diff --git a/dbsim/db_storage_service.hpp b/dbsim/db_storage_service.hpp
index 8974f9e..28eb78e 100644
--- a/dbsim/db_storage_service.hpp
+++ b/dbsim/db_storage_service.hpp
@@ -14,7 +14,8 @@ namespace db
     {
         int start_transaction() override
         { throw wsrep::not_implemented_error(); }
-        int append_fragment(const wsrep::id&, wsrep::client_id,
+        int append_fragment(const wsrep::id&,
+                            wsrep::transaction_id,
                             int,
                             const wsrep::const_buffer&) override
         { throw wsrep::not_implemented_error(); }
diff --git a/include/wsrep/storage_service.hpp b/include/wsrep/storage_service.hpp
index 43d20df..e8f5f24 100644
--- a/include/wsrep/storage_service.hpp
+++ b/include/wsrep/storage_service.hpp
@@ -14,7 +14,7 @@
 #ifndef WSREP_STORAGE_SERVICE_HPP
 #define WSREP_STORAGE_SERVICE_HPP
 
-#include "client_id.hpp"
+#include "transaction_id.hpp"
 #include "id.hpp"
 #include "buffer.hpp"
 
@@ -46,7 +46,7 @@ namespace wsrep
          * Append fragment into stable storage.
          */
         virtual int append_fragment(const wsrep::id& server_id,
-                                    wsrep::client_id client_id,
+                                    wsrep::transaction_id client_id,
                                     int flags,
                                     const wsrep::const_buffer& data) = 0;
 
diff --git a/include/wsrep/streaming_context.hpp b/include/wsrep/streaming_context.hpp
index 2bb4a87..6be91c2 100644
--- a/include/wsrep/streaming_context.hpp
+++ b/include/wsrep/streaming_context.hpp
@@ -5,93 +5,97 @@
 #ifndef WSREP_STREAMING_CONTEXT_HPP
 #define WSREP_STREAMING_CONTEXT_HPP
 
+#include "logger.hpp"
+
 namespace wsrep
 {
-        class streaming_context
+    class streaming_context
+    {
+    public:
+        enum fragment_unit
         {
-        public:
-            enum fragment_unit
-            {
-                row,
-                bytes,
-                statement
-            };
-
-            streaming_context()
-                : fragments_()
-                , rollback_replicated_for_()
-                , fragment_unit_()
-                , fragment_size_()
-                , bytes_certified_()
-                , unit_counter_()
-            { }
-
-            void enable(enum fragment_unit fragment_unit, size_t fragment_size)
-            {
-                assert(fragment_size > 0);
-                fragment_unit_ = fragment_unit;
-                fragment_size_ = fragment_size;
-            }
-
-            enum fragment_unit fragment_unit() const { return fragment_unit_; }
-
-            size_t fragment_size() const { return fragment_size_; }
-
-            void disable()
-            {
-                fragment_size_ = 0;
-            }
-
-            void certified(wsrep::seqno seqno)
-            {
-                fragments_.push_back(seqno);
-            }
-
-            size_t fragments_certified() const
-            {
-                return fragments_.size();
-            }
-
-            size_t bytes_certified() const
-            {
-                return bytes_certified_;
-            }
-
-            void rolled_back(wsrep::transaction_id id)
-            {
-                assert(rollback_replicated_for_ == wsrep::transaction_id::undefined());
-                rollback_replicated_for_ = id;
-            }
-
-            bool rolled_back() const
-            {
-                return (rollback_replicated_for_ !=
-                        wsrep::transaction_id::undefined());
-            }
-
-            size_t unit_counter() const { return unit_counter_; }
-            void increment_unit_counter(size_t inc)
-            { unit_counter_ += inc; }
-            void reset_unit_counter() { unit_counter_ = 0; }
-            const std::vector<wsrep::seqno>& fragments() const
-            {
-                return fragments_;
-            }
-            void cleanup()
-            {
-                fragments_.clear();
-                rollback_replicated_for_ = wsrep::transaction_id::undefined();
-                bytes_certified_ = 0;
-                unit_counter_ = 0;
-            }
-        private:
-            std::vector<wsrep::seqno> fragments_;
-            wsrep::transaction_id rollback_replicated_for_;
-            enum fragment_unit fragment_unit_;
-            size_t fragment_size_;
-            size_t bytes_certified_;
-            size_t unit_counter_;
+            row,
+            bytes,
+            statement
         };
+
+        streaming_context()
+            : fragments_()
+            , rollback_replicated_for_()
+            , fragment_unit_()
+            , fragment_size_()
+            , bytes_certified_()
+            , unit_counter_()
+        { }
+
+        void enable(enum fragment_unit fragment_unit, size_t fragment_size)
+        {
+            wsrep::log_info() << "Enabling streaming: "
+                              << fragment_unit << " " << fragment_size;
+            assert(fragment_size > 0);
+            fragment_unit_ = fragment_unit;
+            fragment_size_ = fragment_size;
+        }
+
+        enum fragment_unit fragment_unit() const { return fragment_unit_; }
+
+        size_t fragment_size() const { return fragment_size_; }
+
+        void disable()
+        {
+            fragment_size_ = 0;
+        }
+
+        void certified(wsrep::seqno seqno)
+        {
+            fragments_.push_back(seqno);
+        }
+
+        size_t fragments_certified() const
+        {
+            return fragments_.size();
+        }
+
+        size_t bytes_certified() const
+        {
+            return bytes_certified_;
+        }
+
+        void rolled_back(wsrep::transaction_id id)
+        {
+            assert(rollback_replicated_for_ == wsrep::transaction_id::undefined());
+            rollback_replicated_for_ = id;
+        }
+
+        bool rolled_back() const
+        {
+            return (rollback_replicated_for_ !=
+                    wsrep::transaction_id::undefined());
+        }
+
+        size_t unit_counter() const { return unit_counter_; }
+        void increment_unit_counter(size_t inc)
+        { unit_counter_ += inc; }
+        void reset_unit_counter() { unit_counter_ = 0; }
+        const std::vector<wsrep::seqno>& fragments() const
+        {
+            return fragments_;
+        }
+        void cleanup()
+        {
+            fragments_.clear();
+            rollback_replicated_for_ = wsrep::transaction_id::undefined();
+            bytes_certified_ = 0;
+            unit_counter_ = 0;
+        }
+    private:
+        std::vector<wsrep::seqno> fragments_;
+        wsrep::transaction_id rollback_replicated_for_;
+        enum fragment_unit fragment_unit_;
+        size_t fragment_size_;
+        size_t bytes_certified_;
+        size_t unit_counter_;
+    };
 }
 
 #endif // WSREP_STREAMING_CONTEXT_HPP
diff --git a/src/client_state.cpp b/src/client_state.cpp
index ebde98c..15ea948 100644
--- a/src/client_state.cpp
+++ b/src/client_state.cpp
@@ -194,6 +194,7 @@ int wsrep::client_state::after_statement()
     // wsrep::unique_lock<wsrep::mutex> lock(mutex_);
     debug_log_state("after_statement: enter");
     assert(state() == s_exec);
+    assert(mode() == m_local);
 #if 0
     /**
      * @todo Check for replay state, do rollback if requested.
diff --git a/src/transaction.cpp b/src/transaction.cpp
index 6ae493d..464face 100644
--- a/src/transaction.cpp
+++ b/src/transaction.cpp
@@ -195,6 +195,7 @@ int wsrep::transaction::append_data(const wsrep::const_buffer& data)
 int wsrep::transaction::after_row()
 {
     wsrep::unique_lock<wsrep::mutex> lock(client_state_.mutex());
+    debug_log_state("after_row_enter");
     if (streaming_context_.fragment_size() > 0)
     {
         switch (streaming_context_.fragment_unit())
@@ -843,7 +844,7 @@ int wsrep::transaction::certify_fragment(
 
     if (storage_service.append_fragment(
             client_state_.server_state().id(),
-            client_state_.id(),
+            id(),
             flags_,
             wsrep::const_buffer(data.data(), data.size())))
     {
diff --git a/test/mock_storage_service.hpp b/test/mock_storage_service.hpp
index 6aaa1be..2270db4 100644
--- a/test/mock_storage_service.hpp
+++ b/test/mock_storage_service.hpp
@@ -21,7 +21,7 @@ class mock_server_state;
         int start_transaction() WSREP_OVERRIDE;
 
         int append_fragment(const wsrep::id&,
-                            wsrep::client_id,
+                            wsrep::transaction_id,
                             int,
                             const wsrep::const_buffer&)
             WSREP_OVERRIDE