Benchmark table reader wiht nanoseconds

Summary: nanosecnods gave us better view of the performance, especially when some operations are fast so that micro seconds may only reveal less informative results. Test Plan: sample output: ./table_reader_bench --plain_table --time_unit=nanosecond ======================================================================================================= InMemoryTableSimpleBenchmark: PlainTable num_key1: 4096 num_key2: 512 non_empty ======================================================================================================= Histogram (unit: nanosecond): Count: 6291456 Average: 475.3867 StdDev: 556.05 Min: 135.0000 Median: 400.1817 Max: 33370.0000 Percentiles: P50: 400.18 P75: 530.02 P99: 887.73 P99.9: 8843.26 P99.99: 9941.21 ------------------------------------------------------ [ 120, 140 ) 2 0.000% 0.000% [ 140, 160 ) 452 0.007% 0.007% [ 160, 180 ) 13683 0.217% 0.225% [ 180, 200 ) 54353 0.864% 1.089% [ 200, 250 ) 101004 1.605% 2.694% [ 250, 300 ) 729791 11.600% 14.294% ## [ 300, 350 ) 616070 9.792% 24.086% ## [ 350, 400 ) 1628021 25.877% 49.963% ##### [ 400, 450 ) 647220 10.287% 60.250% ## [ 450, 500 ) 577206 9.174% 69.424% ## [ 500, 600 ) 1168585 18.574% 87.999% #### [ 600, 700 ) 506875 8.057% 96.055% ## [ 700, 800 ) 147878 2.350% 98.406% [ 800, 900 ) 42633 0.678% 99.083% [ 900, 1000 ) 16304 0.259% 99.342% [ 1000, 1200 ) 7811 0.124% 99.466% [ 1200, 1400 ) 1453 0.023% 99.490% [ 1400, 1600 ) 307 0.005% 99.494% [ 1600, 1800 ) 81 0.001% 99.496% [ 1800, 2000 ) 18 0.000% 99.496% [ 2000, 2500 ) 8 0.000% 99.496% [ 2500, 3000 ) 6 0.000% 99.496% [ 3500, 4000 ) 3 0.000% 99.496% [ 4000, 4500 ) 116 0.002% 99.498% [ 4500, 5000 ) 1144 0.018% 99.516% [ 5000, 6000 ) 1087 0.017% 99.534% [ 6000, 7000 ) 2403 0.038% 99.572% [ 7000, 8000 ) 9840 0.156% 99.728% [ 8000, 9000 ) 12820 0.204% 99.932% [ 9000, 10000 ) 3881 0.062% 99.994% [ 10000, 12000 ) 135 0.002% 99.996% [ 12000, 14000 ) 159 0.003% 99.998% [ 14000, 16000 ) 58 0.001% 99.999% [ 16000, 18000 ) 30 0.000% 100.000% [ 18000, 20000 ) 14 0.000% 100.000% [ 20000, 25000 ) 2 0.000% 100.000% [ 25000, 30000 ) 2 0.000% 100.000% [ 30000, 35000 ) 1 0.000% 100.000% Reviewers: haobo, dhruba, sdong CC: leveldb Differential Revision: https://reviews.facebook.net/D16113
11 years ago · 59cffe02c4
parent b5140a0361
commit 59cffe02c4
1 changed files with 23 additions and 12 deletions
--- a/table/table_reader_bench.cc
+++ b/table/table_reader_bench.cc
@ -40,6 +40,10 @@ static bool DummySaveValue(void* arg, const ParsedInternalKey& ikey,
  return false;
 }

+uint64_t Now(Env* env, bool measured_by_nanosecond) {
+  return measured_by_nanosecond ? env->NowNanos() : env->NowMicros();
+}
+
 // A very simple benchmark that.
 // Create a table with roughly numKey1 * numKey2 keys,
 // where there are numKey1 prefixes of the key, each has numKey2 number of
@ -57,7 +61,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
                          ReadOptions& read_options, int num_keys1,
                          int num_keys2, int num_iter, int prefix_len,
                          bool if_query_empty_keys, bool for_iterator,
-                          bool through_db) {
+                          bool through_db, bool measured_by_nanosecond) {
  rocksdb::InternalKeyComparator ikc(opts.comparator);

