Add logs and stats in DeleteScheduler (#6927)

Summary:
Add logs and stats for files marked as trash and files deleted immediately in DeleteScheduler
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6927

Test Plan: make check -j64

Reviewed By: riversand963

Differential Revision: D21869068

Pulled By: akankshamahajan15

fbshipit-source-id: e9f673c4fa8049ce648b23c75d742f2f9c6c57a1

db/db_impl/db_impl_open.cc

@@ -1569,6 +1569,12 @@ Status DBImpl::Open(const DBOptions& db_options, const std::string& dbname,
   auto sfm = static_cast<SstFileManagerImpl*>(
       impl->immutable_db_options_.sst_file_manager.get());
   if (s.ok() && sfm) {
+    // Set Statistics ptr for SstFileManager to dump the stats of
+    // DeleteScheduler.
+    sfm->SetStatisticsPtr(impl->immutable_db_options_.statistics);
+    ROCKS_LOG_INFO(impl->immutable_db_options_.info_log,
+                   "SstFileManager instance %p", sfm);
+
     // Notify SstFileManager about all sst files that already exist in
     // db_paths[0] and cf_paths[0] when the DB is opened.
 

db/db_sst_test.cc

@@ -376,6 +376,7 @@ TEST_F(DBSSTTest, RateLimitedDelete) {
   env_->SetTimeElapseOnlySleep(&options);
   options.disable_auto_compactions = true;
   options.env = env_;
+  options.statistics = CreateDBStatistics();
 
   int64_t rate_bytes_per_sec = 1024 * 10;  // 10 Kbs / Sec
   Status s;
@@ -425,6 +426,9 @@ TEST_F(DBSSTTest, RateLimitedDelete) {
   }
   ASSERT_GT(time_spent_deleting, expected_penlty * 0.9);
   ASSERT_LT(time_spent_deleting, expected_penlty * 1.1);
+  ASSERT_EQ(4, options.statistics->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(
+      0, options.statistics->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
 
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
@@ -816,6 +820,12 @@ TEST_F(DBSSTTest, CancellingCompactionsWorks) {
   ASSERT_EQ(sfm->GetCompactionsReservedSize(), 0);
   // Make sure the stat is bumped
   ASSERT_GT(dbfull()->immutable_db_options().statistics.get()->getTickerCount(COMPACTION_CANCELLED), 0);
+  ASSERT_EQ(0,
+            dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                FILES_MARKED_TRASH));
+  ASSERT_EQ(4,
+            dbfull()->immutable_db_options().statistics.get()->getTickerCount(
+                FILES_DELETED_IMMEDIATELY));
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
 

file/delete_scheduler.cc

@@ -7,6 +7,7 @@
 
 #include "file/delete_scheduler.h"
 
+#include <cinttypes>
 #include <thread>
 #include <vector>
 
@@ -65,6 +66,12 @@ Status DeleteScheduler::DeleteFile(const std::string& file_path,
     s = fs_->DeleteFile(file_path, IOOptions(), nullptr);
     if (s.ok()) {
       sst_file_manager_->OnDeleteFile(file_path);
+      ROCKS_LOG_INFO(info_log_,
+                     "Deleted file %s immediately, rate_bytes_per_sec %" PRIi64
+                     ", total_trash_size %" PRIu64 " max_trash_db_ratio %lf",
+                     file_path.c_str(), rate_bytes_per_sec_.load(),
+                     total_trash_size_.load(), max_trash_db_ratio_.load());
+      RecordTick(stats_.get(), FILES_DELETED_IMMEDIATELY);
     }
     return s;
   }
@@ -72,6 +79,8 @@ Status DeleteScheduler::DeleteFile(const std::string& file_path,
   // Move file to trash
   std::string trash_file;
   s = MarkAsTrash(file_path, &trash_file);
+  ROCKS_LOG_INFO(info_log_, "Mark file: %s as trash -- %s", trash_file.c_str(),
+                 s.ToString().c_str());
 
   if (!s.ok()) {
     ROCKS_LOG_ERROR(info_log_, "Failed to mark %s as trash -- %s",
@@ -79,10 +88,14 @@ Status DeleteScheduler::DeleteFile(const std::string& file_path,
     s = fs_->DeleteFile(file_path, IOOptions(), nullptr);
     if (s.ok()) {
       sst_file_manager_->OnDeleteFile(file_path);
+      ROCKS_LOG_INFO(info_log_, "Deleted file %s immediately",
+                     trash_file.c_str());
+      RecordTick(stats_.get(), FILES_DELETED_IMMEDIATELY);
     }
     return s;
   }
 
+  RecordTick(stats_.get(), FILES_MARKED_TRASH);
   // Update the total trash size
   uint64_t trash_file_size = 0;
   fs_->GetFileSize(trash_file, IOOptions(), &trash_file_size, nullptr);
@@ -210,6 +223,8 @@ void DeleteScheduler::BackgroundEmptyTrash() {
         current_delete_rate = rate_bytes_per_sec_.load();
         start_time = env_->NowMicros();
         total_deleted_bytes = 0;
+        ROCKS_LOG_INFO(info_log_, "rate_bytes_per_sec is changed to %" PRIi64,
+                       current_delete_rate);
       }
 
       // Get new file to delete
@@ -233,19 +248,27 @@ void DeleteScheduler::BackgroundEmptyTrash() {
         bg_errors_[path_in_trash] = s;
       }
 
-      // Apply penlty if necessary
-      uint64_t total_penlty;
+      // Apply penalty if necessary
+      uint64_t total_penalty;
       if (current_delete_rate > 0) {
         // rate limiting is enabled
-        total_penlty =
+        total_penalty =
             ((total_deleted_bytes * kMicrosInSecond) / current_delete_rate);
-        while (!closing_ && !cv_.TimedWait(start_time + total_penlty)) {}
+        ROCKS_LOG_INFO(info_log_,
+                       "Rate limiting is enabled with penalty %" PRIu64
+                       "after deleting file %s",
+                       total_penalty, path_in_trash.c_str());
+        while (!closing_ && !cv_.TimedWait(start_time + total_penalty)) {
+        }
       } else {
         // rate limiting is disabled
-        total_penlty = 0;
+        total_penalty = 0;
+        ROCKS_LOG_INFO(info_log_,
+                       "Rate limiting is disabled after deleting file %s",
+                       path_in_trash.c_str());
       }
       TEST_SYNC_POINT_CALLBACK("DeleteScheduler::BackgroundEmptyTrash:Wait",
-                               &total_penlty);
+                               &total_penalty);
 
       if (is_complete) {
         pending_files_--;
@@ -356,6 +379,10 @@ void DeleteScheduler::MaybeCreateBackgroundThread() {
   if (bg_thread_ == nullptr && rate_bytes_per_sec_.load() > 0) {
     bg_thread_.reset(
         new port::Thread(&DeleteScheduler::BackgroundEmptyTrash, this));
+    ROCKS_LOG_INFO(info_log_,
+                   "Created background thread for deletion scheduler with "
+                   "rate_bytes_per_sec: %" PRIi64,
+                   rate_bytes_per_sec_.load());
   }
 }
 

file/delete_scheduler.h

@@ -83,6 +83,10 @@ class DeleteScheduler {
   static Status CleanupDirectory(Env* env, SstFileManagerImpl* sfm,
                                  const std::string& path);
 
+  void SetStatisticsPtr(const std::shared_ptr<Statistics>& stats) {
+    stats_ = stats;
+  }
+
  private:
   Status MarkAsTrash(const std::string& file_path, std::string* path_in_trash);
 
@@ -137,6 +141,7 @@ class DeleteScheduler {
   // immediately
   std::atomic<double> max_trash_db_ratio_;
   static const uint64_t kMicrosInSecond = 1000 * 1000LL;
+  std::shared_ptr<Statistics> stats_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

file/delete_scheduler_test.cc

@@ -32,6 +32,7 @@ class DeleteSchedulerTest : public testing::Test {
           ToString(i));
       DestroyAndCreateDir(dummy_files_dirs_.back());
     }
+    stats_ = ROCKSDB_NAMESPACE::CreateDBStatistics();
   }
 
   ~DeleteSchedulerTest() override {
@@ -99,6 +100,7 @@ class DeleteSchedulerTest : public testing::Test {
         new SstFileManagerImpl(env_, fs, nullptr, rate_bytes_per_sec_,
                                /* max_trash_db_ratio= */ 1.1, 128 * 1024));
     delete_scheduler_ = sst_file_mgr_->delete_scheduler();
+    sst_file_mgr_->SetStatisticsPtr(stats_);
   }
 
