Blogs

Blogs

Cluster Details

Announcing a new Marketplace App to help identify your cluster details.

So whenever I set up a new Liferay cluster, I get to the end and I ask myself, "How do I know it is working?"

My standard test is to connect to a node of the cluster and view a page. Then I connect to another node and change the content the first node is displaying. If I refresh the first node, I know it is working if that node shows the updated content instead of the old content. If the content didn't change, something is wrong with the cluster.

It's a simple test, surely, but it gets tedious when you're looking at an 8 node cluster. I mean, who wants to test all of the derivations to ensure things are working right?

Well, I created a new control panel to help view the current cluster state (from a node's perspective), and it is now available in the Liferay Marketplace: Cluster Details.

When you deploy this app, you get a new control panel under the Configuration section labeled Cluster Details.

The control panel has a single view, but this view is valuable:

So this page shows first the node details, including the server name, local node ID (for JGroups tracing), as well as an indicator whether the node is the master or not. When looking at each node in the cluster, only one will be set as the Master, the others will be slaves.

The next section shows the cluster nodes. Each node will know about the other nodes of the cluster, and this table lists all of the connected nodes, their bind address and the flag indicating whether they are alive or not.

In an 8 node cluster, this table will have 8 records in it, one for each node. If you have fewer than 8 or more than 8, you know there is something wrong with the cluster. If nodes are not alive, you know there is something wrong with the cluster and likely will know which nodes are having issues.

Not overly complex, but when you are trying to figure out if your cluster is setup correctly or whether sometime down the road all of the nodes are still forming a cluster, the info provided by this control panel can really verify the current state of your cluster.

Check it out!

Cluster Details in the Marketplace