diff --git a/source/adios2/engine/bp5/BP5Writer.cpp b/source/adios2/engine/bp5/BP5Writer.cpp
index 453e277fd4..1fac7fdcdb 100644
--- a/source/adios2/engine/bp5/BP5Writer.cpp
+++ b/source/adios2/engine/bp5/BP5Writer.cpp
@@ -1212,6 +1212,11 @@ void BP5Writer::PopulateMetadataIndexFileContent(
     position += 8;
 }
 
+size_t BP5Writer::DebugGetDataBufferSize() const
+{
+    return m_BP5Serializer.DebugGetDataBufferSize();
+}
+
 } // end namespace engine
 } // end namespace core
 } // end namespace adios2
diff --git a/source/adios2/engine/bp5/BP5Writer.h b/source/adios2/engine/bp5/BP5Writer.h
index 96402d348d..0c4b1f3417 100644
--- a/source/adios2/engine/bp5/BP5Writer.h
+++ b/source/adios2/engine/bp5/BP5Writer.h
@@ -53,6 +53,8 @@ class BP5Writer : public BP5Engine, public core::Engine
     void EndStep() final;
     void Flush(const int transportIndex = -1) final;
 
+    size_t DebugGetDataBufferSize() const final;
+
 private:
     /** Single object controlling BP buffering */
     format::BP5Serializer m_BP5Serializer;
diff --git a/source/adios2/toolkit/format/bp5/BP5Deserializer.cpp b/source/adios2/toolkit/format/bp5/BP5Deserializer.cpp
index 6619a52d64..6f89265ec0 100644
--- a/source/adios2/toolkit/format/bp5/BP5Deserializer.cpp
+++ b/source/adios2/toolkit/format/bp5/BP5Deserializer.cpp
@@ -859,7 +859,7 @@ bool BP5Deserializer::QueueGet(core::VariableBase &variable, void *DestData)
     }
 }
 
-void BP5Deserializer::GetSingleValueFromMetadata(core::VariableBase &variable,
+bool BP5Deserializer::GetSingleValueFromMetadata(core::VariableBase &variable,
                                                  BP5VarRec *VarRec,
                                                  void *DestData, size_t Step,
                                                  size_t WriterRank)
@@ -867,7 +867,7 @@ void BP5Deserializer::GetSingleValueFromMetadata(core::VariableBase &variable,
     char *src = (char *)GetMetadataBase(VarRec, Step, WriterRank);
 
     if (!src)
-        return;
+        return false;
 
     if (variable.m_SelectionType == adios2::SelectionType::WriteBlock)
         WriterRank = variable.m_BlockID;
@@ -881,6 +881,7 @@ void BP5Deserializer::GetSingleValueFromMetadata(core::VariableBase &variable,
         std::string *TmpStr = static_cast<std::string *>(DestData);
         TmpStr->assign(*(const char **)src);
     }
+    return true;
 }
 
 bool BP5Deserializer::QueueGetSingle(core::VariableBase &variable,
@@ -889,9 +890,13 @@ bool BP5Deserializer::QueueGetSingle(core::VariableBase &variable,
     BP5VarRec *VarRec = VarByKey[&variable];
     if (VarRec->OrigShapeID == ShapeID::GlobalValue)
     {
-        int WriterRank = 0;
-        GetSingleValueFromMetadata(variable, VarRec, DestData, Step,
-                                   WriterRank);
+        for (size_t WriterRank = 0; WriterRank < m_WriterCohortSize;
+             WriterRank++)
+        {
+            if (GetSingleValueFromMetadata(variable, VarRec, DestData, Step,
+                                           WriterRank))
+                return false;
+        }
         return false;
     }
     if (VarRec->OrigShapeID == ShapeID::LocalValue)
@@ -902,8 +907,8 @@ bool BP5Deserializer::QueueGetSingle(core::VariableBase &variable,
              WriterRank < variable.m_Count[0] + variable.m_Start[0];
              WriterRank++)
         {
-            GetSingleValueFromMetadata(variable, VarRec, DestData, Step,
-                                       WriterRank);
+            (void)GetSingleValueFromMetadata(variable, VarRec, DestData, Step,
+                                             WriterRank);
             DestData = (char *)DestData +
                        variable.m_ElementSize; // use variable.m_ElementSize
                                                // because it's the size in local
diff --git a/source/adios2/toolkit/format/bp5/BP5Deserializer.h b/source/adios2/toolkit/format/bp5/BP5Deserializer.h
index e3637d62fc..86be0d40a7 100644
--- a/source/adios2/toolkit/format/bp5/BP5Deserializer.h
+++ b/source/adios2/toolkit/format/bp5/BP5Deserializer.h
@@ -168,7 +168,7 @@ class BP5Deserializer : virtual public BP5Base
                                const size_t *LocalOffsets, size_t *LocalIndex);
     size_t RelativeToAbsoluteStep(const BP5VarRec *VarRec, size_t RelStep);
     int FindOffset(size_t Dims, const size_t *Size, const size_t *Index);
-    void GetSingleValueFromMetadata(core::VariableBase &variable,
+    bool GetSingleValueFromMetadata(core::VariableBase &variable,
                                     BP5VarRec *VarRec, void *DestData,
                                     size_t Step, size_t WriterRank);
     void ExtractSelectionFromPartialRM(int ElementSize, size_t Dims,
diff --git a/source/adios2/toolkit/format/bp5/BP5Serializer.cpp b/source/adios2/toolkit/format/bp5/BP5Serializer.cpp
index aea987c3e0..019f1a8cea 100644
--- a/source/adios2/toolkit/format/bp5/BP5Serializer.cpp
+++ b/source/adios2/toolkit/format/bp5/BP5Serializer.cpp
@@ -1144,5 +1144,12 @@ void *BP5Serializer::GetPtr(int bufferIdx, size_t posInBuffer)
     return CurDataBuffer->GetPtr(bufferIdx, posInBuffer);
 }
 
+size_t BP5Serializer::DebugGetDataBufferSize() const
+{
+    if (CurDataBuffer == NULL)
+        return 0;
+    return CurDataBuffer->Size();
+}
+
 } // end namespace format
 } // end namespace adios2
diff --git a/source/adios2/toolkit/format/bp5/BP5Serializer.h b/source/adios2/toolkit/format/bp5/BP5Serializer.h
index 6859efa01d..feaf620eff 100644
--- a/source/adios2/toolkit/format/bp5/BP5Serializer.h
+++ b/source/adios2/toolkit/format/bp5/BP5Serializer.h
@@ -104,6 +104,8 @@ class BP5Serializer : virtual public BP5Base
     void *GetPtr(int bufferIdx, size_t posInBuffer);
     size_t CalcSize(const size_t Count, const size_t *Vals);
 
+    size_t DebugGetDataBufferSize() const;
+
     int m_StatsLevel = 1;
 
 private:
diff --git a/testing/adios2/engine/bp/CMakeLists.txt b/testing/adios2/engine/bp/CMakeLists.txt
index 6b30e52aae..0baa674086 100644
--- a/testing/adios2/engine/bp/CMakeLists.txt
+++ b/testing/adios2/engine/bp/CMakeLists.txt
@@ -76,7 +76,7 @@ bp3_bp4_gtest_add_tests_helper(WriteFlushRead MPI_ALLOW)
 bp3_bp4_gtest_add_tests_helper(WriteMultiblockRead MPI_ALLOW)
 bp3_bp4_gtest_add_tests_helper(WriteReadMultiblock MPI_ALLOW)
 bp_gtest_add_tests_helper(WriteReadVector MPI_ALLOW)
-bp3_bp4_gtest_add_tests_helper(WriteReadAttributesMultirank MPI_ALLOW)
+bp_gtest_add_tests_helper(WriteReadAttributesMultirank MPI_ALLOW)
 bp_gtest_add_tests_helper(LargeMetadata MPI_ALLOW)
 if(ADIOS2_HAVE_BP5)
    set (BP5LargeMeta "Engine.BP.BPLargeMetadata.BPWrite1D_LargeMetadata.BP5.Serial")
@@ -96,13 +96,13 @@ bp3_bp4_gtest_add_tests_helper(TimeAggregation MPI_ALLOW)
 bp_gtest_add_tests_helper(NoXMLRecovery MPI_ALLOW)
 bp3_bp4_gtest_add_tests_helper(StepsFileGlobalArray MPI_ALLOW)
 bp3_bp4_gtest_add_tests_helper(StepsFileLocalArray MPI_ALLOW)
-bp3_bp4_gtest_add_tests_helper(SelectSteps MPI_ALLOW)
+bp_gtest_add_tests_helper(SelectSteps MPI_ALLOW)
 
