Dynamically configure BlockBasedTableOptions.prepopulate_block_cache (#8620)

Summary:
Dynamically configure BlockBasedTableOptions.prepopulate_block_cache using DB::SetOptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8620

Test Plan: Added new unit test

Reviewed By: anand1976

Differential Revision: D30091319

Pulled By: akankshamahajan15

fbshipit-source-id: fb586d1848a8dd525bba7b2f9eeac34f2fc6d82c

HISTORY.md

@@ -10,6 +10,7 @@
 * Made the EventListener extend the Customizable class.
 * EventListeners that have a non-empty Name() and that are registered with the ObjectRegistry can now be serialized to/from the OPTIONS file.
 * Insert warm blocks (data blocks, uncompressed dict blocks, index and filter blocks) in Block cache during flush under option BlockBasedTableOptions.prepopulate_block_cache. Previously it was enabled for only data blocks.
+* BlockBasedTableOptions.prepopulate_block_cache can be dynamically configured using DB::SetOptions.
 
 ### Performance Improvements
 * Try to avoid updating DBOptions if `SetDBOptions()` does not change any option value.

db/db_block_cache_test.cc

@@ -503,7 +503,7 @@ TEST_F(DBBlockCacheTest, WarmCacheWithDataBlocksDuringFlush) {
   }
 }
 
-// This test cache all types of blocks during flush.
+// This test cache data, index and filter blocks during flush.
 TEST_F(DBBlockCacheTest, WarmCacheWithBlocksDuringFlush) {
   Options options = CurrentOptions();
   options.create_if_missing = true;
@@ -519,7 +519,7 @@ TEST_F(DBBlockCacheTest, WarmCacheWithBlocksDuringFlush) {
   DestroyAndReopen(options);
 
   std::string value(kValueSize, 'a');
-  for (size_t i = 1; i < 2; i++) {
+  for (size_t i = 1; i <= kNumBlocks; i++) {
     ASSERT_OK(Put(ToString(i), value));
     ASSERT_OK(Flush());
     ASSERT_EQ(i, options.statistics->getTickerCount(BLOCK_CACHE_DATA_ADD));
@@ -539,6 +539,56 @@ TEST_F(DBBlockCacheTest, WarmCacheWithBlocksDuringFlush) {
               options.statistics->getTickerCount(BLOCK_CACHE_FILTER_HIT));
   }
 }
+
+TEST_F(DBBlockCacheTest, DynamicallyWarmCacheDuringFlush) {
+  Options options = CurrentOptions();
+  options.create_if_missing = true;
+  options.statistics = ROCKSDB_NAMESPACE::CreateDBStatistics();
+
+  BlockBasedTableOptions table_options;
+  table_options.block_cache = NewLRUCache(1 << 25, 0, false);
+  table_options.cache_index_and_filter_blocks = false;
+  table_options.prepopulate_block_cache =
+      BlockBasedTableOptions::PrepopulateBlockCache::kFlushOnly;
+
+  options.table_factory.reset(NewBlockBasedTableFactory(table_options));
+  DestroyAndReopen(options);
+
+  std::string value(kValueSize, 'a');
+
+  for (size_t i = 1; i <= 5; i++) {
+    ASSERT_OK(Put(ToString(i), value));
+    ASSERT_OK(Flush());
+    ASSERT_EQ(1,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
+
+    ASSERT_EQ(value, Get(ToString(i)));
+    ASSERT_EQ(0,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
+    ASSERT_EQ(
+        0, options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_MISS));
+    ASSERT_EQ(1,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_HIT));
+  }
+
+  ASSERT_OK(dbfull()->SetOptions(
+      {{"block_based_table_factory", "{prepopulate_block_cache=kDisable;}"}}));
+
+  for (size_t i = 6; i <= kNumBlocks; i++) {
+    ASSERT_OK(Put(ToString(i), value));
+    ASSERT_OK(Flush());
+    ASSERT_EQ(0,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
+
+    ASSERT_EQ(value, Get(ToString(i)));
+    ASSERT_EQ(1,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_ADD));
+    ASSERT_EQ(
+        1, options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_MISS));
+    ASSERT_EQ(0,
+              options.statistics->getAndResetTickerCount(BLOCK_CACHE_DATA_HIT));
+  }
+}
 #endif
 
 namespace {

include/rocksdb/table.h

@@ -472,6 +472,10 @@ struct BlockBasedTableOptions {
   // further helps if the workload exhibits high temporal locality, where most
   // of the reads go to recently written data. This also helps in case of
   // Distributed FileSystem.
+  //
+  // This parameter can be changed dynamically by
+  // DB::SetOptions({{"block_based_table_factory",
+  //                  "{prepopulate_block_cache=kFlushOnly;}"}}));
   enum class PrepopulateBlockCache : char {
     // Disable prepopulate block cache.
     kDisable,

include/rocksdb/utilities/options_type.h

@@ -262,10 +262,10 @@ class OptionTypeInfo {
   // @param map The string to enum mapping for this enum
   template <typename T>
   static OptionTypeInfo Enum(
-      int offset, const std::unordered_map<std::string, T>* const map) {
+      int offset, const std::unordered_map<std::string, T>* const map,
+      OptionTypeFlags flags = OptionTypeFlags::kNone) {
     return OptionTypeInfo(
-        offset, OptionType::kEnum, OptionVerificationType::kNormal,
-        OptionTypeFlags::kNone,
+        offset, OptionType::kEnum, OptionVerificationType::kNormal, flags,
         // Uses the map argument to convert the input string into
         // its corresponding enum value.  If value is found in the map,
         // addr is updated to the corresponding map entry.

table/block_based/block_based_table_factory.cc

@@ -427,7 +427,8 @@ static std::unordered_map<std::string, OptionTypeInfo>
         {"prepopulate_block_cache",
          OptionTypeInfo::Enum<BlockBasedTableOptions::PrepopulateBlockCache>(
              offsetof(struct BlockBasedTableOptions, prepopulate_block_cache),
-             &block_base_table_prepopulate_block_cache_string_map)},
+             &block_base_table_prepopulate_block_cache_string_map,
+             OptionTypeFlags::kMutable)},
 
 #endif  // ROCKSDB_LITE
 };