diff --git a/common/workunit/workunit.cpp b/common/workunit/workunit.cpp
index 25f2eeadd44..51339adf1c6 100644
--- a/common/workunit/workunit.cpp
+++ b/common/workunit/workunit.cpp
@@ -2659,7 +2659,7 @@ cost_type aggregateCost(const IConstWorkUnit * wu, const char *scope, bool exclu
     }
 }
 
-void StatisticsAggregator::loadExistingAggregates(IConstWorkUnit &workunit)
+void StatisticsAggregator::loadExistingAggregates(const IConstWorkUnit &workunit)
 {
     StatsScopeId globalScopeId(SSTglobal, (unsigned)0);
     statsCollection.setown(createStatisticCollection(globalScopeId));
@@ -2682,9 +2682,9 @@ void StatisticsAggregator::loadExistingAggregates(IConstWorkUnit &workunit)
 
     WuScopeFilter filter;
     filter.addScopeType(SSTglobal).addScopeType(SSTworkflow).addScopeType(SSTgraph);
-    const unsigned numStats = aggregateKindsMapping.numStatistics();
+    const unsigned numStats = mapping.numStatistics();
     for (unsigned i=0; i<numStats; ++i)
-        filter.addOutputStatistic(aggregateKindsMapping.getKind(i));
+        filter.addOutputStatistic(mapping.getKind(i));
     filter.setDepth(1,3); // 1=global, 2=workflow, 3=graph
     filter.setSources(SSFsearchGlobalStats);
     filter.setIncludeNesting(0);
@@ -2703,7 +2703,7 @@ void StatisticsAggregator::recordStats(IStatisticCollection * sourceStats, unsig
     verifyex(graphScopeId.setScopeText(graphName));
     StatsScopeId wfScopeId(SSTworkflow, wfid);
     StatsScopeId sgScopeId(SSTsubgraph, sgId);
-    statsCollection->recordStats(aggregateKindsMapping, sourceStats, {wfScopeId, graphScopeId, sgScopeId});
+    statsCollection->recordStats(mapping, sourceStats, {wfScopeId, graphScopeId, sgScopeId});
 }
 
 // Recalculate aggregates and then write the aggregates to global stats (dali)
@@ -2712,12 +2712,12 @@ void StatisticsAggregator::updateAggregates(IWorkUnit *wu)
     if (!statsCollection)
         return;
 
-    std::function f = [&](const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)
+    AggregateUpdatedCallBackFunc f = [&](const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)
     {
         wu->setStatistic(queryStatisticsComponentType(), queryStatisticsComponentName(), sst, scope, kind, nullptr, value, 1, 0, StatsMergeReplace);
     };
 
-    statsCollection->refreshAggregates(aggregateKindsMapping, f);
+    statsCollection->refreshAggregates(mapping, f);
 }
 
 //---------------------------------------------------------------------------------------------------------------------
diff --git a/common/workunit/workunit.hpp b/common/workunit/workunit.hpp
index 38e4a31457a..a6579c85d3b 100644
--- a/common/workunit/workunit.hpp
+++ b/common/workunit/workunit.hpp
@@ -1786,13 +1786,13 @@ extern WORKUNIT_API bool executeGraphOnLingeringThor(IConstWorkUnit &workunit, u
 class WORKUNIT_API StatisticsAggregator : public CInterface
 {
 public:
-    StatisticsAggregator() : aggregateKindsMapping(aggregateKindStatistics) {}
-    void loadExistingAggregates(IConstWorkUnit &workunit);
+    StatisticsAggregator(const StatisticsMapping & _mapping) : mapping(_mapping) {}
+    void loadExistingAggregates(const IConstWorkUnit &workunit);
     void recordStats(IStatisticCollection * sourceStats, unsigned wfid, const char * graphName, unsigned graphId);
     void updateAggregates(IWorkUnit *wu);
 private:
     Owned<IStatisticCollection> statsCollection;
-    const StatisticsMapping & aggregateKindsMapping;
+    const StatisticsMapping & mapping;
 };
 
 #endif
diff --git a/ecl/eclagent/agentctx.hpp b/ecl/eclagent/agentctx.hpp
index d919c6c087c..73444006563 100644
--- a/ecl/eclagent/agentctx.hpp
+++ b/ecl/eclagent/agentctx.hpp
@@ -125,7 +125,7 @@ struct IAgentContext : extends IGlobalCodeContext
     virtual void addWuExceptionEx(const char * text, unsigned code, unsigned severity, unsigned audience, char const * source) = 0;
     virtual double queryAgentMachineCost() const = 0;
     virtual void updateAggregates(IWorkUnit* lockedwu) = 0;
-    virtual void mergeAggregatorStats(IStatisticGatherer & stats, unsigned wfid, const char *graphname, unsigned sgId) = 0;
+    virtual void mergeAggregatorStats(IStatisticCollection & stats, unsigned wfid, const char *graphname, unsigned sgId) = 0;
 };
 
