diff --git a/dbcon/joblist/batchprimitiveprocessor-jl.cpp b/dbcon/joblist/batchprimitiveprocessor-jl.cpp
index 483db763e..7b258c4de 100644
--- a/dbcon/joblist/batchprimitiveprocessor-jl.cpp
+++ b/dbcon/joblist/batchprimitiveprocessor-jl.cpp
@@ -1274,6 +1274,10 @@ void BatchPrimitiveProcessorJL::runBPP(ByteStream& bs, uint32_t pmNum, bool isEx
   bs << uniqueID;
   bs << _priority;
 
+  // The weight is used by PrimProc thread pool algo
+  uint32_t weight = calculateBPPWeight();
+  bs << weight;
+
   bs << dbRoot;
   bs << count;
   uint8_t sentByEM = (isExeMgrDEC) ? 1 : 0;
diff --git a/dbcon/joblist/batchprimitiveprocessor-jl.h b/dbcon/joblist/batchprimitiveprocessor-jl.h
index 5418dc169..b0b9a7ae6 100644
--- a/dbcon/joblist/batchprimitiveprocessor-jl.h
+++ b/dbcon/joblist/batchprimitiveprocessor-jl.h
@@ -252,8 +252,27 @@ class BatchPrimitiveProcessorJL
   }
 
  private:
-  // void setLBIDForScan(uint64_t rid, uint32_t dbroot);
+  const size_t perColumnProjectWeight_ = 10;
+  const size_t perColumnFilteringWeight_ = 10;
+  const size_t fe1Weight_ = 10;
+  const size_t fe2Weight_ = 10;
+  const size_t joinWeight_ = 500;
+  const size_t aggregationWeight_ = 500;
 
+  // This is simple SQL operations-based model leveraged by
+  // FairThreadPool run by PP facility.
+  // Every operation mentioned in this calculation spends
+  // some CPU so the morsel uses this op weights more.
+  uint32_t calculateBPPWeight() const
+  {
+    uint32_t weight = perColumnProjectWeight_ * projectCount;
+    weight += filterCount * perColumnFilteringWeight_;
+    weight += tJoiners.size() * joinWeight_;
+    weight += (aggregatorPM) ? aggregationWeight_ : 0;
+    weight += (fe1) ? fe1Weight_ : 0;
+    weight += (fe2) ? fe2Weight_ : 0;
+    return weight;
+  }
   BPSOutputType ot;
 
   bool needToSetLBID;
diff --git a/dbcon/joblist/diskjoinstep.h b/dbcon/joblist/diskjoinstep.h
index 204a7ef60..1acadfb27 100644
--- a/dbcon/joblist/diskjoinstep.h
+++ b/dbcon/joblist/diskjoinstep.h
@@ -20,7 +20,6 @@
 #include "tuplehashjoin.h"
 #include "joinpartition.h"
 #include "threadnaming.h"
-#include "../../utils/threadpool/prioritythreadpool.h"
 
 #pragma once
 
diff --git a/primitives/primproc/batchprimitiveprocessor.cpp b/primitives/primproc/batchprimitiveprocessor.cpp
index 59f298566..1c800ea84 100644
--- a/primitives/primproc/batchprimitiveprocessor.cpp
+++ b/primitives/primproc/batchprimitiveprocessor.cpp
@@ -142,6 +142,7 @@ BatchPrimitiveProcessor::BatchPrimitiveProcessor()
  , firstInstance(false)
  , valuesLBID(0)
  , initiatedByEM_(false)
+ , weight_(0)
 {
   pp.setLogicalBlockMode(true);
   pp.setBlockPtr((int*)blockData);
@@ -196,6 +197,7 @@ BatchPrimitiveProcessor::BatchPrimitiveProcessor(ByteStream& b, double prefetch,
  , firstInstance(true)
  , valuesLBID(0)
  , initiatedByEM_(false)
+ , weight_(0)
 {
   // promote processorThreads to next power of 2.  also need to change the name to bucketCount or similar
   processorThreads = nextPowOf2(processorThreads);
@@ -545,6 +547,7 @@ void BatchPrimitiveProcessor::resetBPP(ByteStream& bs, const SP_UM_MUTEX& w, con
 
   // skip the header, sessionID, stepID, uniqueID, and priority
   bs.advance(sizeof(ISMPacketHeader) + 16);
+  bs >> weight_;
   bs >> dbRoot;
   bs >> count;
   uint8_t u8 = 0;
diff --git a/primitives/primproc/batchprimitiveprocessor.h b/primitives/primproc/batchprimitiveprocessor.h
index e7cd20a89..292a6cf39 100644
--- a/primitives/primproc/batchprimitiveprocessor.h
+++ b/primitives/primproc/batchprimitiveprocessor.h
@@ -135,6 +135,12 @@ class BatchPrimitiveProcessor
   {
     fBusy = b;
   }
+
+  size_t getWeight() const
+  {
+    return weight_;
+  }
+
   uint16_t FilterCount() const
   {
     return filterCount;
@@ -433,9 +439,9 @@ class BatchPrimitiveProcessor
   bool firstInstance;
   uint64_t valuesLBID;
   bool initiatedByEM_;
+  uint32_t weight_;
 
   static const uint64_t maxResultCount = 1048576;  // 2^20
-
   friend class Command;
   friend class ColumnCommand;
   friend class DictStep;
diff --git a/primitives/primproc/bppseeder.h b/primitives/primproc/bppseeder.h
index 5d56d3559..adda29b6a 100644
--- a/primitives/primproc/bppseeder.h
+++ b/primitives/primproc/bppseeder.h
@@ -47,7 +47,7 @@
 
 namespace primitiveprocessor
 {
-class BPPSeeder : public threadpool::PriorityThreadPool::Functor
+class BPPSeeder : public threadpool::FairThreadPool::Functor
 {
  public:
   BPPSeeder(const messageqcpp::SBS&, const SP_UM_MUTEX& wLock, const SP_UM_IOSOCK& ios, const int pmThreads,
@@ -71,6 +71,11 @@ class BPPSeeder : public threadpool::PriorityThreadPool::Functor
   {
     return _priority;
   }
+  size_t getWeight() const
+  {
+    assert(bpp);
+    return bpp->getWeight();
+  }
 
  private:
   BPPSeeder();
diff --git a/primitives/primproc/primitiveserver.cpp b/primitives/primproc/primitiveserver.cpp
index 059dab8dd..271963629 100644
--- a/primitives/primproc/primitiveserver.cpp
+++ b/primitives/primproc/primitiveserver.cpp
@@ -124,7 +124,7 @@ oam::OamCache* oamCache = oam::OamCache::makeOamCache();
 // FIXME: there is an anon ns burried later in between 2 named namespaces...
 namespace primitiveprocessor
 {
-boost::shared_ptr<threadpool::PriorityThreadPool> OOBPool;
+boost::shared_ptr<threadpool::FairThreadPool> OOBPool;
 
 BlockRequestProcessor** BRPp;
 #ifndef _MSC_VER
@@ -1050,7 +1050,7 @@ using namespace primitiveprocessor;
 /** @brief The job type to process a dictionary scan (pDictionaryScan class on the UM)
  * TODO: Move this & the impl into different files
  */
-class DictScanJob : public threadpool::PriorityThreadPool::Functor
+class DictScanJob : public threadpool::FairThreadPool::Functor
 {
  public:
   DictScanJob(SP_UM_IOSOCK ios, SBS bs, SP_UM_MUTEX writeLock);
@@ -1242,7 +1242,7 @@ struct BPPHandler
     scoped.unlock();
   }
 
-  struct BPPHandlerFunctor : public PriorityThreadPool::Functor
+  struct BPPHandlerFunctor : public FairThreadPool::Functor
   {
     BPPHandlerFunctor(boost::shared_ptr<BPPHandler> r, SBS b) : bs(b)
     {
@@ -1710,7 +1710,7 @@ return 0;
   PrimitiveServer* fPrimitiveServerPtr;
 };
 
-class DictionaryOp : public PriorityThreadPool::Functor
+class DictionaryOp : public FairThreadPool::Functor
 {
  public:
   DictionaryOp(SBS cmd) : bs(cmd)
@@ -1947,8 +1947,7 @@ struct ReadThread
   void operator()()
   {
     utils::setThreadName("PPReadThread");
-    boost::shared_ptr<threadpool::PriorityThreadPool> procPoolPtr =
-        fPrimitiveServerPtr->getProcessorThreadPool();
+    threadpool::FairThreadPool* procPoolPtr = fPrimitiveServerPtr->getProcessorThreadPool();
     SBS bs;
     UmSocketSelector* pUmSocketSelector = UmSocketSelector::instance();
 
@@ -2044,35 +2043,69 @@ struct ReadThread
           switch (ismHdr->Command)
           {
             case DICT_CREATE_EQUALITY_FILTER:
-            {
-              PriorityThreadPool::Job job;
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              job.functor = boost::shared_ptr<PriorityThreadPool::Functor>(new CreateEqualityFilter(bs));
-              OOBPool->addJob(job);
-              break;
-            }
-
             case DICT_DESTROY_EQUALITY_FILTER:
+            case BATCH_PRIMITIVE_CREATE:
+            case BATCH_PRIMITIVE_ADD_JOINER:
+            case BATCH_PRIMITIVE_END_JOINER:
+            case BATCH_PRIMITIVE_DESTROY:
+            case BATCH_PRIMITIVE_ABORT:
             {
-              PriorityThreadPool::Job job;
               const uint8_t* buf = bs->buf();
               uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              job.functor = boost::shared_ptr<PriorityThreadPool::Functor>(new DestroyEqualityFilter(bs));
+              const uint32_t txnId = *((uint32_t*)&buf[pos + 2]);
+              const uint32_t stepID = *((uint32_t*)&buf[pos + 6]);
+              const uint32_t uniqueID = *((uint32_t*)&buf[pos + 10]);
+              const uint32_t weight = 1;
+              const uint32_t priority = 0;
+              uint32_t id = 0;
+              boost::shared_ptr<FairThreadPool::Functor> functor;
+              if (ismHdr->Command == DICT_CREATE_EQUALITY_FILTER)
+              {
+                functor.reset(new CreateEqualityFilter(bs));
+              }
+              else if (ismHdr->Command == DICT_DESTROY_EQUALITY_FILTER)
+              {
+                functor.reset(new DestroyEqualityFilter(bs));
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_CREATE)
+              {
+                functor.reset(new BPPHandler::Create(fBPPHandler, bs));
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_ADD_JOINER)
+              {
+                functor.reset(new BPPHandler::AddJoiner(fBPPHandler, bs));
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_END_JOINER)
+              {
+                id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
+                functor.reset(new BPPHandler::LastJoiner(fBPPHandler, bs));
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_DESTROY)
+              {
+                functor.reset(new BPPHandler::Destroy(fBPPHandler, bs));
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_ABORT)
+              {
+                id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
+                functor.reset(new BPPHandler::Abort(fBPPHandler, bs));
+              }
+              FairThreadPool::Job job(uniqueID, stepID, txnId, functor, outIos, weight, priority, id);
               OOBPool->addJob(job);
               break;
             }
 
             case DICT_TOKEN_BY_SCAN_COMPARE:
+            case BATCH_PRIMITIVE_RUN:
             {
-              idbassert(bs->length() >= sizeof(TokenByScanRequestHeader));
-              TokenByScanRequestHeader* hdr = (TokenByScanRequestHeader*)ismHdr;
+              TokenByScanRequestHeader* hdr = nullptr;
+              boost::shared_ptr<FairThreadPool::Functor> functor;
+              uint32_t id = 0;
+              uint32_t weight = 0;
+              uint32_t priority = 0;
+              uint32_t txnId = 0;
+              uint32_t stepID = 0;
+              uint32_t uniqueID = 0;
+              bool isSyscat = false;
 
               if (bRotateDest)
               {
@@ -2090,23 +2123,41 @@ struct ReadThread
                 }
               }
 
