Collect compaction stats by priority and dump to info LOG (#5050)

Summary:
In order to better understand compaction done by different priority thread pool, we now collect compaction stats by priority and also print them to info LOG through stats dump.

```
** Compaction Stats [default] **
Priority    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Low      0/0    0.00 KB   0.0     16.8    11.3      5.5       5.6      0.1       0.0   0.0    406.4    136.1     42.24             34.96        45    0.939     13M  8865K
High      0/0    0.00 KB   0.0      0.0     0.0      0.0      11.4     11.4       0.0   0.0      0.0     76.2    153.00             35.74     12185    0.013       0      0
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5050

Differential Revision: D14408583

Pulled By: miasantreble

fbshipit-source-id: e53746586ea27cb8abc9fec35805bd80ed30f608

db/compaction_job.cc

@@ -312,7 +312,8 @@ CompactionJob::CompactionJob(
     SequenceNumber earliest_write_conflict_snapshot,
     const SnapshotChecker* snapshot_checker, std::shared_ptr<Cache> table_cache,
     EventLogger* event_logger, bool paranoid_file_checks, bool measure_io_stats,
-    const std::string& dbname, CompactionJobStats* compaction_job_stats)
+    const std::string& dbname, CompactionJobStats* compaction_job_stats,
+    Env::Priority thread_pri)
     : job_id_(job_id),
       compact_(new CompactionState(compaction)),
       compaction_job_stats_(compaction_job_stats),
@@ -340,7 +341,8 @@ CompactionJob::CompactionJob(
       bottommost_level_(false),
       paranoid_file_checks_(paranoid_file_checks),
       measure_io_stats_(measure_io_stats),
-      write_hint_(Env::WLTH_NOT_SET) {
+      write_hint_(Env::WLTH_NOT_SET),
+      thread_pri_(thread_pri) {
   assert(log_buffer_ != nullptr);
   const auto* cfd = compact_->compaction->column_family_data();
   ThreadStatusUtil::SetColumnFamily(cfd, cfd->ioptions()->env,
@@ -717,7 +719,7 @@ Status CompactionJob::Install(const MutableCFOptions& mutable_cf_options) {
   Status status = compact_->status;
   ColumnFamilyData* cfd = compact_->compaction->column_family_data();
   cfd->internal_stats()->AddCompactionStats(
-      compact_->compaction->output_level(), compaction_stats_);
+      compact_->compaction->output_level(), thread_pri_, compaction_stats_);
 
   if (status.ok()) {
     status = InstallCompactionResults(mutable_cf_options);

db/compaction_job.h

@@ -62,17 +62,17 @@ class CompactionJob {
                 const EnvOptions env_options, VersionSet* versions,
                 const std::atomic<bool>* shutting_down,
                 const SequenceNumber preserve_deletes_seqnum,
-                LogBuffer* log_buffer,
-                Directory* db_directory, Directory* output_directory,
-                Statistics* stats, InstrumentedMutex* db_mutex,
-                ErrorHandler* db_error_handler,
+                LogBuffer* log_buffer, Directory* db_directory,
+                Directory* output_directory, Statistics* stats,
+                InstrumentedMutex* db_mutex, ErrorHandler* db_error_handler,
                 std::vector<SequenceNumber> existing_snapshots,
                 SequenceNumber earliest_write_conflict_snapshot,
                 const SnapshotChecker* snapshot_checker,
                 std::shared_ptr<Cache> table_cache, EventLogger* event_logger,
                 bool paranoid_file_checks, bool measure_io_stats,
                 const std::string& dbname,
-                CompactionJobStats* compaction_job_stats);
+                CompactionJobStats* compaction_job_stats,
+                Env::Priority thread_pri);
 
   ~CompactionJob();
 
@@ -172,6 +172,7 @@ class CompactionJob {
   // Stores the approx size of keys covered in the range of each subcompaction
   std::vector<uint64_t> sizes_;
   Env::WriteLifeTimeHint write_hint_;
+  Env::Priority thread_pri_;
 };
 
 }  // namespace rocksdb

db/compaction_job_test.cc

@@ -262,7 +262,8 @@ class CompactionJobTest : public testing::Test {
         &shutting_down_, preserve_deletes_seqnum_, &log_buffer, nullptr,
         nullptr, nullptr, &mutex_, &error_handler_, snapshots,
         earliest_write_conflict_snapshot, snapshot_checker, table_cache_,
-        &event_logger, false, false, dbname_, &compaction_job_stats_);
+        &event_logger, false, false, dbname_, &compaction_job_stats_,
+        Env::Priority::USER);
     VerifyInitializationOfCompactionJobStats(compaction_job_stats_);
 
     compaction_job.Prepare();

db/db_impl.h

@@ -948,7 +948,8 @@ class DBImpl : public DB {
       SuperVersionContext* superversion_context,
       std::vector<SequenceNumber>& snapshot_seqs,
       SequenceNumber earliest_write_conflict_snapshot,
-      SnapshotChecker* snapshot_checker, LogBuffer* log_buffer);
+      SnapshotChecker* snapshot_checker, LogBuffer* log_buffer,
+      Env::Priority thread_pri);
 
   // Argument required by background flush thread.
   struct BGFlushArg {
@@ -971,15 +972,22 @@ class DBImpl : public DB {
     SuperVersionContext* superversion_context_;
   };
 
+  // Argument passed to flush thread.
+  struct FlushThreadArg {
+    DBImpl* db_;
+
+    Env::Priority thread_pri_;
+  };
+
   // Flush the memtables of (multiple) column families to multiple files on
   // persistent storage.
   Status FlushMemTablesToOutputFiles(
       const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
-      JobContext* job_context, LogBuffer* log_buffer);
+      JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri);
 
   Status AtomicFlushMemTablesToOutputFiles(
       const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
-      JobContext* job_context, LogBuffer* log_buffer);
+      JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri);
 
   // REQUIRES: log_numbers are sorted in ascending order
   Status RecoverLogFiles(const std::vector<uint64_t>& log_numbers,
@@ -1122,18 +1130,21 @@ class DBImpl : public DB {
   // Runs a pre-chosen universal compaction involving bottom level in a
   // separate, bottom-pri thread pool.
   static void BGWorkBottomCompaction(void* arg);
-  static void BGWorkFlush(void* db);
+  static void BGWorkFlush(void* arg);
   static void BGWorkPurge(void* arg);
-  static void UnscheduleCallback(void* arg);
+  static void UnscheduleCompactionCallback(void* arg);
+  static void UnscheduleFlushCallback(void* arg);
   void BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
-                                Env::Priority bg_thread_pri);
-  void BackgroundCallFlush();
+                                Env::Priority thread_pri);
+  void BackgroundCallFlush(Env::Priority thread_pri);
   void BackgroundCallPurge();
   Status BackgroundCompaction(bool* madeProgress, JobContext* job_context,
                               LogBuffer* log_buffer,
-                              PrepickedCompaction* prepicked_compaction);
+                              PrepickedCompaction* prepicked_compaction,
+                              Env::Priority thread_pri);
   Status BackgroundFlush(bool* madeProgress, JobContext* job_context,
-                         LogBuffer* log_buffer, FlushReason* reason);
+                         LogBuffer* log_buffer, FlushReason* reason,
+                         Env::Priority thread_pri);
 
   bool EnoughRoomForCompaction(ColumnFamilyData* cfd,
                                const std::vector<CompactionInputFiles>& inputs,

db/db_impl_compaction_flush.cc

@@ -135,7 +135,8 @@ Status DBImpl::FlushMemTableToOutputFile(
     SuperVersionContext* superversion_context,
     std::vector<SequenceNumber>& snapshot_seqs,
     SequenceNumber earliest_write_conflict_snapshot,
-    SnapshotChecker* snapshot_checker, LogBuffer* log_buffer) {
+    SnapshotChecker* snapshot_checker, LogBuffer* log_buffer,
+    Env::Priority thread_pri) {
   mutex_.AssertHeld();
   assert(cfd->imm()->NumNotFlushed() != 0);
   assert(cfd->imm()->IsFlushPending());
@@ -149,7 +150,8 @@ Status DBImpl::FlushMemTableToOutputFile(
       GetDataDir(cfd, 0U),
       GetCompressionFlush(*cfd->ioptions(), mutable_cf_options), stats_,
       &event_logger_, mutable_cf_options.report_bg_io_stats,
-      true /* sync_output_directory */, true /* write_manifest */);
+      true /* sync_output_directory */, true /* write_manifest */,
+      thread_pri);
 
   FileMetaData file_meta;
 
@@ -232,10 +234,11 @@ Status DBImpl::FlushMemTableToOutputFile(
 
 Status DBImpl::FlushMemTablesToOutputFiles(
     const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
-    JobContext* job_context, LogBuffer* log_buffer) {
+    JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri) {
   if (immutable_db_options_.atomic_flush) {
     return AtomicFlushMemTablesToOutputFiles(bg_flush_args, made_progress,
-                                             job_context, log_buffer);
+                                             job_context, log_buffer,
+                                             thread_pri);
   }
   std::vector<SequenceNumber> snapshot_seqs;
   SequenceNumber earliest_write_conflict_snapshot;
@@ -250,7 +253,7 @@ Status DBImpl::FlushMemTablesToOutputFiles(
     Status s = FlushMemTableToOutputFile(
         cfd, mutable_cf_options, made_progress, job_context,
         superversion_context, snapshot_seqs, earliest_write_conflict_snapshot,
-        snapshot_checker, log_buffer);
+        snapshot_checker, log_buffer, thread_pri);
     if (!s.ok()) {
       status = s;
       if (!s.IsShutdownInProgress()) {
@@ -274,7 +277,7 @@ Status DBImpl::FlushMemTablesToOutputFiles(
  */
 Status DBImpl::AtomicFlushMemTablesToOutputFiles(
     const autovector<BGFlushArg>& bg_flush_args, bool* made_progress,
-    JobContext* job_context, LogBuffer* log_buffer) {
+    JobContext* job_context, LogBuffer* log_buffer, Env::Priority thread_pri) {
   mutex_.AssertHeld();
 
   autovector<ColumnFamilyData*> cfds;
@@ -331,7 +334,8 @@ Status DBImpl::AtomicFlushMemTablesToOutputFiles(
         snapshot_checker, job_context, log_buffer, directories_.GetDbDir(),
         data_dir, GetCompressionFlush(*cfd->ioptions(), mutable_cf_options),
         stats_, &event_logger_, mutable_cf_options.report_bg_io_stats,
-        false /* sync_output_directory */, false /* write_manifest */);
+        false /* sync_output_directory */, false /* write_manifest */,
+        thread_pri);
     jobs.back().PickMemTable();
   }
 
@@ -957,7 +961,7 @@ Status DBImpl::CompactFilesImpl(
       snapshot_checker, table_cache_, &event_logger_,
       c->mutable_cf_options()->paranoid_file_checks,
       c->mutable_cf_options()->report_bg_io_stats, dbname_,
-      &compaction_job_stats);
+      &compaction_job_stats, Env::Priority::USER);
 
   // Creating a compaction influences the compaction score because the score
   // takes running compactions into account (by skipping files that are already
@@ -1445,7 +1449,7 @@ Status DBImpl::RunManualCompaction(ColumnFamilyData* cfd, int input_level,
       manual.incomplete = false;
       bg_compaction_scheduled_++;
       env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
-                     &DBImpl::UnscheduleCallback);
+                     &DBImpl::UnscheduleCompactionCallback);
       scheduled = true;
     }
   }
@@ -1785,7 +1789,11 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
   while (!is_flush_pool_empty && unscheduled_flushes_ > 0 &&
          bg_flush_scheduled_ < bg_job_limits.max_flushes) {
     bg_flush_scheduled_++;
-    env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::HIGH, this);
+    FlushThreadArg* fta = new FlushThreadArg;
+    fta->db_ = this;
+    fta->thread_pri_ = Env::Priority::HIGH;
+    env_->Schedule(&DBImpl::BGWorkFlush, fta, Env::Priority::HIGH, this,
+                   &DBImpl::UnscheduleFlushCallback);
   }
 
   // special case -- if high-pri (flush) thread pool is empty, then schedule
@@ -1795,7 +1803,11 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
            bg_flush_scheduled_ + bg_compaction_scheduled_ <
                bg_job_limits.max_flushes) {
       bg_flush_scheduled_++;
-      env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::LOW, this);
+      FlushThreadArg* fta = new FlushThreadArg;
+      fta->db_ = this;
+      fta->thread_pri_ = Env::Priority::LOW;
+      env_->Schedule(&DBImpl::BGWorkFlush, fta, Env::Priority::LOW, this,
+                     &DBImpl::UnscheduleFlushCallback);
     }
   }
 
@@ -1825,7 +1837,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
     bg_compaction_scheduled_++;
     unscheduled_compactions_--;
     env_->Schedule(&DBImpl::BGWorkCompaction, ca, Env::Priority::LOW, this,
-                   &DBImpl::UnscheduleCallback);
+                   &DBImpl::UnscheduleCompactionCallback);
   }
 }
 
@@ -1940,10 +1952,13 @@ void DBImpl::SchedulePendingPurge(std::string fname, std::string dir_to_sync,
   purge_queue_.push_back(std::move(file_info));
 }
 
-void DBImpl::BGWorkFlush(void* db) {
-  IOSTATS_SET_THREAD_POOL_ID(Env::Priority::HIGH);
+void DBImpl::BGWorkFlush(void* arg) {
+  FlushThreadArg fta = *(reinterpret_cast<FlushThreadArg*>(arg));
+  delete reinterpret_cast<FlushThreadArg*>(arg);
+
+  IOSTATS_SET_THREAD_POOL_ID(fta.thread_pri_);
   TEST_SYNC_POINT("DBImpl::BGWorkFlush");
-  reinterpret_cast<DBImpl*>(db)->BackgroundCallFlush();
+  reinterpret_cast<DBImpl*>(fta.db_)->BackgroundCallFlush(fta.thread_pri_);
   TEST_SYNC_POINT("DBImpl::BGWorkFlush:done");
 }
 
@@ -1978,7 +1993,7 @@ void DBImpl::BGWorkPurge(void* db) {
   TEST_SYNC_POINT("DBImpl::BGWorkPurge:end");
 }
 
-void DBImpl::UnscheduleCallback(void* arg) {
+void DBImpl::UnscheduleCompactionCallback(void* arg) {
   CompactionArg ca = *(reinterpret_cast<CompactionArg*>(arg));
   delete reinterpret_cast<CompactionArg*>(arg);
   if (ca.prepicked_compaction != nullptr) {
@@ -1987,11 +2002,17 @@ void DBImpl::UnscheduleCallback(void* arg) {
     }
     delete ca.prepicked_compaction;
   }
-  TEST_SYNC_POINT("DBImpl::UnscheduleCallback");
+  TEST_SYNC_POINT("DBImpl::UnscheduleCompactionCallback");
+}
+
+void DBImpl::UnscheduleFlushCallback(void* arg) {
+  delete reinterpret_cast<FlushThreadArg*>(arg);
+  TEST_SYNC_POINT("DBImpl::UnscheduleFlushCallback");
 }
 
 Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context,
-                               LogBuffer* log_buffer, FlushReason* reason) {
+                               LogBuffer* log_buffer, FlushReason* reason,
+                               Env::Priority thread_pri) {
   mutex_.AssertHeld();
 
   Status status;
@@ -2052,7 +2073,7 @@ Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context,
           bg_compaction_scheduled_);
     }
     status = FlushMemTablesToOutputFiles(bg_flush_args, made_progress,
-                                         job_context, log_buffer);
+                                         job_context, log_buffer, thread_pri);
     // All the CFDs in the FlushReq must have the same flush reason, so just
     // grab the first one
     *reason = bg_flush_args[0].cfd_->GetFlushReason();
@@ -2067,7 +2088,7 @@ Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context,
   return status;
 }
 
-void DBImpl::BackgroundCallFlush() {
+void DBImpl::BackgroundCallFlush(Env::Priority thread_pri) {
   bool made_progress = false;
   JobContext job_context(next_job_id_.fetch_add(1), true);
 
@@ -2084,8 +2105,8 @@ void DBImpl::BackgroundCallFlush() {
         CaptureCurrentFileNumberInPendingOutputs();
     FlushReason reason;
 
-    Status s =
-        BackgroundFlush(&made_progress, &job_context, &log_buffer, &reason);
+    Status s = BackgroundFlush(&made_progress, &job_context, &log_buffer,
+                               &reason, thread_pri);
     if (!s.ok() && !s.IsShutdownInProgress() &&
         reason != FlushReason::kErrorRecovery) {
       // Wait a little bit before retrying background flush in
@@ -2168,7 +2189,7 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
             bg_bottom_compaction_scheduled_) ||
            (bg_thread_pri == Env::Priority::LOW && bg_compaction_scheduled_));
     Status s = BackgroundCompaction(&made_progress, &job_context, &log_buffer,
-                                    prepicked_compaction);
+                                    prepicked_compaction, bg_thread_pri);
     TEST_SYNC_POINT("BackgroundCallCompaction:1");
     if (s.IsBusy()) {
       bg_cv_.SignalAll();  // In case a waiter can proceed despite the error
@@ -2255,7 +2276,8 @@ void DBImpl::BackgroundCallCompaction(PrepickedCompaction* prepicked_compaction,
 Status DBImpl::BackgroundCompaction(bool* made_progress,
                                     JobContext* job_context,
                                     LogBuffer* log_buffer,
-                                    PrepickedCompaction* prepicked_compaction) {
+                                    PrepickedCompaction* prepicked_compaction,
+                                    Env::Priority thread_pri) {
   ManualCompactionState* manual_compaction =
       prepicked_compaction == nullptr
           ? nullptr
@@ -2568,7 +2590,7 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
     ca->prepicked_compaction->task_token = std::move(task_token);
     ++bg_bottom_compaction_scheduled_;
     env_->Schedule(&DBImpl::BGWorkBottomCompaction, ca, Env::Priority::BOTTOM,
-                   this, &DBImpl::UnscheduleCallback);
+                   this, &DBImpl::UnscheduleCompactionCallback);
   } else {
     TEST_SYNC_POINT_CALLBACK("DBImpl::BackgroundCompaction:BeforeCompaction",
                              c->column_family_data());
@@ -2587,11 +2609,11 @@ Status DBImpl::BackgroundCompaction(bool* made_progress,
         env_options_for_compaction_, versions_.get(), &shutting_down_,
         preserve_deletes_seqnum_.load(), log_buffer, directories_.GetDbDir(),
         GetDataDir(c->column_family_data(), c->output_path_id()), stats_,
-        &mutex_, &error_handler_, snapshot_seqs, earliest_write_conflict_snapshot,
-        snapshot_checker, table_cache_, &event_logger_,
-        c->mutable_cf_options()->paranoid_file_checks,
+        &mutex_, &error_handler_, snapshot_seqs,
+        earliest_write_conflict_snapshot, snapshot_checker, table_cache_,
+        &event_logger_, c->mutable_cf_options()->paranoid_file_checks,
         c->mutable_cf_options()->report_bg_io_stats, dbname_,
-        &compaction_job_stats);
+        &compaction_job_stats, thread_pri);
     compaction_job.Prepare();
 
     NotifyOnCompactionBegin(c->column_family_data(), c.get(), status,

db/db_impl_open.cc

@@ -1059,7 +1059,7 @@ Status DBImpl::WriteLevel0TableForRecovery(int job_id, ColumnFamilyData* cfd,
   stats.micros = env_->NowMicros() - start_micros;
   stats.bytes_written = meta.fd.GetFileSize();
   stats.num_output_files = 1;
-  cfd->internal_stats()->AddCompactionStats(level, stats);
+  cfd->internal_stats()->AddCompactionStats(level, Env::Priority::USER, stats);
   cfd->internal_stats()->AddCFStats(InternalStats::BYTES_FLUSHED,
                                     meta.fd.GetFileSize());
   RecordTick(stats_, COMPACT_WRITE_BYTES, meta.fd.GetFileSize());

db/external_sst_file_ingestion_job.cc

@@ -227,7 +227,8 @@ void ExternalSstFileIngestionJob::UpdateStats() {
       stats.bytes_moved = f.fd.GetFileSize();
     }
     stats.num_output_files = 1;
-    cfd_->internal_stats()->AddCompactionStats(f.picked_level, stats);
+    cfd_->internal_stats()->AddCompactionStats(f.picked_level,
+                                               Env::Priority::USER, stats);
     cfd_->internal_stats()->AddCFStats(InternalStats::BYTES_INGESTED_ADD_FILE,
                                        f.fd.GetFileSize());
     total_keys += f.num_entries;

db/flush_job.cc

@@ -100,7 +100,8 @@ FlushJob::FlushJob(const std::string& dbname, ColumnFamilyData* cfd,
                    Directory* output_file_directory,
                    CompressionType output_compression, Statistics* stats,
                    EventLogger* event_logger, bool measure_io_stats,
-                   const bool sync_output_directory, const bool write_manifest)
+                   const bool sync_output_directory, const bool write_manifest,
+                   Env::Priority thread_pri)
     : dbname_(dbname),
       cfd_(cfd),
       db_options_(db_options),
@@ -125,7 +126,8 @@ FlushJob::FlushJob(const std::string& dbname, ColumnFamilyData* cfd,
       write_manifest_(write_manifest),
       edit_(nullptr),
       base_(nullptr),
-      pick_memtable_called(false) {
+      pick_memtable_called(false),
+      thread_pri_(thread_pri) {
   // Update the thread status to indicate flush.
   ReportStartedFlush();
   TEST_SYNC_POINT("FlushJob::FlushJob()");
@@ -417,7 +419,7 @@ Status FlushJob::WriteLevel0Table() {
   stats.cpu_micros = db_options_.env->NowCPUNanos() / 1000 - start_cpu_micros;
   stats.bytes_written = meta_.fd.GetFileSize();
   RecordTimeToHistogram(stats_, FLUSH_TIME, stats.micros);
-  cfd_->internal_stats()->AddCompactionStats(0 /* level */, stats);
+  cfd_->internal_stats()->AddCompactionStats(0 /* level */, thread_pri_, stats);
   cfd_->internal_stats()->AddCFStats(InternalStats::BYTES_FLUSHED,
                                      meta_.fd.GetFileSize());
   RecordFlushIOStats();

db/flush_job.h

@@ -68,7 +68,8 @@ class FlushJob {
            LogBuffer* log_buffer, Directory* db_directory,
            Directory* output_file_directory, CompressionType output_compression,
            Statistics* stats, EventLogger* event_logger, bool measure_io_stats,
-           const bool sync_output_directory, const bool write_manifest);
+           const bool sync_output_directory, const bool write_manifest,
+           Env::Priority thread_pri);
 
   ~FlushJob();
 
@@ -137,6 +138,7 @@ class FlushJob {
   VersionEdit* edit_;
   Version* base_;
   bool pick_memtable_called;
+  Env::Priority thread_pri_;
 };
 
 }  // namespace rocksdb

db/flush_job_test.cc

@@ -118,13 +118,14 @@ TEST_F(FlushJobTest, Empty) {
   auto cfd = versions_->GetColumnFamilySet()->GetDefault();
   EventLogger event_logger(db_options_.info_log.get());
   SnapshotChecker* snapshot_checker = nullptr;  // not relavant
-  FlushJob flush_job(
-      dbname_, versions_->GetColumnFamilySet()->GetDefault(), db_options_,
