Bugfix: Correct rocksdb statistics to report column family sums. (#9705)

* Update rocksdb statistics to properly report sums from column families.  Add throttle statistic.

* add cstddef include to allow clean compile with gcc 6.3.0 20170516

arangod/Aql/ShortStringStorage.h

@@ -24,6 +24,7 @@
 #ifndef ARANGOD_AQL_SHORT_STRING_STORAGE_H
 #define ARANGOD_AQL_SHORT_STRING_STORAGE_H 1
 
+#include <cstddef>
 #include <vector>
 
 #include "Basics/Common.h"

arangod/RocksDBEngine/RocksDBEngine.cpp

@@ -2142,6 +2142,23 @@ void RocksDBEngine::getStatistics(VPackBuilder& builder) const {
     }
   };
 
+  // get string property from each column family and return sum;
+  auto addIntAllCf = [&](std::string const& s) {
+    int64_t sum = 0;
+    for (auto cfh : RocksDBColumnFamily::_allHandles) {
+      std::string v;
+      if (_db->GetProperty(cfh, s, &v)) {
+        int64_t temp=basics::StringUtils::int64(v);
+
+        // -1 returned for somethings that are valid property but no value
+        if (0 < temp) {
+          sum += temp;
+        } // if
+      } // if
+    } // for
+    builder.add(s, VPackValue(sum));
+  };
+
   // add column family properties
   auto addCf = [&](std::string const& name, rocksdb::ColumnFamilyHandle* c) {
     std::string v;
@@ -2169,40 +2186,43 @@ void RocksDBEngine::getStatistics(VPackBuilder& builder) const {
 
