Merge branch 'master' of github.com:facebook/rocksdb

.travis.yml

@@ -34,7 +34,7 @@ before_script:
 # as EnvPosixTest::AllocateTest expects within the Travis OpenVZ environment.
 script:
   - if [[ "${TRAVIS_OS_NAME}" == 'linux' ]]; then OPT=-DTRAVIS CLANG_FORMAT_DIFF=/tmp/clang-format-diff.py make format || true; fi
-  - OPT=-DTRAVIS V=1 make -j4 check && OPT=-DTRAVIS V=1 make clean jclean rocksdbjava jtest && make clean && OPT="-DTRAVIS -DROCKSDB_LITE" V=1 make -j4 check
+  - OPT=-DTRAVIS V=1 make -j4 check && OPT=-DTRAVIS V=1 make clean jclean rocksdbjava jtest && make clean && OPT="-DTRAVIS -DROCKSDB_LITE" V=1 make -j4 static_lib
 
 notifications:
     email:

Makefile

@@ -700,7 +700,7 @@ clean:
 
 tags:
 	ctags * -R
-	cscope -b `find . -name '*.cc'` `find . -name '*.h'`
+	cscope -b `find . -name '*.cc'` `find . -name '*.h'` `find . -name '*.c'`
 
 format:
 	build_tools/format-diff.sh

db/auto_roll_logger.cc

@@ -32,8 +32,16 @@ Status AutoRollLogger::ResetLogger() {
 }
 
 void AutoRollLogger::RollLogFile() {
-  std::string old_fname = OldInfoLogFileName(
-      dbname_, env_->NowMicros(), db_absolute_path_, db_log_dir_);
+  // This function is called when log is rotating. Two rotations
+  // can happen quickly (NowMicro returns same value). To not overwrite
+  // previous log file we increment by one micro second and try again.
+  uint64_t now = env_->NowMicros();
+  std::string old_fname;
+  do {
+    old_fname = OldInfoLogFileName(
+      dbname_, now, db_absolute_path_, db_log_dir_);
+    now++;
+  } while (env_->FileExists(old_fname).ok());
   env_->RenameFile(log_fname_, old_fname);
 }
 

db/column_family.cc

@@ -239,6 +239,17 @@ ColumnFamilyOptions SanitizeOptions(const DBOptions& db_options,
          result.level0_slowdown_writes_trigger,
          result.level0_file_num_compaction_trigger);
   }
+
+  if (result.soft_pending_compaction_bytes_limit == 0) {
+    result.soft_pending_compaction_bytes_limit =
+        result.hard_pending_compaction_bytes_limit;
+  } else if (result.hard_pending_compaction_bytes_limit > 0 &&
+             result.soft_pending_compaction_bytes_limit >
+                 result.hard_pending_compaction_bytes_limit) {
+    result.soft_pending_compaction_bytes_limit =
+        result.hard_pending_compaction_bytes_limit;
+  }
+
   if (result.level_compaction_dynamic_level_bytes) {
     if (result.compaction_style != kCompactionStyleLevel ||
         db_options.db_paths.size() > 1U) {
@@ -513,6 +524,21 @@ std::unique_ptr<WriteControllerToken> SetupDelay(
   }
   return write_controller->GetDelayToken(write_rate);
 }
+
+int GetL0ThresholdSpeedupCompaction(int level0_file_num_compaction_trigger,
+                                    int level0_slowdown_writes_trigger) {
+  // SanitizeOptions() ensures it.
+  assert(level0_file_num_compaction_trigger <= level0_slowdown_writes_trigger);
+
+  // 1/4 of the way between L0 compaction trigger threshold and slowdown
+  // condition.
+  // Or twice as compaction trigger, if it is smaller.
+  return std::min(level0_file_num_compaction_trigger * 2,
+                  level0_file_num_compaction_trigger +
+                      (level0_slowdown_writes_trigger -
+                       level0_file_num_compaction_trigger) /
+                          4);
+}
 }  // namespace
 
 void ColumnFamilyData::RecalculateWriteStallConditions(
@@ -531,21 +557,6 @@ void ColumnFamilyData::RecalculateWriteStallConditions(
           "(waiting for flush), max_write_buffer_number is set to %d",
           name_.c_str(), imm()->NumNotFlushed(),
           mutable_cf_options.max_write_buffer_number);
-    } else if (mutable_cf_options.max_write_buffer_number > 3 &&
-               imm()->NumNotFlushed() >=
-                   mutable_cf_options.max_write_buffer_number - 1) {
-      write_controller_token_ =
-          SetupDelay(ioptions_.delayed_write_rate, write_controller,
-                     compaction_needed_bytes, prev_compaction_needed_bytes_,
-                     mutable_cf_options.disable_auto_compactions);
-      internal_stats_->AddCFStats(InternalStats::MEMTABLE_SLOWDOWN, 1);
-      Log(InfoLogLevel::WARN_LEVEL, ioptions_.info_log,
-          "[%s] Stalling writes because we have %d immutable memtables "
-          "(waiting for flush), max_write_buffer_number is set to %d "
-          "rate %" PRIu64,
-          name_.c_str(), imm()->NumNotFlushed(),
-          mutable_cf_options.max_write_buffer_number,
-          write_controller->delayed_write_rate());
     } else if (vstorage->l0_delay_trigger_count() >=
                mutable_cf_options.level0_stop_writes_trigger) {
       write_controller_token_ = write_controller->GetStopToken();
@@ -567,6 +578,21 @@ void ColumnFamilyData::RecalculateWriteStallConditions(
           "[%s] Stopping writes because of estimated pending compaction "
           "bytes %" PRIu64,
           name_.c_str(), compaction_needed_bytes);
+    } else if (mutable_cf_options.max_write_buffer_number > 3 &&
+               imm()->NumNotFlushed() >=
+                   mutable_cf_options.max_write_buffer_number - 1) {
+      write_controller_token_ =
+          SetupDelay(ioptions_.delayed_write_rate, write_controller,
+                     compaction_needed_bytes, prev_compaction_needed_bytes_,
+                     mutable_cf_options.disable_auto_compactions);
+      internal_stats_->AddCFStats(InternalStats::MEMTABLE_SLOWDOWN, 1);
+      Log(InfoLogLevel::WARN_LEVEL, ioptions_.info_log,
+          "[%s] Stalling writes because we have %d immutable memtables "
+          "(waiting for flush), max_write_buffer_number is set to %d "
+          "rate %" PRIu64,
+          name_.c_str(), imm()->NumNotFlushed(),
+          mutable_cf_options.max_write_buffer_number,
+          write_controller->delayed_write_rate());
     } else if (mutable_cf_options.level0_slowdown_writes_trigger >= 0 &&
                vstorage->l0_delay_trigger_count() >=
                    mutable_cf_options.level0_slowdown_writes_trigger) {
@@ -598,6 +624,29 @@ void ColumnFamilyData::RecalculateWriteStallConditions(
           "bytes %" PRIu64 " rate %" PRIu64,
           name_.c_str(), vstorage->estimated_compaction_needed_bytes(),
           write_controller->delayed_write_rate());
+    } else if (vstorage->l0_delay_trigger_count() >=
+               GetL0ThresholdSpeedupCompaction(
+                   mutable_cf_options.level0_file_num_compaction_trigger,
+                   mutable_cf_options.level0_slowdown_writes_trigger)) {
+      write_controller_token_ = write_controller->GetCompactionPressureToken();
+      Log(InfoLogLevel::WARN_LEVEL, ioptions_.info_log,
+          "[%s] Increasing compaction threads because we have %d level-0 "
+          "files ",
+          name_.c_str(), vstorage->l0_delay_trigger_count());
+    } else if (vstorage->estimated_compaction_needed_bytes() >=
+               mutable_cf_options.soft_pending_compaction_bytes_limit / 4) {
+      // Increase compaction threads if bytes needed for compaction exceeds
+      // 1/4 of threshold for slowing down.
+      // If soft pending compaction byte limit is not set, always speed up
+      // compaction.
+      write_controller_token_ = write_controller->GetCompactionPressureToken();
+      if (mutable_cf_options.soft_pending_compaction_bytes_limit > 0) {
+        Log(InfoLogLevel::WARN_LEVEL, ioptions_.info_log,
+            "[%s] Increasing compaction threads because of estimated pending "
+            "compaction "
+            "bytes %" PRIu64,
+            name_.c_str(), vstorage->estimated_compaction_needed_bytes());
+      }
     } else {
       write_controller_token_.reset();
     }

db/column_family_test.cc

@@ -65,6 +65,7 @@ class ColumnFamilyTest : public testing::Test {
 
   ~ColumnFamilyTest() {
     Close();
+    rocksdb::SyncPoint::GetInstance()->DisableProcessing();
     Destroy();
     delete env_;
   }
@@ -2047,7 +2048,6 @@ TEST_F(ColumnFamilyTest, FlushAndDropRaceCondition) {
 
   Close();
   Destroy();
-  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
 }
 
 #ifndef ROCKSDB_LITE
@@ -2125,7 +2125,6 @@ TEST_F(ColumnFamilyTest, CreateAndDropRace) {
   drop_cf_thread.join();
   Close();
   Destroy();
-  rocksdb::SyncPoint::GetInstance()->DisableProcessing();
   for (auto* comparator : comparators) {
     if (comparator) {
       delete comparator;
@@ -2137,6 +2136,9 @@ TEST_F(ColumnFamilyTest, CreateAndDropRace) {
 TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
   const uint64_t kBaseRate = 810000u;
   db_options_.delayed_write_rate = kBaseRate;
+  db_options_.base_background_compactions = 2;
+  db_options_.max_background_compactions = 6;
+
   Open({"default"});
   ColumnFamilyData* cfd =
       static_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())->cfd();
@@ -2162,6 +2164,7 @@ TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
   ASSERT_TRUE(!dbfull()->TEST_write_controler().IsStopped());
   ASSERT_TRUE(dbfull()->TEST_write_controler().NeedsDelay());
   ASSERT_EQ(kBaseRate, dbfull()->TEST_write_controler().delayed_write_rate());
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
 
   vstorage->TEST_set_estimated_compaction_needed_bytes(400);
   cfd->RecalculateWriteStallConditions(mutable_cf_options);
@@ -2169,6 +2172,7 @@ TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
   ASSERT_TRUE(dbfull()->TEST_write_controler().NeedsDelay());
   ASSERT_EQ(kBaseRate / 1.2,
             dbfull()->TEST_write_controler().delayed_write_rate());
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
 
   vstorage->TEST_set_estimated_compaction_needed_bytes(500);
   cfd->RecalculateWriteStallConditions(mutable_cf_options);
@@ -2224,6 +2228,7 @@ TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
   cfd->RecalculateWriteStallConditions(mutable_cf_options);
   ASSERT_TRUE(dbfull()->TEST_write_controler().IsStopped());
   ASSERT_TRUE(!dbfull()->TEST_write_controler().NeedsDelay());
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
 
   vstorage->TEST_set_estimated_compaction_needed_bytes(3001);
   cfd->RecalculateWriteStallConditions(mutable_cf_options);
@@ -2248,6 +2253,7 @@ TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
   ASSERT_TRUE(dbfull()->TEST_write_controler().NeedsDelay());
   ASSERT_EQ(kBaseRate / 1.2,
             dbfull()->TEST_write_controler().delayed_write_rate());
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
 
   vstorage->set_l0_delay_trigger_count(101);
   cfd->RecalculateWriteStallConditions(mutable_cf_options);
@@ -2320,6 +2326,73 @@ TEST_F(ColumnFamilyTest, WriteStallSingleColumnFamily) {
             dbfull()->TEST_write_controler().delayed_write_rate());
 }
 
+TEST_F(ColumnFamilyTest, CompactionSpeedupSingleColumnFamily) {
+  db_options_.base_background_compactions = 2;
+  db_options_.max_background_compactions = 6;
+  Open({"default"});
+  ColumnFamilyData* cfd =
+      static_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())->cfd();
+
+  VersionStorageInfo* vstorage = cfd->current()->storage_info();
+
+  MutableCFOptions mutable_cf_options(
+      Options(db_options_, column_family_options_),
+      ImmutableCFOptions(Options(db_options_, column_family_options_)));
+
+  // Speed up threshold = min(4 * 2, 4 + (36 - 4)/4) = 8
+  mutable_cf_options.level0_file_num_compaction_trigger = 4;
+  mutable_cf_options.level0_slowdown_writes_trigger = 36;
+  mutable_cf_options.level0_stop_writes_trigger = 50;
+  // Speedup threshold = 200 / 4 = 50
+  mutable_cf_options.soft_pending_compaction_bytes_limit = 200;
+  mutable_cf_options.hard_pending_compaction_bytes_limit = 2000;
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(40);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(50);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(300);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(45);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(7);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(9);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(6);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  // Speed up threshold = min(4 * 2, 4 + (12 - 4)/4) = 6
+  mutable_cf_options.level0_file_num_compaction_trigger = 4;
+  mutable_cf_options.level0_slowdown_writes_trigger = 16;
+  mutable_cf_options.level0_stop_writes_trigger = 30;
+
+  vstorage->set_l0_delay_trigger_count(5);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(7);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(3);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+}
+
 TEST_F(ColumnFamilyTest, WriteStallTwoColumnFamilies) {
   const uint64_t kBaseRate = 810000u;
   db_options_.delayed_write_rate = kBaseRate;
@@ -2401,6 +2474,74 @@ TEST_F(ColumnFamilyTest, WriteStallTwoColumnFamilies) {
   ASSERT_EQ(kBaseRate / 1.2,
             dbfull()->TEST_write_controler().delayed_write_rate());
 }
+
+TEST_F(ColumnFamilyTest, CompactionSpeedupTwoColumnFamilies) {
+  db_options_.base_background_compactions = 2;
+  db_options_.max_background_compactions = 6;
+  column_family_options_.soft_pending_compaction_bytes_limit = 200;
+  column_family_options_.hard_pending_compaction_bytes_limit = 2000;
+  Open();
+  CreateColumnFamilies({"one"});
+  ColumnFamilyData* cfd =
+      static_cast<ColumnFamilyHandleImpl*>(db_->DefaultColumnFamily())->cfd();
+  VersionStorageInfo* vstorage = cfd->current()->storage_info();
+
+  ColumnFamilyData* cfd1 =
+      static_cast<ColumnFamilyHandleImpl*>(handles_[1])->cfd();
+  VersionStorageInfo* vstorage1 = cfd1->current()->storage_info();
+
+  MutableCFOptions mutable_cf_options(
+      Options(db_options_, column_family_options_),
+      ImmutableCFOptions(Options(db_options_, column_family_options_)));
+  // Speed up threshold = min(4 * 2, 4 + (36 - 4)/4) = 8
+  mutable_cf_options.level0_file_num_compaction_trigger = 4;
+  mutable_cf_options.level0_slowdown_writes_trigger = 36;
+  mutable_cf_options.level0_stop_writes_trigger = 30;
+  // Speedup threshold = 200 / 4 = 50
+  mutable_cf_options.soft_pending_compaction_bytes_limit = 200;
+  mutable_cf_options.hard_pending_compaction_bytes_limit = 2000;
+
+  MutableCFOptions mutable_cf_options1 = mutable_cf_options;
+  mutable_cf_options1.level0_slowdown_writes_trigger = 16;
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(40);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(60);
+  cfd1->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage1->TEST_set_estimated_compaction_needed_bytes(30);
+  cfd1->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage1->TEST_set_estimated_compaction_needed_bytes(70);
+  cfd1->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->TEST_set_estimated_compaction_needed_bytes(20);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage1->TEST_set_estimated_compaction_needed_bytes(3);
+  cfd1->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(9);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage1->set_l0_delay_trigger_count(2);
+  cfd1->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(6, dbfull()->BGCompactionsAllowed());
+
+  vstorage->set_l0_delay_trigger_count(0);
+  cfd->RecalculateWriteStallConditions(mutable_cf_options);
+  ASSERT_EQ(2, dbfull()->BGCompactionsAllowed());
+}
 }  // namespace rocksdb
 
 int main(int argc, char** argv) {

db/db_compaction_test.cc

@@ -533,6 +533,104 @@ TEST_P(DBCompactionTestWithParam, CompactionTrigger) {
   ASSERT_EQ(NumTableFilesAtLevel(1, 1), 1);
 }
 
+TEST_F(DBCompactionTest, BGCompactionsAllowed) {
+  // Create several column families. Make compaction triggers in all of them
+  // and see number of compactions scheduled to be less than allowed.
+  const int kNumKeysPerFile = 100;
+
+  Options options;
+  options.write_buffer_size = 110 << 10;  // 110KB
+  options.arena_block_size = 4 << 10;
+  options.num_levels = 3;
+  // Should speed up compaction when there are 4 files.
+  options.level0_file_num_compaction_trigger = 2;
+  options.level0_slowdown_writes_trigger = 20;
+  options.soft_pending_compaction_bytes_limit = 1 << 30;  // Infinitely large
+  options.base_background_compactions = 1;
+  options.max_background_compactions = 3;
+  options.memtable_factory.reset(new SpecialSkipListFactory(kNumKeysPerFile));
+  options = CurrentOptions(options);
+
+  // Block all threads in thread pool.
+  const size_t kTotalTasks = 4;
+  env_->SetBackgroundThreads(4, Env::LOW);
+  test::SleepingBackgroundTask sleeping_tasks[kTotalTasks];
+  for (size_t i = 0; i < kTotalTasks; i++) {
+    env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask,
+                   &sleeping_tasks[i], Env::Priority::LOW);
+    sleeping_tasks[i].WaitUntilSleeping();
+  }
+
+  CreateAndReopenWithCF({"one", "two", "three"}, options);
+
+  Random rnd(301);
+  for (int cf = 0; cf < 4; cf++) {
+    for (int num = 0; num < options.level0_file_num_compaction_trigger; num++) {
+      for (int i = 0; i < kNumKeysPerFile; i++) {
+        ASSERT_OK(Put(cf, Key(i), ""));
+      }
+      // put extra key to trigger flush
+      ASSERT_OK(Put(cf, "", ""));
+      dbfull()->TEST_WaitForFlushMemTable(handles_[cf]);
+      ASSERT_EQ(NumTableFilesAtLevel(0, cf), num + 1);
+    }
+  }
+
+  // Now all column families qualify compaction but only one should be
+  // scheduled, because no column family hits speed up condition.
+  ASSERT_EQ(1, env_->GetThreadPoolQueueLen(Env::Priority::LOW));
+
+  // Create two more files for one column family, which triggers speed up
+  // condition, three compactions will be scheduled.
+  for (int num = 0; num < options.level0_file_num_compaction_trigger; num++) {
+    for (int i = 0; i < kNumKeysPerFile; i++) {
+      ASSERT_OK(Put(2, Key(i), ""));
+    }
+    // put extra key to trigger flush
+    ASSERT_OK(Put(2, "", ""));
+    dbfull()->TEST_WaitForFlushMemTable(handles_[2]);
+    ASSERT_EQ(options.level0_file_num_compaction_trigger + num + 1,
+              NumTableFilesAtLevel(0, 2));
+  }
+  ASSERT_EQ(3, env_->GetThreadPoolQueueLen(Env::Priority::LOW));
+
+  // Unblock all threads to unblock all compactions.
+  for (size_t i = 0; i < kTotalTasks; i++) {
+    sleeping_tasks[i].WakeUp();
+    sleeping_tasks[i].WaitUntilDone();
+  }
+  dbfull()->TEST_WaitForCompact();
+
+  // Verify number of compactions allowed will come back to 1.
+
+  for (size_t i = 0; i < kTotalTasks; i++) {
+    sleeping_tasks[i].Reset();
+    env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask,
+                   &sleeping_tasks[i], Env::Priority::LOW);
+    sleeping_tasks[i].WaitUntilSleeping();
+  }
+  for (int cf = 0; cf < 4; cf++) {
+    for (int num = 0; num < options.level0_file_num_compaction_trigger; num++) {
+      for (int i = 0; i < kNumKeysPerFile; i++) {
+        ASSERT_OK(Put(cf, Key(i), ""));
+      }
+      // put extra key to trigger flush
+      ASSERT_OK(Put(cf, "", ""));
+      dbfull()->TEST_WaitForFlushMemTable(handles_[cf]);
+      ASSERT_EQ(NumTableFilesAtLevel(0, cf), num + 1);
+    }
+  }
+
+  // Now all column families qualify compaction but only one should be
+  // scheduled, because no column family hits speed up condition.
+  ASSERT_EQ(1, env_->GetThreadPoolQueueLen(Env::Priority::LOW));
+
+  for (size_t i = 0; i < kTotalTasks; i++) {
+    sleeping_tasks[i].WakeUp();
+    sleeping_tasks[i].WaitUntilDone();
+  }
+}
+
 TEST_P(DBCompactionTestWithParam, CompactionsGenerateMultipleFiles) {
   Options options;
   options.write_buffer_size = 100000000;        // Large write buffer
@@ -2198,6 +2296,25 @@ TEST_P(DBCompactionTestWithParam, CompressLevelCompaction) {
   Destroy(options);
 }
 
+TEST_F(DBCompactionTest, SanitizeCompactionOptionsTest) {
+  Options options = CurrentOptions();
+  options.max_background_compactions = 5;
+  options.soft_pending_compaction_bytes_limit = 0;
+  options.hard_pending_compaction_bytes_limit = 100;
+  options.create_if_missing = true;
+  DestroyAndReopen(options);
+  ASSERT_EQ(5, db_->GetOptions().base_background_compactions);
+  ASSERT_EQ(100, db_->GetOptions().soft_pending_compaction_bytes_limit);
+
+  options.base_background_compactions = 4;
+  options.max_background_compactions = 3;
+  options.soft_pending_compaction_bytes_limit = 200;
+  options.hard_pending_compaction_bytes_limit = 150;
+  DestroyAndReopen(options);
+  ASSERT_EQ(3, db_->GetOptions().base_background_compactions);
+  ASSERT_EQ(150, db_->GetOptions().soft_pending_compaction_bytes_limit);
+}
+
 // This tests for a bug that could cause two level0 compactions running
 // concurrently
 // TODO(aekmekji): Make sure that the reason this fails when run with

db/db_impl.cc

@@ -146,6 +146,12 @@ DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
       result.info_log = nullptr;
     }
   }
+  if (result.base_background_compactions == -1) {
+    result.base_background_compactions = result.max_background_compactions;
+  }
+  if (result.base_background_compactions > result.max_background_compactions) {
+    result.base_background_compactions = result.max_background_compactions;
+  }
   result.env->IncBackgroundThreadsIfNeeded(src.max_background_compactions,
                                            Env::Priority::LOW);
   result.env->IncBackgroundThreadsIfNeeded(src.max_background_flushes,
@@ -2448,12 +2454,14 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
     env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::HIGH, this);
   }
 
+  auto bg_compactions_allowed = BGCompactionsAllowed();
+
   // special case -- if max_background_flushes == 0, then schedule flush on a
   // compaction thread
   if (db_options_.max_background_flushes == 0) {
     while (unscheduled_flushes_ > 0 &&
            bg_flush_scheduled_ + bg_compaction_scheduled_ <
-               db_options_.max_background_compactions) {
+               bg_compactions_allowed) {
       unscheduled_flushes_--;
       bg_flush_scheduled_++;
       env_->Schedule(&DBImpl::BGWorkFlush, this, Env::Priority::LOW, this);
@@ -2466,7 +2474,7 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
     return;
   }
 
-  while (bg_compaction_scheduled_ < db_options_.max_background_compactions &&
+  while (bg_compaction_scheduled_ < bg_compactions_allowed &&
          unscheduled_compactions_ > 0) {
     CompactionArg* ca = new CompactionArg;
     ca->db = this;
@@ -2478,6 +2486,14 @@ void DBImpl::MaybeScheduleFlushOrCompaction() {
   }
 }
 
+int DBImpl::BGCompactionsAllowed() const {
+  if (write_controller_.NeedSpeedupCompaction()) {
+    return db_options_.max_background_compactions;
+  } else {
+    return db_options_.base_background_compactions;
+  }
+}
+
 void DBImpl::AddToCompactionQueue(ColumnFamilyData* cfd) {
   assert(!cfd->pending_compaction());
   cfd->Ref();
@@ -2590,10 +2606,10 @@ Status DBImpl::BackgroundFlush(bool* made_progress, JobContext* job_context,
     LogToBuffer(
         log_buffer,
         "Calling FlushMemTableToOutputFile with column "
-        "family [%s], flush slots available %d, compaction slots available %d",
-        cfd->GetName().c_str(),
-        db_options_.max_background_flushes - bg_flush_scheduled_,
-        db_options_.max_background_compactions - bg_compaction_scheduled_);
+        "family [%s], flush slots available %d, compaction slots allowed %d, "
+        "compaction slots scheduled %d",
+        cfd->GetName().c_str(), db_options_.max_background_flushes,
+        bg_flush_scheduled_, BGCompactionsAllowed() - bg_compaction_scheduled_);
     status = FlushMemTableToOutputFile(cfd, mutable_cf_options, made_progress,
                                        job_context, log_buffer);
     if (cfd->Unref()) {
@@ -3311,6 +3327,7 @@ Status DBImpl::GetImpl(const ReadOptions& read_options,
 
     RecordTick(stats_, NUMBER_KEYS_READ);
     RecordTick(stats_, BYTES_READ, value->size());
+    MeasureTime(stats_, BYTES_PER_READ, value->size());
   }
   return s;
 }
@@ -3421,6 +3438,7 @@ std::vector<Status> DBImpl::MultiGet(
   RecordTick(stats_, NUMBER_MULTIGET_CALLS);
   RecordTick(stats_, NUMBER_MULTIGET_KEYS_READ, num_keys);
   RecordTick(stats_, NUMBER_MULTIGET_BYTES_READ, bytes_read);
+  MeasureTime(stats_, BYTES_PER_MULTIGET, bytes_read);
   PERF_TIMER_STOP(get_post_process_time);
 
   return stat_list;
@@ -4119,7 +4137,9 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
 
     if (write_thread_.CompleteParallelWorker(&w)) {
       // we're responsible for early exit
-      auto last_sequence = w.parallel_group->last_writer->sequence;
+      auto last_sequence =
+          w.parallel_group->last_writer->sequence +
+          WriteBatchInternal::Count(w.parallel_group->last_writer->batch) - 1;
       SetTickerCount(stats_, SEQUENCE_NUMBER, last_sequence);
       versions_->SetLastSequence(last_sequence);
       write_thread_.EarlyExitParallelGroup(&w);
@@ -4305,6 +4325,7 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
     // Record statistics
     RecordTick(stats_, NUMBER_KEYS_WRITTEN, total_count);
     RecordTick(stats_, BYTES_WRITTEN, total_byte_size);
+    MeasureTime(stats_, BYTES_PER_WRITE, total_byte_size);
     PERF_TIMER_STOP(write_pre_and_post_process_time);
 
     if (write_options.disableWAL) {
@@ -4418,7 +4439,9 @@ Status DBImpl::WriteImpl(const WriteOptions& write_options,
             this, true /*dont_filter_deletes*/,
             true /*concurrent_memtable_writes*/);
 
-        assert(last_writer->sequence == last_sequence);
+        assert(last_writer->sequence +
+                   WriteBatchInternal::Count(last_writer->batch) - 1 ==
+               last_sequence);
         // CompleteParallelWorker returns true if this thread should
         // handle exit, false means somebody else did
         exit_completed_early = !write_thread_.CompleteParallelWorker(&w);

db/db_impl.h

@@ -347,6 +347,10 @@ class DBImpl : public DB {
 
 #endif  // NDEBUG
 
+  // Return maximum background compaction alowed to be scheduled based on
+  // compaction status.
+  int BGCompactionsAllowed() const;
+
   // Returns the list of live files in 'live' and the list
   // of all files in the filesystem in 'candidate_files'.
   // If force == false and the last call was less than

db/db_test.cc

@@ -606,6 +606,61 @@ TEST_F(DBTest, EmptyFlush) {
                          kSkipUniversalCompaction | kSkipMergePut));
 }
 
+// Disable because not all platform can run it.
+// It requires more than 9GB memory to run it, With single allocation
+// of more than 3GB.
+TEST_F(DBTest, DISABLED_VeryLargeValue) {
+  const size_t kValueSize = 3221225472u;  // 3GB value
+  const size_t kKeySize = 8388608u;       // 8MB key
+  std::string raw(kValueSize, 'v');
+  std::string key1(kKeySize, 'c');
+  std::string key2(kKeySize, 'd');
+
+  Options options;
+  options.env = env_;
+  options.write_buffer_size = 100000;  // Small write buffer
+  options.paranoid_checks = true;
+  options = CurrentOptions(options);
+  DestroyAndReopen(options);
+
+  ASSERT_OK(Put("boo", "v1"));
+  ASSERT_OK(Put("foo", "v1"));
+  ASSERT_OK(Put(key1, raw));
+  raw[0] = 'w';
+  ASSERT_OK(Put(key2, raw));
+  dbfull()->TEST_WaitForFlushMemTable();
+
+  ASSERT_EQ(1, NumTableFilesAtLevel(0));
+
+  std::string value;
+  Status s = db_->Get(ReadOptions(), key1, &value);
+  ASSERT_OK(s);
+  ASSERT_EQ(kValueSize, value.size());
+  ASSERT_EQ('v', value[0]);
+
+  s = db_->Get(ReadOptions(), key2, &value);
+  ASSERT_OK(s);
+  ASSERT_EQ(kValueSize, value.size());
+  ASSERT_EQ('w', value[0]);
+
+  // Compact all files.
+  Flush();
+  db_->CompactRange(CompactRangeOptions(), nullptr, nullptr);
+
+  // Check DB is not in read-only state.
+  ASSERT_OK(Put("boo", "v1"));
+
+  s = db_->Get(ReadOptions(), key1, &value);
+  ASSERT_OK(s);
+  ASSERT_EQ(kValueSize, value.size());
+  ASSERT_EQ('v', value[0]);
+
+  s = db_->Get(ReadOptions(), key2, &value);
+  ASSERT_OK(s);
+  ASSERT_EQ(kValueSize, value.size());
+  ASSERT_EQ('w', value[0]);
+}
+
 TEST_F(DBTest, GetFromImmutableLayer) {
   do {
     Options options;

db/db_test_util.cc

@@ -85,7 +85,8 @@ bool DBTestBase::ShouldSkipOptions(int option_config, int skip_mask) {
       option_config == kHashCuckoo || option_config == kUniversalCompaction ||
       option_config == kUniversalCompactionMultiLevel ||
       option_config == kUniversalSubcompactions ||
-      option_config == kFIFOCompaction) {
+      option_config == kFIFOCompaction ||
+      option_config == kConcurrentSkipList) {
     return true;
     }
 #endif
@@ -361,6 +362,11 @@ Options DBTestBase::CurrentOptions(
       options.max_subcompactions = 4;
       break;
     }
+    case kConcurrentSkipList: {
+      options.allow_concurrent_memtable_write = true;
+      options.enable_write_thread_adaptive_yield = true;
+      break;
+    }
 
     default:
       break;

db/db_test_util.h

@@ -525,9 +525,10 @@ class DBTestBase : public testing::Test {
     kOptimizeFiltersForHits = 27,
     kRowCache = 28,
     kRecycleLogFiles = 29,
-    kLevelSubcompactions = 30,
-    kUniversalSubcompactions = 31,
-    kEnd = 30
+    kEnd = 30,
+    kConcurrentSkipList = 30,
+    kLevelSubcompactions = 31,
+    kUniversalSubcompactions = 32,
   };
   int option_config_;
 

db/db_universal_compaction_test.cc

@@ -187,14 +187,16 @@ TEST_P(DBTestUniversalCompaction, OptimizeFiltersForHits) {
   env_->Schedule(&test::SleepingBackgroundTask::DoSleepTask, &sleeping_task_low,
                  Env::Priority::LOW);
 
-  Put("", "");
   for (int num = 0; num < options.level0_file_num_compaction_trigger; num++) {
     Put(Key(num * 10), "val");
+    if (num) {
+      dbfull()->TEST_WaitForFlushMemTable();
+    }
     Put(Key(30 + num * 10), "val");
     Put(Key(60 + num * 10), "val");
-
-    dbfull()->TEST_WaitForFlushMemTable();
   }
+  Put("", "");
+  dbfull()->TEST_WaitForFlushMemTable();
 
   // Query set of non existing keys
   for (int i = 5; i < 90; i += 10) {
@@ -205,6 +207,13 @@ TEST_P(DBTestUniversalCompaction, OptimizeFiltersForHits) {
   ASSERT_GT(TestGetTickerCount(options, BLOOM_FILTER_USEFUL), 0);
   auto prev_counter = TestGetTickerCount(options, BLOOM_FILTER_USEFUL);
 
+  // Make sure bloom filter is used for all but the last L0 file when looking
+  // up a non-existent key that's in the range of all L0 files.
+  ASSERT_EQ(Get(Key(35)), "NOT_FOUND");
+  ASSERT_EQ(prev_counter + NumTableFilesAtLevel(0) - 1,
+            TestGetTickerCount(options, BLOOM_FILTER_USEFUL));
+  prev_counter = TestGetTickerCount(options, BLOOM_FILTER_USEFUL);
+
   // Unblock compaction and wait it for happening.
   sleeping_task_low.WakeUp();
   dbfull()->TEST_WaitForCompact();

db/perf_context_test.cc

@@ -589,6 +589,19 @@ TEST_F(PerfContextTest, FalseDBMutexWait) {
     }
   }
 }
+
+TEST_F(PerfContextTest, ToString) {
+  perf_context.Reset();
+  perf_context.block_read_count = 12345;
+
+  std::string zero_included = perf_context.ToString();
+  ASSERT_NE(std::string::npos, zero_included.find("= 0"));
+  ASSERT_NE(std::string::npos, zero_included.find("= 12345"));
+
+  std::string zero_excluded = perf_context.ToString(true);
+  ASSERT_EQ(std::string::npos, zero_excluded.find("= 0"));
+  ASSERT_NE(std::string::npos, zero_excluded.find("= 12345"));
+}
 }
 
 int main(int argc, char** argv) {

db/version_set.cc

@@ -84,15 +84,11 @@ int FindFileInRange(const InternalKeyComparator& icmp,
 // are MergeInProgress).
 class FilePicker {
  public:
-  FilePicker(
-      std::vector<FileMetaData*>* files,
-      const Slice& user_key,
-      const Slice& ikey,
-      autovector<LevelFilesBrief>* file_levels,
-      unsigned int num_levels,
-      FileIndexer* file_indexer,
-      const Comparator* user_comparator,
-      const InternalKeyComparator* internal_comparator)
+  FilePicker(std::vector<FileMetaData*>* files, const Slice& user_key,
+             const Slice& ikey, autovector<LevelFilesBrief>* file_levels,
+             unsigned int num_levels, FileIndexer* file_indexer,
+             const Comparator* user_comparator,
+             const InternalKeyComparator* internal_comparator)
       : num_levels_(num_levels),
         curr_level_(-1),
         hit_file_level_(-1),
@@ -102,6 +98,7 @@ class FilePicker {
         files_(files),
 #endif
         level_files_brief_(file_levels),
+        is_hit_file_last_in_level_(false),
         user_key_(user_key),
         ikey_(ikey),
         file_indexer_(file_indexer),
@@ -126,6 +123,8 @@ class FilePicker {
         // Loops over all files in current level.
         FdWithKeyRange* f = &curr_file_level_->files[curr_index_in_curr_level_];
         hit_file_level_ = curr_level_;
+        is_hit_file_last_in_level_ =
+            curr_index_in_curr_level_ == curr_file_level_->num_files - 1;
         int cmp_largest = -1;
 
         // Do key range filtering of files or/and fractional cascading if:
@@ -209,6 +208,10 @@ class FilePicker {
   // for GET_HIT_L0, GET_HIT_L1 & GET_HIT_L2_AND_UP counts
   unsigned int GetHitFileLevel() { return hit_file_level_; }
 
+  // Returns true if the most recent "hit file" (i.e., one returned by
+  // GetNextFile()) is at the last index in its level.
+  bool IsHitFileLastInLevel() { return is_hit_file_last_in_level_; }
+
  private:
   unsigned int num_levels_;
   unsigned int curr_level_;
@@ -220,6 +223,7 @@ class FilePicker {
 #endif
   autovector<LevelFilesBrief>* level_files_brief_;
   bool search_ended_;
+  bool is_hit_file_last_in_level_;
   LevelFilesBrief* curr_file_level_;
   unsigned int curr_index_in_curr_level_;
   unsigned int start_index_in_curr_level_;
@@ -903,7 +907,8 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
     *status = table_cache_->Get(
         read_options, *internal_comparator(), f->fd, ikey, &get_context,
         cfd_->internal_stats()->GetFileReadHist(fp.GetHitFileLevel()),
-        IsFilterSkipped(static_cast<int>(fp.GetHitFileLevel())));
+        IsFilterSkipped(static_cast<int>(fp.GetHitFileLevel()),
+                        fp.IsHitFileLastInLevel()));
     // TODO: examine the behavior for corrupted key
     if (!status->ok()) {
       return;
@@ -960,10 +965,11 @@ void Version::Get(const ReadOptions& read_options, const LookupKey& k,
   }
 }
 
-bool Version::IsFilterSkipped(int level) {
+bool Version::IsFilterSkipped(int level, bool is_file_last_in_level) {
   // Reaching the bottom level implies misses at all upper levels, so we'll
   // skip checking the filters when we predict a hit.
-  return cfd_->ioptions()->optimize_filters_for_hits && level > 0 &&
+  return cfd_->ioptions()->optimize_filters_for_hits &&
+         (level > 0 || is_file_last_in_level) &&
          level == storage_info_.num_non_empty_levels() - 1;
 }
 

db/version_set.h

@@ -530,7 +530,7 @@ class Version {
   // checked during read operations. In certain cases (trivial move or preload),
   // the filter block may already be cached, but we still do not access it such
   // that it eventually expires from the cache.
-  bool IsFilterSkipped(int level);
+  bool IsFilterSkipped(int level, bool is_file_last_in_level = false);
 
   // The helper function of UpdateAccumulatedStats, which may fill the missing
   // fields of file_mata from its associated TableProperties.

db/write_batch_test.cc

@@ -308,6 +308,120 @@ TEST_F(WriteBatchTest, Blob) {
       handler.seen);
 }
 
+// It requires more than 30GB of memory to run the test. With single memory
+// allocation of more than 30GB.
+// Not all platform can run it. Also it runs a long time. So disable it.
+TEST_F(WriteBatchTest, DISABLED_ManyUpdates) {
+  // Insert key and value of 3GB and push total batch size to 12GB.
+  static const size_t kKeyValueSize = 4u;
+  static const uint32_t kNumUpdates = 3 << 30;
+  std::string raw(kKeyValueSize, 'A');
+  WriteBatch batch(kNumUpdates * (4 + kKeyValueSize * 2) + 1024u);
+  char c = 'A';
+  for (uint32_t i = 0; i < kNumUpdates; i++) {
+    if (c > 'Z') {
+      c = 'A';
+    }
+    raw[0] = c;
+    raw[raw.length() - 1] = c;
+    c++;
+    batch.Put(raw, raw);
+  }
+
+  ASSERT_EQ(kNumUpdates, batch.Count());
+
+  struct NoopHandler : public WriteBatch::Handler {
+    uint32_t num_seen = 0;
+    char expected_char = 'A';
+    virtual Status PutCF(uint32_t column_family_id, const Slice& key,
+                         const Slice& value) override {
+      EXPECT_EQ(kKeyValueSize, key.size());
+      EXPECT_EQ(kKeyValueSize, value.size());
+      EXPECT_EQ(expected_char, key[0]);
+      EXPECT_EQ(expected_char, value[0]);
+      EXPECT_EQ(expected_char, key[kKeyValueSize - 1]);
+      EXPECT_EQ(expected_char, value[kKeyValueSize - 1]);
+      expected_char++;
+      if (expected_char > 'Z') {
+        expected_char = 'A';
+      }
+      ++num_seen;
+      return Status::OK();
+    }
+    virtual Status DeleteCF(uint32_t column_family_id,
+                            const Slice& key) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual Status SingleDeleteCF(uint32_t column_family_id,
+                                  const Slice& key) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual Status MergeCF(uint32_t column_family_id, const Slice& key,
+                           const Slice& value) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual void LogData(const Slice& blob) override { EXPECT_TRUE(false); }
+    virtual bool Continue() override { return num_seen < kNumUpdates; }
+  } handler;
+
+  batch.Iterate(&handler);
+  ASSERT_EQ(kNumUpdates, handler.num_seen);
+}
+
+// The test requires more than 18GB memory to run it, with single memory
+// allocation of more than 12GB. Not all the platform can run it. So disable it.
+TEST_F(WriteBatchTest, DISABLED_LargeKeyValue) {
+  // Insert key and value of 3GB and push total batch size to 12GB.
+  static const size_t kKeyValueSize = 3221225472u;
+  std::string raw(kKeyValueSize, 'A');
+  WriteBatch batch(12884901888u + 1024u);
+  for (char i = 0; i < 2; i++) {
+    raw[0] = 'A' + i;
+    raw[raw.length() - 1] = 'A' - i;
+    batch.Put(raw, raw);
+  }
+
+  ASSERT_EQ(2, batch.Count());
+
+  struct NoopHandler : public WriteBatch::Handler {
+    int num_seen = 0;
+    virtual Status PutCF(uint32_t column_family_id, const Slice& key,
+                         const Slice& value) override {
+      EXPECT_EQ(kKeyValueSize, key.size());
+      EXPECT_EQ(kKeyValueSize, value.size());
+      EXPECT_EQ('A' + num_seen, key[0]);
+      EXPECT_EQ('A' + num_seen, value[0]);
+      EXPECT_EQ('A' - num_seen, key[kKeyValueSize - 1]);
+      EXPECT_EQ('A' - num_seen, value[kKeyValueSize - 1]);
+      ++num_seen;
+      return Status::OK();
+    }
+    virtual Status DeleteCF(uint32_t column_family_id,
+                            const Slice& key) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual Status SingleDeleteCF(uint32_t column_family_id,
+                                  const Slice& key) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual Status MergeCF(uint32_t column_family_id, const Slice& key,
+                           const Slice& value) override {
+      EXPECT_TRUE(false);
+      return Status::OK();
+    }
+    virtual void LogData(const Slice& blob) override { EXPECT_TRUE(false); }
+    virtual bool Continue() override { return num_seen < 2; }
+  } handler;
+
+  batch.Iterate(&handler);
+  ASSERT_EQ(2, handler.num_seen);
+}
+
 TEST_F(WriteBatchTest, Continue) {
   WriteBatch batch;
 

db/write_controller.cc

@@ -26,6 +26,13 @@ std::unique_ptr<WriteControllerToken> WriteController::GetDelayToken(
   return std::unique_ptr<WriteControllerToken>(new DelayWriteToken(this));
 }
 
+std::unique_ptr<WriteControllerToken>
+WriteController::GetCompactionPressureToken() {
+  ++total_compaction_pressure_;
+  return std::unique_ptr<WriteControllerToken>(
+      new CompactionPressureToken(this));
+}
+
 bool WriteController::IsStopped() const { return total_stopped_ > 0; }
 // This is inside DB mutex, so we can't sleep and need to minimize
 // frequency to get time.
@@ -106,4 +113,9 @@ DelayWriteToken::~DelayWriteToken() {
   assert(controller_->total_delayed_ >= 0);
 }
 
+CompactionPressureToken::~CompactionPressureToken() {
+  controller_->total_compaction_pressure_--;
+  assert(controller_->total_compaction_pressure_ >= 0);
+}
+
 }  // namespace rocksdb

db/write_controller.h

@@ -23,6 +23,7 @@ class WriteController {
   explicit WriteController(uint64_t _delayed_write_rate = 1024u * 1024u * 32u)
       : total_stopped_(0),
         total_delayed_(0),
+        total_compaction_pressure_(0),
         bytes_left_(0),
         last_refill_time_(0) {
     set_delayed_write_rate(_delayed_write_rate);
@@ -38,10 +39,16 @@ class WriteController {
   // which returns number of microseconds to sleep.
   std::unique_ptr<WriteControllerToken> GetDelayToken(
       uint64_t delayed_write_rate);
+  // When an actor (column family) requests a moderate token, compaction
+  // threads will be increased
+  std::unique_ptr<WriteControllerToken> GetCompactionPressureToken();
 
-  // these two metods are querying the state of the WriteController
+  // these three metods are querying the state of the WriteController
   bool IsStopped() const;
   bool NeedsDelay() const { return total_delayed_ > 0; }
+  bool NeedSpeedupCompaction() const {
+    return IsStopped() || NeedsDelay() || total_compaction_pressure_ > 0;
+  }
   // return how many microseconds the caller needs to sleep after the call
   // num_bytes: how many number of bytes to put into the DB.
   // Prerequisite: DB mutex held.
@@ -59,9 +66,11 @@ class WriteController {
   friend class WriteControllerToken;
   friend class StopWriteToken;
   friend class DelayWriteToken;
+  friend class CompactionPressureToken;
 
   int total_stopped_;
   int total_delayed_;
+  int total_compaction_pressure_;
   uint64_t bytes_left_;
   uint64_t last_refill_time_;
   uint64_t delayed_write_rate_;
@@ -96,4 +105,11 @@ class DelayWriteToken : public WriteControllerToken {
   virtual ~DelayWriteToken();
 };
 
+class CompactionPressureToken : public WriteControllerToken {
+ public:
+  explicit CompactionPressureToken(WriteController* controller)
+      : WriteControllerToken(controller) {}
+  virtual ~CompactionPressureToken();
+};
+
 }  // namespace rocksdb

include/rocksdb/options.h

@@ -933,8 +933,19 @@ struct DBOptions {
   // regardless of this setting
   uint64_t delete_obsolete_files_period_micros;
 
+  // Suggested number of concurrent background compaction jobs, submitted to
+  // the default LOW priority thread pool.
+  //
+  // Default: max_background_compactions
+  int base_background_compactions;
+
   // Maximum number of concurrent background compaction jobs, submitted to
   // the default LOW priority thread pool.
+  // We first try to schedule compactions based on
+  // `base_background_compactions`. If the compaction cannot catch up , we
+  // will increase number of compaction threads up to
+  // `max_background_compactions`.
+  //
   // If you're increasing this, also consider increasing number of threads in
   // LOW priority thread pool. For more information, see
   // Env::SetBackgroundThreads
@@ -1110,6 +1121,9 @@ struct DBOptions {
   // This option is currently honored only on Windows
   //
   // Default: 1 Mb
+  //
+  // Special value: 0 - means do not maintain per instance buffer. Allocate
+  //                per request buffer and avoid locking.
   size_t random_access_max_buffer_size;
 
   // This is the maximum buffer size that is used by WritableFileWriter.

include/rocksdb/perf_context.h

@@ -21,7 +21,7 @@ struct PerfContext {
 
   void Reset(); // reset all performance counters to zero
 
-  std::string ToString() const;
+  std::string ToString(bool exclude_zero_counters = false) const;
 
   uint64_t user_key_comparison_count; // total number of user key comparisons
   uint64_t block_cache_hit_count;     // total number of block cache hits

include/rocksdb/statistics.h

@@ -280,6 +280,10 @@ enum Histograms : uint32_t {
   SST_READ_MICROS,
   // The number of subcompactions actually scheduled during a compaction
   NUM_SUBCOMPACTIONS_SCHEDULED,
+  // Value size distribution in each operation
+  BYTES_PER_READ,
+  BYTES_PER_WRITE,
+  BYTES_PER_MULTIGET,
   HISTOGRAM_ENUM_MAX,  // TODO(ldemailly): enforce HistogramsNameMap match
 };
 
@@ -307,6 +311,9 @@ const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
     {WRITE_STALL, "rocksdb.db.write.stall"},
     {SST_READ_MICROS, "rocksdb.sst.read.micros"},
     {NUM_SUBCOMPACTIONS_SCHEDULED, "rocksdb.num.subcompactions.scheduled"},
+    {BYTES_PER_READ, "rocksdb.bytes.per.read"},
+    {BYTES_PER_WRITE, "rocksdb.bytes.per.write"},
+    {BYTES_PER_MULTIGET, "rocksdb.bytes.per.multiget"},
 };
 
 struct HistogramData {

port/win/env_win.cc

@@ -766,6 +766,18 @@ class WinRandomAccessFile : public RandomAccessFile {
     return read;
   }
 
+  void CalculateReadParameters(uint64_t offset, size_t bytes_requested,
+                                size_t& actual_bytes_toread,
+                                uint64_t& first_page_start) const {
+
+    const size_t alignment = buffer_.Alignment();
+
+    first_page_start = TruncateToPageBoundary(alignment, offset);
+    const uint64_t last_page_start =
+      TruncateToPageBoundary(alignment, offset + bytes_requested - 1);
+    actual_bytes_toread = (last_page_start - first_page_start) + alignment;
+  }
+
  public:
   WinRandomAccessFile(const std::string& fname, HANDLE hFile, size_t alignment,
                       const EnvOptions& options)
@@ -797,66 +809,87 @@ class WinRandomAccessFile : public RandomAccessFile {
 
   virtual Status Read(uint64_t offset, size_t n, Slice* result,
                       char* scratch) const override {
+
     Status s;
     SSIZE_T r = -1;
     size_t left = n;
     char* dest = scratch;
 
+    if (n == 0) {
+      *result = Slice(scratch, 0);
+      return s;
+    }
+
     // When in unbuffered mode we need to do the following changes:
     // - use our own aligned buffer
     // - always read at the offset of that is a multiple of alignment
     if (!use_os_buffer_) {
-      std::unique_lock<std::mutex> lock(buffer_mut_);
 
-      // Let's see if at least some of the requested data is already
-      // in the buffer
-      if (offset >= buffered_start_ &&
-          offset < (buffered_start_ + buffer_.CurrentSize())) {
-        size_t buffer_offset = offset - buffered_start_;
-        r = buffer_.Read(dest, buffer_offset, left);
-        assert(r >= 0);
+      uint64_t first_page_start = 0;
+      size_t actual_bytes_toread = 0;
+      size_t bytes_requested = left;
 
-        left -= size_t(r);
-        offset += r;
-        dest += r;
-      }
+      if (!read_ahead_ && random_access_max_buffer_size_ == 0) {
+        CalculateReadParameters(offset, bytes_requested, actual_bytes_toread,
+          first_page_start);
 
-      // Still some left or none was buffered
-      if (left > 0) {
-        // Figure out the start/end offset for reading and amount to read
-        const size_t alignment = buffer_.Alignment();
-        const size_t first_page_start =
-            TruncateToPageBoundary(alignment, offset);
+        assert(actual_bytes_toread > 0);
+
+        r = ReadIntoOneShotBuffer(offset, first_page_start,
+          actual_bytes_toread, left, dest);
+      } else {
+
+        std::unique_lock<std::mutex> lock(buffer_mut_);
+
+        // Let's see if at least some of the requested data is already
+        // in the buffer
+        if (offset >= buffered_start_ &&
+          offset < (buffered_start_ + buffer_.CurrentSize())) {
+          size_t buffer_offset = offset - buffered_start_;
+          r = buffer_.Read(dest, buffer_offset, left);
+          assert(r >= 0);
 
-        size_t bytes_requested = left;
-        if (read_ahead_ && bytes_requested < compaction_readahead_size_) {
-          bytes_requested = compaction_readahead_size_;
+          left -= size_t(r);
+          offset += r;
+          dest += r;
         }
 
-        const size_t last_page_start =
-            TruncateToPageBoundary(alignment, offset + bytes_requested - 1);
-        const size_t actual_bytes_toread =
-            (last_page_start - first_page_start) + alignment;
+        // Still some left or none was buffered
+        if (left > 0) {
+          // Figure out the start/end offset for reading and amount to read
+          bytes_requested = left;
 
-        if (buffer_.Capacity() < actual_bytes_toread) {
-          // If we are in read-ahead mode or the requested size
-          // exceeds max buffer size then use one-shot
-          // big buffer otherwise reallocate main buffer
-          if (read_ahead_ ||
+          if (read_ahead_ && bytes_requested < compaction_readahead_size_) {
+            bytes_requested = compaction_readahead_size_;
+          }
+
+          CalculateReadParameters(offset, bytes_requested, actual_bytes_toread,
+            first_page_start);
+
+          assert(actual_bytes_toread > 0);
+
+          if (buffer_.Capacity() < actual_bytes_toread) {
+            // If we are in read-ahead mode or the requested size
+            // exceeds max buffer size then use one-shot
+            // big buffer otherwise reallocate main buffer
+            if (read_ahead_ ||
               (actual_bytes_toread > random_access_max_buffer_size_)) {
-            // Unlock the mutex since we are not using instance buffer
-            lock.unlock();
-            r = ReadIntoOneShotBuffer(offset, first_page_start,
-                                      actual_bytes_toread, left, dest);
-          } else {
-            buffer_.AllocateNewBuffer(actual_bytes_toread);
+              // Unlock the mutex since we are not using instance buffer
+              lock.unlock();
+              r = ReadIntoOneShotBuffer(offset, first_page_start,
+                actual_bytes_toread, left, dest);
+            }
+            else {
+              buffer_.AllocateNewBuffer(actual_bytes_toread);
+              r = ReadIntoInstanceBuffer(offset, first_page_start,
+                actual_bytes_toread, left, dest);
+            }
+          }
+          else {
+            buffer_.Clear();
             r = ReadIntoInstanceBuffer(offset, first_page_start,
-                                       actual_bytes_toread, left, dest);
+              actual_bytes_toread, left, dest);
           }
-        } else {
-          buffer_.Clear();
-          r = ReadIntoInstanceBuffer(offset, first_page_start,
-                                     actual_bytes_toread, left, dest);
         }
       }
     } else {
@@ -1105,6 +1138,8 @@ void WinthreadCall(const char* label, std::error_code result) {
 }
 }
 
+typedef VOID(WINAPI * FnGetSystemTimePreciseAsFileTime)(LPFILETIME);
+
 class WinEnv : public Env {
  public:
   WinEnv();
@@ -1643,25 +1678,29 @@ class WinEnv : public Env {
   }
 
   virtual uint64_t NowMicros() override {
-    // all std::chrono clocks on windows proved to return
-    // values that may repeat that is not good enough for some uses.
-    const int64_t c_UnixEpochStartTicks = 116444736000000000i64;
-    const int64_t c_FtToMicroSec = 10;
-
-    // This interface needs to return system time and not
-    // just any microseconds because it is often used as an argument
-    // to TimedWait() on condition variable
-    FILETIME ftSystemTime;
-    GetSystemTimePreciseAsFileTime(&ftSystemTime);
-
-    LARGE_INTEGER li;
-    li.LowPart = ftSystemTime.dwLowDateTime;
-    li.HighPart = ftSystemTime.dwHighDateTime;
-    // Subtract unix epoch start
-    li.QuadPart -= c_UnixEpochStartTicks;
-    // Convert to microsecs
-    li.QuadPart /= c_FtToMicroSec;
-    return li.QuadPart;
+    if (GetSystemTimePreciseAsFileTime_ != NULL) {
+      // all std::chrono clocks on windows proved to return
+      // values that may repeat that is not good enough for some uses.
+      const int64_t c_UnixEpochStartTicks = 116444736000000000i64;
+      const int64_t c_FtToMicroSec = 10;
+
+      // This interface needs to return system time and not
+      // just any microseconds because it is often used as an argument
+      // to TimedWait() on condition variable
+      FILETIME ftSystemTime;
+      GetSystemTimePreciseAsFileTime_(&ftSystemTime);
+
+      LARGE_INTEGER li;
+      li.LowPart = ftSystemTime.dwLowDateTime;
+      li.HighPart = ftSystemTime.dwHighDateTime;
+      // Subtract unix epoch start
+      li.QuadPart -= c_UnixEpochStartTicks;
+      // Convert to microsecs
+      li.QuadPart /= c_FtToMicroSec;
+      return li.QuadPart;
+    }
+    using namespace std::chrono;
+    return duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
   }
 
   virtual uint64_t NowNanos() override {
@@ -2071,6 +2110,7 @@ class WinEnv : public Env {
   std::vector<ThreadPool> thread_pools_;
   mutable std::mutex mu_;
   std::vector<std::thread> threads_to_join_;
+  FnGetSystemTimePreciseAsFileTime GetSystemTimePreciseAsFileTime_;
 };
 
 WinEnv::WinEnv()
@@ -2079,7 +2119,15 @@ WinEnv::WinEnv()
       page_size_(4 * 1012),
       allocation_granularity_(page_size_),
       perf_counter_frequency_(0),
-      thread_pools_(Priority::TOTAL) {
+      thread_pools_(Priority::TOTAL),
+      GetSystemTimePreciseAsFileTime_(NULL) {
+
+  HMODULE module = GetModuleHandle("kernel32.dll");
+  if (module != NULL) {
+    GetSystemTimePreciseAsFileTime_ = (FnGetSystemTimePreciseAsFileTime)GetProcAddress(
+      module, "GetSystemTimePreciseAsFileTime");
+  }
+
   SYSTEM_INFO sinfo;
   GetSystemInfo(&sinfo);
 

util/options.cc

@@ -229,6 +229,7 @@ DBOptions::DBOptions()
       db_log_dir(""),
       wal_dir(""),
       delete_obsolete_files_period_micros(6ULL * 60 * 60 * 1000000),
+      base_background_compactions(-1),
       max_background_compactions(1),
       max_subcompactions(1),
       max_background_flushes(1),
@@ -295,6 +296,7 @@ DBOptions::DBOptions(const Options& options)
       wal_dir(options.wal_dir),
       delete_obsolete_files_period_micros(
           options.delete_obsolete_files_period_micros),
+      base_background_compactions(options.base_background_compactions),
       max_background_compactions(options.max_background_compactions),
       max_subcompactions(options.max_subcompactions),
       max_background_flushes(options.max_background_flushes),
@@ -383,6 +385,8 @@ void DBOptions::Dump(Logger* log) const {
         table_cache_numshardbits);
     Header(log, "    Options.delete_obsolete_files_period_micros: %" PRIu64,
         delete_obsolete_files_period_micros);
+    Header(log, "             Options.base_background_compactions: %d",
+           base_background_compactions);
     Header(log, "             Options.max_background_compactions: %d",
         max_background_compactions);
     Header(log, "                     Options.max_subcompactions: %" PRIu32,
@@ -652,6 +656,7 @@ Options::PrepareForBulkLoad()
   // to L1. This is helpful so that all files that are
   // input to the manual compaction are all at L0.
   max_background_compactions = 2;
+  base_background_compactions = 2;
 
   // The compaction would create large files in L1.
   target_file_size_base = 256 * 1024 * 1024;

util/options_helper.h

@@ -208,7 +208,7 @@ static std::unordered_map<std::string, OptionTypeInfo> db_options_type_info = {
      {offsetof(struct DBOptions, random_access_max_buffer_size),
       OptionType::kSizeT, OptionVerificationType::kNormal}},
     {"writable_file_max_buffer_size",
-     {offsetof(struct DBOptions, writable_file_max_buffer_size),  
+     {offsetof(struct DBOptions, writable_file_max_buffer_size),
       OptionType::kSizeT, OptionVerificationType::kNormal}},
     {"use_adaptive_mutex",
      {offsetof(struct DBOptions, use_adaptive_mutex), OptionType::kBoolean,
@@ -219,6 +219,9 @@ static std::unordered_map<std::string, OptionTypeInfo> db_options_type_info = {
     {"max_background_compactions",
      {offsetof(struct DBOptions, max_background_compactions), OptionType::kInt,
       OptionVerificationType::kNormal}},
+    {"base_background_compactions",
+     {offsetof(struct DBOptions, base_background_compactions), OptionType::kInt,
+      OptionVerificationType::kNormal}},
     {"max_background_flushes",
      {offsetof(struct DBOptions, max_background_flushes), OptionType::kInt,
       OptionVerificationType::kNormal}},

util/options_test.cc

@@ -1669,50 +1669,7 @@ TEST_F(OptionsParserTest, DBOptionsAllFieldsSettable) {
                              "table_cache_numshardbits=28;"
                              "max_open_files=72;"
                              "max_file_opening_threads=35;"
-                             "max_background_compactions=33;"
-                             "use_fsync=true;"
-                             "use_adaptive_mutex=false;"
-                             "max_total_wal_size=4295005604;"
-                             "compaction_readahead_size=0;"
-                             "new_table_reader_for_compaction_inputs=false;"
-                             "keep_log_file_num=4890;"
-                             "skip_stats_update_on_db_open=false;"
-                             "max_manifest_file_size=4295009941;"
-                             "db_log_dir=path/to/db_log_dir;"
-                             "skip_log_error_on_recovery=true;"
-                             "writable_file_max_buffer_size=1048576;"
-                             "paranoid_checks=true;"
-                             "is_fd_close_on_exec=false;"
-                             "bytes_per_sync=4295013613;"
-                             "enable_thread_tracking=false;"
-                             "disable_data_sync=false;"
-                             "recycle_log_file_num=0;"
-                             "disableDataSync=false;"
-                             "create_missing_column_families=true;"
-                             "log_file_time_to_roll=3097;"
-                             "max_background_flushes=35;"
-                             "create_if_missing=false;"
-                             "error_if_exists=true;"
-                             "allow_os_buffer=false;"
-                             "delayed_write_rate=4294976214;"
-                             "manifest_preallocation_size=1222;"
-                             "allow_mmap_writes=false;"
-                             "stats_dump_period_sec=70127;"
-                             "allow_fallocate=true;"
-                             "allow_mmap_reads=false;"
-                             "max_log_file_size=4607;"
-                             "random_access_max_buffer_size=1048576;"
-                             "advise_random_on_open=true;"
-                             "wal_bytes_per_sync=4295048118;"
-                             "delete_obsolete_files_period_micros=4294967758;"
-                             "WAL_ttl_seconds=4295008036;"
-                             "WAL_size_limit_MB=4295036161;"
-                             "wal_dir=path/to/wal_dir;"
-                             "db_write_buffer_size=2587;"
-                             "max_subcompactions=64330;"
-                             "table_cache_numshardbits=28;"
-                             "max_open_files=72;"
-                             "max_file_opening_threads=35;"
+                             "base_background_compactions=3;"
                              "max_background_compactions=33;"
                              "use_fsync=true;"
                              "use_adaptive_mutex=false;"

util/perf_context.cc

@@ -61,32 +61,54 @@ void PerfContext::Reset() {
 #endif
 }
 
-#define OUTPUT(counter) #counter << " = " << counter << ", "
+#define OUTPUT(counter)                          \
+  if (!exclude_zero_counters || (counter > 0)) { \
+    ss << #counter << " = " << counter << ", ";  \
+  }
 
-std::string PerfContext::ToString() const {
+std::string PerfContext::ToString(bool exclude_zero_counters) const {
 #if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)
   return "";
 #else
   std::ostringstream ss;
-  ss << OUTPUT(user_key_comparison_count) << OUTPUT(block_cache_hit_count)
-     << OUTPUT(block_read_count) << OUTPUT(block_read_byte)
-     << OUTPUT(block_read_time) << OUTPUT(block_checksum_time)
-     << OUTPUT(block_decompress_time) << OUTPUT(internal_key_skipped_count)
-     << OUTPUT(internal_delete_skipped_count) << OUTPUT(write_wal_time)
-     << OUTPUT(get_snapshot_time) << OUTPUT(get_from_memtable_time)
-     << OUTPUT(get_from_memtable_count) << OUTPUT(get_post_process_time)
-     << OUTPUT(get_from_output_files_time) << OUTPUT(seek_on_memtable_time)
-     << OUTPUT(seek_on_memtable_count) << OUTPUT(seek_child_seek_time)
-     << OUTPUT(seek_child_seek_count) << OUTPUT(seek_min_heap_time)
-     << OUTPUT(seek_internal_seek_time) << OUTPUT(find_next_user_entry_time)
-     << OUTPUT(write_pre_and_post_process_time) << OUTPUT(write_memtable_time)
-     << OUTPUT(db_mutex_lock_nanos) << OUTPUT(db_condition_wait_nanos)
-     << OUTPUT(merge_operator_time_nanos) << OUTPUT(write_delay_time)
-     << OUTPUT(read_index_block_nanos) << OUTPUT(read_filter_block_nanos)
-     << OUTPUT(new_table_block_iter_nanos) << OUTPUT(new_table_iterator_nanos)
-     << OUTPUT(block_seek_nanos) << OUTPUT(find_table_nanos)
-     << OUTPUT(bloom_memtable_hit_count) << OUTPUT(bloom_memtable_miss_count)
-     << OUTPUT(bloom_sst_hit_count) << OUTPUT(bloom_sst_miss_count);
+  OUTPUT(user_key_comparison_count);
+  OUTPUT(block_cache_hit_count);
+  OUTPUT(block_read_count);
+  OUTPUT(block_read_byte);
+  OUTPUT(block_read_time);
+  OUTPUT(block_checksum_time);
+  OUTPUT(block_decompress_time);
+  OUTPUT(internal_key_skipped_count);
+  OUTPUT(internal_delete_skipped_count);
+  OUTPUT(write_wal_time);
+  OUTPUT(get_snapshot_time);
+  OUTPUT(get_from_memtable_time);
+  OUTPUT(get_from_memtable_count);
+  OUTPUT(get_post_process_time);
+  OUTPUT(get_from_output_files_time);
+  OUTPUT(seek_on_memtable_time);
+  OUTPUT(seek_on_memtable_count);
+  OUTPUT(seek_child_seek_time);
+  OUTPUT(seek_child_seek_count);
+  OUTPUT(seek_min_heap_time);
+  OUTPUT(seek_internal_seek_time);
+  OUTPUT(find_next_user_entry_time);
+  OUTPUT(write_pre_and_post_process_time);
+  OUTPUT(write_memtable_time);
+  OUTPUT(db_mutex_lock_nanos);
+  OUTPUT(db_condition_wait_nanos);
+  OUTPUT(merge_operator_time_nanos);
+  OUTPUT(write_delay_time);
+  OUTPUT(read_index_block_nanos);
+  OUTPUT(read_filter_block_nanos);
+  OUTPUT(new_table_block_iter_nanos);
+  OUTPUT(new_table_iterator_nanos);
+  OUTPUT(block_seek_nanos);
+  OUTPUT(find_table_nanos);
+  OUTPUT(bloom_memtable_hit_count);
+  OUTPUT(bloom_memtable_miss_count);
+  OUTPUT(bloom_sst_hit_count);
+  OUTPUT(bloom_sst_miss_count);
   return ss.str();
 #endif
 }