Add rocksdb.file.read.db.open.micros

HISTORY.md

@@ -6,6 +6,7 @@
 * Improve the operational safety of publishing a DB or SST files to many hosts by using different block cache hash seeds on different hosts. The exact behavior is controlled by new option `ShardedCacheOptions::hash_seed`, which also documents the solved problem in more detail.
 * Introduced a new option `CompactionOptionsFIFO::file_temperature_age_thresholds` that allows FIFO compaction to compact files to different temperatures based on key age (#11428).
 * Added a new ticker stat to count how many times RocksDB detected a corruption while verifying a block checksum: `BLOCK_CHECKSUM_MISMATCH_COUNT`.
+* New statistics `rocksdb.file.read.db.open.micros` that measures read time of block-based SST tables or blob files during db open.
 
 ### Public API Changes
 * Add `MakeSharedCache()` construction functions to various cache Options objects, and deprecated the `NewWhateverCache()` functions with long parameter lists.

file/random_access_file_reader.cc

@@ -26,6 +26,7 @@ const std::array<Histograms, std::size_t(Env::IOActivity::kUnknown)>
     kReadHistograms{{
         FILE_READ_FLUSH_MICROS,
         FILE_READ_COMPACTION_MICROS,
+        FILE_READ_DB_OPEN_MICROS,
     }};
 inline void RecordIOStats(Statistics* stats, Temperature file_temperature,
                           bool is_last_level, size_t size) {

include/rocksdb/statistics.h

@@ -512,9 +512,10 @@ enum Histograms : uint32_t {
   // Time spent in reading block-based or plain SST table
   SST_READ_MICROS,
   // Time spent in reading SST table (currently only block-based table) or blob
-  // file for flush or compaction
+  // file corresponding to `Env::IOActivity`
   FILE_READ_FLUSH_MICROS,
   FILE_READ_COMPACTION_MICROS,
+  FILE_READ_DB_OPEN_MICROS,
 
   // The number of subcompactions actually scheduled during a compaction
   NUM_SUBCOMPACTIONS_SCHEDULED,

java/rocksjni/portal.h

@@ -5627,6 +5627,8 @@ class HistogramTypeJni {
         return 0x3A;
       case ROCKSDB_NAMESPACE::Histograms::FILE_READ_COMPACTION_MICROS:
         return 0x3B;
+      case ROCKSDB_NAMESPACE::Histograms::FILE_READ_DB_OPEN_MICROS:
+        return 0x3C;
       case ROCKSDB_NAMESPACE::Histograms::HISTOGRAM_ENUM_MAX:
         // 0x1F for backwards compatibility on current minor version.
         return 0x1F;
@@ -5750,6 +5752,8 @@ class HistogramTypeJni {
         return ROCKSDB_NAMESPACE::Histograms::FILE_READ_FLUSH_MICROS;
       case 0x3B:
         return ROCKSDB_NAMESPACE::Histograms::FILE_READ_COMPACTION_MICROS;
+      case 0x3C:
+        return ROCKSDB_NAMESPACE::Histograms::FILE_READ_DB_OPEN_MICROS;
       case 0x1F:
         // 0x1F for backwards compatibility on current minor version.
         return ROCKSDB_NAMESPACE::Histograms::HISTOGRAM_ENUM_MAX;

java/src/main/java/org/rocksdb/HistogramType.java

@@ -173,6 +173,8 @@ public enum HistogramType {
 
   FILE_READ_COMPACTION_MICROS((byte) 0x3B),
 
+  FILE_READ_DB_OPEN_MICROS((byte) 0x3C),
+
   // 0x1F for backwards compatibility on current minor version.
   HISTOGRAM_ENUM_MAX((byte) 0x1F);
 

monitoring/statistics.cc

@@ -256,6 +256,7 @@ const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
     {SST_READ_MICROS, "rocksdb.sst.read.micros"},
     {FILE_READ_FLUSH_MICROS, "rocksdb.file.read.flush.micros"},
     {FILE_READ_COMPACTION_MICROS, "rocksdb.file.read.compaction.micros"},
+    {FILE_READ_DB_OPEN_MICROS, "rocksdb.file.read.db.open.micros"},
     {NUM_SUBCOMPACTIONS_SCHEDULED, "rocksdb.num.subcompactions.scheduled"},
     {BYTES_PER_READ, "rocksdb.bytes.per.read"},
     {BYTES_PER_WRITE, "rocksdb.bytes.per.write"},