   builder.openObject();
   for (int i = 0; i < _options.num_levels; ++i) {
-    addStr(rocksdb::DB::Properties::kNumFilesAtLevelPrefix + std::to_string(i));
-    addStr(rocksdb::DB::Properties::kCompressionRatioAtLevelPrefix + std::to_string(i));
+    addIntAllCf(rocksdb::DB::Properties::kNumFilesAtLevelPrefix + std::to_string(i));
+    // ratio needs new calculation with all cf, not a simple add operation
+    addIntAllCf(rocksdb::DB::Properties::kCompressionRatioAtLevelPrefix + std::to_string(i));
   }
-  addInt(rocksdb::DB::Properties::kNumImmutableMemTable);
-  addInt(rocksdb::DB::Properties::kNumImmutableMemTableFlushed);
-  addInt(rocksdb::DB::Properties::kMemTableFlushPending);
-  addInt(rocksdb::DB::Properties::kCompactionPending);
+  // caution:  you must read rocksdb/db/interal_stats.cc carefully to
+  //           determine if a property is for whole database or one column family
+  addIntAllCf(rocksdb::DB::Properties::kNumImmutableMemTable);
+  addIntAllCf(rocksdb::DB::Properties::kNumImmutableMemTableFlushed);
+  addIntAllCf(rocksdb::DB::Properties::kMemTableFlushPending);
+  addIntAllCf(rocksdb::DB::Properties::kCompactionPending);
   addInt(rocksdb::DB::Properties::kBackgroundErrors);
-  addInt(rocksdb::DB::Properties::kCurSizeActiveMemTable);
-  addInt(rocksdb::DB::Properties::kCurSizeAllMemTables);
-  addInt(rocksdb::DB::Properties::kSizeAllMemTables);
-  addInt(rocksdb::DB::Properties::kNumEntriesActiveMemTable);
-  addInt(rocksdb::DB::Properties::kNumEntriesImmMemTables);
-  addInt(rocksdb::DB::Properties::kNumDeletesActiveMemTable);
-  addInt(rocksdb::DB::Properties::kNumDeletesImmMemTables);
-  addInt(rocksdb::DB::Properties::kEstimateNumKeys);
-  addInt(rocksdb::DB::Properties::kEstimateTableReadersMem);
+  addIntAllCf(rocksdb::DB::Properties::kCurSizeActiveMemTable);
+  addIntAllCf(rocksdb::DB::Properties::kCurSizeAllMemTables);
+  addIntAllCf(rocksdb::DB::Properties::kSizeAllMemTables);
+  addIntAllCf(rocksdb::DB::Properties::kNumEntriesActiveMemTable);
+  addIntAllCf(rocksdb::DB::Properties::kNumEntriesImmMemTables);
+  addIntAllCf(rocksdb::DB::Properties::kNumDeletesActiveMemTable);
+  addIntAllCf(rocksdb::DB::Properties::kNumDeletesImmMemTables);
+  addIntAllCf(rocksdb::DB::Properties::kEstimateNumKeys);
+  addIntAllCf(rocksdb::DB::Properties::kEstimateTableReadersMem);
   addInt(rocksdb::DB::Properties::kNumSnapshots);
   addInt(rocksdb::DB::Properties::kOldestSnapshotTime);
-  addInt(rocksdb::DB::Properties::kNumLiveVersions);
+  addIntAllCf(rocksdb::DB::Properties::kNumLiveVersions);
   addInt(rocksdb::DB::Properties::kMinLogNumberToKeep);
-  addInt(rocksdb::DB::Properties::kEstimateLiveDataSize);
-  addInt(rocksdb::DB::Properties::kLiveSstFilesSize);
+  addIntAllCf(rocksdb::DB::Properties::kEstimateLiveDataSize);
+  addIntAllCf(rocksdb::DB::Properties::kLiveSstFilesSize);
   addStr(rocksdb::DB::Properties::kDBStats);
   addStr(rocksdb::DB::Properties::kSSTables);
   addInt(rocksdb::DB::Properties::kNumRunningCompactions);
   addInt(rocksdb::DB::Properties::kNumRunningFlushes);
   addInt(rocksdb::DB::Properties::kIsFileDeletionsEnabled);
-  addInt(rocksdb::DB::Properties::kEstimatePendingCompactionBytes);
+  addIntAllCf(rocksdb::DB::Properties::kEstimatePendingCompactionBytes);
   addInt(rocksdb::DB::Properties::kBaseLevel);
   addInt(rocksdb::DB::Properties::kBlockCacheCapacity);
   addInt(rocksdb::DB::Properties::kBlockCacheUsage);
   addInt(rocksdb::DB::Properties::kBlockCachePinnedUsage);
-  addInt(rocksdb::DB::Properties::kTotalSstFilesSize);
+  addIntAllCf(rocksdb::DB::Properties::kTotalSstFilesSize);
   addInt(rocksdb::DB::Properties::kActualDelayedWriteRate);
   addInt(rocksdb::DB::Properties::kIsWriteStopped);
 
@@ -2233,6 +2253,7 @@ void RocksDBEngine::getStatistics(VPackBuilder& builder) const {
   }
 
   // print column family statistics
+  //  warning: output format limits numbers to 3 digits of precision or less.
   builder.add("columnFamilies", VPackValue(VPackValueType::Object));
   addCf("definitions", RocksDBColumnFamily::definitions());
   addCf("documents", RocksDBColumnFamily::documents());
@@ -2243,6 +2264,10 @@ void RocksDBEngine::getStatistics(VPackBuilder& builder) const {
   addCf("fulltext", RocksDBColumnFamily::fulltext());
   builder.close();
 
+  if (_listener) {
+    builder.add("rocksdbengine.throttle.bps", VPackValue(_listener->GetThrottle()));
+  } // if
+
   builder.close();
 }
 

arangod/RocksDBEngine/RocksDBThrottle.h

@@ -87,6 +87,8 @@ class RocksDBThrottle : public rocksdb::EventListener {
 
   void StopThread();
 
+  uint64_t GetThrottle() const {return _throttleBps;};
+
  protected:
   void Startup(rocksdb::DB* db);
 
@@ -139,7 +141,7 @@ class RocksDBThrottle : public rocksdb::EventListener {
   ThrottleData_t _throttleData[THROTTLE_INTERVALS];
   size_t _replaceIdx;
 
-  uint64_t _throttleBps;
+  std::atomic<uint64_t> _throttleBps;
   bool _firstThrottle;
 
   std::unique_ptr<WriteControllerToken> _delayToken;