1. 31 Jul, 2020 3 commits
    • Kirill Smelkov's avatar
      [ZEO4] Include both modified and just created objects into invalidations · f2fae122
      Kirill Smelkov authored
      ( Upstream commit ab86bd72 )
      
      This is ZEO4 backport of https://github.com/zopefoundation/ZEO/pull/160
      
      It changes ZEO4 to both include created objects into invalidation
      messages, and, in turn, not to skip sending invalidation message at
      all if committed transaction only creates objects. Please see original
      description for details below.
      
      Extra changes compared to ZEO5 patch:
      
      - tests/servertesting.py: provide callAsyncNoSend to avoid the following crash:
      
        File ".../ZEO/tests/testZEO2.py", line 156, in ZEO.tests.testZEO2.proper_handling_of_errors_in_restart
        Failed example:
            zs1.tpc_finish('1').set_sender(0, conn1)
        Exception raised:
            Traceback (most recent call last):
              File "/usr/lib/python2.7/doctest.py", line 1315, in __run
                compileflags, 1) in test.globs
              File "<doctest ZEO.tests.testZEO2.proper_handling_of_errors_in_restart[18]>", line 1, in <module>
                zs1.tpc_finish('1').set_sender(0, conn1)
              File ".../ZEO/StorageServer.py", line 408, in tpc_finish
                self.storage.tpc_finish(self.transaction, self._invalidate)
              File ".../ZODB/FileStorage/FileStorage.py", line 741, in tpc_finish
                f(self._tid)
              File ".../ZEO/StorageServer.py", line 418, in _invalidate
                self.invalidated, self.get_size_info())
              File ".../ZEO/StorageServer.py", line 1110, in invalidate
                p.client.invalidateTransaction(tid, invalidated)
              File ".../ZEO/StorageServer.py", line 1466, in invalidateTransaction
                self.rpc.callAsyncNoSend('invalidateTransaction', tid, args)
            AttributeError: Connection instance has no attribute 'callAsyncNoSend'
      
      - testZEO2.proper_handling_of_errors_in_restart: adjust it since now an
        invalidation message is sent and previously it was completely avoided
        because objects in that test are only created.
      
      ---- 8< ---- (original description)
      
      Starting from 1999 (b3805a2f "just getting started") only modified - not
      just created - objects were included into ZEO invalidation messages:
      
      https://github.com/zopefoundation/ZEO/commit/b3805a2f#diff-52fb76aaf08a1643cdb8fdaf69e37802R126-R127
      
      In 2000 this behaviour was further changed to not send invalidation
      message at all if the only objects a transaction has were the created ones:
      
      https://github.com/zopefoundation/ZEO/commit/230ffbe8#diff-52fb76aaf08a1643cdb8fdaf69e37802L163-R163
      
      In 2016 the latter was reconsidered as bug and fixed in ZEO5 because
      ZODB5 relies more heavily on MVCC semantic and needs to be notified
      about every transaction committed to storage to be able to properly
      update ZODB.Connection view:
      
      https://github.com/zopefoundation/ZEO/commit/02943acd#diff-52fb76aaf08a1643cdb8fdaf69e37802L889-R834
      https://github.com/zopefoundation/ZEO/commit/9613f09b
      
      In 2020, with this patch, I'm proposing to reconsider initial "send only
      modified, not created objects" as bug, and include both modified and
      just created objects into invalidation messages at least for the
      following reasons:
      
      - a ZODB client (not necessarily native ZODB/py client) can maintain
        raw cache for the storage. If such client tries to load an oid at
        database view when that object did not existed yet, gets "no object"
        reply and stores that information into raw cache, to properly invalidate
        the cache it needs an invalidation message from ZODB server that
        _includes_ created object.
      
      - tools like `zodb watch` [1,2,3] don't work properly (give incorrect output)
        if not all objects modified/created by a transaction are included into
        invalidation messages.
      
      - similarly to `zodb watch`, a monitoring tool, that would want to be
        notified of all created/modified objects, won't see full
        database-change picture, and so won't work properly without knowing
        which objects were created.
      
      - wendelin.core 2 - which builds data from ZODB BTrees and data objects
        into virtual filesystem - needs to get invalidation messages with both
        modified and created objects to properly implement its own lazy
        invalidation and isolation protocol for file blocks in OS cache: when
        a block of file is accessed, all clients, that have this block mmaped,
        need to be notified and asked to remmap that block into particular
        revision of the file depending on a client's view of the filesystem and
        database [4,5].
      
        To compute to where a client needs to remmap the block, WCFS server
        (that in turn acts as ZODB client wrt ZEO/NEO server), needs to be able
        to see whether client's view of the filesystem is before object creation
        (and then ask that client to pin that block to hole), or after creation
        (and then ask the client to pin that block to corresponding revision).
      
        This computation needs ZODB server to send invalidation messages in
        full: with both modified and just created objects.
      
      The patch is simple - it removes `if serial != b"\0\0\0\0\0\0\0\0"`
      before queuing oid into ZEOStorage.invalidated, and adjusts the tests
      correspondingly. From my point of view and experience, in practice, this
      patch should not cause any compatibility break nor performance regressions.
      
      Thanks beforehand,
      Kirill
      
      /cc @jimfulton
      
      [1] https://lab.nexedi.com/kirr/neo/blob/ea53a795/go/zodb/zodbtools/watch.go
      [2] kirr/neo@e0d59f5d
      [3] kirr/neo@c41c2907
      
      [4] https://lab.nexedi.com/kirr/wendelin.core/blob/1efb5876/wcfs/wcfs.go#L94-182
      [5] https://lab.nexedi.com/kirr/wendelin.core/blob/1efb5876/wcfs/client/wcfs.h#L20-71
      f2fae122
    • Julien Muchembled's avatar
      [ZEO4] Enable TCP_NODELAY for inet(6) sockets · 5114f909
      Julien Muchembled authored
      See commit 3d886d42.
      
      ----
      
      Originally included in slapos: slapos@5cf4cf1f
      5114f909
    • Kirill Smelkov's avatar
      [ZEO4] Start of 4-nxd branch · eb1cd547
      Kirill Smelkov authored
      ZEO4 is considered "dead" by upstream:
      
      	https://github.com/zopefoundation/ZEO/pull/161#pullrequestreview-447245642
      
      Keep on patching ZEO4 in our local fork until ZEO4 is used.
      eb1cd547
  2. 11 Jan, 2017 1 commit
  3. 18 Nov, 2016 1 commit
  4. 05 Aug, 2016 1 commit
    • Jim Fulton's avatar
      Add caching · bc92bdd7
      Jim Fulton authored
      Mainly to have a backup cache for new branches (although this won't
      help that much because of the differences between ZEO4 and ZEO5,
      still...
      
      Also stop testing on mac. I do that enough already. :)
      
      Also, use a simpler leaner install script.
      bc92bdd7
  5. 02 Aug, 2016 2 commits
  6. 19 Jul, 2016 1 commit
  7. 14 Jul, 2016 3 commits
  8. 13 Jul, 2016 1 commit
  9. 12 Jul, 2016 2 commits
  10. 30 Jun, 2016 1 commit
  11. 24 Jun, 2016 3 commits
  12. 16 Jun, 2016 2 commits
  13. 15 Jun, 2016 5 commits
  14. 09 Jun, 2016 4 commits
  15. 08 Jun, 2016 8 commits
  16. 07 Jun, 2016 2 commits
    • Jim Fulton's avatar
      Fixed insideous test failure · ec718f5a
      Jim Fulton authored
      A test was counting on a cache being written to, but it wasn't because
      the storage got an invalidation later than expected (on suitably slow
      machines, like travis and an AWS dev machine of mine).
      ec718f5a
    • Jim Fulton's avatar
      got rid of an unnecessary wait_until · 6d6537c6
      Jim Fulton authored
      that was making a test failure hard to interpret.
      6d6537c6