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  1. WiredTiger
  2. WT-1967

Support long-running snapshot readers

    Details

    • Type: New Feature
    • Status: Resolved
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: WT2.7.0
    • Labels:
      None

      Description

      WiredTiger currently provides named snapshots, which allow applications to assign a name to a point in transaction time and perform reads as-of that time.

      The current implementation keeps all updates more recent than the oldest named snapshot pinned in cache, so it can easily cause the cache to become full of dirty pages that cannot be evicted. Find a solution so that ordinary reads and writes are not blocked by long-running readers.

        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: Merge pull request #2072 from wiredtiger/wt-1967-evict-any

          WT-1967: evict pages where updates are still required by older readers.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/6a5a4616654e09427a15d5d6db530ac5e06b1ebf

          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: Merge pull request #2072 from wiredtiger/wt-1967-evict-any WT-1967 : evict pages where updates are still required by older readers. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/6a5a4616654e09427a15d5d6db530ac5e06b1ebf
          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-1967 fix an "uninitialized variable" warning.
          ../src/reconcile/rec_write.c: In function '__rec_split_write':
          ../src/reconcile/rec_write.c:3252: warning: 'upd' may be used uninitialized in this function

          Make it really obvious to dumb compilers that we're not going to continue after an illegal value.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/24ffc14c026a6b9b8d509696beabdab7baf08cd2

          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-1967 fix an "uninitialized variable" warning. ../src/reconcile/rec_write.c: In function '__rec_split_write': ../src/reconcile/rec_write.c:3252: warning: 'upd' may be used uninitialized in this function Make it really obvious to dumb compilers that we're not going to continue after an illegal value. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/24ffc14c026a6b9b8d509696beabdab7baf08cd2
          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 #2161 from wiredtiger/WT-1967-warning

          WT-1967 fix an "uninitialized variable" warning.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/1e35c7d9d28479a228cb7b40c4454ac61d2a84de

          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 #2161 from wiredtiger/ WT-1967 -warning WT-1967 fix an "uninitialized variable" warning. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/1e35c7d9d28479a228cb7b40c4454ac61d2a84de
          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 #2161 from wiredtiger/WT-1967-warning

          WT-1967 fix an "uninitialized variable" warning.
          Branch: develop
          https://github.com/wiredtiger/wiredtiger/commit/1e35c7d9d28479a228cb7b40c4454ac61d2a84de

          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 #2161 from wiredtiger/ WT-1967 -warning WT-1967 fix an "uninitialized variable" warning. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/1e35c7d9d28479a228cb7b40c4454ac61d2a84de
          Hide
          michael.cahill Michael Cahill added a comment -

          All the changes are merged, I believe we're done. If we see any further issues with this feature, we should open new tickets.

          Show
          michael.cahill Michael Cahill added a comment - All the changes are merged, I believe we're done. If we see any further issues with this feature, we should open new tickets.

            People

            • Assignee:
              keith.bostic Keith Bostic
              Reporter:
              michael.cahill Michael Cahill
            • Votes:
              0 Vote for this issue
              Watchers:
              5 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: