Fix wrong smallest key of delete range tombstones

Summary:
Since tombstones are not stored in order, we may get a wrong smallest key if we only consider the first added tombstone.
Check https://github.com/facebook/rocksdb/issues/2752 for more details.
Closes https://github.com/facebook/rocksdb/pull/2799

Differential Revision: D5728217

Pulled By: ajkr

fbshipit-source-id: 4a53edb0ca80d2a9fcf10749e52d47d57d6417d3
This commit is contained in:
Huachao Huang 2017-08-29 18:27:21 -07:00 committed by Facebook Github Bot
parent b767972313
commit 0980dc6c9a
2 changed files with 36 additions and 2 deletions

View File

@ -962,6 +962,40 @@ TEST_F(DBRangeDelTest, CompactionTreatsSplitInputLevelDeletionAtomically) {
}
}
TEST_F(DBRangeDelTest, UnorderedTombstones) {
// Regression test for #2752. Range delete tombstones between
// different snapshot stripes are not stored in order, so the first
// tombstone of each snapshot stripe should be checked as a smallest
// candidate.
Options options = CurrentOptions();
DestroyAndReopen(options);
auto cf = db_->DefaultColumnFamily();
ASSERT_OK(db_->Put(WriteOptions(), cf, "a", "a"));
ASSERT_OK(db_->Flush(FlushOptions(), cf));
ASSERT_EQ(1, NumTableFilesAtLevel(0));
ASSERT_OK(dbfull()->TEST_CompactRange(0, nullptr, nullptr));
ASSERT_EQ(1, NumTableFilesAtLevel(1));
ASSERT_OK(db_->DeleteRange(WriteOptions(), cf, "b", "c"));
// Hold a snapshot to separate these two delete ranges.
auto snapshot = db_->GetSnapshot();
ASSERT_OK(db_->DeleteRange(WriteOptions(), cf, "a", "b"));
ASSERT_OK(db_->Flush(FlushOptions(), cf));
db_->ReleaseSnapshot(snapshot);
std::vector<std::vector<FileMetaData>> files;
dbfull()->TEST_GetFilesMetaData(cf, &files);
ASSERT_EQ(1, files[0].size());
ASSERT_EQ("a", files[0][0].smallest.user_key());
ASSERT_EQ("c", files[0][0].largest.user_key());
std::string v;
auto s = db_->Get(ReadOptions(), "a", &v);
ASSERT_TRUE(s.IsNotFound());
}
#endif // ROCKSDB_LITE
} // namespace rocksdb

View File

@ -413,8 +413,8 @@ void RangeDelAggregator::AddToBuilder(
// Note the order in which tombstones are stored is insignificant since we
// insert them into a std::map on the read path.
bool first_added = false;
while (stripe_map_iter != rep_->stripe_map_.end()) {
bool first_added = false;
for (auto tombstone_map_iter = stripe_map_iter->second.raw_map.begin();
tombstone_map_iter != stripe_map_iter->second.raw_map.end();
++tombstone_map_iter) {
@ -453,7 +453,7 @@ void RangeDelAggregator::AddToBuilder(
builder->Add(ikey_and_end_key.first.Encode(), ikey_and_end_key.second);
if (!first_added) {
first_added = true;
InternalKey smallest_candidate = std::move(ikey_and_end_key.first);;
InternalKey smallest_candidate = std::move(ikey_and_end_key.first);
if (lower_bound != nullptr &&
icmp_.user_comparator()->Compare(smallest_candidate.user_key(),
*lower_bound) <= 0) {