More sophisticated discovery of Infinispan instances from JOPR agent

Currently, JOPR agent to Infinispan discovery is hardcoded to localhost. This needs further sophistication as indicated in:

Oct 01 10:39:25 <galderz> pilhuhn, one question
Oct 01 10:39:40 <galderz> the <plugin-configuration>, who uses it?
Oct 01 10:40:05 <pilhuhn> that is used to pass in connection properties
Oct 01 10:40:15 <galderz> to who?
Oct 01 10:40:27 <galderz> to the jopr plugin itself?
Oct 01 10:40:42 <pilhuhn> So in the ispn case, the remote jnp url would go int there , yes the plugin itself
Oct 01 10:40:56 <pilhuhn> in the plugin DiscoveryCOmponent you e.g. do
Oct 01 10:41:01 <galderz> right, so that currently is not in use at all, correct?
Oct 01 10:41:07 <pilhuhn> yes
Oct 01 10:41:23 <pilhuhn> Configuration c = resourceDiscoveryContext.getConfiguration();
Oct 01 10:41:49 <galderz> and what's c:template about?
Oct 01 10:42:04 <pilhuhn> String jnp Url = c.getSimpleProperty("xxx", "jmx:servive......"); with xxx being the property name from the deployment descirptor
Oct 01 10:42:23 <pilhuhn> c:template allows you to provide tempates for the values a user can enter
Oct 01 10:44:12 <pilhuhn> have a look at http://viewvc.rhq-project.org/cgi-bin/viewvc.cgi/rhq/trunk/modules/plugins/twitter/src/main/resources/META-INF/rhq-plugin.xml?view=log
Oct 01 10:44:27 <galderz> so, let me get one thing straight
Oct 01 10:44:43 <galderz> does it make sense to have anything other than localhost in the connectorAddress?
Oct 01 10:44:56 <pilhuhn> There are 2 templates for Twitter and identi.ca that pre-fill the basic connection properties for that plugin to connect to the remote services
Oct 01 10:45:07 <galderz> at the end of the day, can u assume the plugin will always be local to the infinispan instance?
Oct 01 10:45:44 <pilhuhn> This depends on your usage. If you want an agent on all nodes with ispn on, then you can assume localhost
Oct 01 10:46:02 <galderz> well, we have to make a choice
Oct 01 10:46:11 <galderz> or rethink this cos either
Oct 01 10:46:19 <pilhuhn> if you say that you only want one agent for e.g. 10 ispn nodes, then not :->
Oct 01 10:46:21 <galderz> the rhq-plugin.xml is generated at build it
Oct 01 10:46:59 <galderz> i think that at least
Oct 01 10:47:17 <pilhuhn> A plugin can support manual-add and autodiscovery. Meaning that you can autodiscover ispn on the localhost and stil have a user manually add an instance on a remote host - here he has to provide the correct connection properties
Oct 01 10:47:19 <galderz> that the port and host need to have a ${:} format
Oct 01 10:47:54 <galderz> so that at least, when u start the agent, u can pass (optionally) the location of the infinispan instance
Oct 01 10:48:04 <pilhuhn> That is done via c.getSimpleProperty(propertyName, defaultValue) in the plugin code
Oct 01 10:48:28 <pilhuhn> but yes, you could do it your way too
Oct 01 10:48:48 <galderz> hmmm, not sure if I like default values in code rather than in xml
Oct 01 10:49:05 <galderz> but let me have a think about it
Oct 01 10:49:33 <galderz> so, to get this right
Oct 01 10:49:42 <galderz> how do u call up on the default template?
Oct 01 10:49:58 <galderz> iow, how do I get the default template values?
Oct 01 10:50:25 <pilhuhn> hm. dunno if you can get them.
Oct 01 10:50:40 <pilhuhn> stop
Oct 01 10:50:44 <pilhuhn> let me rephrase
Oct 01 10:51:34 <pilhuhn> IIrc you get this just passed in (the default values you specify in plugin-xml) when you call c.getSimpleProperty();
Oct 01 10:54:22 <galderz> another question, how can an agent connect to multiple infinispan instances?
Oct 01 10:54:27 <galderz> each in different host and port?
Oct 01 10:55:00 <pilhuhn> yes
Oct 01 10:55:06 <galderz> how?
Oct 01 10:55:19 <pilhuhn> You just need one resource in inventory per ispn instance
Oct 01 10:55:40 <galderz> but the agent, how does it connect to each?
Oct 01 10:55:49 <galderz> the agent has a single connectorAddress
Oct 01 10:56:05 <galderz> so how on earth does it discover several instances in diff nodes?
Oct 01 10:57:22 <pilhuhn> you could in the Discovery component e.g. sweep a whole subnet. Just do a loop for each IP, and if an ispn instance is found, create one DiscoveredResourceDetails object per instance found and return all of those instances
Oct 01 10:58:25 <pilhuhn> or you could, if you have found one, (require one to start at localhost) ask this ispn instance for connection data of other instances in the grid and then create the DiscoveredResourceDetails objects for all of those
Oct 01 10:58:28 <galderz> right, so the connector address is no longer a simple property
Oct 01 10:58:38 <galderz> but makes sense to implement it as a list property
Oct 01 10:58:45 <pilhuhn> no
Oct 01 10:59:13 <pilhuhn> each resource runs in a separate context. per resource we instantiate one IspnComponent class
Oct 01 10:59:32 <pilhuhn> with its own set of values for the plugin config
Oct 01 10:59:49 <galderz> i don't get this
Oct 01 10:59:57 <galderz> the plugin runs in an agent
Oct 01 11:00:01 <galderz> that executes the discoveru
Oct 01 11:00:05 <pilhuhn> yes
Oct 01 11:00:13 <galderz> how do u past a list of ispn isstance urls to that plugin?
Oct 01 11:00:20 <galderz> so that discovery can act on each of them?
Oct 01 11:00:34 <pilhuhn> ah ok, yes that could be done via list
Oct 01 11:00:37 <galderz> i.e. node1:6996, node2:6996...etc
Oct 01 11:00:43 <pilhuhn> But then the user needs to provide the list
Oct 01 11:00:59 <galderz> via a sys property
Oct 01 11:01:14 <pilhuhn> what I was thinking is that you require 1 ispn instance on the host, the agent runs on.
Oct 01 11:01:15 <galderz> it's not uncommon to have properties that act either as single value or lists
Oct 01 11:02:01 <galderz> i..e tcpping host names
Oct 01 11:02:09 <galderz> the possibilities are varios here, i agree
Oct 01 11:02:17 <pilhuhn> ispn should know its topology?
Oct 01 11:02:30 <galderz> ispn knows about the cluster
Oct 01 11:02:37 <galderz> but an agent could be managing diff clusters
Oct 01 11:02:40 <galderz> that don't talk to each other
Oct 01 11:03:02 <galderz> anyway, this requires further thought
Oct 01 11:03:22 <galderz> the easiest way is simply: 1 agent, 1 ispn instance
Oct 01 11:03:38 <pilhuhn> yes
Oct 01 11:04:00 <galderz> i'll suggest diff solutions in the list and see which ones make most sense to implement before GA