 #endif // AGENTCTX_HPP_INCL
diff --git a/ecl/eclagent/eclagent.cpp b/ecl/eclagent/eclagent.cpp
index 99a6eb4edd0..a9de717e852 100644
--- a/ecl/eclagent/eclagent.cpp
+++ b/ecl/eclagent/eclagent.cpp
@@ -509,7 +509,7 @@ class EclAgentPluginCtx : public SimplePluginCtx
 //=======================================================================================
 
 EclAgent::EclAgent(IConstWorkUnit *wu, const char *_wuid, bool _checkVersion, bool _resetWorkflow, bool _noRetry, char const * _logname, const char *_allowedPipeProgs, IPropertyTree *_queryXML, ILogMsgHandler * _logMsgHandler)
-    : wuRead(wu), wuid(_wuid), checkVersion(_checkVersion), resetWorkflow(_resetWorkflow), noRetry(_noRetry), allowedPipeProgs(_allowedPipeProgs), logMsgHandler(_logMsgHandler)
+    : wuRead(wu), wuid(_wuid), checkVersion(_checkVersion), resetWorkflow(_resetWorkflow), noRetry(_noRetry), allowedPipeProgs(_allowedPipeProgs), logMsgHandler(_logMsgHandler), statsAggregator(stdAggregateKindStatistics)
 {
     isAborting = false;
     isStandAloneExe = false;
diff --git a/ecl/eclagent/eclagent.ipp b/ecl/eclagent/eclagent.ipp
index c8c35aaa2bc..3aafca17a3e 100644
--- a/ecl/eclagent/eclagent.ipp
+++ b/ecl/eclagent/eclagent.ipp
@@ -254,7 +254,7 @@ public:
     {
         ctx->updateAggregates(lockedwu);
     }
-    virtual void mergeAggregatorStats(IStatisticGatherer & stats, unsigned wfid, const char *graphname, unsigned sgId) override
+    virtual void mergeAggregatorStats(IStatisticCollection & stats, unsigned wfid, const char *graphname, unsigned sgId) override
     {
         ctx->mergeAggregatorStats(stats, wfid, graphname, sgId);
     }
@@ -718,10 +718,9 @@ public:
     {
         statsAggregator.updateAggregates(lockedwu);
     }
-    virtual void mergeAggregatorStats(IStatisticGatherer & stats, unsigned wfid, const char *graphname, unsigned sgId) override
+    virtual void mergeAggregatorStats(IStatisticCollection & stats, unsigned wfid, const char *graphname, unsigned sgId) override
     {
-        Linked<IStatisticCollection> statsCollection = stats.getResult();
-        statsAggregator.recordStats(statsCollection, wfid, graphname, sgId);
+        statsAggregator.recordStats(&stats, wfid, graphname, sgId);
     }
 };
 
diff --git a/ecl/eclagent/eclgraph.cpp b/ecl/eclagent/eclgraph.cpp
index 2430d1cce19..e1de571cecd 100644
--- a/ecl/eclagent/eclgraph.cpp
+++ b/ecl/eclagent/eclgraph.cpp
@@ -879,7 +879,8 @@ void EclSubGraph::updateProgress()
         Owned<IWUGraphStats> progress = parent.updateStats(queryStatisticsComponentType(), queryStatisticsComponentName(), parent.queryWfid(), id);
         IStatisticGatherer & stats = progress->queryStatsBuilder();
         updateProgress(stats);
-        agent->mergeAggregatorStats(stats, parent.queryWfid(), parent.queryGraphName(), id);
+        Owned<IStatisticCollection> statsCollection = stats.getResult();
+        agent->mergeAggregatorStats(*statsCollection, parent.queryWfid(), parent.queryGraphName(), id);
         if (startGraphTime || elapsedGraphCycles)
         {
             WorkunitUpdate lockedwu(agent->updateWorkUnit());
@@ -1351,7 +1352,8 @@ void EclGraph::updateLibraryProgress()
         Owned<IWUGraphStats> progress =  wu->updateStats(queryGraphName(), queryStatisticsComponentType(), queryStatisticsComponentName(), wfid, cur.id, false);
         IStatisticGatherer & stats = progress->queryStatsBuilder();
         cur.updateProgress(stats);
-        agent->mergeAggregatorStats(stats, wfid, queryGraphName(), cur.id);
+        Owned<IStatisticCollection> statsCollection = stats.getResult();
+        agent->mergeAggregatorStats(*statsCollection, wfid, queryGraphName(), cur.id);
     }
 }
 
