Perf Context to report DB mutex waiting time

Summary: Add counters in perf context to allow users to figure out how time spent on waiting for DB mutex

Test Plan: Add a test and run it.

Reviewers: yhchiang, rven, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D33177
main
sdong 10 years ago
parent 863009b5a5
commit 6d6305dd7d
  1. 24
      db/perf_context_test.cc
  2. 3
      include/rocksdb/perf_context.h
  3. 4
      util/instrumented_mutex.cc
  4. 6
      util/perf_context.cc

@ -14,6 +14,7 @@
#include "util/histogram.h"
#include "util/stop_watch.h"
#include "util/testharness.h"
#include "util/thread_status_util.h"
#include "util/string_util.h"
@ -210,6 +211,8 @@ void ProfileQueries(bool enabled_time = false) {
HistogramImpl hist_write_wal_time;
HistogramImpl hist_write_memtable_time;
uint64_t total_db_mutex_nanos = 0;
std::cout << "Inserting " << FLAGS_total_keys << " key/value pairs\n...\n";
std::vector<int> keys;
@ -225,13 +228,17 @@ void ProfileQueries(bool enabled_time = false) {
if (FLAGS_random_key) {
std::random_shuffle(keys.begin(), keys.end());
}
#ifndef NDEBUG
ThreadStatusUtil::TEST_SetStateDelay(ThreadStatus::STATE_MUTEX_WAIT, 1U);
#endif
int num_mutex_waited = 0;
for (const int i : keys) {
if (i == kFlushFlag) {
FlushOptions fo;
db->Flush(fo);
continue;
}
std::string key = "k" + ToString(i);
std::string value = "v" + ToString(i);
@ -239,11 +246,20 @@ void ProfileQueries(bool enabled_time = false) {
perf_context.Reset();
db->Put(write_options, key, value);
if (++num_mutex_waited > 3) {
#ifndef NDEBUG
ThreadStatusUtil::TEST_SetStateDelay(ThreadStatus::STATE_MUTEX_WAIT, 0U);
#endif
}
hist_write_pre_post.Add(perf_context.write_pre_and_post_process_time);
hist_write_wal_time.Add(perf_context.write_wal_time);
hist_write_memtable_time.Add(perf_context.write_memtable_time);
hist_put.Add(perf_context.user_key_comparison_count);
total_db_mutex_nanos += perf_context.db_mutex_lock_nanos;
}
#ifndef NDEBUG
ThreadStatusUtil::TEST_SetStateDelay(ThreadStatus::STATE_MUTEX_WAIT, 0U);
#endif
for (const int i : keys) {
std::string key = "k" + ToString(i);
@ -279,7 +295,8 @@ void ProfileQueries(bool enabled_time = false) {
<< " Writing WAL time: \n"
<< hist_write_wal_time.ToString() << "\n"
<< " Writing Mem Table time: \n"
<< hist_write_memtable_time.ToString() << "\n";
<< hist_write_memtable_time.ToString() << "\n"
<< " Total DB mutex nanos: \n" << total_db_mutex_nanos << "\n";
std::cout << "Get(): Time to get snapshot: \n" << hist_get_snapshot.ToString()
<< " Time to get value from memtables: \n"
@ -316,6 +333,9 @@ void ProfileQueries(bool enabled_time = false) {
ASSERT_GT(hist_mget_files.Average(), 0);
ASSERT_GT(hist_mget_post_process.Average(), 0);
ASSERT_GT(hist_mget_num_memtable_checked.Average(), 0);
#ifndef NDEBUG
ASSERT_GT(total_db_mutex_nanos, 2000U);
#endif
}
db.reset();

@ -65,6 +65,9 @@ struct PerfContext {
uint64_t write_wal_time; // total time spent on writing to WAL
// total time spent on writing to mem tables
uint64_t write_memtable_time;
uint64_t db_mutex_lock_nanos; // time spent on acquiring DB mutex.
// Time spent on waiting with a condition variable created with DB mutex.
uint64_t db_condition_wait_nanos;
};
#if defined(NPERF_CONTEXT) || defined(IOS_CROSS_COMPILE)

@ -3,11 +3,13 @@
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#include "util/perf_context_imp.h"
#include "util/instrumented_mutex.h"
#include "util/thread_status_util.h"
namespace rocksdb {
void InstrumentedMutex::Lock() {
PERF_TIMER_GUARD(db_mutex_lock_nanos);
uint64_t wait_time_micros = 0;
if (env_ != nullptr && stats_ != nullptr) {
{
@ -28,6 +30,7 @@ void InstrumentedMutex::LockInternal() {
}
void InstrumentedCondVar::Wait() {
PERF_TIMER_GUARD(db_condition_wait_nanos);
uint64_t wait_time_micros = 0;
if (env_ != nullptr && stats_ != nullptr) {
{
@ -48,6 +51,7 @@ void InstrumentedCondVar::WaitInternal() {
}
bool InstrumentedCondVar::TimedWait(uint64_t abs_time_us) {
PERF_TIMER_GUARD(db_condition_wait_nanos);
uint64_t wait_time_micros = 0;
bool result = false;
if (env_ != nullptr && stats_ != nullptr) {

@ -51,6 +51,8 @@ void PerfContext::Reset() {
find_next_user_entry_time = 0;
write_pre_and_post_process_time = 0;
write_memtable_time = 0;
db_mutex_lock_nanos = 0;
db_condition_wait_nanos = 0;
#endif
}
@ -82,7 +84,9 @@ std::string PerfContext::ToString() const {
<< OUTPUT(seek_internal_seek_time)
<< OUTPUT(find_next_user_entry_time)
<< OUTPUT(write_pre_and_post_process_time)
<< OUTPUT(write_memtable_time);
<< OUTPUT(write_memtable_time)
<< OUTPUT(db_mutex_lock_nanos)
<< OUTPUT(db_condition_wait_nanos);
return ss.str();
#endif
}

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