-      *cfd->GetLatestMutableCFOptions(), nullptr /* memtable_id */,
-      env_options_, versions_.get(), &mutex_, &shutting_down_, {},
-      kMaxSequenceNumber, snapshot_checker, &job_context, nullptr, nullptr,
-      nullptr, kNoCompression, nullptr, &event_logger, false,
-      true /* sync_output_directory */, true /* write_manifest */);
+  FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
+                     db_options_, *cfd->GetLatestMutableCFOptions(),
+                     nullptr /* memtable_id */, env_options_, versions_.get(),
+                     &mutex_, &shutting_down_, {}, kMaxSequenceNumber,
+                     snapshot_checker, &job_context, nullptr, nullptr, nullptr,
+                     kNoCompression, nullptr, &event_logger, false,
+                     true /* sync_output_directory */,
+                     true /* write_manifest */, Env::Priority::USER);
   {
     InstrumentedMutexLock l(&mutex_);
     flush_job.PickMemTable();
@@ -165,13 +166,14 @@ TEST_F(FlushJobTest, NonEmpty) {
 
   EventLogger event_logger(db_options_.info_log.get());
   SnapshotChecker* snapshot_checker = nullptr;  // not relavant
-  FlushJob flush_job(
-      dbname_, versions_->GetColumnFamilySet()->GetDefault(), db_options_,
-      *cfd->GetLatestMutableCFOptions(), nullptr /* memtable_id */,
-      env_options_, versions_.get(), &mutex_, &shutting_down_, {},
-      kMaxSequenceNumber, snapshot_checker, &job_context, nullptr, nullptr,
-      nullptr, kNoCompression, db_options_.statistics.get(), &event_logger,
-      true, true /* sync_output_directory */, true /* write_manifest */);
+  FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
+                     db_options_, *cfd->GetLatestMutableCFOptions(),
+                     nullptr /* memtable_id */, env_options_, versions_.get(),
+                     &mutex_, &shutting_down_, {}, kMaxSequenceNumber,
+                     snapshot_checker, &job_context, nullptr, nullptr, nullptr,
+                     kNoCompression, db_options_.statistics.get(),
+                     &event_logger, true, true /* sync_output_directory */,
+                     true /* write_manifest */, Env::Priority::USER);
 
   HistogramData hist;
   FileMetaData file_meta;
@@ -228,13 +230,14 @@ TEST_F(FlushJobTest, FlushMemTablesSingleColumnFamily) {
   uint64_t smallest_memtable_id = memtable_ids.front();
   uint64_t flush_memtable_id = smallest_memtable_id + num_mems_to_flush - 1;
 
-  FlushJob flush_job(
-      dbname_, versions_->GetColumnFamilySet()->GetDefault(), db_options_,
-      *cfd->GetLatestMutableCFOptions(), &flush_memtable_id, env_options_,
-      versions_.get(), &mutex_, &shutting_down_, {}, kMaxSequenceNumber,
-      snapshot_checker, &job_context, nullptr, nullptr, nullptr, kNoCompression,
-      db_options_.statistics.get(), &event_logger, true,
-      true /* sync_output_directory */, true /* write_manifest */);
+  FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
+                     db_options_, *cfd->GetLatestMutableCFOptions(),
+                     &flush_memtable_id, env_options_, versions_.get(), &mutex_,
+                     &shutting_down_, {}, kMaxSequenceNumber, snapshot_checker,
+                     &job_context, nullptr, nullptr, nullptr, kNoCompression,
+                     db_options_.statistics.get(), &event_logger, true,
+                     true /* sync_output_directory */,
+                     true /* write_manifest */, Env::Priority::USER);
   HistogramData hist;
   FileMetaData file_meta;
   mutex_.Lock();
@@ -304,7 +307,8 @@ TEST_F(FlushJobTest, FlushMemtablesMultipleColumnFamilies) {
         &shutting_down_, snapshot_seqs, kMaxSequenceNumber, snapshot_checker,
         &job_context, nullptr, nullptr, nullptr, kNoCompression,
         db_options_.statistics.get(), &event_logger, true,
-        false /* sync_output_directory */, false /* write_manifest */);
+        false /* sync_output_directory */, false /* write_manifest */,
+        Env::Priority::USER);
     k++;
   }
   HistogramData hist;
@@ -413,13 +417,14 @@ TEST_F(FlushJobTest, Snapshots) {
 
   EventLogger event_logger(db_options_.info_log.get());
   SnapshotChecker* snapshot_checker = nullptr;  // not relavant
-  FlushJob flush_job(
-      dbname_, versions_->GetColumnFamilySet()->GetDefault(), db_options_,