-              PriorityThreadPool::Job job;
-              job.functor = boost::shared_ptr<DictScanJob>(new DictScanJob(outIos, bs, writeLock));
-              job.id = hdr->Hdr.UniqueID;
-              job.weight = LOGICAL_BLOCK_RIDS;
-              job.priority = hdr->Hdr.Priority;
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-
-              if (hdr->flags & IS_SYSCAT)
+              if (ismHdr->Command == DICT_TOKEN_BY_SCAN_COMPARE)
+              {
+                idbassert(bs->length() >= sizeof(TokenByScanRequestHeader));
+                hdr = (TokenByScanRequestHeader*)ismHdr;
+                functor.reset(new DictScanJob(outIos, bs, writeLock));
+                id = hdr->Hdr.UniqueID;
+                weight = LOGICAL_BLOCK_RIDS;
+                priority = hdr->Hdr.Priority;
+                const uint8_t* buf = bs->buf();
+                const uint32_t pos = sizeof(ISMPacketHeader) - 2;
+                txnId = *((uint32_t*)&buf[pos + 2]);
+                stepID = *((uint32_t*)&buf[pos + 6]);
+                uniqueID = *((uint32_t*)&buf[pos + 10]);
+                isSyscat = hdr->flags & IS_SYSCAT;
+              }
+              else if (ismHdr->Command == BATCH_PRIMITIVE_RUN)
+              {
+                functor.reset(new BPPSeeder(bs, writeLock, outIos,
+                  fPrimitiveServerPtr->ProcessorThreads(),
+                  fPrimitiveServerPtr->PTTrace()));
+                BPPSeeder* bpps = dynamic_cast<BPPSeeder*>(functor.get());
+                id = bpps->getID();
+                priority = bpps->priority();
+                const uint8_t* buf = bs->buf();
+                const uint32_t pos = sizeof(ISMPacketHeader) - 2;
+                txnId = *((uint32_t*)&buf[pos + 2]);
+                stepID = *((uint32_t*)&buf[pos + 6]);
+                uniqueID = *((uint32_t*)&buf[pos + 10]);
+                weight = ismHdr->Size + *((uint32_t*)&buf[pos + 18]);
+                isSyscat = bpps->isSysCat();
+              }
+              FairThreadPool::Job job(uniqueID, stepID, txnId, functor, outIos, weight, priority, id);
+
+              if (isSyscat)
               {
-                // boost::thread t(DictScanJob(outIos, bs, writeLock));
-                // using already-existing threads may cut latency
-                // if it's changed back to running in an independent thread
-                // change the issyscat() checks in BPPSeeder as well
                 OOBPool->addJob(job);
               }
               else
@@ -2117,146 +2168,11 @@ struct ReadThread
               break;
             }
 
-            case BATCH_PRIMITIVE_RUN:
-            {
-              if (bRotateDest)
-              {
-                if (!pUmSocketSelector->nextIOSocket(fIos, outIos, writeLock))
-                {
-                  // If we ever fall into this part of the
-                  // code we have a "bug" of some sort.
-                  // See handleUmSockSelErr() for more info.
-                  // We reset ios and mutex to defaults.
-                  handleUmSockSelErr(string("BPR cmd"));
-                  outIos = outIosDefault;
-                  writeLock = writeLockDefault;
-                  pUmSocketSelector->delConnection(fIos);
-                  bRotateDest = false;
-                }
-              }
-
-              /* Decide whether this is a syscat call and run
-              right away instead of queueing */
-              boost::shared_ptr<BPPSeeder> bpps(new BPPSeeder(bs, writeLock, outIos,
-                                                              fPrimitiveServerPtr->ProcessorThreads(),
-                                                              fPrimitiveServerPtr->PTTrace()));
-              PriorityThreadPool::Job job;
-              job.functor = bpps;
-              job.id = bpps->getID();
-              job.weight = ismHdr->Size;
-              job.priority = bpps->priority();
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-
-              if (bpps->isSysCat())
-              {
-                // boost::thread t(*bpps);
-                // using already-existing threads may cut latency
-                // if it's changed back to running in an independent thread
-                // change the issyscat() checks in BPPSeeder as well
-                OOBPool->addJob(job);
-              }
-              else
-              {
-                procPoolPtr->addJob(job);
-              }
-
-              break;
-            }
-
-            case BATCH_PRIMITIVE_CREATE:
-            {
-              PriorityThreadPool::Job job;
-              job.functor =
-                  boost::shared_ptr<PriorityThreadPool::Functor>(new BPPHandler::Create(fBPPHandler, bs));
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              OOBPool->addJob(job);
-              // fBPPHandler->createBPP(*bs);
-              break;
-            }
-
-            case BATCH_PRIMITIVE_ADD_JOINER:
-            {
-              PriorityThreadPool::Job job;
-              job.functor =
-                  boost::shared_ptr<PriorityThreadPool::Functor>(new BPPHandler::AddJoiner(fBPPHandler, bs));
-              job.id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              OOBPool->addJob(job);
-              // fBPPHandler->addJoinerToBPP(*bs);
-              break;
-            }
-
-            case BATCH_PRIMITIVE_END_JOINER:
-            {
-              // lastJoinerMsg can block; must do this in a different thread
-              // OOBPool->invoke(BPPHandler::LastJoiner(fBPPHandler, bs));  // needs a threadpool that can
-              // resched boost::thread tmp(BPPHandler::LastJoiner(fBPPHandler, bs));
-              PriorityThreadPool::Job job;
-              job.functor =
-                  boost::shared_ptr<PriorityThreadPool::Functor>(new BPPHandler::LastJoiner(fBPPHandler, bs));
-              job.id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              OOBPool->addJob(job);
-              break;
-            }
-
-            case BATCH_PRIMITIVE_DESTROY:
-            {
-              // OOBPool->invoke(BPPHandler::Destroy(fBPPHandler, bs));  // needs a threadpool that can
-              // resched boost::thread tmp(BPPHandler::Destroy(fBPPHandler, bs));
-              PriorityThreadPool::Job job;
-              job.functor =
-                  boost::shared_ptr<PriorityThreadPool::Functor>(new BPPHandler::Destroy(fBPPHandler, bs));
-              job.id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              OOBPool->addJob(job);
-              // fBPPHandler->destroyBPP(*bs);
-              break;
-            }
-
             case BATCH_PRIMITIVE_ACK:
             {
               fBPPHandler->doAck(*bs);
               break;
             }
-
-            case BATCH_PRIMITIVE_ABORT:
-            {
-              // OBPool->invoke(BPPHandler::Abort(fBPPHandler, bs));
-              // fBPPHandler->doAbort(*bs);
-              PriorityThreadPool::Job job;
-              job.functor =
-                  boost::shared_ptr<PriorityThreadPool::Functor>(new BPPHandler::Abort(fBPPHandler, bs));
-              job.id = fBPPHandler->getUniqueID(bs, ismHdr->Command);
-              const uint8_t* buf = bs->buf();
-              uint32_t pos = sizeof(ISMPacketHeader) - 2;
-              job.stepID = *((uint32_t*)&buf[pos + 6]);
-              job.uniqueID = *((uint32_t*)&buf[pos + 10]);
-              job.sock = outIos;
-              OOBPool->addJob(job);
-              break;
-            }
-
             default:
             {
               std::ostringstream os;
@@ -2406,12 +2322,12 @@ PrimitiveServer::PrimitiveServer(int serverThreads, int serverQueueSize, int pro
   fServerpool.setQueueSize(fServerQueueSize);
   fServerpool.setName("PrimitiveServer");
 
