Description Philipp Hahn 2013-07-29 15:14:49 CEST

Currently UVMM translates queries and requests multiple times:
0. qemu-kvm || xen
  unix-socket(QMP)  || http(Xen-RPC)
1. libvirtd @ server
  libvirt-RPC
2. libvirt @ master
  UMCP(Python-pickle)
3. uvmm-UMC-Module @ master
  HTTP(JSON)
4. Browser @ client

This is a maintenance overhead and also implies a small performance problem, since currently multiple implementations have to be maintained.

It would help if the uvmm-UMC-module part would be moved into UVMMd itself, so that the uvmm-JavaScript-Code would more-or-less directly talks to UVMMd itself, where the UMC module passes through all data:
1. The Python representation is only used by the UMC backend module and by the uvmm-CLI-tool.
2. DVS is no longer relevant, so one one other interfaces with UVMMd directly.
3. No more maintenance of univention.uvmm.protocol and dunivention.uvmm.command.

Long-term it would be best if UMCP would be replaced by REST or some other something commonly accepted RPC mechanism.


For the performance issues I have no hard data, but a simple UMCP command to query one VM takes 1 second longer than talking to UVMMd directly on xen12:
  uri="qemu://$(hostname -f)/system"
  uuid="c78e2da0-17a6-4f4a-336b-190bf3cc1717"
  UMCC () { umc-command -r -U Administrator -P univention "$@"; }
  time UMCC uvmm/domain/get -o domainURI="$uri#$uuid"
real    0m1.067s
user    0m0.200s
sys     0m0.020s
  time uvmm domain_info "$uri" "$uuid"
real    0m0.081s
user    0m0.068s
sys     0m0.008s


See Bug #20818 more more cleanup.