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I wanna know if this is a good idea to go with?

I have a couple java services which run in different boxes in aws vpc right now. Recently I read about docker and think it is really awesome. So my question is that if it is a good idea to replace these current boxes with docker boxes and put my java services on top of them? Of course still in vpc.

The biggest benefit which I could image is by doing so it could save us the amount of work we spend on testing integration and debugging and so on.

But I do concern about things like

performance loss (if any)? network configuring? service status monitoring?

I am really newbie on docker, so plz point me to any resource which you think might help, thx a lot.

Aeolus
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1 Answers1

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Performance of containers is very close to bare metal (or, in that case, to VMs, since you will be running in VMs).

Specifically:

  • on volumes, disk I/O performance is native;
  • outside of volumes, there is a tiny overhead when opening files, and another overhead when doing the first change to a file in the original image (as the file gets copied to the RW layer), but after that, performance is native;
  • network connections go through an extra NAT layer, which should amount to <<1ms (rather 0.01 to 0.1ms) until you get 1000s of requests per second; then you can bypass the NAT layer with tools like Pipework;
  • CPU performance is native;
  • memory performance is native by default; but if you enable memory accounting+limiting there is an impact (a few %, up to 5-10% for memory intensive workloads which grow and shrink their memory usage a lot).

Status monitoring should be exactly the same as for regular apps.

Network configuration: if your apps expose well-known TCP ports, you will be fine with Docker port-mapping features. If you need large ranges of TCP ports, or dynamic allocation of ports, the above-mentioned Pipework will help.

Don't hesitate if you have other questions! We also have an IRC channel (#docker on Freenode) and a mailing list (docker-user on Google groups).

jpetazzo
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