使用Java连接到Docker上的多节点Couchbase集群

Question

I created a first couchbase server with the following command:

docker run -d --name db1 -p 8091-8094:8091-8094 -p 11210:11210 couchbase

The second server I created without the parameters for port because otherwise docker can't deploy the container:

docker run -d --name db2 couchbase

Now I can access the web console of the first container and create a cluster with the second container.

The problem is that I can't connect to the created cluster in Java because port 11210 is not published for the second container. I'm always getting a TimeoutException . How can I solve this?

Answer 1

You will have to expose the ports for the second container too, just as you did in first container (those "parameters" are port mappings).

Most likely, you were unable to run the second container with parameters because you tried mapping the same ports as you did in first container; aka, you tried this command:

docker run -d --name db2 -p 8091-8094:8091-8094 -p 11210:11210 couchbase

This wouldn't work because you cannot use ports that are already being used. So try mapping to different set of ports. For example:

docker run -d --name db2 -p 9091-9094:8091-8094 -p 11210:11210 couchbase

Notice how I am now using 9091-9094 instead of 8091-8094 . The above command means: map ports 8091-8094 from the container to ports 9091-9094 in the host . Any requests sent to 9091-9094 on host will be forwarded to 8091-8094 inside container automatically.

And then you can connect to your second container by specifying the new ports ( 9091-9094 ).

I suggest you to check the docker basics, especially the documentation for port mapping .

Answer 2

Finally I could solve the problem by setting up virtual machines for the servers with vagrants . This way it is no problem to have multiple Couchbase instances with the same ports.