diff --git a/include/wsrep/transaction.hpp b/include/wsrep/transaction.hpp
index 56ce1e8..d2079e7 100644
--- a/include/wsrep/transaction.hpp
+++ b/include/wsrep/transaction.hpp
@@ -238,6 +238,8 @@ namespace wsrep
 
         wsrep::provider& provider();
         void flags(int flags) { flags_ = flags; }
+        int before_prepare_local(wsrep::unique_lock<wsrep::mutex>&);
+        int before_prepare_high_priority(wsrep::unique_lock<wsrep::mutex>&);
         int before_commit_local(wsrep::unique_lock<wsrep::mutex>&);
         int before_commit_high_priority(wsrep::unique_lock<wsrep::mutex>&);
         // Return true if the transaction must abort, is aborting,
diff --git a/src/transaction.cpp b/src/transaction.cpp
index 2c82990..414fcad 100644
--- a/src/transaction.cpp
+++ b/src/transaction.cpp
@@ -225,6 +225,8 @@ int wsrep::transaction::prepare_for_ordering(
 
 int wsrep::transaction::assign_read_view(const wsrep::gtid* const gtid)
 {
+    assert(active());
+    assert(client_state_.mode() == wsrep::client_state::m_local);
     try
     {
         return provider().assign_read_view(ws_handle_, gtid);
@@ -239,6 +241,7 @@ int wsrep::transaction::assign_read_view(const wsrep::gtid* const gtid)
 int wsrep::transaction::append_key(const wsrep::key& key)
 {
     assert(active());
+    assert(client_state_.mode() == wsrep::client_state::m_local);
     try
     {
         debug_log_key_append(key);
@@ -255,11 +258,13 @@ int wsrep::transaction::append_key(const wsrep::key& key)
 int wsrep::transaction::append_data(const wsrep::const_buffer& data)
 {
     assert(active());
+    assert(client_state_.mode() == wsrep::client_state::m_local);
     return provider().append_data(ws_handle_, data);
 }
 
 int wsrep::transaction::after_row()
 {
+    assert(client_state_.mode() == wsrep::client_state::m_local);
     wsrep::unique_lock<wsrep::mutex> lock(client_state_.mutex());
     debug_log_state("after_row_enter");
     int ret(0);
@@ -272,106 +277,121 @@ int wsrep::transaction::after_row()
     return ret;
 }
 
+int wsrep::transaction::before_prepare_local(
+    wsrep::unique_lock<wsrep::mutex>& lock)
+{
+    assert(lock.owns_lock());
+    assert(client_state_.mode() == wsrep::client_state::m_local);
+    assert(state() == s_executing || state() == s_must_abort ||
+           state() == s_replaying);
+
+    if (state() == s_must_abort)
+    {
+        client_state_.override_error(wsrep::e_deadlock_error);
+        return 1;
+    }
+
+    int ret = 0;
+    if (is_streaming())
+    {
+        client_service_.debug_crash(
+            "crash_last_fragment_commit_before_fragment_removal");
+        lock.unlock();
+        if (client_service_.statement_allowed_for_streaming() == false)
+        {
+            client_state_.override_error(wsrep::e_error_during_commit,
+                                         wsrep::provider::error_not_allowed);
+            ret = 1;
+        }
+        else if (!is_xa())
+        {
+            // Note: we can't remove fragments here for XA,
+            // the transaction has already issued XA END and
+            // is in IDLE state, no more changes allowed!
+            ret = client_service_.remove_fragments();
+            if (ret)
+            {
+                client_state_.override_error(wsrep::e_deadlock_error);
+            }
+        }
+        lock.lock();
+        client_service_.debug_crash(
+            "crash_last_fragment_commit_after_fragment_removal");
+        if (state() == s_must_abort)
+        {
+            client_state_.override_error(wsrep::e_deadlock_error);
+            ret = 1;
+        }
+    }
+
+    if (ret == 0)
+    {
+        if (is_xa())
+        {
+            // Force fragment replication on XA prepare
+            flags(flags() | wsrep::provider::flag::prepare);
+            pa_unsafe(true);
+            append_sr_keys_for_commit();
+            const bool force_streaming_step = true;
+            ret = streaming_step(lock, force_streaming_step);
+            if (ret == 0)
+            {
+                assert(state() == s_executing);
+                state(lock, s_preparing);
+            }
+        }
+        else
+        {
+            ret = certify_commit(lock);
+        }
+
+        assert((ret == 0 && state() == s_preparing)
+               || (state() == s_must_abort || state() == s_must_replay
+                   || state() == s_cert_failed));
+
+        if (ret)
+        {
+            assert(state() == s_must_replay || client_state_.current_error());
+            ret = 1;
+        }
+    }
+    return ret;
+}
+
+int wsrep::transaction::before_prepare_high_priority(
+    wsrep::unique_lock<wsrep::mutex>& lock)
+{
+    assert(lock.owns_lock());
+    assert(client_state_.mode() == wsrep::client_state::m_high_priority);
+    assert(state() == s_executing || state() == s_replaying);
+    // Note: fragment removal is done from applying
+    // context for high priority mode.
+    if (is_xa())
+    {
+        assert(state() == s_executing || state() == s_replaying);
+        if (state() == s_replaying)
+        {
+            return 0;
+        }
+    }
+    state(lock, s_preparing);
+    return 0;
+}
+
 int wsrep::transaction::before_prepare(
     wsrep::unique_lock<wsrep::mutex>& lock)
 {
     assert(lock.owns_lock());
     int ret(0);
     debug_log_state("before_prepare_enter");
-    assert(state() == s_executing || state() == s_must_abort ||
-           state() == s_replaying);
-
-    if (state() == s_must_abort)
-    {
-        assert(client_state_.mode() == wsrep::client_state::m_local);
-        client_state_.override_error(wsrep::e_deadlock_error);
-        return 1;
-    }
 
     switch (client_state_.mode())
     {
     case wsrep::client_state::m_local:
-        if (is_streaming())
-        {
-            client_service_.debug_crash(
-                "crash_last_fragment_commit_before_fragment_removal");
-            lock.unlock();
-            if (client_service_.statement_allowed_for_streaming() == false)
-            {
-                client_state_.override_error(
-                    wsrep::e_error_during_commit,
-                    wsrep::provider::error_not_allowed);
-                ret = 1;
-            }
-            else if (!is_xa())
-            {
-                // Note: we can't remove fragments here for XA,
-                // the transaction has already issued XA END and
-                // is in IDLE state, no more changes allowed!
-                ret = client_service_.remove_fragments();
-                if (ret)
-                {
-                    client_state_.override_error(wsrep::e_deadlock_error);
-                }
-            }
-            lock.lock();
-            client_service_.debug_crash(
-                "crash_last_fragment_commit_after_fragment_removal");
-            if (state() == s_must_abort)
-            {
-                client_state_.override_error(wsrep::e_deadlock_error);
-                ret = 1;
-            }
-        }
-
-        if (ret == 0)
-        {
-            if (is_xa())
-            {
-                // Force fragment replication on XA prepare
-                flags(flags() | wsrep::provider::flag::prepare);
-                pa_unsafe(true);
-                append_sr_keys_for_commit();
-                const bool force_streaming_step = true;
-                ret = streaming_step(lock, force_streaming_step);
-                if (ret == 0)
-                {
-                    assert(state() == s_executing);
-                    state(lock, s_preparing);
-                }
-            }
-            else
-            {
-                ret = certify_commit(lock);
-            }
-
-            assert((ret == 0 && state() == s_preparing) ||
-                   (state() == s_must_abort ||
-                    state() == s_must_replay ||
-                    state() == s_cert_failed));
-
-            if (ret)
-            {
-                assert(state() == s_must_replay ||
-                       client_state_.current_error());
-                ret = 1;
-            }
-        }
-
+        ret = before_prepare_local(lock);
         break;
     case wsrep::client_state::m_high_priority:
-        // Note: fragment removal is done from applying
-        // context for high priority mode.
-        if (is_xa())
-        {
-            assert(state() == s_executing ||
-                   state() == s_replaying);
-            if (state() == s_replaying)
-            {
-                break;
-            }
-        }
-        state(lock, s_preparing);
+        ret = before_prepare_high_priority(lock);
         break;
     default:
         assert(0);
@@ -441,6 +461,8 @@ int wsrep::transaction::after_prepare(
 int wsrep::transaction::before_commit_local(
     wsrep::unique_lock<wsrep::mutex>& lock)
 {
+    assert(lock.owns_lock());
+
     int ret = 1;
     assert(state() == s_executing || state() == s_prepared
            || state() == s_committing || state() == s_must_abort
@@ -512,6 +534,8 @@ int wsrep::transaction::before_commit_local(
 int wsrep::transaction::before_commit_high_priority(
     wsrep::unique_lock<wsrep::mutex>& lock)
 {
+    assert(lock.owns_lock());
+
     int ret = 1;
     assert(certified());
     assert(ordered());