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I would be very interested to know what network applications show high overhead. Do you have any apps/number you could share? Does high overhead mean they are

I would be very interested to know what network applications show high overhead. Do you have any apps/number you could share? Does high overhead mean they are generally slower or that they consume more CPU or both? (I ask this as a researcher in computer science looking at container overheads)

spooneybarger 8y ago
The amount of bytes we can push through a network connection (with a single thread), using the same test application is lower when running in Docker than without. Its particularly noticeable with Docker for OSX which shouldnt be surprising as its running a VM. The overhead is much lower on Linux as one would expect. I don't have anything handy. I brought up the OSX overhead as I wanted to be comprehensive given the somewhat ambigous nature of the original question. Docker Swarm inter-container networking is pretty bad. It consistenly collapses on us where throughputs drops by orders of magnitude. I know we weren't alone in this as we found an issue that had been open for the problem for quite some time. (And thus ended our quick experimentation for using Docker Swarm as a demo environment).
- idunno246 8y ago
  All of the OS X performance differences is from the busy box vm, not from docker. And for networking, if you use a different network driver than default the performance issues go away - the bridge/proxy stuff is slower, but you can expose raw interfaces. That said I’m also not a fan of docker except in certain cases(ie if you need polyglot deployment). The development story is worse- OS X disk performance is bad, and good luck getting a debugger or most tooling to work. It’s an extra layer to worry about, such as now you manage number of containers and number of servers instead of just servers.
  - spooneybarger 8y ago
    "if you use a different network driver than default the performance issues go away - the bridge/proxy stuff is slower" <-- issues go away does not match our experience. "better than bridge", yes. "goes away however does not match our experiences.
    - idunno246 8y ago
      We found macvlan did, but I’m sure our tests aren’t exhaustive. Also not talking about swarm networking, know nothing about that.
      - spooneybarger 8y ago
        In our experience, Swarm intercontainer networking is best avoided.

spooneybarger 8y ago

The amount of bytes we can push through a network connection (with a single thread), using the same test application is lower when running in Docker than without. Its particularly noticeable with Docker for OSX which shouldnt be surprising as its running a VM. The overhead is much lower on Linux as one would expect. I don't have anything handy. I brought up the OSX overhead as I wanted to be comprehensive given the somewhat ambigous nature of the original question. Docker Swarm inter-container networking is pretty bad. It consistenly collapses on us where throughputs drops by orders of magnitude. I know we weren't alone in this as we found an issue that had been open for the problem for quite some time. (And thus ended our quick experimentation for using Docker Swarm as a demo environment).

idunno246 8y ago
All of the OS X performance differences is from the busy box vm, not from docker. And for networking, if you use a different network driver than default the performance issues go away - the bridge/proxy stuff is slower, but you can expose raw interfaces. That said I’m also not a fan of docker except in certain cases(ie if you need polyglot deployment). The development story is worse- OS X disk performance is bad, and good luck getting a debugger or most tooling to work. It’s an extra layer to worry about, such as now you manage number of containers and number of servers instead of just servers.
- spooneybarger 8y ago
  "if you use a different network driver than default the performance issues go away - the bridge/proxy stuff is slower" <-- issues go away does not match our experience. "better than bridge", yes. "goes away however does not match our experiences.
  - idunno246 8y ago
    We found macvlan did, but I’m sure our tests aren’t exhaustive. Also not talking about swarm networking, know nothing about that.
    - spooneybarger 8y ago
      In our experience, Swarm intercontainer networking is best avoided.