view tests/test-push-http.t @ 35793:4fb2bb61597c

bundle2: increase payload part chunk size to 32kb

Bundle2 payload parts are framed chunks. Esentially, we obtain
data in equal size chunks of size `preferedchunksize` and emit those
to a generator. That generator is fed into a compressor (which can
be the no-op compressor, which just re-emits the generator). And
the output from the compressor likely goes to a file descriptor
or socket.

What this means is that small chunk sizes create more Python objects
and Python function calls than larger chunk sizes. And as we know,
Python object and function call overhead in performance sensitive
code matters (at least with CPython).

This commit increases the bundle2 part payload chunk size from 4k
to 32k. Practically speaking, this means that the chunks we feed
into a compressor (implemented in C code) or feed directly into a
file handle or socket write() are larger. It's possible the chunks
might be larger than what the receiver can handle in one logical
operation. But at that point, we're in C code, which is much more
efficient at dealing with splitting up the chunk and making multiple
function calls than Python is.

A downside to larger chunks is that the receiver has to wait for that
much data to arrive (either raw or from a decompressor) before it
can process the chunk. But 32kb still feels like a small buffer to
have to wait for. And in many cases, the client will convert from
8 read(4096) to 1 read(32768). That's happening in Python land. So
we cut down on the number of Python objects and function calls,
making the client faster as well. I don't think there are any
significant concerns to increasing the payload chunk size to 32kb.

The impact of this change on performance significant. Using `curl`
to obtain a stream clone bundle2 payload from a server on localhost
serving the mozilla-unified repository:

before: 20.78 user; 7.71 system;  80.5 MB/s
after:  13.90 user; 3.51 system; 132 MB/s
legacy:  9.72 user; 8.16 system; 132 MB/s

bundle2 stream clone generation is still more resource intensive than
legacy stream clone (that's likely because of the use of a
util.chunkbuffer). But the throughput is the same. We might
be in territory we're this is effectively a benchmark of the
networking stack or Python's syscall throughput.

From the client perspective, `hg clone -U --stream`:

before: 33.50 user; 7.95 system; 53.3 MB/s
after:  22.82 user; 7.33 system; 72.7 MB/s
legacy: 29.96 user; 7.94 system; 58.0 MB/s

And for `hg clone --stream` with a working directory update of
~230k files:

after:  119.55 user; 26.47 system; 0:57.08 wall
legacy: 126.98 user; 26.94 system; 1:05.56 wall

So, it appears that bundle2's stream clone is now definitively faster
than legacy stream clone!

Differential Revision: https://phab.mercurial-scm.org/D1932

#require killdaemons

  $ hg init test
  $ cd test
  $ echo a > a
  $ hg ci -Ama
  adding a
  $ cd ..
  $ hg clone test test2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd test2
  $ echo a >> a
  $ hg ci -mb
  $ req() {
  >     hg serve -p $HGPORT -d --pid-file=hg.pid -E errors.log
  >     cat hg.pid >> $DAEMON_PIDS
  >     hg --cwd ../test2 push http://localhost:$HGPORT/
  >     exitstatus=$?
  >     killdaemons.py
  >     echo % serve errors
  >     cat errors.log
  >     return $exitstatus
  > }
  $ cd ../test

expect ssl error

  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: HTTP Error 403: ssl required
  % serve errors
  [255]

expect authorization error

  $ echo '[web]' > .hg/hgrc
  $ echo 'push_ssl = false' >> .hg/hgrc
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: authorization failed
  % serve errors
  [255]

expect authorization error: must have authorized user

  $ echo 'allow_push = unperson' >> .hg/hgrc
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: authorization failed
  % serve errors
  [255]

expect success

  $ cat > $TESTTMP/hook.sh <<'EOF'
  > echo "phase-move: $HG_NODE:  $HG_OLDPHASE -> $HG_PHASE"
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > allow_push = *
  > [hooks]
  > changegroup = sh -c "printenv.py changegroup 0"
  > pushkey = sh -c "printenv.py pushkey 0"
  > txnclose-phase.test = sh $TESTTMP/hook.sh 
  > EOF
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: phase-move: cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b:  draft -> public
  remote: phase-move: ba677d0156c1196c1a699fa53f390dcfc3ce3872:   -> public
  remote: changegroup hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_NODE_LAST=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:http:$LOCALIP: (glob)
  % serve errors
  $ hg rollback
  repository tip rolled back to revision 0 (undo serve)

expect success, server lacks the httpheader capability

  $ CAP=httpheader
  $ . "$TESTDIR/notcapable"
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: phase-move: cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b:  draft -> public
  remote: phase-move: ba677d0156c1196c1a699fa53f390dcfc3ce3872:   -> public
  remote: changegroup hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_NODE_LAST=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:http:$LOCALIP: (glob)
  % serve errors
  $ hg rollback
  repository tip rolled back to revision 0 (undo serve)

expect success, server lacks the unbundlehash capability

  $ CAP=unbundlehash
  $ . "$TESTDIR/notcapable"
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: phase-move: cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b:  draft -> public
  remote: phase-move: ba677d0156c1196c1a699fa53f390dcfc3ce3872:   -> public
  remote: changegroup hook: HG_BUNDLE2=1 HG_HOOKNAME=changegroup HG_HOOKTYPE=changegroup HG_NODE=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_NODE_LAST=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:http:$LOCALIP: (glob)
  % serve errors
  $ hg rollback
  repository tip rolled back to revision 0 (undo serve)

expect push success, phase change failure

  $ cat > .hg/hgrc <<EOF
  > [web]
  > push_ssl = false
  > allow_push = *
  > [hooks]
  > prepushkey = sh -c "printenv.py prepushkey 1"
  > [devel]
  > legacy.exchange=phases
  > EOF
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  remote: prepushkey hook: HG_BUNDLE2=1 HG_HOOKNAME=prepushkey HG_HOOKTYPE=prepushkey HG_KEY=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_NAMESPACE=phases HG_NEW=0 HG_NODE=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_NODE_LAST=ba677d0156c1196c1a699fa53f390dcfc3ce3872 HG_OLD=1 HG_PENDING=$TESTTMP/test HG_PHASES_MOVED=1 HG_SOURCE=serve HG_TXNID=TXN:$ID$ HG_URL=remote:http:$LOCALIP: (glob)
  remote: pushkey-abort: prepushkey hook exited with status 1
  remote: transaction abort!
  remote: rollback completed
  abort: updating ba677d0156c1 to public failed
  % serve errors
  [255]

expect phase change success

  $ cat >> .hg/hgrc <<EOF
  > prepushkey = sh -c "printenv.py prepushkey 0"
  > [devel]
  > legacy.exchange=
  > EOF
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  % serve errors
  $ hg rollback
  repository tip rolled back to revision 0 (undo serve)

expect authorization error: all users denied

  $ echo '[web]' > .hg/hgrc
  $ echo 'push_ssl = false' >> .hg/hgrc
  $ echo 'deny_push = *' >> .hg/hgrc
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: authorization failed
  % serve errors
  [255]

expect authorization error: some users denied, users must be authenticated

  $ echo 'deny_push = unperson' >> .hg/hgrc
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: authorization failed
  % serve errors
  [255]

  $ cat > .hg/hgrc <<EOF
  > [web]
  > push_ssl = false
  > allow_push = *
  > [experimental]
  > httppostargs=true
  > EOF
  $ req
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  % serve errors

  $ cd ..