diff --git a/system/jlib/jstats.cpp b/system/jlib/jstats.cpp
index 13e567a7606..6b694eb46c5 100644
--- a/system/jlib/jstats.cpp
+++ b/system/jlib/jstats.cpp
@@ -1331,7 +1331,7 @@ const StatisticsMapping diskLocalStatistics({StCycleDiskReadIOCycles, StSizeDisk
 const StatisticsMapping diskRemoteStatistics({StTimeDiskReadIO, StSizeDiskRead, StNumDiskReads, StTimeDiskWriteIO, StSizeDiskWrite, StNumDiskWrites, StNumDiskRetries});
 const StatisticsMapping diskReadRemoteStatistics({StTimeDiskReadIO, StSizeDiskRead, StNumDiskReads, StNumDiskRetries, StCycleDiskReadIOCycles});
 const StatisticsMapping diskWriteRemoteStatistics({StTimeDiskWriteIO, StSizeDiskWrite, StNumDiskWrites, StNumDiskRetries, StCycleDiskWriteIOCycles});
-const StatisticsMapping aggregateKindStatistics({StCostExecute, StCostFileAccess, StSizeGraphSpill, StSizeSpillFile});
+const StatisticsMapping stdAggregateKindStatistics({StCostExecute, StCostFileAccess, StSizeGraphSpill, StSizeSpillFile});
 
 const StatisticsMapping * queryStatsMapping(const StatsScopeId & scope, unsigned hashcode)
 {
@@ -1799,7 +1799,7 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
         isDirty=true;
         if (parent) parent->markDirty();
     }
-    void refreshAggregates(CRuntimeStatisticCollection & parentTotals, std::function<void(const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)> & fWhenAggregateUpdated)
+    void refreshAggregates(CRuntimeStatisticCollection & parentTotals, AggregateUpdatedCallBackFunc & fWhenAggregateUpdated)
     {
         const StatisticsMapping & mapping = parentTotals.queryMapping();
         // if this scope is not dirty, the aggregates are accurate at this level so return totals (no need to descend)
@@ -1811,8 +1811,8 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
             {
                 Statistic & stat = stats.element(i);
                 StatisticKind kind = stat.queryKind();
-                if (kind != (StatisticKind)(kind & StKindMask))
-                    continue; // ignore variants
+                if (queryStatsVariant(kind) != 0)
+                    continue; // ignore variants (shouldn't happen as the mapping ensure only the aggregator kinds are present)
                 if (mapping.hasKind(kind))
                 {
                     // Totals required from this level by parent, even if they are not dirty
@@ -1941,20 +1941,6 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
         kind = cur.kind;
         value = cur.value;
     }
-    virtual bool getStatisticSum(StatisticKind kind, unsigned __int64 & value) const override
-    {
-        bool found = false;
-        ForEachItemIn(i, stats)
-        {
-            const Statistic & cur = stats.item(i);
-            if (cur.kind == kind)
-            {
-                value += cur.value;
-                found = true;
-            }
-        }
-        return found;
-    }
     virtual IStatisticCollectionIterator & getScopes(const char * filter, bool sorted) override
     {
         assertex(!filter);
@@ -2092,7 +2078,7 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
         for (auto const & cur : children)
             cur.visit(visitor);
     }
-    virtual void refreshAggregates(const StatisticsMapping & mapping, std::function<void(const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)> & fWhenAggregateUpdated) override
+    virtual void refreshAggregates(const StatisticsMapping & mapping, AggregateUpdatedCallBackFunc & fWhenAggregateUpdated) override
     {
         if (isDirty)
         {
@@ -2102,8 +2088,8 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
     }
     virtual stat_type aggregateStatistic(StatisticKind kind) const override
     {
-        stat_type sum;
-        if (!getStatisticSum(kind, sum)) // get sum of statistics at this level
+        stat_type sum = 0;
+        if (!getStatistic(kind, sum)) // get sum of statistics at this level
         {
             // if no stats at this level, then get sum of stats from children
             for (auto & child : children)
@@ -2115,7 +2101,7 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
     {
         CStatisticCollection * curSrcCollection = static_cast<CStatisticCollection *>(sourceStatsCollection);
         const StatsScopeId * scopeItem = path.begin();
-
+        // n.b. sourceStatsCollection has workflow as root but this collection has global as root
         // Locate the collection with the stats and make curSrcCollection point to that
         if (!curSrcCollection || curSrcCollection->queryScopeId().compare(*scopeItem)!=0)
             return; // Required path doesn't exist in source collection so nothing more to do here
@@ -2134,7 +2120,7 @@ class CStatisticCollection : public CInterfaceOf<IStatisticCollection>
         ForEachItemIn(i, curSrcCollection->stats)
         {
             Statistic & cur = curSrcCollection->stats.element(i);
-            if (cur.kind != (StatisticKind)(cur.kind & StKindMask))
+            if (queryStatsVariant(cur.kind) != 0)
                 continue; // ignore variants
             if (mapping.hasKind(cur.kind))
             {
diff --git a/system/jlib/jstats.h b/system/jlib/jstats.h
index d9603aef04b..cacdb23684e 100644
--- a/system/jlib/jstats.h
+++ b/system/jlib/jstats.h
@@ -105,6 +105,8 @@ interface IStatisticGatherer;
 interface IStatisticVisitor;
 
