Enhance db_bench write rate limit

Summary: 1) changes tools/{benchmark,run_flash_bench}.sh to optionally use the write rate limit 2) removes code for --writes_per_second and switches the 'background' write rate limit to use --benchmark_write_rate_limit Replaces https://reviews.facebook.net/D49113 Task ID: #9555881 Blame Rev: Test Plan: tools/run_flash_bench.sh Revert Plan: Database Impact: Memcache Impact: Other Notes: EImportant: - begin *PUBLIC* platform impact section - Bugzilla: # - end platform impact - Reviewers: igor Reviewed By: igor Subscribers: dhruba Differential Revision: https://reviews.facebook.net/D52485
harrywong · Jan 4, 2016 · 4041903 · 4041903
1 parent 3993432
commit 4041903
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Showing 4 changed files with 60 additions and 53 deletions.
diff --git a/build_tools/regression_build_test.sh b/build_tools/regression_build_test.sh
@@ -243,7 +243,7 @@ make release
     --bloom_bits=10 \
     --num=$((NUM / 4)) \
     --reads=$((NUM / 4)) \
-    --writes_per_second=1000 \
+    --benchmark_write_rate_limit=$(( 110 * 1024 )) \
     --write_buffer_size=100000000 \
     --cache_size=6442450944 \
     --cache_numshardbits=6 \
@@ -329,7 +329,7 @@ common_in_mem_args="--db=/dev/shm/rocksdb \
     --use_existing_db=1 \
     --duration=600 \
     --threads=32 \
-    --writes_per_second=81920 > ${STAT_FILE}.readwhilewriting_in_ram
+    --benchmark_write_rate_limit=9502720 > ${STAT_FILE}.readwhilewriting_in_ram
 
 # Seekrandomwhilewriting
 ./db_bench \
@@ -342,7 +342,7 @@ common_in_mem_args="--db=/dev/shm/rocksdb \
     --use_tailing_iterator=1 \
     --duration=600 \
     --threads=32 \
-    --writes_per_second=81920 > ${STAT_FILE}.seekwhilewriting_in_ram
+    --benchmark_write_rate_limit=9502720 > ${STAT_FILE}.seekwhilewriting_in_ram
 
 # measure fillseq with bunch of column families
 ./db_bench \

diff --git a/db/db_bench.cc b/db/db_bench.cc
@@ -420,10 +420,6 @@ static class std::shared_ptr<rocksdb::Statistics> dbstats;
 DEFINE_int64(writes, -1, "Number of write operations to do. If negative, do"
              " --num reads.");
 
-DEFINE_int32(writes_per_second, 0, "Per-thread rate limit on writes and merges "
-             "  per second. No limit when <= 0. Only for the readwhilewriting "
-             "  and readwhilemerging tests.");
-
 DEFINE_bool(sync, false, "Sync all writes to disk");
 
 DEFINE_bool(disable_data_sync, false, "If true, do not wait until data is"
@@ -668,7 +664,8 @@ DEFINE_uint64(rate_limiter_bytes_per_sec, 0, "Set options.rate_limiter value.");
 
 DEFINE_uint64(
     benchmark_write_rate_limit, 0,
-    "If non-zero, db_bench will rate-limit the writes going into RocksDB");
+    "If non-zero, db_bench will rate-limit the writes going into RocksDB. This "
+    "is the global rate in bytes/second.");
 
 DEFINE_int32(max_grandparent_overlap_factor, 10, "Control maximum bytes of "
              "overlaps in grandparent (i.e., level+2) before we stop building a"
@@ -1312,6 +1309,11 @@ class Stats {
     }
   }
 
+  void ResetLastOpTime() {
+    // Set to now to avoid latency from calls to SleepForMicroseconds
+    last_op_finish_ = FLAGS_env->NowMicros();
+  }
+
   void FinishedOps(DBWithColumnFamilies* db_with_cfh, DB* db, int64_t num_ops,
                    enum OperationType op_type = kOthers) {
     if (reporter_agent_) {
@@ -1633,7 +1635,8 @@ class Benchmark {
             (((FLAGS_key_size + FLAGS_value_size * FLAGS_compression_ratio)
               * num_)
              / 1048576.0));
-    fprintf(stdout, "Writes per second: %d\n", FLAGS_writes_per_second);
+    fprintf(stdout, "Write rate: %" PRIu64 " bytes/second\n",
+            FLAGS_benchmark_write_rate_limit);
     if (FLAGS_enable_numa) {
       fprintf(stderr, "Running in NUMA enabled mode.\n");
 #ifndef NUMA
@@ -2845,14 +2848,22 @@ class Benchmark {
           }
         }
       }
+
       size_t id = thread->rand.Next() % num_key_gens;
       DBWithColumnFamilies* db_with_cfh = SelectDBWithCfh(id);
       batch.Clear();
+
+      if (thread->shared->write_rate_limiter.get() != nullptr) {
+        thread->shared->write_rate_limiter->Request(
+            entries_per_batch_ * (value_size_ + key_size_),
+            Env::IO_HIGH);
+        // Set time at which last op finished to Now() to hide latency and
+        // sleep from rate limiter. Also, do the check once per batch, not
+        // once per write.
+        thread->stats.ResetLastOpTime();
+      }
+
       for (int64_t j = 0; j < entries_per_batch_; j++) {
-        if (thread->shared->write_rate_limiter.get() != nullptr) {
-          thread->shared->write_rate_limiter->Request(value_size_ + key_size_,
-                                                      Env::IO_HIGH);
-        }
         int64_t rand_num = key_gens[id]->Next();
         GenerateKeyFromInt(rand_num, FLAGS_num, &key);
         if (FLAGS_num_column_families <= 1) {
@@ -3253,16 +3264,13 @@ class Benchmark {
   void BGWriter(ThreadState* thread, enum OperationType write_merge) {
     // Special thread that keeps writing until other threads are done.
     RandomGenerator gen;
-    uint64_t last = FLAGS_env->NowMicros();
-    int writes_per_second_by_10 = 0;
-    int num_writes = 0;
     int64_t bytes = 0;
 
-    // --writes_per_second rate limit is enforced per 100 milliseconds
-    // intervals to avoid a burst of writes at the start of each second.
-
-    if (FLAGS_writes_per_second > 0)
-      writes_per_second_by_10 = FLAGS_writes_per_second / 10;
+    std::unique_ptr<RateLimiter> write_rate_limiter;
+    if (FLAGS_benchmark_write_rate_limit > 0) {
+      write_rate_limiter.reset(
+          NewGenericRateLimiter(FLAGS_benchmark_write_rate_limit));
+    }
 
     // Don't merge stats from this thread with the readers.
     thread->stats.SetExcludeFromMerge();
@@ -3296,18 +3304,10 @@ class Benchmark {
       bytes += key.size() + value_size_;
       thread->stats.FinishedOps(&db_, db_.db, 1, kWrite);
 
-      ++num_writes;
-      if (writes_per_second_by_10 && num_writes >= writes_per_second_by_10) {
-        uint64_t now = FLAGS_env->NowMicros();
-        uint64_t usecs_since_last = now - last;
-
-        num_writes = 0;
-        last = now;
-
-        if (usecs_since_last < 100000) {
-          FLAGS_env->SleepForMicroseconds(static_cast<int>(100000 - usecs_since_last));
-          last = FLAGS_env->NowMicros();
-        }
+      if (FLAGS_benchmark_write_rate_limit > 0) {
+        write_rate_limiter->Request(
+            entries_per_batch_ * (value_size_ + key_size_),
+            Env::IO_HIGH);
       }
     }
     thread->stats.AddBytes(bytes);

diff --git a/tools/benchmark.sh b/tools/benchmark.sh
@@ -37,8 +37,7 @@ if [ ! -z $DB_BENCH_NO_SYNC ]; then
 fi
 
 num_threads=${NUM_THREADS:-16}
-# Only for *whilewriting, *whilemerging
-writes_per_second=${WRITES_PER_SECOND:-$((10 * K))}
+mb_written_per_sec=${MB_WRITE_PER_SEC:-0}
 # Only for tests that do range scans
 num_nexts_per_seek=${NUM_NEXTS_PER_SEEK:-10}
 cache_size=${CACHE_SIZE:-$((1 * G))}
@@ -67,6 +66,7 @@ const_params="
   --level_compaction_dynamic_level_bytes=true \
   --bytes_per_sync=$((8 * M)) \
   --cache_index_and_filter_blocks=0 \
+  --benchmark_write_rate_limit=$(( 1024 * 1024 * $mb_written_per_sec )) \
   \
   --hard_rate_limit=3 \
   --rate_limit_delay_max_milliseconds=1000000 \
@@ -231,7 +231,6 @@ function run_readwhile {
        --sync=$syncval \
        $params_w \
        --threads=$num_threads \
-       --writes_per_second=$writes_per_second \
        --merge_operator=\"put\" \
        --seed=$( date +%s ) \
        2>&1 | tee -a $output_dir/${out_name}"
@@ -251,7 +250,6 @@ function run_rangewhile {
        --sync=$syncval \
        $params_w \
        --threads=$num_threads \
-       --writes_per_second=$writes_per_second \
        --merge_operator=\"put\" \
        --seek_nexts=$num_nexts_per_seek \
        --reverse_iterator=$reverse_arg \

diff --git a/tools/run_flash_bench.sh b/tools/run_flash_bench.sh
@@ -23,9 +23,13 @@
 #
 # The environment variables are also optional. The variables are:
 #   NKEYS         - number of key/value pairs to load
-#   NWRITESPERSEC - the writes/second rate limit for the *whilewriting* tests.
+#   BG_MBWRITEPERSEC - write rate limit in MB/second for tests in which
+#                   there is one thread doing writes and stats are
+#                   reported for read threads. "BG" stands for background.
 #                   If this is too large then the non-writer threads can get
-#                   starved.
+#                   starved. This is used for the "readwhile" tests.
+#   FG_MBWRITEPERSEC - write rate limit in MB/second for tests like overwrite
+#                   where stats are reported for the write threads.
 #   NSECONDS      - number of seconds for which to run each test in steps 2,
 #                   3 and 4. There are currently 15 tests in those steps and
 #                   they are repeated for each entry in list-of-threads so
@@ -57,7 +61,10 @@ M=$((1024 * K))
 G=$((1024 * M))
 
 num_keys=${NKEYS:-$((1 * G))}
-wps=${NWRITESPERSEC:-$((10 * K))}
+# write rate for readwhile... tests
+bg_mbwps=${BG_MBWRITEPERSEC:-4}
+# write rate for tests other than readwhile, 0 means no limit
+fg_mbwps=${FG_MBWRITEPERSEC:-0}
 duration=${NSECONDS:-$((60 * 60))}
 nps=${RANGE_LIMIT:-10}
 vs=${VAL_SIZE:-400}
@@ -178,52 +185,54 @@ done
 
 for num_thr in "${nthreads[@]}" ; do
   # Test 7: overwrite with sync=0
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr DB_BENCH_NO_SYNC=1 \
-    ./tools/benchmark.sh overwrite
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$fg_mbwps \
+    DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh overwrite
 
   # Test 8: overwrite with sync=1
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr ./tools/benchmark.sh overwrite
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$fg_mbwps \
+    ./tools/benchmark.sh overwrite
 
   # Test 9: random update with sync=0
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr DB_BENCH_NO_SYNC=1 \
-    ./tools/benchmark.sh updaterandom
+      ./tools/benchmark.sh updaterandom
 
   # Test 10: random update with sync=1
   env $ARGS DURATION=$duration NUM_THREADS=$num_thr ./tools/benchmark.sh updaterandom
 
   # Test 11: random read while writing
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh readwhilewriting
 
   # Test 12: range scan while writing
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilewriting
 
   # Test 13: reverse range scan while writing
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilewriting
 done
 
 ###### Merge tests
 
 for num_thr in "${nthreads[@]}" ; do
   # Test 14: random merge with sync=0
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr DB_BENCH_NO_SYNC=1 \
-    ./tools/benchmark.sh mergerandom
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$fg_mbwps \
+    DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh mergerandom
 
   # Test 15: random merge with sync=1
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr ./tools/benchmark.sh mergerandom
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$fg_mbwps \
+    ./tools/benchmark.sh mergerandom
 
   # Test 16: random read while merging 
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 ./tools/benchmark.sh readwhilemerging
 
   # Test 17: range scan while merging 
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh fwdrangewhilemerging
 
   # Test 18: reverse range scan while merging 
-  env $ARGS DURATION=$duration NUM_THREADS=$num_thr WRITES_PER_SECOND=$wps \
+  env $ARGS DURATION=$duration NUM_THREADS=$num_thr MB_WRITE_PER_SEC=$bg_mbwps \
     DB_BENCH_NO_SYNC=1 NUM_NEXTS_PER_SEEK=$nps ./tools/benchmark.sh revrangewhilemerging
 done