 bp3_bp4_gtest_add_tests_helper(SelectionsOnRowMajorData MPI_NONE)
 bp3_bp4_gtest_add_tests_helper(SelectionsOnColumnMajorData MPI_NONE)
 
 if(NOT MSVC)
-  bp3_bp4_gtest_add_tests_helper(BufferSize MPI_NONE)
+  bp_gtest_add_tests_helper(BufferSize MPI_NONE)
 endif()
 
 if(ADIOS2_HAVE_MPI)
diff --git a/testing/adios2/engine/bp/TestBPStepsFileGlobalArray.cpp b/testing/adios2/engine/bp/TestBPStepsFileGlobalArray.cpp
index 64e0f669e7..625ba665ba 100644
--- a/testing/adios2/engine/bp/TestBPStepsFileGlobalArray.cpp
+++ b/testing/adios2/engine/bp/TestBPStepsFileGlobalArray.cpp
@@ -159,13 +159,13 @@ TEST_P(BPStepsFileGlobalArrayReaders, EveryStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
-
     if (readMode == ReadMode::ReadFileAll)
     {
         /// Read back data with File reading mode
         /// Read back the whole thing and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with File reading mode, read all steps at once"
@@ -210,6 +210,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, EveryStep)
     {
         /// Read back data with File reading mode
         /// Read back step by step and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with File reading mode, read step by step"
@@ -239,6 +242,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, EveryStep)
     {
         /// Read back data with File reading mode
         /// Read back step by step and block by block and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with File reading mode, read step by step, "
@@ -274,6 +280,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, EveryStep)
     {
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with Stream reading mode, read step by step"
@@ -302,6 +311,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, EveryStep)
     }
     else if (readMode == ReadMode::ReadStreamBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
         if (!mpiRank)
@@ -412,11 +424,12 @@ TEST_P(BPStepsFileGlobalArrayReaders, NewVarPerStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
 
     if (readMode == ReadMode::ReadFileAll)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back each variable with File reading mode
         /// Use SetStepSelection(0,1) explicitly
         if (!mpiRank)
@@ -459,6 +472,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, NewVarPerStep)
     }
     else if (readMode == ReadMode::ReadFileStepByStep)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back each variable with File reading mode
         /// and do not use SetStepSelection() so default read after open is
         /// tested
@@ -490,6 +506,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, NewVarPerStep)
     }
     else if (readMode == ReadMode::ReadFileStepByStepBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back each variable with File reading mode
         /// Read back block by block and check data
         if (!mpiRank)
@@ -527,6 +546,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, NewVarPerStep)
     }
     else if (readMode == ReadMode::ReadStream)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         /// Read back each variable with Streaming reading mode
         if (!mpiRank)
         {
@@ -561,6 +583,9 @@ TEST_P(BPStepsFileGlobalArrayReaders, NewVarPerStep)
     }
     else if (readMode == ReadMode::ReadStreamBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         /// Read back each variable with Streaming reading mode
         if (!mpiRank)
         {
@@ -699,11 +724,12 @@ TEST_P(BPStepsFileGlobalArrayParameters, EveryOtherStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
 
     if (readMode == ReadMode::ReadFileAll)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back data with File reading mode
         /// Read back the whole thing and check data
         if (!mpiRank)
@@ -736,6 +762,9 @@ TEST_P(BPStepsFileGlobalArrayParameters, EveryOtherStep)
     }
     else if (readMode == ReadMode::ReadFileStepByStep)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back data with File reading mode
         /// Read back step by step and check data
         if (!mpiRank)
@@ -767,6 +796,9 @@ TEST_P(BPStepsFileGlobalArrayParameters, EveryOtherStep)
     }
     else if (readMode == ReadMode::ReadFileStepByStepBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back data with File reading mode
         /// Read back step by step, block by block and check data
         if (!mpiRank)
@@ -804,6 +836,9 @@ TEST_P(BPStepsFileGlobalArrayParameters, EveryOtherStep)
     }
     else if (readMode == ReadMode::ReadStream)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
         if (!mpiRank)
@@ -845,6 +880,9 @@ TEST_P(BPStepsFileGlobalArrayParameters, EveryOtherStep)
     }
     else if (readMode == ReadMode::ReadStreamBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
         if (!mpiRank)
diff --git a/testing/adios2/engine/bp/TestBPStepsFileLocalArray.cpp b/testing/adios2/engine/bp/TestBPStepsFileLocalArray.cpp
index b12192daa2..9bf1c5fcc3 100644
--- a/testing/adios2/engine/bp/TestBPStepsFileLocalArray.cpp
+++ b/testing/adios2/engine/bp/TestBPStepsFileLocalArray.cpp
@@ -151,13 +151,13 @@ TEST_P(BPStepsFileLocalArrayReaders, EveryStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
-
     if (readMode == ReadMode::ReadFileStepByStepBlocks)
     {
         /// Read back data with File reading mode
         /// Read back step by step and block by block and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with File reading mode, read step by step, "
@@ -194,6 +194,9 @@ TEST_P(BPStepsFileLocalArrayReaders, EveryStep)
     {
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout << "Read with Stream reading mode, read step by step, "
@@ -303,13 +306,13 @@ TEST_P(BPStepsFileLocalArrayReaders, NewVarPerStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
-
     if (readMode == ReadMode::ReadFileStepByStepBlocks)
     {
         /// Read back each variable with File reading mode
         /// Read back block by block and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout
@@ -347,6 +350,9 @@ TEST_P(BPStepsFileLocalArrayReaders, NewVarPerStep)
     else if (readMode == ReadMode::ReadStreamBlocks)
     {
         /// Read back each variable with Streaming reading mode
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout
@@ -482,11 +488,11 @@ TEST_P(BPStepsFileLocalArrayParameters, EveryOtherStep)
     {
         io.SetEngine(engineName);
     }
-    adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
-    EXPECT_TRUE(engine);
-
     if (readMode == ReadMode::ReadFileStepByStepBlocks)
     {
+        adios2::Engine engine = io.Open(fname, adios2::Mode::ReadRandomAccess);
+        EXPECT_TRUE(engine);
+
         /// Read back data with File reading mode
         /// Read back step by step, block by block and check data
         if (!mpiRank)
@@ -527,6 +533,9 @@ TEST_P(BPStepsFileLocalArrayParameters, EveryOtherStep)
     {
         /// Read back data with Stream reading mode
         /// Read back step by step and check data
+        adios2::Engine engine = io.Open(fname, adios2::Mode::Read);
+        EXPECT_TRUE(engine);
+
         if (!mpiRank)
         {
             std::cout
diff --git a/testing/adios2/engine/bp/TestBPWriteReadAttributesMultirank.cpp b/testing/adios2/engine/bp/TestBPWriteReadAttributesMultirank.cpp
index 0feb3c1790..13824f3ab5 100644
--- a/testing/adios2/engine/bp/TestBPWriteReadAttributesMultirank.cpp
+++ b/testing/adios2/engine/bp/TestBPWriteReadAttributesMultirank.cpp
@@ -90,7 +90,8 @@ TEST_F(BPWriteReadAttributeTestMultirank, ADIOS2BPWriteReadArrayTypes)
             ioRead.SetEngine(engineName);
         }
 
-        adios2::Engine bpRead = ioRead.Open(fName, adios2::Mode::Read);
+        adios2::Engine bpRead =
+            ioRead.Open(fName, adios2::Mode::ReadRandomAccess);
 
         auto var = ioRead.InquireVariable<int>(varpath);
         EXPECT_TRUE(var);