PSMDB-191 take into account dropped prefixes when calculating _maxPre…

…fix (#134)
mongodb-partners · Feb 16, 2018 · 72d1ce2 · 72d1ce2
1 parent 997db32
commit 72d1ce2
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Showing 3 changed files with 6 additions and 4 deletions.
diff --git a/src/rocks_compaction_scheduler.cpp b/src/rocks_compaction_scheduler.cpp
@@ -347,11 +347,12 @@ namespace mongo {
         return _droppedPrefixes;
     }
 
-    void RocksCompactionScheduler::loadDroppedPrefixes(rocksdb::Iterator* iter) {
+    uint32_t RocksCompactionScheduler::loadDroppedPrefixes(rocksdb::Iterator* iter) {
         invariant(iter);
         const uint32_t rocksdbSkippedDeletionsInitial =
             (uint32_t)get_internal_delete_skipped_count();
         int dropped_count = 0;
+        uint32_t int_prefix = 0;
         for (iter->Seek(kDroppedPrefix); iter->Valid() && iter->key().starts_with(kDroppedPrefix);
              iter->Next()) {
             invariantRocksOK(iter->status());
@@ -360,7 +361,6 @@ namespace mongo {
 
             // let's instruct the compaction scheduler to compact dropped prefix
             ++dropped_count;
-            uint32_t int_prefix;
             bool ok = extractPrefix(prefix, &int_prefix);
             invariant(ok);
             {
@@ -375,6 +375,7 @@ namespace mongo {
         const uint32_t skippedDroppedPrefixMarkers =
             (uint32_t)get_internal_delete_skipped_count() - rocksdbSkippedDeletionsInitial;
         _droppedPrefixesCount.fetch_add(skippedDroppedPrefixMarkers, std::memory_order_relaxed);
+        return int_prefix;
     }
 
     Status RocksCompactionScheduler::dropPrefixesAtomic(

diff --git a/src/rocks_compaction_scheduler.h b/src/rocks_compaction_scheduler.h
@@ -68,7 +68,7 @@ namespace mongo {
 
         rocksdb::CompactionFilterFactory* createCompactionFilterFactory() const;
         std::unordered_set<uint32_t> getDroppedPrefixes() const;
-        void loadDroppedPrefixes(rocksdb::Iterator* iter);
+        uint32_t loadDroppedPrefixes(rocksdb::Iterator* iter);
         Status dropPrefixesAtomic(const std::vector<std::string>& prefixesToDrop,
                                   const rocksdb::WriteOptions& syncOptions,
                                   rocksdb::WriteBatch& wb);

diff --git a/src/rocks_engine.cpp b/src/rocks_engine.cpp
@@ -255,7 +255,8 @@ namespace mongo {
 
         // start compaction thread and load dropped prefixes
         _compactionScheduler->start(_db.get());
-        _compactionScheduler->loadDroppedPrefixes(iter.get());
+        auto maxDroppedPrefix = _compactionScheduler->loadDroppedPrefixes(iter.get());
+        _maxPrefix = std::max(_maxPrefix, maxDroppedPrefix);
 
         _durabilityManager.reset(new RocksDurabilityManager(_db.get(), _durable));