-  fProcessorPool.reset(new threadpool::PriorityThreadPool(fProcessorWeight, highPriorityThreads,
-                                                          medPriorityThreads, lowPriorityThreads, 0));
+  fProcessorPool = new threadpool::FairThreadPool(fProcessorWeight, highPriorityThreads,
+                                                      medPriorityThreads, lowPriorityThreads, 0);
 
   // We're not using either the priority or the job-clustering features, just need a threadpool
   // that can reschedule jobs, and an unlimited non-blocking queue
-  OOBPool.reset(new threadpool::PriorityThreadPool(1, 5, 0, 0, 1));
+  OOBPool.reset(new threadpool::FairThreadPool(1, 5, 0, 0, 1));
   // Initialize a local pointer.
   fOOBPool = OOBPool;
 
diff --git a/primitives/primproc/primitiveserver.h b/primitives/primproc/primitiveserver.h
index 2b1fe2939..3c3817405 100644
--- a/primitives/primproc/primitiveserver.h
+++ b/primitives/primproc/primitiveserver.h
@@ -37,6 +37,7 @@
 
 #include "threadpool.h"
 #include "../../utils/threadpool/prioritythreadpool.h"
+#include "fair_threadpool.h"
 #include "messagequeue.h"
 #include "blockrequestprocessor.h"
 #include "batchprimitiveprocessor.h"
@@ -48,7 +49,7 @@ extern oam::OamCache* oamCache;
 
 namespace primitiveprocessor
 {
-extern boost::shared_ptr<threadpool::PriorityThreadPool> OOBPool;
+extern boost::shared_ptr<threadpool::FairThreadPool> OOBPool;
 extern dbbc::BlockRequestProcessor** BRPp;
 extern BRM::DBRM* brm;
 extern boost::mutex bppLock;
@@ -130,12 +131,12 @@ class PrimitiveServer
 
   /** @brief get a pointer the shared processor thread pool
    */
-  inline boost::shared_ptr<threadpool::PriorityThreadPool> getProcessorThreadPool() const
+  inline boost::shared_ptr<threadpool::FairThreadPool> getProcessorThreadPool() const
   {
     return fProcessorPool;
   }
 
-  inline boost::shared_ptr<threadpool::PriorityThreadPool> getOOBThreadPool() const
+  inline boost::shared_ptr<threadpool::FairThreadPool> getOOBThreadPool() const
   {
     return fOOBPool;
   }
@@ -172,8 +173,8 @@ class PrimitiveServer
   /** @brief the thread pool used to process
    * primitive commands
    */
-  boost::shared_ptr<threadpool::PriorityThreadPool> fProcessorPool;
-  boost::shared_ptr<threadpool::PriorityThreadPool> fOOBPool;
+  boost::shared_ptr<threadpool::FairThreadPool> fProcessorPool;
+  boost::shared_ptr<threadpool::FairThreadPool> fOOBPool;
 
   int fServerThreads;
   int fServerQueueSize;
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 4ac31e2c1..aaf40fc4a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -52,6 +52,11 @@ if (WITH_UNITTESTS)
     target_link_libraries(simd_processors ${ENGINE_LDFLAGS} ${MARIADB_CLIENT_LIBS} ${ENGINE_WRITE_LIBS} ${GTEST_LIBRARIES} processor dbbc)
     gtest_add_tests(TARGET simd_processors TEST_PREFIX columnstore:)
 
