Reduce the block cache configurations into a single one

kvrocks.conf

@@ -530,22 +530,36 @@ migrate-sequence-gap 10000
 
 ################################ ROCKSDB #####################################
 
+# Specify the capacity of column family block cache. A larger block cache
+# may make requests faster while more keys would be cached. Max Size is 400*1024.
+# Default: 4096MB
+rocksdb.block_cache_size 4096
+
+# If this configuration is set to yes, the following block cache settings
+# (rocksdb.metadata_block_cache_size, rocksdb.subkey_block_cache_size,
+# rocksdb.share_metadata_and_subkey_block_cache) will be ignored, only using
+# rocksdb.block_cache_size to configure.
+# If this configuration is set to no, the following block cache settings
+# should be set.
+# Default: yes
+rocksdb.set_block_cache_size yes
+
 # Specify the capacity of metadata column family block cache. A larger block cache
 # may make requests faster while more keys would be cached. Max Size is 200*1024.
 # Default: 2048MB
-rocksdb.metadata_block_cache_size 2048
+#rocksdb.metadata_block_cache_size 2048
 
 # Specify the capacity of subkey column family block cache. A larger block cache
 # may make requests faster while more keys would be cached. Max Size is 200*1024.
 # Default: 2048MB
-rocksdb.subkey_block_cache_size 2048
+#rocksdb.subkey_block_cache_size 2048
 
 # Metadata column family and subkey column family will share a single block cache
 # if set 'yes'. The capacity of shared block cache is
 # metadata_block_cache_size + subkey_block_cache_size
 #
 # Default: yes
-rocksdb.share_metadata_and_subkey_block_cache yes
+#rocksdb.share_metadata_and_subkey_block_cache yes
 
 # A global cache for table-level rows in RocksDB. If almost always point
 # lookups, enlarging row cache may improve read performance. Otherwise,

src/config/config.cc

@@ -186,10 +186,12 @@ Config::Config() {
       {"rocksdb.enable_pipelined_write", true, new YesNoField(&rocks_db.enable_pipelined_write, false)},
       {"rocksdb.stats_dump_period_sec", false, new IntField(&rocks_db.stats_dump_period_sec, 0, 0, INT_MAX)},
       {"rocksdb.cache_index_and_filter_blocks", true, new YesNoField(&rocks_db.cache_index_and_filter_blocks, false)},
+      {"rocksdb.block_cache_size", true, new IntField(&rocks_db.block_cache_size, 4096, 0, INT_MAX)},
+      {"rocksdb.set_block_cache_size", true, new YesNoField(&rocks_db.set_block_cache_size, true)},
       {"rocksdb.subkey_block_cache_size", true, new IntField(&rocks_db.subkey_block_cache_size, 2048, 0, INT_MAX)},
       {"rocksdb.metadata_block_cache_size", true, new IntField(&rocks_db.metadata_block_cache_size, 2048, 0, INT_MAX)},
       {"rocksdb.share_metadata_and_subkey_block_cache", true,
-       new YesNoField(&rocks_db.share_metadata_and_subkey_block_cache, true)},
+       new YesNoField(&rocks_db.share_metadata_and_subkey_block_cache, false)},
       {"rocksdb.row_cache_size", true, new IntField(&rocks_db.row_cache_size, 0, 0, INT_MAX)},
       {"rocksdb.compaction_readahead_size", false,
        new IntField(&rocks_db.compaction_readahead_size, 2 * MiB, 0, 64 * MiB)},

src/config/config.h

@@ -156,6 +156,8 @@ struct Config {
   struct RocksDB {
     int block_size;
     bool cache_index_and_filter_blocks;
+    int block_cache_size;
+    bool set_block_cache_size;
     int metadata_block_cache_size;
     int subkey_block_cache_size;
     bool share_metadata_and_subkey_block_cache;

src/storage/storage.cc

@@ -235,6 +235,7 @@ Status Storage::Open(bool read_only) {
   db_closing_ = false;
 
   bool cache_index_and_filter_blocks = config_->rocks_db.cache_index_and_filter_blocks;
+  size_t block_cache_size = config_->rocks_db.block_cache_size * MiB;
   size_t metadata_block_cache_size = config_->rocks_db.metadata_block_cache_size * MiB;
   size_t subkey_block_cache_size = config_->rocks_db.subkey_block_cache_size * MiB;
 
@@ -244,7 +245,9 @@ Status Storage::Open(bool read_only) {
   }
 
   std::shared_ptr<rocksdb::Cache> shared_block_cache;
-  if (config_->rocks_db.share_metadata_and_subkey_block_cache) {
+  if (config_->rocks_db.set_block_cache_size) {
+    shared_block_cache = rocksdb::NewLRUCache(block_cache_size, -1, false, 0.75);
+  } else if (config_->rocks_db.share_metadata_and_subkey_block_cache) {
     size_t shared_block_cache_size = metadata_block_cache_size + subkey_block_cache_size;
     shared_block_cache = rocksdb::NewLRUCache(shared_block_cache_size, -1, false, 0.75);
   }