Tigase as external component

There are cases when you want to deploy one or more Tigase components separately from the main server or perhaps you want to run some Tigase components connecting to a different XMPP server or perhaps you work on a component and you do not want to restart the main server every time you make a change. There is a way to run the Tigase server in "external component mode". In fact you can run any of Tigase components as an external component and connect them to the main XMPP server either via XEP-0114 or XEP-0225 connection. Let's look at the examples...

A simple case - MUC as an external component

A few assumptions:

1. We want to run a MUC component for a domain: 'muc.devel.tigase.org' and password 'muc-pass'
2. The main server works at an address: devel.tigase.org and for the same virtual domain
3. We want to connect to the server using XEP-0114 protocol and port '5270'.

There is a special configuration type for this case which simplifies setting needed to run the Tigase as an external component: config-type=--gen-config-comp. This generates a configuration for the Tigase with only one component loaded by default - component used for external component connection. If you use this configuration type, your init.properties file may look like this:

config-type = --gen-config-comp
--debug = server
--user-db = derby
--admins = admin@devel.tigase.org
--user-db-uri = jdbc:derby:/tigasedb
--virt-hosts = devel.tigase.org
--comp-name-1 = muc
--comp-class-1 = tigase.muc.MUCComponent
--external = muc.devel.tigase.org:muc-pass:connect:5270:devel.tigase.org:accept

Please note, you do not need lines:

--comp-name-1 = ext
--comp-class-1 = tigase.server.ext.ComponentProtocol

as the --gen-config-comp automatically includes them.

More components

Suppose you want to run more components as external components within one Tigase instance. Let's add another - PubSub component to the configuration above and see how to set it up. The way which seems to be most straightforward is just to add another component and another connection to the main server for the component domain:

config-type = --gen-config-comp
--debug = server
--user-db = derby
--admins = admin@devel.tigase.org
--user-db-uri = jdbc:derby:/tigasedb
--virt-hosts = devel.tigase.org
--comp-name-1 = muc
--comp-class-1 = tigase.muc.MUCComponent
--comp-name-2 = pubsub
--comp-class-2 = tigase.pubsub.PubSubComponent
--external = muc.devel.tigase.org:muc-pass:connect:5270:devel.tigase.org:accept, \
  pubsub.devel.tigase.org:pubsub-pass:connect:5270:devel.tigase.org:accept

Please note however that we are opening two connections to the same server. This is kind of wasting resources and overcomplicating system. What if we want to run even more components? Opening a separate connection for each component seems to be an overkill. In fact there is a way to reuse the connection for all component domains running as an external component. The property '--bind-ext-hostnames' contains a comma separated list of all hostnames (external domains) which should reuse the existing connection. There is one catch however. Connection reusing (hostname binding is defined in XEP-0225 only, hence you must use this protocol for the functionality. Here is an example configuration with a single connection over XEP-0225 protocol used by both external domains:

config-type = --gen-config-comp
--debug = server
--user-db = derby
--admins = admin@devel.tigase.org
--user-db-uri = jdbc:derby:/tigasedb
--virt-hosts = devel.tigase.org
--comp-name-1 = muc
--comp-class-1 = tigase.muc.MUCComponent
--comp-name-2 = pubsub
--comp-class-2 = tigase.pubsub.PubSubComponent
--external = muc.devel.tigase.org:muc-pass:connect:5270:devel.tigase.org:client
--bind-ext-hostnames=pubsub.devel.tigase.org