Uploaded image for project: 'WiredTiger'
  1. WiredTiger
  2. WT-2243

Don't keep transaction IDs pinned for reading from checkpoints

    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: WT2.7.0
    • Labels:
      None
    • # Replies:
      5
    • Last comment by Customer:
      true

      Description

      We currently treat all btree cursors the same, and make sure that a transactional context is setup for reads before the cursor is positioned. However, for cursors on checkpoints, this is unnecessary because checkpoints are read-only and thus don't need to distinguish between multiple versions of updates.

      There are several workloads that should be improved by not allocating snapshots when reading from checkpoints, including test/checkpoint and LSM Bloom / merge operations.

        Issue Links

          Activity

          Hide
          xgen-internal-githook Githook User added a comment -

          Author:

          {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'}

          Message: WT-2243 Don't keep transaction IDs pinned for reading from checkpoints.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/3f306ce74f9dc72c1abc372ec0cc2bedfe96c317

          Show
          xgen-internal-githook Githook User added a comment - Author: {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'} Message: WT-2243 Don't keep transaction IDs pinned for reading from checkpoints. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/3f306ce74f9dc72c1abc372ec0cc2bedfe96c317
          Hide
          xgen-internal-githook Githook User added a comment -

          Author:

          {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'}

          Message: WT-2243 Only clear btree cursor flags associated with position.

          Previously, we were clearing the new "no transaction" flag every time a cursor was repositioned.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/8fe7bb1eceae210d0a9a9166ccfeb835a022a7f0

          Show
          xgen-internal-githook Githook User added a comment - Author: {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'} Message: WT-2243 Only clear btree cursor flags associated with position. Previously, we were clearing the new "no transaction" flag every time a cursor was repositioned. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/8fe7bb1eceae210d0a9a9166ccfeb835a022a7f0
          Hide
          xgen-internal-githook Githook User added a comment -

          Author:

          {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'}

          Message: Merge pull request #2339 from wiredtiger/WT-2243

          WT-2243 Don't keep transaction IDs pinned for reading from checkpoints.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/39dfd21030ac08e425213f9bc382877dff9458da

          Show
          xgen-internal-githook Githook User added a comment - Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'} Message: Merge pull request #2339 from wiredtiger/ WT-2243 WT-2243 Don't keep transaction IDs pinned for reading from checkpoints. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/39dfd21030ac08e425213f9bc382877dff9458da
          Hide
          xgen-internal-githook Githook User added a comment -

          Author:

          {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'}

          Message: Merge pull request #2339 from wiredtiger/WT-2243

          WT-2243 Don't keep transaction IDs pinned for reading from checkpoints.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/39dfd21030ac08e425213f9bc382877dff9458da

          Show
          xgen-internal-githook Githook User added a comment - Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexander.gorrod@mongodb.com'} Message: Merge pull request #2339 from wiredtiger/ WT-2243 WT-2243 Don't keep transaction IDs pinned for reading from checkpoints. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/39dfd21030ac08e425213f9bc382877dff9458da
          Hide
          xgen-internal-githook Githook User added a comment -

          Author:

          {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'}

          Message: Import wiredtiger-wiredtiger-mongodb-3.2-rc4-41-g8326df6.tar.gz from wiredtiger branch mongodb-3.2

          ref: b65381f..8326df6

          4c49948 WT-2244 Trigger in-memory splits sooner.
          9f2e4f3 WT-2248 WT_SESSION.close is updating WT_CONNECTION_IMPL.default_session.
          a6da10e SERVER-21553 Enable fast-path truncate after splits.
          39dfd21 WT-2243 Don't keep transaction IDs pinned for reading from checkpoints.
          4e1844c WT-2230 multi-split error path.
          cace179 WT-2228 avoid unnecessary raw-compression calls.
          890ee34 SERVER-21619 Don't do internal page splits after a tree is marked DEAD.
          6c7338f WT-2241 Use a lock to protect transaction ID allocation.
          978c237 WT-2234 Coverity analysis warnings.
          Branch: master
          https://github.com/mongodb/mongo/commit/e7181b542b25981db42f74cdaee4e7fc323d3e9d

          Show
          xgen-internal-githook Githook User added a comment - Author: {u'username': u'michaelcahill', u'name': u'Michael Cahill', u'email': u'michael.cahill@mongodb.com'} Message: Import wiredtiger-wiredtiger-mongodb-3.2-rc4-41-g8326df6.tar.gz from wiredtiger branch mongodb-3.2 ref: b65381f..8326df6 4c49948 WT-2244 Trigger in-memory splits sooner. 9f2e4f3 WT-2248 WT_SESSION.close is updating WT_CONNECTION_IMPL.default_session. a6da10e SERVER-21553 Enable fast-path truncate after splits. 39dfd21 WT-2243 Don't keep transaction IDs pinned for reading from checkpoints. 4e1844c WT-2230 multi-split error path. cace179 WT-2228 avoid unnecessary raw-compression calls. 890ee34 SERVER-21619 Don't do internal page splits after a tree is marked DEAD. 6c7338f WT-2241 Use a lock to protect transaction ID allocation. 978c237 WT-2234 Coverity analysis warnings. Branch: master https://github.com/mongodb/mongo/commit/e7181b542b25981db42f74cdaee4e7fc323d3e9d

            People

            • Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:
                Days since reply:
                1 year, 21 weeks, 6 days ago
                Date of 1st Reply: