diff --git a/FWCore/Framework/interface/Event.h b/FWCore/Framework/interface/Event.h
index e9968c1619217..0c6b666abcc0e 100644
--- a/FWCore/Framework/interface/Event.h
+++ b/FWCore/Framework/interface/Event.h
@@ -35,6 +35,7 @@ For its usage, see "FWCore/Framework/interface/PrincipalGetAdapter.h"
 #include "FWCore/Utilities/interface/TypeID.h"
 #include "FWCore/Utilities/interface/EDGetToken.h"
 #include "FWCore/Utilities/interface/ProductKindOfType.h"
+#include "FWCore/Utilities/interface/StreamID.h"
 
 #include "boost/shared_ptr.hpp"
 
@@ -63,6 +64,11 @@ namespace edm {
     
     // AUX functions are defined in EventBase
     EventAuxiliary const& eventAuxiliary() const {return aux_;}
+    
+    ///\return The id for the particular Stream processing the Event
+    StreamID streamID() const {
+      return streamID_;
+    }
 
     LuminosityBlock const&
     getLuminosityBlock() const {
@@ -246,6 +252,8 @@ namespace edm {
 
     // We own the retrieved Views, and have to destroy them.
     mutable std::vector<boost::shared_ptr<ViewBase> > gotViews_;
+    
+    StreamID streamID_;
 
     static const std::string emptyString_;
   };
diff --git a/FWCore/Framework/interface/EventPrincipal.h b/FWCore/Framework/interface/EventPrincipal.h
index cad6d4bca613c..28f84eee5562a 100644
--- a/FWCore/Framework/interface/EventPrincipal.h
+++ b/FWCore/Framework/interface/EventPrincipal.h
@@ -18,6 +18,7 @@ is the DataBlock.
 #include "DataFormats/Provenance/interface/BranchMapper.h"
 #include "DataFormats/Provenance/interface/EventAuxiliary.h"
 #include "DataFormats/Provenance/interface/EventSelectionID.h"
+#include "FWCore/Utilities/interface/StreamID.h"
 #include "FWCore/Framework/interface/Principal.h"
 
 #include "boost/shared_ptr.hpp"
@@ -49,7 +50,8 @@ namespace edm {
         boost::shared_ptr<ProductRegistry const> reg,
         boost::shared_ptr<BranchIDListHelper const> branchIDListHelper,
         ProcessConfiguration const& pc,
-        HistoryAppender* historyAppender);
+        HistoryAppender* historyAppender,
+        StreamID const& streamID = StreamID::invalidStreamID());
     ~EventPrincipal() {}
 
     void fillEventPrincipal(EventAuxiliary const& aux,
@@ -102,6 +104,11 @@ namespace edm {
       return aux_;
     }
 
+    StreamID streamID() const { return streamID_;}
+    void setStreamID(StreamID const& iID) {
+      streamID_ = iID;
+    }
+    
     LuminosityBlockNumber_t luminosityBlock() const {
       return id().luminosityBlock();
     }
@@ -176,6 +183,8 @@ namespace edm {
     boost::shared_ptr<BranchListIndexes> branchListIndexes_;
 
     std::map<BranchListIndex, ProcessIndex> branchListIndexToProcessIndex_;
+    
+    StreamID streamID_;
 
   };
 
diff --git a/FWCore/Framework/interface/LuminosityBlock.h b/FWCore/Framework/interface/LuminosityBlock.h
index 871f7c159376d..6413b1c0e15af 100644
--- a/FWCore/Framework/interface/LuminosityBlock.h
+++ b/FWCore/Framework/interface/LuminosityBlock.h
@@ -25,6 +25,7 @@ For its usage, see "FWCore/Framework/interface/PrincipalGetAdapter.h"
 #include "FWCore/Framework/interface/PrincipalGetAdapter.h"
 #include "FWCore/Utilities/interface/EDGetToken.h"
 #include "FWCore/Utilities/interface/ProductKindOfType.h"
+#include "FWCore/Utilities/interface/LuminosityBlockIndex.h"
 
 
 #include "boost/shared_ptr.hpp"
@@ -46,6 +47,10 @@ namespace edm {
     // AUX functions are defined in LuminosityBlockBase
     LuminosityBlockAuxiliary const& luminosityBlockAuxiliary() const {return aux_;}
 
+    /**\return Reusable index which can be used to separate data for different simultaneous LuminosityBlocks.
+     */
+    LuminosityBlockIndex index() const;
+    
     //Used in conjunction with EDGetToken
     void setConsumer(EDConsumerBase const* iConsumer);
     template <typename PROD>
diff --git a/FWCore/Framework/interface/LuminosityBlockPrincipal.h b/FWCore/Framework/interface/LuminosityBlockPrincipal.h
index 05d8c776fbbb4..e8c8ceb2aba6a 100644
--- a/FWCore/Framework/interface/LuminosityBlockPrincipal.h
+++ b/FWCore/Framework/interface/LuminosityBlockPrincipal.h
@@ -15,6 +15,7 @@ is the DataBlock.
 
 #include "DataFormats/Provenance/interface/LuminosityBlockAuxiliary.h"
 #include "DataFormats/Provenance/interface/RunID.h"
+#include "FWCore/Utilities/interface/LuminosityBlockIndex.h"
 #include "FWCore/Framework/interface/Principal.h"
 
 #include "boost/shared_ptr.hpp"
@@ -35,7 +36,8 @@ namespace edm {
         boost::shared_ptr<LuminosityBlockAuxiliary> aux,
         boost::shared_ptr<ProductRegistry const> reg,
         ProcessConfiguration const& pc,
-        HistoryAppender* historyAppender);
+        HistoryAppender* historyAppender,
+        unsigned int index);
 
     ~LuminosityBlockPrincipal() {}
 
@@ -53,6 +55,10 @@ namespace edm {
       runPrincipal_ = rp;
     }
 
+    LuminosityBlockIndex index() const {
+      return index_;
+    }
+    
     LuminosityBlockID id() const {
       return aux().id();
     }
@@ -109,6 +115,8 @@ namespace edm {
 
     boost::shared_ptr<LuminosityBlockAuxiliary> aux_;
 
+    LuminosityBlockIndex index_;
+    
     bool complete_;
   };
 }
diff --git a/FWCore/Framework/interface/Run.h b/FWCore/Framework/interface/Run.h
index f70190032392a..4faeebad7e50e 100644
--- a/FWCore/Framework/interface/Run.h
+++ b/FWCore/Framework/interface/Run.h
@@ -23,6 +23,7 @@ For its usage, see "FWCore/Framework/interface/PrincipalGetAdapter.h"
 #include "FWCore/Common/interface/RunBase.h"
 #include "FWCore/Utilities/interface/EDGetToken.h"
 #include "FWCore/Utilities/interface/ProductKindOfType.h"
+#include "FWCore/Utilities/interface/RunIndex.h"
 
 #include <memory>
 #include <set>
@@ -53,6 +54,10 @@ namespace edm {
 //     Timestamp const& beginTime() const {return aux_.beginTime();}
 //     Timestamp const& endTime() const {return aux_.endTime();}
 
+    /**\return Reusable index which can be used to separate data for different simultaneous Runs.
+     */
+    RunIndex index() const;
+
     template <typename PROD>
     bool
     getByLabel(std::string const& label, Handle<PROD>& result) const;
diff --git a/FWCore/Framework/interface/RunPrincipal.h b/FWCore/Framework/interface/RunPrincipal.h
index 5702f57cbd3a9..4c094dcebdd00 100644
--- a/FWCore/Framework/interface/RunPrincipal.h
+++ b/FWCore/Framework/interface/RunPrincipal.h
@@ -18,6 +18,7 @@ is the DataBlock.
 #include "boost/shared_ptr.hpp"
 
 #include "DataFormats/Provenance/interface/RunAuxiliary.h"
+#include "FWCore/Utilities/interface/RunIndex.h"
 #include "FWCore/Framework/interface/Principal.h"
 
 namespace edm {
@@ -34,11 +35,23 @@ namespace edm {
         boost::shared_ptr<RunAuxiliary> aux,
         boost::shared_ptr<ProductRegistry const> reg,
         ProcessConfiguration const& pc,
-        HistoryAppender* historyAppender);
+        HistoryAppender* historyAppender,
+        unsigned int iRunIndex);
     ~RunPrincipal() {}
 
     void fillRunPrincipal(DelayedReader* reader = 0);
 
+    /** Multiple Runs may be processed simultaneously. The
+     return value can be used to identify a particular Run.
+     The value will range from 0 to one less than
+     the maximum number of allowed simultaneous Runs. A particular
+     value will be reused once the processing of the previous Run 
+     using that index has been completed.
+     */
+    RunIndex index() const {
+      return index_;
+    }
+    
     RunAuxiliary const& aux() const {
       return *aux_;
     }
@@ -89,6 +102,7 @@ namespace edm {
 
     // A vector of product holders.
     boost::shared_ptr<RunAuxiliary> aux_;
+    RunIndex index_;
 
     bool complete_;
   };
diff --git a/FWCore/Framework/src/Event.cc b/FWCore/Framework/src/Event.cc
index dd1fc5fdd5ed8..0f79c85251828 100644
--- a/FWCore/Framework/src/Event.cc
+++ b/FWCore/Framework/src/Event.cc
@@ -19,7 +19,9 @@ namespace edm {
       aux_(ep.aux()),
       luminosityBlock_(ep.luminosityBlockPrincipalPtrValid() ? new LuminosityBlock(ep.luminosityBlockPrincipal(), md) : 0),
       gotBranchIDs_(),
-      gotViews_() {
+      gotViews_(),
+      streamID_(ep.streamID())
+  {
   }
 
   Event::~Event() {
diff --git a/FWCore/Framework/src/EventPrincipal.cc b/FWCore/Framework/src/EventPrincipal.cc
index eefc5881c8bc2..814aef4d82b87 100644
--- a/FWCore/Framework/src/EventPrincipal.cc
+++ b/FWCore/Framework/src/EventPrincipal.cc
@@ -22,7 +22,8 @@ namespace edm {
         boost::shared_ptr<ProductRegistry const> reg,
         boost::shared_ptr<BranchIDListHelper const> branchIDListHelper,
         ProcessConfiguration const& pc,
-        HistoryAppender* historyAppender) :
+        HistoryAppender* historyAppender,
+        StreamID const& streamID) :
     Base(reg, reg->productLookup(InEvent), pc, InEvent, historyAppender),
           aux_(),
           luminosityBlockPrincipal_(),
@@ -32,7 +33,8 @@ namespace edm {
           eventSelectionIDs_(new EventSelectionIDVector),
           branchIDListHelper_(branchIDListHelper),
           branchListIndexes_(new BranchListIndexes),
-          branchListIndexToProcessIndex_() {}
+          branchListIndexToProcessIndex_(),
+          streamID_(streamID){}
 
   void
   EventPrincipal::clearEventPrincipal() {
diff --git a/FWCore/Framework/src/EventProcessor.cc b/FWCore/Framework/src/EventProcessor.cc
index 0ff363e855033..da20cf43189b4 100644
--- a/FWCore/Framework/src/EventProcessor.cc
+++ b/FWCore/Framework/src/EventProcessor.cc
@@ -54,6 +54,7 @@
 #include "FWCore/Utilities/interface/RandomNumberGenerator.h"
 #include "FWCore/Utilities/interface/UnixSignalHandlers.h"
 #include "FWCore/Utilities/interface/ExceptionCollector.h"
+#include "FWCore/Utilities/interface/StreamID.h"
 
 #include "MessageForSource.h"
 #include "MessageForParent.h"
@@ -658,7 +659,11 @@ namespace edm {
     connectSigs(this);
 
     // Reusable event principal
-    boost::shared_ptr<EventPrincipal> ep(new EventPrincipal(preg_, branchIDListHelper_, *processConfiguration_, historyAppender_.get()));
+    boost::shared_ptr<EventPrincipal> ep(new EventPrincipal(preg_,
+                                                            branchIDListHelper_,
+                                                            *processConfiguration_,
+                                                            historyAppender_.get(),
+                                                            StreamID{0}));
     principalCache_.insert(ep);
       
     // initialize the subprocess, if there is one
diff --git a/FWCore/Framework/src/InputSource.cc b/FWCore/Framework/src/InputSource.cc
index 91110975ca235..c67eb1896c559 100644
--- a/FWCore/Framework/src/InputSource.cc
+++ b/FWCore/Framework/src/InputSource.cc
@@ -286,7 +286,7 @@ namespace edm {
   boost::shared_ptr<RunPrincipal>
   InputSource::readAndCacheRun(HistoryAppender& historyAppender) {
     RunSourceSentry sentry(*this);
-    boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(runAuxiliary(), productRegistry_, processConfiguration(), &historyAppender));
+    boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(runAuxiliary(), productRegistry_, processConfiguration(), &historyAppender,0));
     callWithTryCatchAndPrint<boost::shared_ptr<RunPrincipal> >( [this,&rp](){ return readRun_(rp); }, "Calling InputSource::readRun_" );
     return rp;
   }
@@ -304,7 +304,7 @@ namespace edm {
       new LuminosityBlockPrincipal(luminosityBlockAuxiliary(),
                                    productRegistry_,
                                    processConfiguration(),
-                                   &historyAppender));
+                                   &historyAppender,0));
     callWithTryCatchAndPrint<boost::shared_ptr<LuminosityBlockPrincipal> >( [this,&lbp](){ return readLuminosityBlock_(lbp); },
                                                                             "Calling InputSource::readLuminosityBlock_" );
     if(remainingLumis_ > 0) {
diff --git a/FWCore/Framework/src/LuminosityBlock.cc b/FWCore/Framework/src/LuminosityBlock.cc
index 23478b402cae2..6c0057c296c10 100644
--- a/FWCore/Framework/src/LuminosityBlock.cc
+++ b/FWCore/Framework/src/LuminosityBlock.cc
@@ -20,6 +20,12 @@ namespace edm {
     for_all(putProducts_, principal_get_adapter_detail::deleter());
   }
 
+  LuminosityBlockIndex
+  LuminosityBlock::index() const {
+    return luminosityBlockPrincipal().index();
+  }
+
+  
   LuminosityBlockPrincipal&
   LuminosityBlock::luminosityBlockPrincipal() {
     return dynamic_cast<LuminosityBlockPrincipal&>(provRecorder_.principal());
diff --git a/FWCore/Framework/src/LuminosityBlockPrincipal.cc b/FWCore/Framework/src/LuminosityBlockPrincipal.cc
index 93d913a2d08ce..fd2b5d0e94156 100644
--- a/FWCore/Framework/src/LuminosityBlockPrincipal.cc
+++ b/FWCore/Framework/src/LuminosityBlockPrincipal.cc
@@ -12,10 +12,12 @@ namespace edm {
       boost::shared_ptr<LuminosityBlockAuxiliary> aux,
       boost::shared_ptr<ProductRegistry const> reg,
       ProcessConfiguration const& pc,
-      HistoryAppender* historyAppender) :
+      HistoryAppender* historyAppender,
+      unsigned int index) :
     Base(reg, reg->productLookup(InLumi), pc, InLumi, historyAppender),
         runPrincipal_(),
         aux_(aux),
+        index_(index),
         complete_(false) {
   }
 
diff --git a/FWCore/Framework/src/Run.cc b/FWCore/Framework/src/Run.cc
index 9613194f2148a..016d037e8f20c 100644
--- a/FWCore/Framework/src/Run.cc
+++ b/FWCore/Framework/src/Run.cc
@@ -18,6 +18,8 @@ namespace edm {
     for_all(putProducts_, principal_get_adapter_detail::deleter());
   }
 
+  RunIndex Run::index() const { return runPrincipal().index();}
+  
   RunPrincipal&
   Run::runPrincipal() {
     return dynamic_cast<RunPrincipal&>(provRecorder_.principal());
diff --git a/FWCore/Framework/src/RunPrincipal.cc b/FWCore/Framework/src/RunPrincipal.cc
index 182e1ff10dc34..8ca7a78efbb1e 100644
--- a/FWCore/Framework/src/RunPrincipal.cc
+++ b/FWCore/Framework/src/RunPrincipal.cc
@@ -12,9 +12,10 @@ namespace edm {
     boost::shared_ptr<RunAuxiliary> aux,
     boost::shared_ptr<ProductRegistry const> reg,
     ProcessConfiguration const& pc,
-    HistoryAppender* historyAppender) :
+    HistoryAppender* historyAppender,
+    unsigned int iRunIndex) :
     Base(reg, reg->productLookup(InRun), pc, InRun, historyAppender),
-      aux_(aux), complete_(false) {
+      aux_(aux), index_(iRunIndex), complete_(false) {
   }
 
   void
diff --git a/FWCore/Framework/src/SubProcess.cc b/FWCore/Framework/src/SubProcess.cc
index 003aa3d27a1d5..ce40945529292 100644
--- a/FWCore/Framework/src/SubProcess.cc
+++ b/FWCore/Framework/src/SubProcess.cc
@@ -122,7 +122,8 @@ namespace edm {
     std::map<std::string, std::vector<std::pair<std::string, int> > > outputModulePathPositions;
     setEventSelectionInfo(outputModulePathPositions, parentProductRegistry->anyProductProduced());
 
-    boost::shared_ptr<EventPrincipal> ep(new EventPrincipal(preg_, branchIDListHelper_, *processConfiguration_, historyAppender_.get()));
+    boost::shared_ptr<EventPrincipal> ep(new EventPrincipal(preg_, branchIDListHelper_, *processConfiguration_, historyAppender_.get(),
+                                                            StreamID::invalidStreamID()));
     principalCache_.insert(ep);
 
     if(subProcessParameterSet) {
@@ -194,6 +195,7 @@ namespace edm {
     }
 
     EventPrincipal& ep = principalCache_.eventPrincipal();
+    ep.setStreamID(principal.streamID());
     ep.fillEventPrincipal(aux,
                           esids,
                           boost::shared_ptr<BranchListIndexes>(new BranchListIndexes(principal.branchListIndexes())),
@@ -220,7 +222,7 @@ namespace edm {
   SubProcess::beginRun(RunPrincipal const& principal) {
     boost::shared_ptr<RunAuxiliary> aux(new RunAuxiliary(principal.aux()));
     aux->setProcessHistoryID(principal.processHistoryID());
-    boost::shared_ptr<RunPrincipal> rpp(new RunPrincipal(aux, preg_, *processConfiguration_, historyAppender_.get()));
+    boost::shared_ptr<RunPrincipal> rpp(new RunPrincipal(aux, preg_, *processConfiguration_, historyAppender_.get(),principal.index()));
     rpp->fillRunPrincipal(principal.reader());
     principalCache_.insert(rpp);
 
@@ -286,7 +288,7 @@ namespace edm {
   SubProcess::beginLuminosityBlock(LuminosityBlockPrincipal const& principal) {
     boost::shared_ptr<LuminosityBlockAuxiliary> aux(new LuminosityBlockAuxiliary(principal.aux()));
     aux->setProcessHistoryID(principal.processHistoryID());
-    boost::shared_ptr<LuminosityBlockPrincipal> lbpp(new LuminosityBlockPrincipal(aux, preg_, *processConfiguration_, historyAppender_.get()));
+    boost::shared_ptr<LuminosityBlockPrincipal> lbpp(new LuminosityBlockPrincipal(aux, preg_, *processConfiguration_, historyAppender_.get(),principal.index()));
     lbpp->fillLuminosityBlockPrincipal(principal.reader());
     lbpp->setRunPrincipal(principalCache_.runPrincipalPtr());
     principalCache_.insert(lbpp);
diff --git a/FWCore/Framework/test/Event_t.cpp b/FWCore/Framework/test/Event_t.cpp
index ea172b8a90e60..857f1158cf38f 100644
--- a/FWCore/Framework/test/Event_t.cpp
+++ b/FWCore/Framework/test/Event_t.cpp
@@ -365,13 +365,13 @@ void testEvent::setUp() {
   EventID id = make_id();
   ProcessConfiguration const& pc = currentModuleDescription_->processConfiguration();
   boost::shared_ptr<RunAuxiliary> runAux(new RunAuxiliary(id.run(), time, time));
-  boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(runAux, preg, pc, &historyAppender_));
+  boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(runAux, preg, pc, &historyAppender_,0));
   boost::shared_ptr<LuminosityBlockAuxiliary> lumiAux(new LuminosityBlockAuxiliary(rp->run(), 1, time, time));
-  boost::shared_ptr<LuminosityBlockPrincipal>lbp(new LuminosityBlockPrincipal(lumiAux, preg, pc, &historyAppender_));
+  boost::shared_ptr<LuminosityBlockPrincipal>lbp(new LuminosityBlockPrincipal(lumiAux, preg, pc, &historyAppender_,0));
   lbp->setRunPrincipal(rp);
   EventAuxiliary eventAux(id, uuid, time, true);
   const_cast<ProcessHistoryID &>(eventAux.processHistoryID()) = processHistoryID;
-  principal_.reset(new edm::EventPrincipal(preg, branchIDListHelper_, pc, &historyAppender_));
+  principal_.reset(new edm::EventPrincipal(preg, branchIDListHelper_, pc, &historyAppender_,edm::StreamID::invalidStreamID()));
   principal_->fillEventPrincipal(eventAux);
   principal_->setLuminosityBlockPrincipal(lbp);
   currentEvent_.reset(new Event(*principal_, *currentModuleDescription_));
diff --git a/FWCore/Framework/test/event_getrefbeforeput_t.cppunit.cc b/FWCore/Framework/test/event_getrefbeforeput_t.cppunit.cc
index 5cf3c69483710..11765c599aa4d 100644
--- a/FWCore/Framework/test/event_getrefbeforeput_t.cppunit.cc
+++ b/FWCore/Framework/test/event_getrefbeforeput_t.cppunit.cc
@@ -73,12 +73,12 @@ void testEventGetRefBeforePut::failGetProductNotRegisteredTest() {
   edm::ProcessConfiguration pc("PROD", edm::ParameterSetID(), edm::getReleaseVersion(), edm::getPassID());
   boost::shared_ptr<edm::ProductRegistry const> pregc(preg.release());
   boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(col.run(), fakeTime, fakeTime));
-  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_,0));
   boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(new edm::LuminosityBlockAuxiliary(rp->run(), 1, fakeTime, fakeTime));
-  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_,0));
   lbp->setRunPrincipal(rp);
   edm::EventAuxiliary eventAux(col, uuid, fakeTime, true);
-  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_);
+  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_,edm::StreamID::invalidStreamID());
   ep.fillEventPrincipal(eventAux);
   ep.setLuminosityBlockPrincipal(lbp);
   try {
@@ -145,12 +145,12 @@ void testEventGetRefBeforePut::getRefTest() {
   edm::ProcessConfiguration& pc = *pcPtr;
   boost::shared_ptr<edm::ProductRegistry const> pregc(preg.release());
   boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(col.run(), fakeTime, fakeTime));
-  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_,0));
   boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(new edm::LuminosityBlockAuxiliary(rp->run(), 1, fakeTime, fakeTime));
-  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_,0));
   lbp->setRunPrincipal(rp);
   edm::EventAuxiliary eventAux(col, uuid, fakeTime, true);
-  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_);
+  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_,edm::StreamID::invalidStreamID());
   ep.fillEventPrincipal(eventAux);
   ep.setLuminosityBlockPrincipal(lbp);
 