-      *cfd->GetLatestMutableCFOptions(), nullptr /* memtable_id */,
-      env_options_, versions_.get(), &mutex_, &shutting_down_, snapshots,
-      kMaxSequenceNumber, snapshot_checker, &job_context, nullptr, nullptr,
-      nullptr, kNoCompression, db_options_.statistics.get(), &event_logger,
-      true, true /* sync_output_directory */, true /* write_manifest */);
+  FlushJob flush_job(dbname_, versions_->GetColumnFamilySet()->GetDefault(),
+                     db_options_, *cfd->GetLatestMutableCFOptions(),
+                     nullptr /* memtable_id */, env_options_, versions_.get(),
+                     &mutex_, &shutting_down_, snapshots, kMaxSequenceNumber,
+                     snapshot_checker, &job_context, nullptr, nullptr, nullptr,
+                     kNoCompression, db_options_.statistics.get(),
+                     &event_logger, true, true /* sync_output_directory */,
+                     true /* write_manifest */, Env::Priority::USER);
   mutex_.Lock();
   flush_job.PickMemTable();
   ASSERT_OK(flush_job.Run());

db/internal_stats.cc

@@ -58,7 +58,8 @@ const double kMB = 1048576.0;
 const double kGB = kMB * 1024;
 const double kMicrosInSec = 1000000.0;
 
-void PrintLevelStatsHeader(char* buf, size_t len, const std::string& cf_name) {
+void PrintLevelStatsHeader(char* buf, size_t len, const std::string& cf_name,
+                           const std::string& group_by) {
   int written_size =
       snprintf(buf, len, "\n** Compaction Stats [%s] **\n", cf_name.c_str());
   auto hdr = [](LevelStatType t) {
@@ -66,17 +67,18 @@ void PrintLevelStatsHeader(char* buf, size_t len, const std::string& cf_name) {
   };
   int line_size = snprintf(
       buf + written_size, len - written_size,
-      "Level    %s   %s     %s %s  %s %s %s %s %s %s %s %s %s %s %s %s %s %s\n",
+      "%s    %s   %s     %s %s  %s %s %s %s %s %s %s %s %s %s %s %s %s %s\n",
       // Note that we skip COMPACTED_FILES and merge it with Files column
-      hdr(LevelStatType::NUM_FILES), hdr(LevelStatType::SIZE_BYTES),
-      hdr(LevelStatType::SCORE), hdr(LevelStatType::READ_GB),
-      hdr(LevelStatType::RN_GB), hdr(LevelStatType::RNP1_GB),
-      hdr(LevelStatType::WRITE_GB), hdr(LevelStatType::W_NEW_GB),
-      hdr(LevelStatType::MOVED_GB), hdr(LevelStatType::WRITE_AMP),
-      hdr(LevelStatType::READ_MBPS), hdr(LevelStatType::WRITE_MBPS),
-      hdr(LevelStatType::COMP_SEC), hdr(LevelStatType::COMP_CPU_SEC),
-      hdr(LevelStatType::COMP_COUNT), hdr(LevelStatType::AVG_SEC),
-      hdr(LevelStatType::KEY_IN), hdr(LevelStatType::KEY_DROP));
+      group_by.c_str(), hdr(LevelStatType::NUM_FILES),
+      hdr(LevelStatType::SIZE_BYTES), hdr(LevelStatType::SCORE),
+      hdr(LevelStatType::READ_GB), hdr(LevelStatType::RN_GB),
+      hdr(LevelStatType::RNP1_GB), hdr(LevelStatType::WRITE_GB),
+      hdr(LevelStatType::W_NEW_GB), hdr(LevelStatType::MOVED_GB),
+      hdr(LevelStatType::WRITE_AMP), hdr(LevelStatType::READ_MBPS),
+      hdr(LevelStatType::WRITE_MBPS), hdr(LevelStatType::COMP_SEC),
+      hdr(LevelStatType::COMP_CPU_SEC), hdr(LevelStatType::COMP_COUNT),
+      hdr(LevelStatType::AVG_SEC), hdr(LevelStatType::KEY_IN),
+      hdr(LevelStatType::KEY_DROP));
 
   written_size += line_size;
   snprintf(buf + written_size, len - written_size, "%s\n",
@@ -1152,6 +1154,20 @@ void InternalStats::DumpCFMapStats(
   (*levels_stats)[-1] = sum_stats;  //  -1 is for the Sum level
 }
 
+void InternalStats::DumpCFMapStatsByPriority(
+    std::map<int, std::map<LevelStatType, double>>* priorities_stats) {
+  for (size_t priority = 0; priority < comp_stats_by_pri_.size(); priority++) {
+    if (comp_stats_by_pri_[priority].micros > 0) {
+      std::map<LevelStatType, double> priority_stats;
+      PrepareLevelStats(&priority_stats, 0 /* num_files */,
+                        0 /* being_compacted */, 0 /* total_file_size */,
+                        0 /* compaction_score */, 0 /* w_amp */,
+                        comp_stats_by_pri_[priority]);
+      (*priorities_stats)[static_cast<int>(priority)] = priority_stats;
+    }
+  }
+}
+
 void InternalStats::DumpCFMapStatsIOStalls(
     std::map<std::string, std::string>* cf_stats) {
   (*cf_stats)["io_stalls.level0_slowdown"] =
