Comment 16 for bug 740759

So one more hack. Changing twisted.python.Failure to just have:

 tb = None

before it actually does anything with the traceback. Doing that the times are:

***** TB = NONE ******
0.033 hpss request: [140029379712768] BzrDirFormat.initialize_ex_1.16
0.372 end: [140029379712768] 0.352s
0.037 hpss request: [140029379712768] BzrDirFormat.initialize_ex_1.16
0.287 end: [140029379712768] 0.254s
0.035 hpss request: [140029379712768] BzrDirFormat.initialize_ex_1.16
0.252 end: [140029379712768] 0.220s
0.035 hpss request: [140029379712768] BzrDirFormat.initialize_ex_1.16
0.215 end: [140029379712768] 0.183s

So best case time around 183ms. Digging further into that:

0.035 hpss request: [140029379712768] BzrDirFormat.initialize_ex_1.16
0.061 method: translatePath (243652, '//~jameinel/%2Bjunk/x')
  took 0.025s
0.105 method: createBranch (243652, '/~jameinel/%2Bjunk/x')
  took 0.043s
0.130 method: translatePath (243652, '//~jameinel/%2Bjunk/x')
  took 0.024s
0.167 method: translatePath (243652, '//~jameinel/%2Bjunk/.bzr/branch-format')
  took 0.023s
0.186 method: translatePath (243652, '//~jameinel/.bzr/branch-format')
  took 0.018s
0.200 method: translatePath (243652, '//.bzr/branch-format')
  took 0.014s
0.201 creating repository in lp-79166544:///~jameinel/%2Bjunk/x/.bzr.
0.215 response: [140029379712768] ('.', 'yes', 'no', 'yes'
0.215 response end: [140029379712768] -1301322142.923s
0.215 end: [140029379712768] 0.183s

So the XMLRPC calls end up costing: 147ms. Plus the baseline of 30ms or so. (And looking at the 'slow' version, the XMLRPC time is 300ms).

So a summary:

  30ms raw-bzrlib
 150ms xmlrpc calls to get and create branch mapping
 300ms Twisted Failure traceback handling
 -----
 480ms Time in codehosting on my VM.

That sure looks like a lot of overhead for our virtualization efforts.