diff --git a/FWCore/Framework/test/eventprincipal_t.cppunit.cc b/FWCore/Framework/test/eventprincipal_t.cppunit.cc
index 6fd267400ef1e..97f9a4f7f22a7 100644
--- a/FWCore/Framework/test/eventprincipal_t.cppunit.cc
+++ b/FWCore/Framework/test/eventprincipal_t.cppunit.cc
@@ -186,12 +186,12 @@ void test_ep::setUp() {
     std::string uuid = edm::createGlobalIdentifier();
     edm::Timestamp now(1234567UL);
     boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(eventID_.run(), now, now));
-    boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pProductRegistry_, *process, &historyAppender_));
+    boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pProductRegistry_, *process, &historyAppender_,0));
     boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(new edm::LuminosityBlockAuxiliary(rp->run(), 1, now, now));
-    boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pProductRegistry_, *process, &historyAppender_));
+    boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pProductRegistry_, *process, &historyAppender_,0));
     lbp->setRunPrincipal(rp);
     edm::EventAuxiliary eventAux(eventID_, uuid, now, true);
-    pEvent_.reset(new edm::EventPrincipal(pProductRegistry_, branchIDListHelper, *process, &historyAppender_));
+    pEvent_.reset(new edm::EventPrincipal(pProductRegistry_, branchIDListHelper, *process, &historyAppender_,edm::StreamID::invalidStreamID()));
     pEvent_->fillEventPrincipal(eventAux);
     pEvent_->setLuminosityBlockPrincipal(lbp);
     pEvent_->put(branchFromRegistry, product, prov);
diff --git a/FWCore/Framework/test/generichandle_t.cppunit.cc b/FWCore/Framework/test/generichandle_t.cppunit.cc
index 38e0c5b1d9821..8eadef1450ce3 100644
--- a/FWCore/Framework/test/generichandle_t.cppunit.cc
+++ b/FWCore/Framework/test/generichandle_t.cppunit.cc
@@ -85,14 +85,14 @@ void testGenericHandle::failgetbyLabelTest() {
   boost::shared_ptr<edm::ProductRegistry const> preg(new edm::ProductRegistry);
   preg->setFrozen();
   boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(id.run(), time, time));
-  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, preg, pc, &historyAppender_));
+  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, preg, pc, &historyAppender_,0));
   boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(new edm::LuminosityBlockAuxiliary(rp->run(), 1, time, time));
-  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, preg, pc, &historyAppender_));
+  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, preg, pc, &historyAppender_,0));
   lbp->setRunPrincipal(rp);
   boost::shared_ptr<edm::BranchIDListHelper> branchIDListHelper(new edm::BranchIDListHelper());
   branchIDListHelper->updateRegistries(*preg);
   edm::EventAuxiliary eventAux(id, uuid, time, true);
-  edm::EventPrincipal ep(preg, branchIDListHelper, pc, &historyAppender_);
+  edm::EventPrincipal ep(preg, branchIDListHelper, pc, &historyAppender_,edm::StreamID::invalidStreamID());
   ep.fillEventPrincipal(eventAux);
   ep.setLuminosityBlockPrincipal(lbp);
   edm::GenericHandle h("edmtest::DummyProduct");
@@ -176,12 +176,12 @@ void testGenericHandle::getbyLabelTest() {
   edm::ProcessConfiguration pc("PROD", dummyProcessPset.id(), edm::getReleaseVersion(), edm::getPassID());
   boost::shared_ptr<edm::ProductRegistry const> pregc(preg.release());
   boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(col.run(), fakeTime, fakeTime));
-  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, pregc, pc, &historyAppender_,0));
   boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(new edm::LuminosityBlockAuxiliary(rp->run(), 1, fakeTime, fakeTime));
-  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_));
+  boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(new edm::LuminosityBlockPrincipal(lumiAux, pregc, pc, &historyAppender_,0));
   lbp->setRunPrincipal(rp);
   edm::EventAuxiliary eventAux(col, uuid, fakeTime, true);
-  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_);
+  edm::EventPrincipal ep(pregc, branchIDListHelper, pc, &historyAppender_,edm::StreamID::invalidStreamID());
   ep.fillEventPrincipal(eventAux);
   ep.setLuminosityBlockPrincipal(lbp);
   edm::BranchDescription const& branchFromRegistry = it->second;
diff --git a/FWCore/Integration/test/TestRunLumiSource.cc b/FWCore/Integration/test/TestRunLumiSource.cc
index ce21cbc099a4f..2310fe327d345 100644
--- a/FWCore/Integration/test/TestRunLumiSource.cc
+++ b/FWCore/Integration/test/TestRunLumiSource.cc
@@ -107,19 +107,19 @@ namespace edm {
 
     boost::shared_ptr<RunAuxiliary> runAux(new RunAuxiliary(run, ts, Timestamp::invalidTimestamp()));
     boost::shared_ptr<RunPrincipal> rp2(
-                                        new RunPrincipal(runAux, productRegistry(), processConfiguration(), &historyAppender_));
+                                        new RunPrincipal(runAux, productRegistry(), processConfiguration(), &historyAppender_,0));
 
     boost::shared_ptr<LuminosityBlockAuxiliary> lumiAux(
 	new LuminosityBlockAuxiliary(rp2->run(), lumi, ts, Timestamp::invalidTimestamp()));
     boost::shared_ptr<LuminosityBlockPrincipal> lbp2(
-        new LuminosityBlockPrincipal(lumiAux, productRegistry(), processConfiguration(), &historyAppender_));
+        new LuminosityBlockPrincipal(lumiAux, productRegistry(), processConfiguration(), &historyAppender_,0));
     lbp2->setRunPrincipal(rp2);
 
     EventID id(run, lbp2->luminosityBlock(), event);
     currentIndex_ += 3;
     EventAuxiliary eventAux(id, processGUID(), ts, false);
     boost::shared_ptr<BranchIDListHelper> branchIDListHelper(new BranchIDListHelper());
-    EventPrincipal* result(new EventPrincipal(productRegistry(), branchIDListHelper, processConfiguration(), &historyAppender_));
+    EventPrincipal* result(new EventPrincipal(productRegistry(), branchIDListHelper, processConfiguration(), &historyAppender_,eventPrincipal.streamID()));
     result->fillEventPrincipal(eventAux);
     result->setLuminosityBlockPrincipal(lbp2);
     return result;
diff --git a/FWCore/TFWLiteSelector/src/TFWLiteSelectorBasic.cc b/FWCore/TFWLiteSelector/src/TFWLiteSelectorBasic.cc
index 9a400106d0864..3e8bd0fdbd07d 100644
--- a/FWCore/TFWLiteSelector/src/TFWLiteSelectorBasic.cc
+++ b/FWCore/TFWLiteSelector/src/TFWLiteSelectorBasic.cc
@@ -282,11 +282,11 @@ TFWLiteSelectorBasic::Process(Long64_t iEntry) {
       try {
          m_->reader_->setEntry(iEntry);
          boost::shared_ptr<edm::RunAuxiliary> runAux(new edm::RunAuxiliary(aux.run(), aux.time(), aux.time()));
-         boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, m_->reg_, m_->pc_, nullptr));
+         boost::shared_ptr<edm::RunPrincipal> rp(new edm::RunPrincipal(runAux, m_->reg_, m_->pc_, nullptr,0));
          boost::shared_ptr<edm::LuminosityBlockAuxiliary> lumiAux(
                 new edm::LuminosityBlockAuxiliary(rp->run(), 1, aux.time(), aux.time()));
          boost::shared_ptr<edm::LuminosityBlockPrincipal>lbp(
-                new edm::LuminosityBlockPrincipal(lumiAux, m_->reg_, m_->pc_, nullptr));
+                new edm::LuminosityBlockPrincipal(lumiAux, m_->reg_, m_->pc_, nullptr,0));
          m_->ep_->fillEventPrincipal(*eaux, eventSelectionIDs_, branchListIndexes_, m_->mapper_, m_->reader_.get());
          lbp->setRunPrincipal(rp);
          m_->ep_->setLuminosityBlockPrincipal(lbp);
@@ -452,7 +452,7 @@ TFWLiteSelectorBasic::setupNewFile(TFile& iFile) {
     }
   }
   m_->branchIDListHelper_->updateFromInput(*branchIDListsPtr);
-  m_->ep_.reset(new edm::EventPrincipal(m_->reg_, m_->branchIDListHelper_, m_->pc_, nullptr));
+  m_->ep_.reset(new edm::EventPrincipal(m_->reg_, m_->branchIDListHelper_, m_->pc_, nullptr,edm::StreamID::invalidStreamID()));
   everythingOK_ = true;
 }
 
diff --git a/FWCore/Utilities/interface/LuminosityBlockIndex.h b/FWCore/Utilities/interface/LuminosityBlockIndex.h
new file mode 100644
index 0000000000000..cef771edf638a
--- /dev/null
+++ b/FWCore/Utilities/interface/LuminosityBlockIndex.h
@@ -0,0 +1,70 @@
+#ifndef FWCore_Utilities_LuminosityBlockIndex_h
+#define FWCore_Utilities_LuminosityBlockIndex_h
+// -*- C++ -*-
+//
+// Package:     FWCore/Utilities
+// Class  :     edm::LuminosityBlockIndex
+// 
+/**\class edm::LuminosityBlockIndex LuminosityBlockIndex.h "FWCore/Utilities/interface/LuminosityBlockIndex.h"
+
+ Description: Identifies a 'slot' being used to hold an active LuminosityBlock
+
+ Usage:
+ Various APIs used this to access per LuminosityBlock information.
+ It is important to realize that the same LuminosityBockIndex may be used to refer
+ to different LuminosityBlocks over the lifetime of a job. A LuminosityBlockIndex
+ will only get a new LuminosityBlock after the previous LuminosityBlock using
+ that index has finished being used.
+
+*/
+//
+// Original Author:  Chris Jones
+//         Created:  Fri, 26 Apr 2013 19:39:10 GMT
+// $Id$
+//
+
+// system include files
+
+// user include files
+
+// forward declarations
+namespace edm {
+  class LuminosityBlockPrincipal;
+  
+  class LuminosityBlockIndex
+  {
+    
+  public:
+    LuminosityBlockIndex(const LuminosityBlockIndex&) = default;
+    LuminosityBlockIndex& operator=(const LuminosityBlockIndex&) = default;
+    ~LuminosityBlockIndex() = default;
+    
+    // ---------- const member functions ---------------------
+    operator unsigned int() const {
+      return value_;
+    }
+    
+    bool operator==(LuminosityBlockIndex const& iRHS) const {
+      return value() == iRHS.value();
+    }
+
+    /** \return value ranging from 0 to one less than max number of simultaneous luminosityblocks.
+     */
+    unsigned int value() const { return value_;}
+    
+  private:
+    ///Only the LuminosityBlockPrincipal is allowed to make one of these
+    friend class LuminosityBlockPrincipal;
+
+    explicit LuminosityBlockIndex(unsigned int iValue): value_{iValue} {}
+    
+    LuminosityBlockIndex()= delete;
+    
+    // ---------- member data --------------------------------
+    unsigned int value_;
+    
+  };
+}
+
+
+#endif
diff --git a/FWCore/Utilities/interface/RunIndex.h b/FWCore/Utilities/interface/RunIndex.h
new file mode 100644
index 0000000000000..c40acc17c4b0a
--- /dev/null
+++ b/FWCore/Utilities/interface/RunIndex.h
@@ -0,0 +1,68 @@
+#ifndef FWCore_Utilities_RunIndex_h
+#define FWCore_Utilities_RunIndex_h
+// -*- C++ -*-
+//
+// Package:     FWCore/Utilities
+// Class  :     edm::RunIndex
+// 
+/**\class edm::RunIndex RunIndex.h "FWCore/Utilities/interface/RunIndex.h"
+
+ Description: Identifies a 'slot' being used to hold an active Run
+
+ Usage:
+    Various APIs used this to access per Run information.
+ It is important to realize that the same RunIndex may be used to refer
+ to different Runs over the lifetime of a job. An RunIndex will only get
+ a new Run after the previous Run using that index has finished being used.
+
+*/
+//
+// Original Author:  Chris Jones
+//         Created:  Fri, 26 Apr 2013 19:38:56 GMT
+// $Id$
+//
+
+// system include files
+
+// user include files
+
+// forward declarations
+namespace edm {
+  class RunPrincipal;
+  
+  class RunIndex
+  {
+    
+  public:
+    ~RunIndex() = default;
+    RunIndex(const RunIndex&) = default;
+    RunIndex& operator=(const RunIndex&) = default;
+    
+    // ---------- const member functions ---------------------
+    bool operator==(const RunIndex& iIndex) const {
+      return value() == iIndex.value();
+    }
+    operator unsigned int() const {
+      return value_;
+    }
+    
+    /** \return value ranging from 0 to one less than max number of simultaneous runs.
+     */
+    unsigned int value() const { return value_;}
+    
+    
+  private:
+    ///Only the RunPrincipal is allowed to make one of these
+    friend class RunPrincipal;
+    explicit RunIndex(unsigned int iIndex) : value_(iIndex) {}
+
+    RunIndex() = delete;
+    
+    // ---------- member data --------------------------------
+    unsigned int value_;
+    
+  };
+}
+
+
+#endif
diff --git a/FWCore/Utilities/interface/StreamID.h b/FWCore/Utilities/interface/StreamID.h
new file mode 100644
index 0000000000000..b36c5a9f94c93
--- /dev/null
+++ b/FWCore/Utilities/interface/StreamID.h
@@ -0,0 +1,65 @@
+#ifndef FWCore_Utilities_StreamID_h
+#define FWCore_Utilities_StreamID_h
+// -*- C++ -*-
+//
+// Package:     FWCore/Utilities
+// Class  :     edm::StreamID
+// 
