Remove bytes_per_sync config option (#14276)

Summary:
Pull Request resolved: #14276

No production user of Legacy overrides the default value of `bytes_per_sync`. Replace the option with a constant `kBytesPerSync` to further reduce legacy blob db customizability / configuration surface.

Reviewed By: xingbowang

Differential Revision: D91089096

fbshipit-source-id: 162df65646a4f3a3fab3586cf6ff223e1917d86e

Author: mszeszko-meta

db_stress_tool/db_stress_common.h

@@ -297,7 +297,6 @@ DECLARE_uint32(occ_lock_bucket_count);
 
 // Options for StackableDB-based BlobDB
 DECLARE_bool(use_blob_db);
-DECLARE_uint64(blob_db_bytes_per_sync);
 DECLARE_uint64(blob_db_file_size);
 DECLARE_bool(blob_db_enable_gc);
 

db_stress_tool/db_stress_gflags.cc

@@ -425,11 +425,6 @@ DEFINE_bool(enable_write_thread_adaptive_yield,
 // Options for StackableDB-based BlobDB
 DEFINE_bool(use_blob_db, false, "[Stacked BlobDB] Use BlobDB.");
 
-DEFINE_uint64(
-    blob_db_bytes_per_sync,
-    ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().bytes_per_sync,
-    "[Stacked BlobDB] Sync blob files once per every N bytes written.");
-
 DEFINE_uint64(blob_db_file_size,
               ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().blob_file_size,
               "[Stacked BlobDB] Target size of each blob file.");

db_stress_tool/db_stress_test_base.cc

@@ -3844,7 +3844,6 @@ void StressTest::Open(SharedState* shared, bool reopen) {
         // StackableDB-based BlobDB
         if (FLAGS_use_blob_db) {
           blob_db::BlobDBOptions blob_db_options;
-          blob_db_options.bytes_per_sync = FLAGS_blob_db_bytes_per_sync;
           blob_db_options.blob_file_size = FLAGS_blob_db_file_size;
           blob_db_options.enable_garbage_collection = FLAGS_blob_db_enable_gc;
 

tools/db_bench_tool.cc

@@ -1064,10 +1064,6 @@ DEFINE_uint64(
     ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().ttl_range_secs,
     "[Stacked BlobDB] TTL bucket size to use when creating blob files.");
 
-DEFINE_uint64(blob_db_bytes_per_sync,
-              ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().bytes_per_sync,
-              "[Stacked BlobDB] Bytes to sync blob file at.");
-
 DEFINE_uint64(blob_db_file_size,
               ROCKSDB_NAMESPACE::blob_db::BlobDBOptions().blob_file_size,
               "[Stacked BlobDB] Target size of each blob file.");
@@ -5178,7 +5174,6 @@ class Benchmark {
       blob_db_options.enable_garbage_collection = FLAGS_blob_db_enable_gc;
       blob_db_options.max_db_size = FLAGS_blob_db_max_db_size;
       blob_db_options.ttl_range_secs = FLAGS_blob_db_ttl_range_secs;
-      blob_db_options.bytes_per_sync = FLAGS_blob_db_bytes_per_sync;
       blob_db_options.blob_file_size = FLAGS_blob_db_file_size;
       blob_db::BlobDB* ptr = nullptr;
       s = hooks.Open(options, blob_db_options, db_name, &ptr);

utilities/blob_db/blob_db.cc

@@ -74,9 +74,6 @@ void BlobDBOptions::Dump(Logger* log) const {
   ROCKS_LOG_HEADER(
       log, "                            BlobDBOptions.ttl_range_secs: %" PRIu64,
       ttl_range_secs);
-  ROCKS_LOG_HEADER(
-      log, "                            BlobDBOptions.bytes_per_sync: %" PRIu64,
-      bytes_per_sync);
   ROCKS_LOG_HEADER(
       log, "                            BlobDBOptions.blob_file_size: %" PRIu64,
       blob_file_size);

utilities/blob_db/blob_db.h

@@ -28,6 +28,10 @@ constexpr uint64_t kNoExpiration = std::numeric_limits<uint64_t>::max();
 // Name of the directory under the base DB where blobs will be stored.
 constexpr const char* kBlobDirName = "blob_dir";
 
+// Allows OS to incrementally sync blob files to disk for every
+// kBytesPerSync bytes written.
+constexpr uint64_t kBytesPerSync = 512 * 1024;
+
 struct BlobDBOptions {
   // Maximum size of the database (including SST files and blob files).
   //
@@ -42,11 +46,6 @@ struct BlobDBOptions {
   // and so on
   uint64_t ttl_range_secs = 3600;
 
-  // Allows OS to incrementally sync blob files to disk for every
-  // bytes_per_sync bytes written. Users shouldn't rely on it for
-  // persistency guarantee.
-  uint64_t bytes_per_sync = 512 * 1024;
-
   // the target size of each blob file. File will become immutable
   // after it exceeds that size
   uint64_t blob_file_size = 256 * 1024 * 1024;

utilities/blob_db/blob_db_impl.cc

@@ -89,7 +89,7 @@ BlobDBImpl::BlobDBImpl(const std::string& dbname,
       debug_level_(0) {
   clock_ = env_->GetSystemClock().get();
   blob_dir_ = dbname + "/" + kBlobDirName;
-  file_options_.bytes_per_sync = blob_db_options.bytes_per_sync;
+  file_options_.bytes_per_sync = kBytesPerSync;
 }
 
 BlobDBImpl::~BlobDBImpl() {

utilities/blob_db/blob_db_test.cc

@@ -1786,7 +1786,6 @@ TEST_F(BlobDBTest, SyncBlobFileBeforeClose) {
   options.statistics = CreateDBStatistics();
 
   BlobDBOptions blob_options;
-  blob_options.bytes_per_sync = 1 << 20;
   blob_options.disable_background_tasks = true;
 
   Open(blob_options, options);
@@ -1805,7 +1804,6 @@ TEST_F(BlobDBTest, SyncBlobFileBeforeCloseIOError) {
   options.env = fault_injection_env_.get();
 
   BlobDBOptions blob_options;
-  blob_options.bytes_per_sync = 1 << 20;
   blob_options.disable_background_tasks = true;
 
   Open(blob_options, options);