 class jlib_decl StatisticsMapping;
+typedef std::function<void(const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)> AggregateUpdatedCallBackFunc;
+
 interface IStatisticCollection : public IInterface
 {
 public:
@@ -115,7 +117,6 @@ interface IStatisticCollection : public IInterface
     virtual unsigned getNumStatistics() const = 0;
     virtual bool getStatistic(StatisticKind kind, unsigned __int64 & value) const = 0;
     virtual void getStatistic(StatisticKind & kind, unsigned __int64 & value, unsigned idx) const = 0;
-    virtual bool getStatisticSum(StatisticKind kind, unsigned __int64 & value) const = 0;
     virtual IStatisticCollectionIterator & getScopes(const char * filter, bool sorted) = 0;
     virtual void getMinMaxScope(IStringVal & minValue, IStringVal & maxValue, StatisticScopeType searchScopeType) const = 0;
     virtual void getMinMaxActivity(unsigned & minValue, unsigned & maxValue) const = 0;
@@ -126,7 +127,7 @@ interface IStatisticCollection : public IInterface
     virtual StringBuffer &toXML(StringBuffer &out) const = 0;
     virtual void visit(IStatisticVisitor & target) const = 0;
     virtual void visitChildren(IStatisticVisitor & target) const = 0;
-    virtual void refreshAggregates(const StatisticsMapping & mapping, std::function<void(const char * scope, StatisticScopeType sst, StatisticKind kind, stat_type value)> & fWhenAggregateUpdated) = 0;
+    virtual void refreshAggregates(const StatisticsMapping & mapping, AggregateUpdatedCallBackFunc & fWhenAggregateUpdated) = 0;
     virtual stat_type aggregateStatistic(StatisticKind kind) const = 0;
     virtual void recordStats(const StatisticsMapping & mapping, IStatisticCollection * statsCollection, std::initializer_list<const StatsScopeId> path) = 0;
 };
@@ -503,7 +504,7 @@ extern const jlib_decl StatisticsMapping diskRemoteStatistics;
 extern const jlib_decl StatisticsMapping diskReadRemoteStatistics;
 extern const jlib_decl StatisticsMapping diskWriteRemoteStatistics;
 extern const jlib_decl StatisticsMapping jhtreeCacheStatistics;
-extern const jlib_decl StatisticsMapping aggregateKindStatistics;
+extern const jlib_decl StatisticsMapping stdAggregateKindStatistics;
 
 //---------------------------------------------------------------------------------------------------------------------
 
diff --git a/thorlcr/master/thdemonserver.cpp b/thorlcr/master/thdemonserver.cpp
index 1b0065508bc..5b4094c3315 100644
--- a/thorlcr/master/thdemonserver.cpp
+++ b/thorlcr/master/thdemonserver.cpp
@@ -133,9 +133,9 @@ class DeMonServer : public CSimpleInterface, implements IDeMonServer
     {
         Owned<IWUGraphStats> stats = currentWU.updateStats(graphName, SCTthor, queryStatisticsComponentName(), wfid, graph.queryGraphId(), false);
         IStatisticGatherer & statsBuilder = stats->queryStatsBuilder();
-        reportGraph(statsBuilder, & graph);
+        reportGraph(statsBuilder, &graph);
         // Merge only the stats at the specified scope level
-        Linked<IStatisticCollection> statsCollection = statsBuilder.getResult();
+        Owned<IStatisticCollection> statsCollection = statsBuilder.getResult();
         statsAggregator.recordStats(statsCollection, wfid, graphName, graph.queryGraphId());
     }
     void reportActiveGraphs(bool finished, bool success=true)
@@ -201,7 +201,7 @@ class DeMonServer : public CSimpleInterface, implements IDeMonServer
 public:
     IMPLEMENT_IINTERFACE_USING(CSimpleInterface);
 
-    DeMonServer()
+    DeMonServer() : statsAggregator(stdAggregateKindStatistics)
     {
         lastReport = msTick();
         reportRate = globals->getPropInt("@watchdogProgressInterval", 30);