+/**\class edm::StreamID StreamID.h "FWCore/Utilities/interface/StreamID.h"
+
+ Description: Identifies an edm stream
+
+ Usage:
+    Various APIs use this type to allow access to per stream information.
+
+*/
+//
+// Original Author:  Chris Jones
+//         Created:  Fri, 26 Apr 2013 19:37:37 GMT
+// $Id$
+//
+
+// system include files
+
+// user include files
+
+// forward declarations
+namespace edm {
+  class EventProcessor;
+  
+  class StreamID
+  {
+    
+  public:
+    ~StreamID() = default;
+    StreamID(const StreamID&) = default;
+    StreamID& operator=(const StreamID&) = default;
+    
+    bool operator==(const StreamID& iID) const {
+      return iID.value_ == value_;
+    }
+
+    operator unsigned int() const {return value_;}
+    
+    /** \return value ranging from 0 to one less than max number of streams.
+     */
+    unsigned int value() const { return value_; }
+    
+    static StreamID invalidStreamID() {
+      return StreamID(0xFFFFFFFFU);
+    }
+    
+  private:
+    ///Only a Schedule is allowed to create one of these
+    friend class EventProcessor;
+    explicit StreamID(unsigned int iValue) : value_(iValue) {}
+    
+    StreamID() = delete;
+    
+    // ---------- member data --------------------------------
+    unsigned int value_;
+  };
+}
+
+
+#endif
diff --git a/IOPool/Input/src/PoolSource.cc b/IOPool/Input/src/PoolSource.cc
index a2b47e63615e9..9a31b32c4ac97 100644
--- a/IOPool/Input/src/PoolSource.cc
+++ b/IOPool/Input/src/PoolSource.cc
@@ -60,7 +60,7 @@ namespace edm {
                            new RootInputFileSequence(pset, *this, catalog(1), InputType::SecondaryFile)),
     secondaryRunPrincipal_(),
     secondaryLumiPrincipal_(),
-    secondaryEventPrincipal_(secondaryFileSequence_ ? new EventPrincipal(secondaryFileSequence_->fileProductRegistry(), secondaryFileSequence_->fileBranchIDListHelper(), processConfiguration(), nullptr) : 0),
+  secondaryEventPrincipal_(secondaryFileSequence_ ? new EventPrincipal(secondaryFileSequence_->fileProductRegistry(), secondaryFileSequence_->fileBranchIDListHelper(), processConfiguration(), nullptr,StreamID::invalidStreamID()) : 0),
     branchIDsToReplace_() {
     if(secondaryFileSequence_) {
       assert(primary());
@@ -138,7 +138,7 @@ namespace edm {
       if(found) {
         boost::shared_ptr<RunAuxiliary> secondaryAuxiliary = secondaryFileSequence_->readRunAuxiliary_();
         checkConsistency(primaryPrincipal->aux(), *secondaryAuxiliary);
-        boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(secondaryAuxiliary, secondaryFileSequence_->fileProductRegistry(), processConfiguration(), nullptr));
+        boost::shared_ptr<RunPrincipal> rp(new RunPrincipal(secondaryAuxiliary, secondaryFileSequence_->fileProductRegistry(), processConfiguration(), nullptr,runPrincipal->index()));
         secondaryRunPrincipal_ = secondaryFileSequence_->readRun_(rp);
         checkHistoryConsistency(*primaryPrincipal, *secondaryRunPrincipal_);
         primaryPrincipal->recombine(*secondaryRunPrincipal_, branchIDsToReplace_[InRun]);
@@ -160,7 +160,7 @@ namespace edm {
       if(found) {
         boost::shared_ptr<LuminosityBlockAuxiliary> secondaryAuxiliary = secondaryFileSequence_->readLuminosityBlockAuxiliary_();
         checkConsistency(primaryPrincipal->aux(), *secondaryAuxiliary);
-        boost::shared_ptr<LuminosityBlockPrincipal> lbp(new LuminosityBlockPrincipal(secondaryAuxiliary, secondaryFileSequence_->fileProductRegistry(), processConfiguration(), nullptr));
+        boost::shared_ptr<LuminosityBlockPrincipal> lbp(new LuminosityBlockPrincipal(secondaryAuxiliary, secondaryFileSequence_->fileProductRegistry(), processConfiguration(), nullptr,lumiPrincipal->index()));
         secondaryLumiPrincipal_ = secondaryFileSequence_->readLuminosityBlock_(lbp);
         checkHistoryConsistency(*primaryPrincipal, *secondaryLumiPrincipal_);
         primaryPrincipal->recombine(*secondaryLumiPrincipal_, branchIDsToReplace_[InLumi]);
diff --git a/IOPool/SecondaryInput/test/SecondaryProducer.cc b/IOPool/SecondaryInput/test/SecondaryProducer.cc
index fff2d6fa44d20..4db3870a5cc7e 100644
--- a/IOPool/SecondaryInput/test/SecondaryProducer.cc
+++ b/IOPool/SecondaryInput/test/SecondaryProducer.cc
@@ -65,7 +65,7 @@ namespace edm {
     eventPrincipal_.reset(new EventPrincipal(secInput_->productRegistry(),
                                             secInput_->branchIDListHelper(),
                                             *processConfiguration_,
-                                            nullptr));
+                                             nullptr, StreamID::invalidStreamID()));
 
   }