTERISK] {
#!ifdef WITH_DISPATCHER
if(ds_is_from_list("1", "3")) {
xlog("L_DBG","$rm from $fU@$si:$sp: Call from Asterisk cluster\n");
return 1;
}
return -1;
#!else
if ($si==$sel(cfg_get.asterisk.bindip)) {
return 1;
}
return -1;
#!endif
}
onreply_route[MANAGE_REPLY] {
xdbg("incoming reply\n");
#!ifdef WITH_DISPATCHER
if(is_method("INVITE") && ds_is_from_list("1", "3")) {
if(status=~"2[0-9][0-9]") {
ds_load_update();
}
else if(status=~"[3-7][0-9][0-9]") {
ds_load_unset();
}
}
#!endif
if(status=~"[12][0-9][0-9]")
route(NATMANAGE);
}
#!ifdef WITH_DISPATCHER
failure_route[RTF_DISPATCH] {
if (t_is_canceled()) {
exit;
}
# next DST - only for 500 or local timeout
if (t_check_status("500") or (t_branch_timeout() and !t_branch_replied())) {
                # mark the destination Inactive and Probing
ds_mark_dst("IP");
                # select the new destination
if(ds_next_dst()) {
t_on_failure("RTF_DISPATCH");
route(RELAY);
exit;
}
                else {
                        # last available node failed to reply, no other
destinations available
                        send_reply("404", "No destination");
                        exit;
                }
}
}
#!endif
route[TOASTERISK] {
#!ifdef WITH_DISPATCHER
# ds_mark_dst("IP");
# Call load distribution
if(!ds_select_dst("1", "10")) {
sl_send_reply("500", "Service Unavailable");
xlog("L_INFO","$rm from $fU@$si:$sp: No destinations available for $rd\n");
                exit;
        }
xlog("L_DBG", "--- SCRIPT: going to <$ru> via <$du>\n");
t_on_failure("RTF_DISPATCH");
#!else
$du = "sip:" + $sel(cfg_get.asterisk.bindip) + ":"
+ $sel(cfg_get.asterisk.bindport);
#!endif
route(RELAY);
exit;
}
# Dispatcher detects a destination goes down
event_route[dispatcher:dst-down] {
    xlog("L_ERR", "Destination down: $rm $ru ($du)\n");
}
# Dispatcher detects a destination comes up
event_route[dispatcher:dst-up] {
    xlog("L_ERR", "Destination up: $rm $ru\n");
}