@@ -1192,7 +1208,7 @@ void InternalStats::DumpCFStats(std::string* value) {
 void InternalStats::DumpCFStatsNoFileHistogram(std::string* value) {
   char buf[2000];
   // Per-ColumnFamily stats
-  PrintLevelStatsHeader(buf, sizeof(buf), cfd_->GetName());
+  PrintLevelStatsHeader(buf, sizeof(buf), cfd_->GetName(), "Level");
   value->append(buf);
 
   // Print stats for each level
@@ -1238,6 +1254,21 @@ void InternalStats::DumpCFStatsNoFileHistogram(std::string* value) {
   PrintLevelStats(buf, sizeof(buf), "Int", 0, 0, 0, 0, w_amp, interval_stats);
   value->append(buf);
 
+  PrintLevelStatsHeader(buf, sizeof(buf), cfd_->GetName(), "Priority");
+  value->append(buf);
+  std::map<int, std::map<LevelStatType, double>> priorities_stats;
+  DumpCFMapStatsByPriority(&priorities_stats);
+  for (size_t priority = 0; priority < comp_stats_by_pri_.size(); ++priority) {
+    if (priorities_stats.find(static_cast<int>(priority)) !=
+        priorities_stats.end()) {
+      PrintLevelStats(
+          buf, sizeof(buf),
+          Env::PriorityToString(static_cast<Env::Priority>(priority)),
+          priorities_stats[static_cast<int>(priority)]);
+      value->append(buf);
+    }
+  }
+
   double seconds_up = (env_->NowMicros() - started_at_ + 1) / kMicrosInSec;
   double interval_seconds_up = seconds_up - cf_stats_snapshot_.seconds_up;
   snprintf(buf, sizeof(buf), "Uptime(secs): %.1f total, %.1f interval\n",

db/internal_stats.h

@@ -125,6 +125,7 @@ class InternalStats {
         cf_stats_value_{},
         cf_stats_count_{},
         comp_stats_(num_levels),
+        comp_stats_by_pri_(Env::Priority::TOTAL),
         file_read_latency_(num_levels),
         bg_error_count_(0),
         number_levels_(num_levels),
@@ -318,8 +319,10 @@ class InternalStats {
     started_at_ = env_->NowMicros();
   }
 
-  void AddCompactionStats(int level, const CompactionStats& stats) {
+  void AddCompactionStats(int level, Env::Priority thread_pri,
+                          const CompactionStats& stats) {
     comp_stats_[level].Add(stats);
+    comp_stats_by_pri_[thread_pri].Add(stats);
   }
 
   void IncBytesMoved(int level, uint64_t amount) {
@@ -381,6 +384,8 @@ class InternalStats {
   void DumpCFMapStats(
       std::map<int, std::map<LevelStatType, double>>* level_stats,
       CompactionStats* compaction_stats_sum);
+  void DumpCFMapStatsByPriority(
+      std::map<int, std::map<LevelStatType, double>>* priorities_stats);
   void DumpCFMapStatsIOStalls(std::map<std::string, std::string>* cf_stats);
   void DumpCFStats(std::string* value);
   void DumpCFStatsNoFileHistogram(std::string* value);
@@ -395,6 +400,7 @@ class InternalStats {
   uint64_t cf_stats_count_[INTERNAL_CF_STATS_ENUM_MAX];
   // Per-ColumnFamily/level compaction stats
   std::vector<CompactionStats> comp_stats_;
+  std::vector<CompactionStats> comp_stats_by_pri_;
   std::vector<HistogramImpl> file_read_latency_;
 
   // Used to compute per-interval statistics
@@ -625,7 +631,8 @@ class InternalStats {
     void Subtract(const CompactionStats& /*c*/) {}
   };
 
-  void AddCompactionStats(int /*level*/, const CompactionStats& /*stats*/) {}
+  void AddCompactionStats(int /*level*/, Env::Priority /*thread_pri*/,
+                          const CompactionStats& /*stats*/) {}
 
   void IncBytesMoved(int /*level*/, uint64_t /*amount*/) {}
 

env/env.cc

@@ -30,6 +30,8 @@ std::string Env::PriorityToString(Env::Priority priority) {
       return "Low";
     case Env::Priority::HIGH:
       return "High";
+    case Env::Priority::USER:
+      return "User";
     case Env::Priority::TOTAL:
       assert(false);
   }

include/rocksdb/env.h

@@ -319,7 +319,7 @@ class Env {
   virtual Status UnlockFile(FileLock* lock) = 0;
 
   // Priority for scheduling job in thread pool
-  enum Priority { BOTTOM, LOW, HIGH, TOTAL };
+  enum Priority { BOTTOM, LOW, HIGH, USER, TOTAL };
 
   static std::string PriorityToString(Priority priority);
 

util/threadpool_imp.cc

@@ -292,6 +292,9 @@ void* ThreadPoolImpl::Impl::BGThreadWrapper(void* arg) {
     case Env::Priority::BOTTOM:
       thread_type = ThreadStatus::BOTTOM_PRIORITY;
       break;
+    case Env::Priority::USER:
+      thread_type = ThreadStatus::USER;
+      break;
     case Env::Priority::TOTAL:
       assert(false);
       return nullptr;