+    add_executable(fair_threadpool_test fair_threadpool.cpp)
+    add_dependencies(fair_threadpool_test googletest)
+    target_link_libraries(fair_threadpool_test ${ENGINE_LDFLAGS} ${MARIADB_CLIENT_LIBS} ${ENGINE_WRITE_LIBS} ${GTEST_LIBRARIES} processor dbbc)
+    gtest_discover_tests(fair_threadpool_test TEST_PREFIX columnstore:)
+
     # CPPUNIT TESTS
     add_executable(we_shared_components_tests shared_components_tests.cpp)
     add_dependencies(we_shared_components_tests loggingcpp)
diff --git a/tests/fair_threadpool.cpp b/tests/fair_threadpool.cpp
new file mode 100644
index 000000000..c4a299bd1
--- /dev/null
+++ b/tests/fair_threadpool.cpp
@@ -0,0 +1,173 @@
+/* Copyright (C) 2022 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#include <iostream>
+#include <gtest/gtest.h>
+#include <vector>
+
+#include "utils/threadpool/fair_threadpool.h"
+
+using namespace primitiveprocessor;
+using namespace std;
+using namespace threadpool;
+
+using ResultsType = std::vector<int>;
+static ResultsType results;
+
+class FairThreadPoolTest : public testing::Test {
+  public:
+
+  void SetUp() override
+  {
+    results.clear();
+    threadPool = new FairThreadPool(1, 1, 0, 0);
+  }
+
+
+  FairThreadPool* threadPool;
+};
+
+class TestFunctor: public FairThreadPool::Functor
+{
+ public:
+  TestFunctor(const size_t id, const size_t delay): id_(id), delay_(delay)
+  {
+  }
+  ~TestFunctor() {};
+  int operator()() override
+  {
+    usleep(delay_);
+    results.push_back(id_);
+    return 0;
+  }
+ private:
+  size_t id_;
+  size_t delay_;
+};
+
+class TestRescheduleFunctor: public FairThreadPool::Functor
+{
+ public:
+  TestRescheduleFunctor(const size_t id, const size_t delay): id_(id), delay_(delay)
+  {
+  }
+  ~TestRescheduleFunctor() {};
+  int operator()() override
+  {
+    if (firstRun)
+    {
+      firstRun = false;
+      return 1; // re-schedule the Job
+    }
+    usleep(delay_);
+    results.push_back(id_);
+    return 0;
+  }
+ private:
+  size_t id_;
+  size_t delay_;
+  bool firstRun = true;
+};
+
+testing::AssertionResult isThisOrThat(const ResultsType& arr, const size_t idxA, const int a, const size_t idxB, const int b)
+{
+  if (arr.empty() || arr.size() <= max(idxA, idxB))
+    return testing::AssertionFailure() << "The supplied vector is either empty or not big enough.";
+  if (arr[idxA] == a && arr[idxB] == b)
+    return testing::AssertionSuccess();
+  if (arr[idxA] == b && arr[idxB] == a)
+    return testing::AssertionSuccess();
+  return testing::AssertionFailure() << "The values at positions "<< idxA << " " << idxB
+    << " are not " << a << " and " << b << std::endl;
+}
+
+TEST_F(FairThreadPoolTest, FairThreadPoolAdd)
+{
+  SP_UM_IOSOCK sock(new messageqcpp::IOSocket);
+  auto functor1 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(1, 50000));
+  FairThreadPool::Job job1(1, 1, 1, functor1, sock, 1);
+  auto functor2 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(2, 5000));
+  FairThreadPool::Job job2(2, 1, 1, functor2, sock, 1);
+  auto functor3 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(3, 5000));
+  FairThreadPool::Job job3(3, 1, 2, functor3, sock, 1);
+
+  threadPool->addJob(job1);
+  threadPool->addJob(job2);
+  threadPool->addJob(job3);
+
+  while (threadPool->queueSize())
+  {
+    usleep(250000);
+  }
+
+  EXPECT_EQ(threadPool->queueSize(), 0ULL);
+  EXPECT_EQ(results.size(), 3ULL);
+  EXPECT_EQ(results[0], 1);
+  EXPECT_EQ(results[1], 3);
+  EXPECT_EQ(results[2], 2);
+}
+
+TEST_F(FairThreadPoolTest, FairThreadPoolRemove)
+{
+  SP_UM_IOSOCK sock(new messageqcpp::IOSocket);
+  auto functor1 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(1, 100000));
+  FairThreadPool::Job job1(1, 1, 1, functor1, sock, 1, 0, 1);
+  auto functor2 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(2, 50000));
+  FairThreadPool::Job job2(2, 1, 1, functor2, sock, 1, 0, 2);
+  auto functor3 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(3, 50000));
+  FairThreadPool::Job job3(3, 1, 2, functor3, sock, 1, 0, 3);
+
+  threadPool->addJob(job1);
+  threadPool->addJob(job2);
+  threadPool->addJob(job3);
+  threadPool->removeJobs(job2.id_);
+
+  while (threadPool->queueSize())
+  {
+    usleep(250000);
+  }
+
+  EXPECT_EQ(threadPool->queueSize(), 0ULL);
+  EXPECT_EQ(results.size(), 2ULL);
+  EXPECT_EQ(results[0], 1);
+  EXPECT_EQ(results[1], 3);
+}
+
+TEST_F(FairThreadPoolTest, FairThreadPoolReschedule)
+{
+  SP_UM_IOSOCK sock(new messageqcpp::IOSocket);
+  auto functor1 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(1, 100000));
+  FairThreadPool::Job job1(1, 1, 1, functor1, sock, 1, 0, 1);
+  auto functor2 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(2, 50000));
+  FairThreadPool::Job job2(2, 1, 2, functor2, sock, 1, 0, 2);
+  auto functor3 = boost::shared_ptr<FairThreadPool::Functor>(new TestFunctor(3, 50000));
+  FairThreadPool::Job job3(3, 1, 3, functor3, sock, 1, 0, 3);
+
+  threadPool->addJob(job1);
+  threadPool->addJob(job2);
+  threadPool->addJob(job3);
+
+  while (threadPool->queueSize())
+  {
+    usleep(250000);
+  }
+
+  EXPECT_EQ(threadPool->queueSize(), 0ULL);
+  EXPECT_EQ(results.size(), 3ULL);
+  EXPECT_EQ(results[0], 1);
+  EXPECT_TRUE(isThisOrThat(results, 1, 2, 2, 3));
+}
\ No newline at end of file
diff --git a/utils/threadpool/CMakeLists.txt b/utils/threadpool/CMakeLists.txt
index 519ba3b5c..dd96304de 100644
--- a/utils/threadpool/CMakeLists.txt
+++ b/utils/threadpool/CMakeLists.txt
@@ -4,11 +4,8 @@ include_directories( ${ENGINE_COMMON_INCLUDES} )
 
