Prevent intraL0 when L0L1 is ready but is blocked by intraL0

db/compaction/compaction_picker_level.cc

@@ -95,6 +95,8 @@ class LevelCompactionBuilder {
   // Return true if a L0 trivial move is picked up.
   bool TryPickL0TrivialMove();
 
+  bool IsL0L1ready();
+
   // For L0->L0, picks the longest span of files that aren't currently
   // undergoing compaction for which work-per-deleted-file decreases. The span
   // always starts from the newest L0 file.
@@ -212,6 +214,11 @@ void LevelCompactionBuilder::SetupInitialFiles() {
         start_level_inputs_.clear();
         if (start_level_ == 0) {
           skipped_l0_to_base = true;
+          // Dont start an IntraL0Compaction if L0L1 compaction will be blocked
+          // by it.
+          if (IsL0L1ready()) {
+            continue;
+          }
           // L0->base_level may be blocked due to ongoing L0->base_level
           // compactions. It may also be blocked by an ongoing compaction from
           // base_level downwards.
@@ -857,6 +864,35 @@ bool LevelCompactionBuilder::PickFileToCompact() {
   return start_level_inputs_.size() > 0;
 }
 
+bool LevelCompactionBuilder::IsL0L1ready() {
+  // L0L1 compaction is not ready to go when its score is lower than L1,
+  // or its already running.
+  int l0_score = 0;
+  int l1_score = 0;
+
+  for (int i = 0; i < compaction_picker_->NumberLevels() - 1; i++) {
+    int level = vstorage_->CompactionScoreLevel(i);
+    if (level == 0) {
+      l0_score = vstorage_->CompactionScore(i);
+    } else if (level == 1) {
+      l1_score = vstorage_->CompactionScore(i);
+    }
+  }
+  if (l1_score > l0_score) {
+    return false;
+  }
+
+  auto l0_compactions_in_progress =
+      compaction_picker_->level0_compactions_in_progress();
+  for (Compaction* c : *l0_compactions_in_progress) {
+    if (c->output_level() == vstorage_->base_level()) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 bool LevelCompactionBuilder::PickIntraL0Compaction() {
   start_level_inputs_.clear();
   const std::vector<FileMetaData*>& level_files =