ejabberd clustering problems and solutions - xmpp

Question

Setup Details
2 ejabberd nodes with postgresql as database (OS : Ubuntu 16.04)
Trying to do clustering of two ejabberd as mentioned in
https://docs.ejabberd.im/admin/guide/clustering/
After starting the master node the following steps have been performed on the slave node
copy .erlang.cookie to the slave node
copy ejabbed.yml from master to slave.
slave started successfully but shows the below error.
=====Error=========
Eshell V9.2 (abort with ^G)
(ejabberd#gim-Veriton-M6650G)1> 18:29:41.856 [notice] Changed loghwm of /usr/local/var/log/ejabberd/error.log to 100
18:29:41.856 [notice] Changed loghwm of /usr/local/var/log/ejabberd/ejabberd.log to 100
18:29:41.857 [info] Application lager started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.860 [info] Application crypto started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.865 [info] Application sasl started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.871 [info] Application asn1 started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.871 [info] Application public_key started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.880 [info] Application ssl started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.881 [info] Application p1_utils started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.883 [info] Application fast_yaml started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.888 [info] Application fast_tls started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.892 [info] Application fast_xml started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.895 [info] Application stringprep started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.899 [info] Application xmpp started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.903 [info] Application cache_tab started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.910 [info] Application eimp started on node 'ejabberd#gim-Veriton-M6650G'
18:29:41.910 [info] Loading configuration from /usr/local/etc/ejabberd/ejabberd.yml
18:29:41.913 [error] CRASH REPORT Process <0.67.0> with 0 neighbours exited with reason: no case clause matching <<>> in ejabberd_config:get_config_option_key/2 line 473 in application_master:init/4 line 134
18:29:41.913 [info] Application ejabberd exited with reason: no case clause matching <<>> in ejabberd_config:get_config_option_key/2 line 473
(ejabberd#gim-Veriton-M6650G)1>
I've tried re creating mnesia DB also but didn't help.
ejabberdctl status shows ejabberd is not running in that node
Can some oe please look into the issue and help.

Answer 1

Finally I found the solution to the problem
The issue is with the node name as the node name of the master ia FQ name
but the slave node's name is without a domain.
Also added both the node names in the /etc/hosts file
For ejabberd clustering ,Please refer the below steps.
Before starting , configure proper entries in the /etc/hosts files of both nodes.
ie the nodes should resolve each other using their host names.
set ejaberd node name in ejabberd.cfg file , both the nodes should have different node names.
1.cofigure ejabberd in one master node with a proper node name (either a FQDN or just a name of your convenience)
2.Configure slave node with the same config as that of master ie. bot the nodes should have the same configuration in ejabberd.yml file)
3.copy erlang.cookie from master node to slave and the ejabberd user should be ale to read the cookie file.
4.Start the master node in live mode (ejabberdctl live )
5.Start slave node in live mode
6.Check the cookie value in erlang console of both the nodes using the command 'erlang:get_cookie().' , both the nodes should have the same value.
7.If bot the nodes have same value then execute "ejabberdctl --not-timeout join_cluser ejabberd#nodename" in the slave.
change ejabberd#nodename according to your environment.
In my case I ran ejabberd with 'ejabberd' user with node name as ejabberd#cluster-node1 (If you want you can use a FQDN also like ejabberd#example.com)
8.If the abode command executed without any error then the nodes are in cluster
9.Confirm the cluster in any of the erlang console using the command mnesia:info(). here you will get the node details in "running_db_nodes"
10.Hurrayyyy you are done...
For load balancing the cluster you can use HAProxy
Please refer https://blog.onefellow.com/post/76702632637/haproxy-and-ejabberd for details
I've not done load balancing using any hardware load balancer , need to check on that
If anyone have done that please do post here ..