ejabberd - Comments for "Failover HA behaviour"

The table 'passwd' must be replicated in each node.

mfoss — Sun, 18 May 2008 17:49:39 +0000

TFerguson wrote:

if the first (primary) node is offline, I cannot log in to my ejabberd domain via the second (secondary) node. Is this the intended behavior, or should secondary nodes still be able to operate (as an ejabberd server) in the event the primary node is down?

The ejabberd Guide says:

Now you can add replicas of various tables to this node with `mnesia:add_table_copy' or `mnesia:change_table_copy_type' as above (just replace `schema' with another table name and `disc_copies' can be replaced with `ram_copies' or `disc_only_copies').

Which tables to replicate is very dependant on your needs, you can get some hints from the command `mnesia:info().', by looking at the size of tables and the default storage type for each table on 'first'.

Replicating a table makes lookups in this table faster on this node. Writing, on the other hand, will be slower. And of course if machine with one of the replicas is down, other replicas will be used.

If you didn't instruct Mnesia @ node2 to replicate the table 'passwd' from node1, then you can only login in node2 when node1 is available.

If you already configured Mnesia @ node2 to replicate the table 'passwd' from node1, then I don't have clues of where is the problem.

Clarification Question on ejabberd Clustering

TFerguson — Fri, 16 May 2008 17:20:53 +0000

I have two machines set up in an ejabberd cluster, and everything works as advertised when they are both online. However, if the first (primary) node is offline, I cannot log in to my ejabberd domain via the second (secondary) node. Is this the intended behavior, or should secondary nodes still be able to operate (as an ejabberd server) in the event the primary node is down? When I look at the databases for each node in the Web Admin, they are identical for each node, which I assumed meant they were operating independently, but with replication of the tables. It's like it is looking for something for authentication that only exists on the primary server??

If this is not the intended behavior, are there any clues for where I can begin to look for misconfiguration? I don't see anything that looks out of order in the logs, etc. I have no hacks to my setup, just used the standard config with the clustering setup instructions in the doc.

TIA -TF

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ejabberd 2.0.0 on OpenSuSE 10.2

What do you mean ? The

mremond — Tue, 17 Jul 2007 15:38:05 +0000

What do you mean ?

The cluster in ejabberd is top notch and I doubt you can do better with some quick hack ...

--
Mickaël Rémond
Process-one

Thanks - seems like I will

S.T.E.N.C.H. — Tue, 17 Jul 2007 13:48:00 +0000

Thanks - seems like I will have to make my own arrangements!

ejabberd nodes in a cluster

mfoss — Fri, 06 Jul 2007 11:06:16 +0000

ejabberd nodes in a cluster can share some tables of the database: accounts (username and password), roster, offline messages, vcard...

Each node has his own client and server connections. When a node crashes, all his connections are lost.

I don't know what will happen with messages in the flight.