   Env* env_;
@@ -106,6 +108,7 @@ class DeleteSchedulerTest : public testing::Test {
   int64_t rate_bytes_per_sec_;
   DeleteScheduler* delete_scheduler_;
   std::unique_ptr<SstFileManagerImpl> sst_file_mgr_;
+  std::shared_ptr<Statistics> stats_;
 };
 
 // Test the basic functionality of DeleteScheduler (Rate Limiting).
@@ -182,6 +185,8 @@ TEST_F(DeleteSchedulerTest, BasicRateLimiting) {
     ASSERT_EQ(num_files, dir_synced);
 
     ASSERT_EQ(CountTrashFiles(), 0);
+    ASSERT_EQ(num_files, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+    ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
     ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
   }
 }
@@ -219,6 +224,9 @@ TEST_F(DeleteSchedulerTest, MultiDirectoryDeletionsScheduled) {
     ASSERT_EQ(0, CountTrashFiles(i));
   }
 
+  ASSERT_EQ(kNumFiles, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
+
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
 
@@ -301,6 +309,10 @@ TEST_F(DeleteSchedulerTest, RateLimitingMultiThreaded) {
 
     ASSERT_EQ(CountNormalFiles(), 0);
     ASSERT_EQ(CountTrashFiles(), 0);
+    ASSERT_EQ(num_files * thread_cnt,
+              stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+    ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
+
     ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
   }
 }
@@ -318,8 +330,9 @@ TEST_F(DeleteSchedulerTest, DisableRateLimiting) {
 
   rate_bytes_per_sec_ = 0;
   NewDeleteScheduler();
+  constexpr int num_files = 10;
 
-  for (int i = 0; i < 10; i++) {
+  for (int i = 0; i < num_files; i++) {
     // Every file we delete will be deleted immediately
     std::string dummy_file = NewDummyFile("dummy.data");
     ASSERT_OK(delete_scheduler_->DeleteFile(dummy_file, ""));
@@ -329,6 +342,9 @@ TEST_F(DeleteSchedulerTest, DisableRateLimiting) {
   }
 
   ASSERT_EQ(bg_delete_file, 0);
+  ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(num_files,
+            stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
 
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
@@ -365,6 +381,8 @@ TEST_F(DeleteSchedulerTest, ConflictNames) {
 
   auto bg_errors = delete_scheduler_->GetBackgroundErrors();
   ASSERT_EQ(bg_errors.size(), 0);
+  ASSERT_EQ(10, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
 
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }
@@ -439,9 +457,12 @@ TEST_F(DeleteSchedulerTest, StartBGEmptyTrashMultipleTimes) {
 
     auto bg_errors = delete_scheduler_->GetBackgroundErrors();
     ASSERT_EQ(bg_errors.size(), 0);
+    ASSERT_EQ(10, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+    ASSERT_EQ(0, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
   }
 
   ASSERT_EQ(bg_delete_file, 50);
+
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->EnableProcessing();
 }
 
@@ -653,6 +674,8 @@ TEST_F(DeleteSchedulerTest, ImmediateDeleteOn25PercDBSize) {
   // When we end up with 26 files in trash we will start
   // deleting new files immediately
   ASSERT_EQ(fg_delete_file, 74);
+  ASSERT_EQ(26, stats_->getAndResetTickerCount(FILES_MARKED_TRASH));
+  ASSERT_EQ(74, stats_->getAndResetTickerCount(FILES_DELETED_IMMEDIATELY));
 
   ROCKSDB_NAMESPACE::SyncPoint::GetInstance()->DisableProcessing();
 }

file/sst_file_manager_impl.h

@@ -135,6 +135,11 @@ class SstFileManagerImpl : public SstFileManager {
   // once in the object's lifetime, and before the destructor
   void Close();
 
+  void SetStatisticsPtr(const std::shared_ptr<Statistics>& stats) override {
+    stats_ = stats;
+    delete_scheduler_.SetStatisticsPtr(stats);
+  }
+
  private:
   // REQUIRES: mutex locked
   void OnAddFileImpl(const std::string& file_path, uint64_t file_size,
@@ -190,6 +195,7 @@ class SstFileManagerImpl : public SstFileManager {
   std::list<ErrorHandler*> error_handler_list_;
   // Pointer to ErrorHandler instance that is currently processing recovery
   ErrorHandler* cur_instance_;
+  std::shared_ptr<Statistics> stats_;
 };
 