 ########### next target ###############
 
-set(threadpool_LIB_SRCS weightedthreadpool.cpp threadpool.cpp prioritythreadpool.cpp)
-
+set(threadpool_LIB_SRCS weightedthreadpool.cpp threadpool.cpp prioritythreadpool.cpp fair_threadpool.cpp)
 add_library(threadpool SHARED ${threadpool_LIB_SRCS})
-
 add_dependencies(threadpool loggingcpp)
 target_link_libraries(threadpool Boost::chrono)
-
-install(TARGETS threadpool DESTINATION ${ENGINE_LIBDIR} COMPONENT columnstore-engine)
+install(TARGETS threadpool DESTINATION ${ENGINE_LIBDIR} COMPONENT columnstore-engine)
\ No newline at end of file
diff --git a/utils/threadpool/fair_threadpool.cpp b/utils/threadpool/fair_threadpool.cpp
new file mode 100644
index 000000000..44d9cd3a9
--- /dev/null
+++ b/utils/threadpool/fair_threadpool.cpp
@@ -0,0 +1,295 @@
+/* Copyright (c) 2022 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#include <atomic>
+#include <stdexcept>
+#include <unistd.h>
+#include <exception>
+using namespace std;
+
+#include "messageobj.h"
+#include "messagelog.h"
+#include "threadnaming.h"
+using namespace logging;
+
+#include "fair_threadpool.h"
+using namespace boost;
+
+#include "dbcon/joblist/primitivemsg.h"
+
+namespace threadpool
+{
+FairThreadPool::FairThreadPool(uint targetWeightPerRun, uint highThreads, uint midThreads, uint lowThreads,
+                               uint ID)
+ : weightPerRun(targetWeightPerRun), id(ID)
+{
+  boost::thread* newThread;
+  size_t numberOfThreads = highThreads + midThreads + lowThreads;
+  for (uint32_t i = 0; i < numberOfThreads; ++i)
+  {
+    newThread = threads.create_thread(ThreadHelper(this, PriorityThreadPool::Priority::HIGH));
+    newThread->detach();
+  }
+  cout << "FairThreadPool started " << numberOfThreads << " thread/-s.\n";
+  threadCounts_.store(numberOfThreads, std::memory_order_relaxed);
+  defaultThreadCounts = numberOfThreads;
+}
+
+FairThreadPool::~FairThreadPool()
+{
+  stop();
+}
+
+void FairThreadPool::addJob(const Job& job)
+{
+  addJob_(job);
+}
+
+void FairThreadPool::addJob_(const Job& job, bool useLock)
+{
+  boost::thread* newThread;
+  std::unique_lock<std::mutex> lk(mutex, std::defer_lock_t());
+
+  // Create any missing threads
+  if (defaultThreadCounts != threadCounts_.load(std::memory_order_relaxed))
+  {
+    newThread = threads.create_thread(ThreadHelper(this, PriorityThreadPool::Priority::HIGH));
+    newThread->detach();
+    threadCounts_.fetch_add(1, std::memory_order_relaxed);
+  }
+
+  if (useLock)
+    lk.lock();
+
+  auto jobsListMapIter = txn2JobsListMap_.find(job.txnIdx_);
+  if (jobsListMapIter == txn2JobsListMap_.end())  // there is no txn in the map
+  {
+    ThreadPoolJobsList* jobsList = new ThreadPoolJobsList;
+    jobsList->push_back(job);
+    txn2JobsListMap_[job.txnIdx_] = jobsList;
+    weightedTxnsQueue_.push({job.weight_, job.txnIdx_});
+  }
+  else  // txn is in the map
+  {
+    if (jobsListMapIter->second->empty())  // there are no jobs for the txn
+    {
+      weightedTxnsQueue_.push({job.weight_, job.txnIdx_});
+    }
+    jobsListMapIter->second->push_back(job);
+  }
+
+  if (useLock)
+    newJob.notify_one();
+}
+
+void FairThreadPool::removeJobs(uint32_t id)
+{
+  std::unique_lock<std::mutex> lk(mutex);
+
+  for (auto& txnJobsMapPair : txn2JobsListMap_)
+  {
+    ThreadPoolJobsList* txnJobsList = txnJobsMapPair.second;
+    auto job = txnJobsList->begin();
+    while (job != txnJobsList->end())
+    {
+      if (job->id_ == id)
+      {
+        job = txnJobsList->erase(job);  // update the job iter
+        if (txnJobsList->empty())
+        {
+          txn2JobsListMap_.erase(txnJobsMapPair.first);
+          delete txnJobsList;
+          break;
+          // There is no clean-up for PQ. It will happen later in threadFcn
+        }
+        continue;  // go-on skiping job iter increment
+      }
+      ++job;
+    }
+  }
+}
+
+void FairThreadPool::threadFcn(const PriorityThreadPool::Priority preferredQueue)
+{
+  utils::setThreadName("Idle");
+  RunListT runList(1);  // This is a vector to allow to grab multiple jobs
+  RescheduleVecType reschedule;
+  bool running = false;
+  bool rescheduleJob = false;
+
+  try
+  {
+    while (!stop_.load(std::memory_order_relaxed))
+    {
+      runList.clear();  // remove the job
+      std::unique_lock<std::mutex> lk(mutex);
+
+      if (weightedTxnsQueue_.empty())
+      {
+        newJob.wait(lk);
+        continue;  // just go on w/o re-taking the lock
+      }
+
+      WeightedTxnT weightedTxn = weightedTxnsQueue_.top();
+      auto txnAndJobListPair = txn2JobsListMap_.find(weightedTxn.second);
+      // Looking for non-empty jobsList in a loop
