Closes google#320 During compaction it was possible that records from a block b1=(l1,u1) would be pushed down from level i to level i+1. If there is a block b2=(l2,u2) at level i with k1 = user_key(u1) = user_key(l2) then a subsequent search for k1 will yield the record l2 which has a smaller sequence number than u1 because the sort order for records sorts increasing by user key but decreaing by sequence number. This change add a call to a new function AddBoundaryInputs to SetupOtherInputs. AddBoundaryInputs searches for a block b2 matching the criteria above and adds it to the set of files to be compacted. Whenever AddBoundaryInputs is called it is important that the compaction fileset in level i+1 (known as c->inputs_[1] in the code) be recomputed. Each call to AddBoundaryInputs is followed by a call to GetOverlappingInputs. SetupOtherInputs is called on both manual and automated compaction passes. It is called for both level zero and for levels greater than 0. The original change posted in google#339 has been modified to also include changed made by Chris Mumford<cmumford@google.com> in cmumford@4b72cb1 1. Releasing snapshots during test cleanup to avoid memory leak warnings. 2. Refactored test to use testutil.h to be in line with other issue tests and to create the test database in the correct temporary location. 3. Added copyright banner. Otherwise, just minor formatting and limiting character width to 80 characters. Additionally the change was rebased on top of current master and changes previously made to the Makefile were ported to the CMakeLists.txt. Testing Done: A test program (issue320_test) was constructed that performs mutations while snapshots are active. issue320_test fails without this bug fix after 64k writes. It passes with this bug fix. It was run with 200M writes and passed. Unit tests were written for the new function that was added to the code. Make test was run and seen to pass. Signed-off-by: Richard Cole <richcole@amazon.com>

Commits

Commits on Apr 1, 2019

Fix snapshot compaction bug