使用FarmWarDeployer部署WebApp tomcat 7集群

Question

I build a tomcat cluster with 2 nodes. I configured the cluster deployer FarmWarDeployer to watch a directory for war file. All works fine if the 2 nodes are started: deploying a war on watch dir in the node1 will send war file to node2. But if the copy of the war file in the watch directory is done while node2 is down, the node2 doesn't receive the new war file.

Is there any configuration to let the nodes check new war filese and receive it when it starts?

Answer 1

I don't believe that this is possible. As I understand it, the FarmWarDeployer listens for cluster messages which are sent when a new WAR file is found or when a WAR needs to be undeployed. If one of the nodes in your cluster is down, it's going to miss those messages.

I suppose that you could run touch <your-war-file> after the downed node was restarted and trigger another deploy. Alternatively since you have a small cluster, you could just manually copy the WAR file to the downed node before you restart it. Then that node will be up-to-date when it restarts.

Outside of that, I'd suggest looking at a different way of deploying your WAR file. Some quick suggestions that work for small clusters:

1. Copy the WAR file to shared storage (ie mounted to both nodes). Add a cron job or small background task to each node that monitors the shared storage mount and when a new file is found, deploy it (ie copy to webapps directory). Don't deploy directly from the shared storage, that's asking for trouble.

2. Use scp or a similar tool to copy the WAR file to your nodes. Use a similar cron job or background task to take the uploaded file and deploy it.

For larger installations, you could look at using a deployment tool like Puppet, Chef, Ansible or another similar technology. Really you could use these for a smaller installation to, it just might be overkill

Answer 2

Im using the below config, rem to nest inside .. (your cluster has to work first, i use unicast clustering).

<Deployer className="org.apache.catalina.ha.deploy.FarmWarDeployer" tempDir="/var/tmp/war-tmp/" deployDir="/usr/local/tomcat8053/webapps/" watchDir="/var/tmp/war-watch/" watchEnabled="true" processDeployFrequency="1" />

repeat the config for every other nodes in the cluster, but set the watchEnabled="false" then refresh, even if is to re-copy, the war files in the watchDir . Give the host node some time, it will deploy and then deploy to the other nodes. for prod, may need to set processDeployFrequency="2" to watch less often.

hope this helps someone.