+      // The loop waits on newJob cond_var if PQ is empty(no jobs in this thread pool)
+      while (txnAndJobListPair == txn2JobsListMap_.end() || txnAndJobListPair->second->empty())
+      {
+        // JobList is empty. This can happen when this method pops the last Job.
+        if (txnAndJobListPair != txn2JobsListMap_.end())
+        {
+          ThreadPoolJobsList* txnJobsList = txnAndJobListPair->second;
+          delete txnJobsList;
+          txn2JobsListMap_.erase(txnAndJobListPair->first);
+        }
+        weightedTxnsQueue_.pop();
+        if (weightedTxnsQueue_.empty())  // remove the empty
+        {
+          break;
+        }
+        weightedTxn = weightedTxnsQueue_.top();
+        txnAndJobListPair = txn2JobsListMap_.find(weightedTxn.second);
+      }
+
+      if (weightedTxnsQueue_.empty())
+      {
+        newJob.wait(lk);  // might need a lock here
+        continue;
+      }
+
+      // We have non-empty jobsList at this point.
+      // Remove the txn from a queue first to add it later
+      weightedTxnsQueue_.pop();
+      TransactionIdxT txnIdx = txnAndJobListPair->first;
+      ThreadPoolJobsList* jobsList = txnAndJobListPair->second;
+      runList.push_back(jobsList->front());
+
+      jobsList->pop_front();
+      // Add the jobList back into the PQ adding some weight to it
+      // Current algo doesn't reduce total txn weight if the job is rescheduled.
+      if (!jobsList->empty())
+      {
+        weightedTxnsQueue_.push({weightedTxn.first + runList[0].weight_, txnIdx});
+      }
+
+      lk.unlock();
+
+      running = true;
+      jobsRunning_.fetch_add(1, std::memory_order_relaxed);
+      rescheduleJob = (*(runList[0].functor_))();  // run the functor
+      jobsRunning_.fetch_sub(1, std::memory_order_relaxed);
+      running = false;
+
+      utils::setThreadName("Idle");
+
+      if (rescheduleJob)
+      {
+        // to avoid excessive CPU usage waiting for data from storage
+        usleep(500);
+        lk.lock();
+        addJob_(runList[0], false);
+        newJob.notify_one();
+        lk.unlock();
+      }
+    }
+  }
+  catch (std::exception& ex)
+  {
+    if (running)
+    {
+      jobsRunning_.fetch_sub(1, std::memory_order_relaxed);
+    }
+    // Log the exception and exit this thread
+    try
+    {
+      threadCounts_.fetch_sub(1, std::memory_order_relaxed);
+#ifndef NOLOGGING
+      logging::Message::Args args;
+      logging::Message message(5);
+      args.add("threadFcn: Caught exception: ");
+      args.add(ex.what());
+
+      message.format(args);
+
+      logging::LoggingID lid(22);
+      logging::MessageLog ml(lid);
+
+      ml.logErrorMessage(message);
+#endif
+
+      if (running)
+        sendErrorMsg(runList[0].uniqueID_, runList[0].stepID_, runList[0].sock_);
+    }
+    catch (...)
+    {
+    }
+  }
+  catch (...)
+  {
+    // Log the exception and exit this thread
+    try
+    {
+      if (running)
+      {
+        jobsRunning_.fetch_sub(1, std::memory_order_relaxed);
+      }
+      threadCounts_.fetch_sub(1, std::memory_order_relaxed);
+      ;
+#ifndef NOLOGGING
+      logging::Message::Args args;
+      logging::Message message(6);
+      args.add("threadFcn: Caught unknown exception!");
+
+      message.format(args);
+
+      logging::LoggingID lid(22);
+      logging::MessageLog ml(lid);
+
+      ml.logErrorMessage(message);
+#endif
+
+      if (running)
+        sendErrorMsg(runList[0].uniqueID_, runList[0].stepID_, runList[0].sock_);
+    }
+    catch (...)
+    {
+    }
+  }
+}
+
+void FairThreadPool::sendErrorMsg(uint32_t id, uint32_t step, primitiveprocessor::SP_UM_IOSOCK sock)
+{
+  ISMPacketHeader ism;
+  PrimitiveHeader ph = {0, 0, 0, 0, 0, 0};
+
+  ism.Status = logging::primitiveServerErr;
+  ph.UniqueID = id;
+  ph.StepID = step;
+  messageqcpp::ByteStream msg(sizeof(ISMPacketHeader) + sizeof(PrimitiveHeader));
+  msg.append((uint8_t*)&ism, sizeof(ism));
+  msg.append((uint8_t*)&ph, sizeof(ph));
+
+  sock->write(msg);
+}
+
+void FairThreadPool::stop()
+{
+  stop_.store(true, std::memory_order_relaxed);
+}
+
+}  // namespace threadpool
\ No newline at end of file
diff --git a/utils/threadpool/fair_threadpool.h b/utils/threadpool/fair_threadpool.h
new file mode 100644
index 000000000..ab3afaa71
--- /dev/null
+++ b/utils/threadpool/fair_threadpool.h
@@ -0,0 +1,165 @@
+/* Copyright (c) 2022 MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#pragma once
+
+#include <condition_variable>
+#include <string>
+#include <iostream>
+#include <cstdlib>
+#include <sstream>
+#include <stdexcept>
+#include <boost/thread/thread.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/condition.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/function.hpp>
+#include <atomic>
+#include <queue>
+#include <unordered_map>
+#include <list>
+#include <functional>
+
+#include "primitives/primproc/umsocketselector.h"
+#include "prioritythreadpool.h"
+
+namespace threadpool
+{
+// The idea of this thread pool is to run morsel jobs(primitive job) is to equaly distribute CPU time
+// b/w multiple parallel queries(thread maps morsel to query using txnId). Query(txnId) has its weight
+// stored in PriorityQueue that thread increases before run another morsel for the query. When query is
+// done(ThreadPoolJobsList is empty) it is removed from PQ and the Map(txn to ThreadPoolJobsList).
+// I tested multiple morsels per one loop iteration in ::threadFcn. This approach reduces CPU consumption
+// and increases query timings.
+class FairThreadPool
+{
+ public:
+  using Functor = PriorityThreadPool::Functor;
+
+  using TransactionIdxT = uint32_t;
+  struct Job
+  {
+    Job() : weight_(1), priority_(0), id_(0)
+    {
+    }
+    Job(const uint32_t uniqueID, const uint32_t stepID, const TransactionIdxT txnIdx,
+        const boost::shared_ptr<Functor>& functor, const primitiveprocessor::SP_UM_IOSOCK& sock,
+        const uint32_t weight = 1, const uint32_t priority = 0, const uint32_t id = 0)
+     : uniqueID_(uniqueID)
+     , stepID_(stepID)
+     , txnIdx_(txnIdx)
+     , functor_(functor)
+     , sock_(sock)
+     , weight_(weight)
+     , priority_(priority)
+     , id_(id)
+    {
+    }
+    uint32_t uniqueID_;
+    uint32_t stepID_;
+    TransactionIdxT txnIdx_;
+    boost::shared_ptr<Functor> functor_;
+    primitiveprocessor::SP_UM_IOSOCK sock_;
+    uint32_t weight_;
+    uint32_t priority_;
+    uint32_t id_;
+  };
+
+  /*********************************************
+   *  ctor/dtor
+   *
+   *********************************************/
+
+  /** @brief ctor
+   */
+
+  FairThreadPool(uint targetWeightPerRun, uint highThreads, uint midThreads, uint lowThreads, uint id = 0);
+  virtual ~FairThreadPool();
+
+  void removeJobs(uint32_t id);
+  void addJob(const Job& job);
+  void stop();
+
+  /** @brief for use in debugging
+   */
+  void dump();
+
+  size_t queueSize() const
+  {
+    return weightedTxnsQueue_.size();
+  }
+  // This method enables a pool current workload estimate.
+  size_t jobsRunning() const
+  {
+    return jobsRunning_.load(std::memory_order_relaxed);
+  }
+
+ protected:
+ private:
+  struct ThreadHelper
+  {
+    ThreadHelper(FairThreadPool* impl, PriorityThreadPool::Priority queue) : ptp(impl), preferredQueue(queue)
+    {
+    }
+    void operator()()
+    {
+      ptp->threadFcn(preferredQueue);
+    }
+    FairThreadPool* ptp;
+    PriorityThreadPool::Priority preferredQueue;
+  };
+
+  explicit FairThreadPool();
+  explicit FairThreadPool(const FairThreadPool&);
+  FairThreadPool& operator=(const FairThreadPool&);
+
+  void addJob_(const Job& job, bool useLock = true);
+  void threadFcn(const PriorityThreadPool::Priority preferredQueue);
+  void sendErrorMsg(uint32_t id, uint32_t step, primitiveprocessor::SP_UM_IOSOCK sock);
+
+  uint32_t defaultThreadCounts;
+  std::mutex mutex;
+  std::condition_variable newJob;
+  boost::thread_group threads;
+  uint32_t weightPerRun;
+  volatile uint id;  // prevent it from being optimized out
+
+  using WeightT = uint32_t;
+  using WeightedTxnT = std::pair<WeightT, TransactionIdxT>;
+  using WeightedTxnVec = std::vector<WeightedTxnT>;
+  struct PrioQueueCmp
+  {
+    bool operator()(WeightedTxnT lhs, WeightedTxnT rhs)
+    {
+      if (lhs.first == rhs.first)
+        return lhs.second > rhs.second;
+      return lhs.first > rhs.first;
+    }
+  };
+  using RunListT = std::vector<Job>;
+  using RescheduleVecType = std::vector<bool>;
+  using WeightedTxnPrioQueue = std::priority_queue<WeightedTxnT, WeightedTxnVec, PrioQueueCmp>;
+  using ThreadPoolJobsList = std::list<Job>;
+  using Txn2ThreadPoolJobsListMap = std::unordered_map<TransactionIdxT, ThreadPoolJobsList*>;
+  Txn2ThreadPoolJobsListMap txn2JobsListMap_;
+  WeightedTxnPrioQueue weightedTxnsQueue_;
+  std::atomic<size_t> jobsRunning_{0};
+  std::atomic<size_t> threadCounts_{0};
+  std::atomic<bool> stop_{false};
+};
+
+}  // namespace threadpool
\ No newline at end of file
diff --git a/utils/threadpool/prioritythreadpool.h b/utils/threadpool/prioritythreadpool.h
index 7608b4166..fbd479966 100644
--- a/utils/threadpool/prioritythreadpool.h
+++ b/utils/threadpool/prioritythreadpool.h
@@ -53,8 +53,6 @@ class PriorityThreadPool
     virtual int operator()() = 0;
   };
 
-  // typedef boost::function0<int> Functor;
-
   struct Job
   {
     Job() : weight(1), priority(0), id(0)