  Slice prefix = Slice();
@ -126,7 +130,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
        if (!for_iterator) {
          // Query one existing key;
          std::string key = MakeKey(r1, r2, through_db);
-          uint64_t start_micros = env->NowMicros();
+          uint64_t start_micros = Now(env, measured_by_nanosecond);
          port::MemoryBarrier();
          if (!through_db) {
            s = table_reader->Get(read_options, key, arg, DummySaveValue,
@ -135,7 +139,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
            s = db->Get(read_options, key, &result);
          }
          port::MemoryBarrier();
-          hist.Add(env->NowMicros() - start_micros);
+          hist.Add(Now(env, measured_by_nanosecond) - start_micros);
        } else {
          int r2_len;
          if (if_query_empty_keys) {
@ -153,7 +157,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
            read_options.prefix = &prefix;
          }
          uint64_t total_time = 0;
-          uint64_t start_micros = env->NowMicros();
+          uint64_t start_micros = Now(env, measured_by_nanosecond);
          port::MemoryBarrier();
          Iterator* iter;
          if (!through_db) {
@ -168,9 +172,9 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
            }
            // verify key;
            port::MemoryBarrier();
-            total_time += env->NowMicros() - start_micros;
+            total_time += Now(env, measured_by_nanosecond) - start_micros;
            assert(Slice(MakeKey(r1, r2 + count, through_db)) == iter->key());
-            start_micros = env->NowMicros();
+            start_micros = Now(env, measured_by_nanosecond);
            if (++count >= r2_len) {
              break;
            }
@ -183,7 +187,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
          }
          delete iter;
          port::MemoryBarrier();
-          total_time += env->NowMicros() - start_micros;
+          total_time += Now(env, measured_by_nanosecond) - start_micros;
          hist.Add(total_time);
        }
      }
@ -198,9 +202,10 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
      "num_key2: %5d  %10s\n"
      "==================================================="
      "===================================================="
-      "\nHistogram (unit: microseconds): \n%s",
+      "\nHistogram (unit: %s): \n%s",
      opts.table_factory->Name(), num_keys1, num_keys2,
-      for_iterator? "iterator" : (if_query_empty_keys ? "empty" : "non_empty"),
+      for_iterator ? "iterator" : (if_query_empty_keys ? "empty" : "non_empty"),
+      measured_by_nanosecond ? "nanosecond" : "microsecond",
      hist.ToString().c_str());
  if (!through_db) {
    env->DeleteFile(file_name);
@ -210,7 +215,7 @@ void TableReaderBenchmark(Options& opts, EnvOptions& env_options,
    DestroyDB(dbname, opts);
  }
 }
-} // namespace rocksdb
+}  // namespace rocksdb

 DEFINE_bool(query_empty, false, "query non-existing keys instead of existing "
            "ones.");
@ -223,7 +228,9 @@ DEFINE_bool(through_db, false, "If enable, a DB instance will be created and "
            "the query will be against DB. Otherwise, will be directly against "
            "a table reader.");
 DEFINE_bool(plain_table, false, "Use PlainTable");
-
+DEFINE_string(time_unit, "microsecond",
+              "The time unit used for measuring performance. User can specify "
+              "`microsecond` (default) or `nanosecond`");

 int main(int argc, char** argv) {
  google::SetUsageMessage(std::string("\nUSAGE:\n") + std::string(argv[0]) +
@ -252,11 +259,15 @@ int main(int argc, char** argv) {
  } else {
    tf = new rocksdb::BlockBasedTableFactory();
  }
+  // if user provides invalid options, just fall back to microsecond.
+  bool measured_by_nanosecond = FLAGS_time_unit == "nanosecond";
+
  options.table_factory =
      std::shared_ptr<rocksdb::TableFactory>(tf);
  TableReaderBenchmark(options, env_options, ro, FLAGS_num_keys1,
                       FLAGS_num_keys2, FLAGS_iter, FLAGS_prefix_len,
-                       FLAGS_query_empty, FLAGS_iterator, FLAGS_through_db);
+                       FLAGS_query_empty, FLAGS_iterator, FLAGS_through_db,
+                       measured_by_nanosecond);
  delete tf;
  return 0;
 }