 }  // namespace ROCKSDB_NAMESPACE

include/rocksdb/sst_file_manager.h

@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "rocksdb/file_system.h"
+#include "rocksdb/statistics.h"
 #include "rocksdb/status.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -80,6 +81,9 @@ class SstFileManager {
   // Return the total size of trash files
   // thread-safe
   virtual uint64_t GetTotalTrashSize() = 0;
+
+  // Set the statistics ptr to dump the stat information
+  virtual void SetStatisticsPtr(const std::shared_ptr<Statistics>& stats) = 0;
 };
 
 // Create a new SstFileManager that can be shared among multiple RocksDB

include/rocksdb/statistics.h

@@ -360,6 +360,12 @@ enum Tickers : uint32_t {
   //           <= BLOCK_CACHE_COMPRESSION_DICT_ADD
   BLOCK_CACHE_COMPRESSION_DICT_ADD_REDUNDANT,
 
+  // # of files marked as trash by sst file manager and will be deleted
+  // later by background thread.
+  FILES_MARKED_TRASH,
+  // # of files deleted immediately by sst file manger through delete scheduler.
+  FILES_DELETED_IMMEDIATELY,
+
   TICKER_ENUM_MAX
 };
 

java/rocksjni/portal.h

@@ -1292,8 +1292,8 @@ class ByteBufferJni : public JavaClass {
     return constructWith(env, direct, nullptr, capacity, jbytebuffer_clazz);
   }
 
-  static jobject constructWith(
-      JNIEnv* env, const bool direct, const char* buf, const size_t capacity, 
+  static jobject constructWith(JNIEnv* env, const bool direct, const char* buf,
+                               const size_t capacity,
                                jclass jbytebuffer_clazz = nullptr) {
     if (direct) {
       bool allocated = false;
@@ -4945,6 +4945,11 @@ class TickerTypeJni {
         return -0x0C;
       case ROCKSDB_NAMESPACE::Tickers::TXN_GET_TRY_AGAIN:
         return -0x0D;
+      case ROCKSDB_NAMESPACE::Tickers::FILES_MARKED_TRASH:
+        return -0x0E;
+      case ROCKSDB_NAMESPACE::Tickers::FILES_DELETED_IMMEDIATELY:
+        return -0X0F;
+
       case ROCKSDB_NAMESPACE::Tickers::TICKER_ENUM_MAX:
         // 0x5F for backwards compatibility on current minor version.
         return 0x5F;
@@ -5240,6 +5245,10 @@ class TickerTypeJni {
         return ROCKSDB_NAMESPACE::Tickers::TXN_SNAPSHOT_MUTEX_OVERHEAD;
       case -0x0D:
         return ROCKSDB_NAMESPACE::Tickers::TXN_GET_TRY_AGAIN;
+      case -0x0E:
+        return ROCKSDB_NAMESPACE::Tickers::FILES_MARKED_TRASH;
+      case -0x0F:
+        return ROCKSDB_NAMESPACE::Tickers::FILES_DELETED_IMMEDIATELY;
       case 0x5F:
         // 0x5F for backwards compatibility on current minor version.
         return ROCKSDB_NAMESPACE::Tickers::TICKER_ENUM_MAX;

java/src/main/java/org/rocksdb/TickerType.java

@@ -722,6 +722,16 @@ public enum TickerType {
      */
     TXN_GET_TRY_AGAIN((byte) -0x0D),
 
+    /**
+     * # of files marked as trash by delete scheduler
+     */
+    FILES_MARKED_TRASH((byte) -0x0E),
+
+    /**
+     * # of files deleted immediately by delete scheduler
+     */
+    FILES_DELETED_IMMEDIATELY((byte) -0x0f),
+
     TICKER_ENUM_MAX((byte) 0x5F);
 
     private final byte value;

monitoring/statistics.cc

@@ -184,6 +184,8 @@ const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
     {BLOCK_CACHE_DATA_ADD_REDUNDANT, "rocksdb.block.cache.data.add.redundant"},
     {BLOCK_CACHE_COMPRESSION_DICT_ADD_REDUNDANT,
      "rocksdb.block.cache.compression.dict.add.redundant"},
+    {FILES_MARKED_TRASH, "rocksdb.files.marked.trash"},
+    {FILES_DELETED_IMMEDIATELY, "rocksdb.files.deleted.immediately"},
 };
 
 const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {