Uploaded image for project: 'WiredTiger'
  1. WiredTiger
  2. WT-2192

A race in eviction determining whether an internal page is dirty

        Details

        • Type: Bug
        • Status: Resolved
        • Priority: Major - P3
        • Resolution: Fixed
        • Affects Version/s: None
        • Fix Version/s: WT2.7.0
        • Labels:
          None
        • # Replies:
          4
        • Last comment by Customer:
          true

          Description

          There was a test/format failure in Jenkins that triggered the following assertion:

          t, file:wt, eviction-worker: ../src/btree/bt_discard.c, 57: !__wt_page_is_modified(page)

          i.e: That a page is clean when we are attempting to discard it. The particular page is an internal page and all of it's children are marked deleted.

          Failure:
          http://build.wiredtiger.com:8080/job/wiredtiger-test-format-stress/9003/

            Issue Links

            is depended on by

            Improvement - An improvement or enhancement to an existing feature or task. SERVER-21173 WiredTiger changes for 3.2.0-rc2

            • Major - P3 - Major loss of function.
            • Closed

              Activity

              • Comments
              Ascending order - Click to sort in descending order
              Hide
              Permalink
              alexander.gorrod Alexander Gorrod added a comment -

              There was a change to __evict_review recently that switched the order of the is evictable and is modified checks. The change was related to code shuffling triggered by WT-2178.

              There is nothing stopping a child ref being switching from WT_REF_MEM to WT_REF_DISK while eviction is walking the index of child pages. If that happens the parent page will become modified.

              Show
              alexander.gorrod Alexander Gorrod added a comment - There was a change to __evict_review recently that switched the order of the is evictable and is modified checks. The change was related to code shuffling triggered by WT-2178 . There is nothing stopping a child ref being switching from WT_REF_MEM to WT_REF_DISK while eviction is walking the index of child pages. If that happens the parent page will become modified.
              Hide
              Permalink
              xgen-internal-githook Githook User added a comment -

              Author:

              {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexg@wiredtiger.com'}

              Message: WT-2192 Fix the logic around checking whether internal page is evictable.

              There is a race between checking whether all children are in state
              WT_REF_DISK and whether the internal page is modified.
              Branch: develop
              https://github.com/wiredtiger/wiredtiger/commit/72efdadb71084ba15887e5950e81998277435392

              Show
              xgen-internal-githook Githook User added a comment - Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexg@wiredtiger.com'} Message: WT-2192 Fix the logic around checking whether internal page is evictable. There is a race between checking whether all children are in state WT_REF_DISK and whether the internal page is modified. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/72efdadb71084ba15887e5950e81998277435392
              Hide
              Permalink
              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 #2281 from wiredtiger/evict-clean-internal

              WT-2192 Fix the logic around checking whether internal page is evictable.
              Branch: develop
              https://github.com/wiredtiger/wiredtiger/commit/4ba56985d6cb290e1981018fd04b017f5dcdad90

              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 #2281 from wiredtiger/evict-clean-internal WT-2192 Fix the logic around checking whether internal page is evictable. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/4ba56985d6cb290e1981018fd04b017f5dcdad90
              Hide
              Permalink
              xgen-internal-githook Githook User added a comment -

              Author:

              {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexg@wiredtiger.com'}

              Message: WT-2192 Update a comment to describe a race condition better.
              Branch: develop
              https://github.com/wiredtiger/wiredtiger/commit/a3019fcc09f00dd104efb675dd3df4bc564e08bb

              Show
              xgen-internal-githook Githook User added a comment - Author: {u'username': u'agorrod', u'name': u'Alex Gorrod', u'email': u'alexg@wiredtiger.com'} Message: WT-2192 Update a comment to describe a race condition better. Branch: develop https://github.com/wiredtiger/wiredtiger/commit/a3019fcc09f00dd104efb675dd3df4bc564e08bb

                People

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

                  Dates

                  • Created:
                    Updated:
                    Resolved:
                    Days since reply:
                    1 year, 33 weeks, 5 days ago
                    Date of 1st Reply: