As was explained in the answer to this question: https://stackoverflow.com/questions/11730590/what-are-some-of-the-tricks-to-using-openshift it should be possible to ssh into some of the other gears when using a scaled app with openshift.
Unfortunately the link mentioned there (https://openshift.redhat.com/community/faq/can-i-access-my-applications-gear) seems to be gone.
Via [my app url]/haproxy-status/ I can see the names of the other gears. They are long names like gear-[long number]-[app name]. Using that name I can no longer ssh into them when I'm ssh'ed into the main gear. ssh there just immediately returns without any error.
If I do ssh blala the same thing happened, so it looks like ssh had been replaced by a noop command on the primary gear?
When I examine the haproxy conf file, I see entries like;
server gear-[long number]-[app name] ex-std-node[number].prod.rhcloud.com:[number] check fall 2 ...
I tried ssh'ing into this ext-std-node... address as well, both from the main/primary application gear as well as from my desktop, but it didn't work in both cases.
How can I get shell access to my other gears?
This command shows how to access individual gears:
rhc app show <appname> --gears
The last column of output is the ssh URL. It is of the form $UUID@$UUID-$NAMESPACE.rhcloud.com . You can ssh into them directly, and they are also accessible via ssh from the "head" gear; they have to be, since git pushes are synchronized from the head gear to the others via ssh.