From 2df65c118cd80dfcd0289ab1879bcfd5a9802b7b Mon Sep 17 00:00:00 2001
From: Haobo Xu <haobo@fb.com>
Date: Tue, 28 May 2013 12:35:43 -0700
Subject: [PATCH] [RocksDB] Dump counters and histogram data periodically with
 compaction stats

Summary: As title

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10995
---
 db/db_impl.cc | 36 ++++++++++++++++++++++++++++++++++++
 db/db_impl.h  |  6 ++++--
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/db/db_impl.cc b/db/db_impl.cc
index 77956409a..4aa797ce4 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -307,6 +307,41 @@ const Status DBImpl::CreateArchivalDirectory() {
   return Status::OK();
 }
 
+void DBImpl::PrintHistogram(Histograms histogram_type, std::string name) {
+  assert(options_.statistics);
+  HistogramData histogramData;
+  options_.statistics->histogramData(histogram_type, &histogramData);
+  Log(options_.info_log, "%s statistics Percentiles :", name.c_str());
+  Log(options_.info_log, "50 : %f ",histogramData.median);
+  Log(options_.info_log, "95 : %f ", histogramData.percentile95);
+  Log(options_.info_log, "99 : %f\n", histogramData.percentile99);
+}
+
+void DBImpl::PrintStatistics() {
+  auto dbstats = options_.statistics;
+  if (dbstats) {
+    Log(options_.info_log,
+        "Statistics counters:\n"
+        "File opened:%ld closed:%ld errors:%ld\n"
+        "Block Cache Hit Count:%ld Block Cache Miss Count:%ld\n"
+        "Bloom Filter Useful: %ld \n"
+        "Compaction key_drop_newer_entry: %ld key_drop_obsolete: %ld "
+        "Compaction key_drop_user: %ld\n",
+        dbstats->getTickerCount(NO_FILE_OPENS),
+        dbstats->getTickerCount(NO_FILE_CLOSES),
+        dbstats->getTickerCount(NO_FILE_ERRORS),
+        dbstats->getTickerCount(BLOCK_CACHE_HIT),
+        dbstats->getTickerCount(BLOCK_CACHE_MISS),
+        dbstats->getTickerCount(BLOOM_FILTER_USEFUL),
+        dbstats->getTickerCount(COMPACTION_KEY_DROP_NEWER_ENTRY),
+        dbstats->getTickerCount(COMPACTION_KEY_DROP_OBSOLETE),
+        dbstats->getTickerCount(COMPACTION_KEY_DROP_USER));
+    PrintHistogram(DB_GET, "DB_GET");
+    PrintHistogram(DB_WRITE, "DB_WRITE");
+    PrintHistogram(COMPACTION_TIME, "COMPACTION_TIME");
+  }
+}
+
 void DBImpl::MaybeDumpStats() {
   if (options_.stats_dump_period_sec == 0) return;
 
@@ -323,6 +358,7 @@ void DBImpl::MaybeDumpStats() {
     std::string stats;
     GetProperty("leveldb.stats", &stats);
     Log(options_.info_log, "%s", stats.c_str());
+    PrintStatistics();
   }
 }
 
diff --git a/db/db_impl.h b/db/db_impl.h
index 5a8d4fdbe..7d434dad4 100644
--- a/db/db_impl.h
+++ b/db/db_impl.h
@@ -204,12 +204,14 @@ class DBImpl : public DB {
   //  return true if
   bool CheckFileExistsAndEmpty(const LogFile& file);
 
-
   Status ReadFirstRecord(const LogFile& file, WriteBatch* const result);
 
-
   Status ReadFirstLine(const std::string& fname, WriteBatch* const batch);
 
+  void PrintHistogram(Histograms histogram_type, std::string name);
+
+  void PrintStatistics();
+
   // dump leveldb.stats to LOG
   void MaybeDumpStats();