Add counters for SST File reads/blocks in MultiGet. (#308)

rockset · Dec 8, 2023 · 376b44f · 376b44f
1 parent f4ecc86
commit 376b44f
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Showing 3 changed files with 46 additions and 1 deletion.
diff --git a/db/version_set.cc b/db/version_set.cc
@@ -2521,9 +2521,17 @@ void Version::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
  if (fp.GetHitFileLevel() == 0) {
  dump_stats_for_l0_file = true;
  }
+ // RocksDB-Cloud contribution begin
+ RecordTick(db_statistics_, MULTIGET_SST_FILE_READ_COUNT, 1);
+ // RocksDB-Cloud contribution end
  }
  if (s.ok()) {
  f = fp.GetNextFileInLevel();
+ // RocksDB-Cloud contribution begin
+ if (f) {
+ RecordTick(db_statistics_, MULTIGET_SST_SERIALIZED_FILE_READ_COUNT, 1);
+ }
+ // RocksDB-Cloud contribution end
  }
 #if USE_COROUTINES
  } else {
@@ -2567,6 +2575,9 @@ void Version::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
  if (mget_tasks.size() > 0) {
  RecordTick(db_statistics_, MULTIGET_COROUTINE_COUNT,
  mget_tasks.size());
+ // RocksDB-Cloud contribution begin
+ RecordTick(db_statistics_, MULTIGET_SST_FILE_READ_COUNT, mget_tasks.size());
+ // RocksDB-Cloud contribution end
  // Collect all results so far
  std::vector<Status> statuses = folly::coro::blockingWait(
  folly::coro::collectAllRange(std::move(mget_tasks))
@@ -2582,6 +2593,12 @@ void Version::MultiGet(const ReadOptions& read_options, MultiGetRange* range,
 
  if (s.ok() && fp.KeyMaySpanNextFile()) {
  f = fp.GetNextFileInLevel();
+ // RocksDB-Cloud contribution begin
+ if (f) {
+ RecordTick(db_statistics_, 
+ MULTIGET_SST_SERIALIZED_FILE_READ_COUNT, 1);
+ }
+ // RocksDB-Cloud contribution end
  }
  }
 #endif // USE_COROUTINES
@@ -2763,6 +2780,10 @@ Status Version::ProcessBatch(
  table_handle, std::get<0>(stat->second),
  std::get<1>(stat->second),
  std::get<2>(stat->second));
+ // RocksDB-Cloud contribution begin
+ RecordTick(db_statistics_, 
+ MULTIGET_SST_FILE_READ_COUNT, mget_tasks.size());
+ // RocksDB-Cloud contribution end
  } else {
  mget_tasks.emplace_back(MultiGetFromSSTCoroutine(
  read_options, file_range, fp.GetHitFileLevel(), skip_filters,
@@ -2853,6 +2874,10 @@ Status Version::MultiGetAsync(
  if (mget_tasks.size() > 0) {
  assert(waiting.size());
  RecordTick(db_statistics_, MULTIGET_COROUTINE_COUNT, mget_tasks.size());
+ // RocksDB-Cloud contribution begin
+ RecordTick(db_statistics_, 
+ MULTIGET_SST_FILE_READ_COUNT, mget_tasks.size());
+ // RocksDB-Cloud contribution end
  // Collect all results so far
  std::vector<Status> statuses = folly::coro::blockingWait(
  folly::coro::collectAllRange(std::move(mget_tasks))
@@ -2879,6 +2904,11 @@ Status Version::MultiGetAsync(
  // and no need to prepare the next level.
  if (!fp.GetHitFile() && !fp.GetRange().empty()) {
  fp.PrepareNextLevelForSearch();
+ } else {
+ // RocksDB-Cloud contribution begin
+ RecordTick(db_statistics_, 
+ MULTIGET_SST_SERIALIZED_FILE_READ_COUNT, 1);
+ // RocksDB-Cloud contribution end
  }
  }
  to_process.swap(waiting);

diff --git a/include/rocksdb/statistics.h b/include/rocksdb/statistics.h
@@ -452,6 +452,15 @@ enum Tickers : uint32_t {
  READ_ASYNC_MICROS,
  // Number of errors returned to the async read callback
  ASYNC_READ_ERROR_COUNT,
+
+ // RocksDB-Cloud contribution begin
+
+ // Total number of files read in MultiGet operations
+ MULTIGET_SST_FILE_READ_COUNT,
+ // Number of times file reads were serialized behind other reads
+ MULTIGET_SST_SERIALIZED_FILE_READ_COUNT,
+
+ // RocksDB-Cloud contribution end
 
  TICKER_ENUM_MAX
 };

diff --git a/monitoring/statistics.cc b/monitoring/statistics.cc
@@ -235,7 +235,13 @@ const std::vector<std::pair<Tickers, std::string>> TickersNameMap = {
  {BLOB_DB_CACHE_BYTES_READ, "rocksdb.blobdb.cache.bytes.read"},
  {BLOB_DB_CACHE_BYTES_WRITE, "rocksdb.blobdb.cache.bytes.write"},
  {READ_ASYNC_MICROS, "rocksdb.read.async.micros"},
- {ASYNC_READ_ERROR_COUNT, "rocksdb.async.read.error.count"}};
+ {ASYNC_READ_ERROR_COUNT, "rocksdb.async.read.error.count"},
+ // RocksDB-Cloud contribution begin
+ {MULTIGET_SST_FILE_READ_COUNT, "rodksdb.number.multiget.sst_file_reads"},
+ {MULTIGET_SST_SERIALIZED_FILE_READ_COUNT,
+ "rocksdb.number.multiget.sst_serialized_file_reads"}
+ // RocksDB-Cloud contribution end
+ };
 
 const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
  {DB_GET, "rocksdb.db.get.micros"},