annotate tests/test-clone-stream-revlog-split.t @ 50641:5460424092e2

stream-clone: smoothly detect and handle a case were a revlog is split

This detect and handle the most common case for a race condition around stream
and revlog splitting. The one were the revlog is split between the initial
collection of data and the time were we start considering stream that data.

In such case, we repatch an inlined version of that revlog together when this
happens. This is necessary as stream-v2 promised a specific number of bytes and
a specific number of files to the client. In stream-v3, we will have the
opportunity to just send a split revlog instead.

Getting a better version of the protocol for stream-v3 is still useful, but it
is no longer a blocket to fix that race condition.

Note that another, rarer race condition exist, were the revlog is split while
we creating the revlog and extracing content from it. This can be dealt with
later.

Test stream cloning while a revlog split happens
------------------------------------------------

#testcases stream-bundle2-v2 stream-bundle2-v3

#if stream-bundle2-v3
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > stream-v3 = yes
  > EOF
#endif

setup a repository for tests
----------------------------

  $ cat >> $HGRCPATH << EOF
  > [format]
  > # skip compression to make it easy to trigger a split
  > revlog-compression=none
  > [phases]
  > publish=no
  > EOF

  $ hg init server
  $ cd server
  $ file="some-file"
  $ printf '%20d' '1' > $file
  $ hg commit -Aqma
  $ printf '%1024d' '1' > $file
  $ hg commit -Aqmb
  $ printf '%20d' '1' > $file
  $ hg commit -Aqmc

check the revlog is inline

  $ f -s .hg/store/data/some-file*
  .hg/store/data/some-file.i: size=1259
  $ hg debug-revlog-index some-file
     rev linkrev       nodeid    p1-nodeid    p2-nodeid
       0       0 ed70cecbc103 000000000000 000000000000
       1       1 7241018db64c ed70cecbc103 000000000000
       2       2 fa1120531cc1 7241018db64c 000000000000
  $ cd ..

setup synchronisation file

  $ HG_TEST_STREAM_WALKED_FILE_1="$TESTTMP/sync_file_walked_1"
  $ export HG_TEST_STREAM_WALKED_FILE_1
  $ HG_TEST_STREAM_WALKED_FILE_2="$TESTTMP/sync_file_walked_2"
  $ export HG_TEST_STREAM_WALKED_FILE_2
  $ HG_TEST_STREAM_WALKED_FILE_3="$TESTTMP/sync_file_walked_3"
  $ export HG_TEST_STREAM_WALKED_FILE_3


Test stream-clone raced by a revlog-split
=========================================

Test stream-clone where the file is split right after the lock section is done

Start the server

  $ hg serve -R server \
  >   -p $HGPORT1 -d --error errors.log --pid-file=hg.pid \
  >   --config extensions.stream_steps="$RUNTESTDIR/testlib/ext-stream-clone-steps.py"
  $ cat hg.pid >> $DAEMON_PIDS

Start a client doing a streaming clone

  $ ( \
  >    hg clone --debug --stream -U http://localhost:$HGPORT1 \
  >    clone-while-split > client.log 2>&1; \
  >    touch "$HG_TEST_STREAM_WALKED_FILE_3" \
  > ) &

Wait for the server to be done collecting data

  $ $RUNTESTDIR/testlib/wait-on-file 10 $HG_TEST_STREAM_WALKED_FILE_1

trigger a split

  $ dd if=/dev/zero of=server/$file bs=1k count=128 > /dev/null 2>&1
  $ hg -R server ci -m "triggering a split" --config ui.timeout.warn=-1

unlock the stream generation

  $ touch $HG_TEST_STREAM_WALKED_FILE_2

wait for the client to be done cloning.

  $ $RUNTESTDIR/testlib/wait-on-file 10 $HG_TEST_STREAM_WALKED_FILE_3

Check everything is fine

  $ cat client.log
  using http://localhost:$HGPORT1/
  sending capabilities command
  query 1; heads
  sending batch command
  streaming all changes
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "stream2" (params: 3 mandatory) supported (stream-bundle2-v2 !)
  bundle2-input-part: "stream3-exp" (params: 3 mandatory) supported (stream-bundle2-v3 !)
  applying stream bundle
  7 files to transfer, 2.11 KB of data
  adding [s] data/some-file.i (1.23 KB)
  adding [s] phaseroots (43 bytes)
  adding [s] 00manifest.i (348 bytes)
  adding [s] 00changelog.i (381 bytes)
  adding [c] branch2-served (94 bytes)
  adding [c] rbc-names-v1 (7 bytes)
  adding [c] rbc-revs-v1 (24 bytes)
  updating the branch cache
  transferred 2.11 KB in * seconds (* */sec) (glob)
  bundle2-input-part: total payload size 2268
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-bundle: 2 parts total
  checking for updated bookmarks
  updating the branch cache
  (sent 3 HTTP requests and * bytes; received * bytes in responses) (glob)
  $ tail -2 errors.log
  $ hg -R clone-while-split verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checking dirstate
  checked 3 changesets with 3 changes to 1 files
  $ hg -R clone-while-split tip
  changeset:   2:dbd9854c38a6
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  $ hg -R clone-while-split debug-revlog-index some-file
     rev linkrev       nodeid    p1-nodeid    p2-nodeid
       0       0 ed70cecbc103 000000000000 000000000000
       1       1 7241018db64c ed70cecbc103 000000000000
       2       2 fa1120531cc1 7241018db64c 000000000000
  $ hg -R server phase --rev 'all()'
  0: draft
  1: draft
  2: draft
  3: draft
  $ hg -R clone-while-split phase --rev 'all()'
  0: draft
  1: draft
  2: draft

subsequent pull work

  $ hg -R clone-while-split pull
  pulling from http://localhost:$HGPORT1/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets df05c6cb1406 (1 drafts)
  (run 'hg update' to get a working copy)

  $ hg -R clone-while-split debug-revlog-index some-file
     rev linkrev       nodeid    p1-nodeid    p2-nodeid
       0       0 ed70cecbc103 000000000000 000000000000
       1       1 7241018db64c ed70cecbc103 000000000000
       2       2 fa1120531cc1 7241018db64c 000000000000
       3       3 a631378adaa3 fa1120531cc1 000000000000
  $ hg -R clone-while-split verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checking dirstate
  checked 4 changesets with 4 changes to 1 files