diff --git a/dbsim/db_high_priority_service.hpp b/dbsim/db_high_priority_service.hpp
index db9abce..84c55f6 100644
--- a/dbsim/db_high_priority_service.hpp
+++ b/dbsim/db_high_priority_service.hpp
@@ -37,9 +37,10 @@ namespace db
         void switch_execution_context(wsrep::high_priority_service&) override
         { }
         int log_dummy_write_set(const wsrep::ws_handle&,
-                                const wsrep::ws_meta&)
+                                const wsrep::ws_meta&) override
         { return 0; }
-        bool is_replaying() const;
+        bool is_replaying() const override;
+        void debug_crash(const char*) override { }
     private:
         high_priority_service(const high_priority_service&);
         high_priority_service& operator=(const high_priority_service&);
diff --git a/include/wsrep/high_priority_service.hpp b/include/wsrep/high_priority_service.hpp
index 24e7206..4c95029 100644
--- a/include/wsrep/high_priority_service.hpp
+++ b/include/wsrep/high_priority_service.hpp
@@ -169,6 +169,11 @@ namespace wsrep
         virtual bool is_replaying() const = 0;
 
         bool must_exit() const { return must_exit_; }
+
+        /**
+         * Debug facility to crash the server at given point.
+         */
+        virtual void debug_crash(const char* crash_point) = 0;
     protected:
         wsrep::server_state& server_state_;
         bool must_exit_;
diff --git a/src/server_state.cpp b/src/server_state.cpp
index 8dc430f..638effd 100644
--- a/src/server_state.cpp
+++ b/src/server_state.cpp
@@ -44,11 +44,14 @@ static int apply_fragment(wsrep::server_state& server_state,
     {
         wsrep::high_priority_switch sw(high_priority_service,
                                        streaming_applier);
+
         ret = streaming_applier.apply_write_set(ws_meta, data);
         streaming_applier.after_apply();
     }
+    high_priority_service.debug_crash("crash_apply_cb_before_append_frag");
     ret = ret || high_priority_service.append_fragment_and_commit(
         ws_handle, ws_meta, data);
+    high_priority_service.debug_crash("crash_apply_cb_after_append_frag");
     high_priority_service.after_apply();
     return ret;
 }
@@ -67,9 +70,17 @@ static int commit_fragment(wsrep::server_state& server_state,
     {
         wsrep::high_priority_switch sw(
             high_priority_service, *streaming_applier);
-        ret = streaming_applier->apply_write_set(ws_meta, data) ||
-            streaming_applier->remove_fragments(ws_meta) ||
-            streaming_applier->commit(ws_handle, ws_meta);
+        ret = streaming_applier->apply_write_set(ws_meta, data);
+        streaming_applier->debug_crash(
+            "crash_apply_cb_before_fragment_removal");
+        ret = ret || streaming_applier->remove_fragments(ws_meta);
+        streaming_applier->debug_crash(
+            "crash_apply_cb_after_fragment_removal");
+        streaming_applier->debug_crash(
+            "crash_commit_cb_before_last_fragment_commit");
+        ret = ret || streaming_applier->commit(ws_handle, ws_meta);
+        streaming_applier->debug_crash(
+            "crash_commit_cb_last_fragment_commit_success");
         streaming_applier->after_apply();
     }
     if (ret == 0)
diff --git a/test/mock_high_priority_service.hpp b/test/mock_high_priority_service.hpp
index f4f91ec..19d090a 100644
--- a/test/mock_high_priority_service.hpp
+++ b/test/mock_high_priority_service.hpp
@@ -57,6 +57,8 @@ namespace wsrep
                                 const wsrep::ws_meta&)
             WSREP_OVERRIDE { return 0; }
         bool is_replaying() const WSREP_OVERRIDE { return replaying_; }
+        void debug_crash(const char*) WSREP_OVERRIDE { /* Not in unit tests*/}
+
         wsrep::mock_client_state* client_state()
         {
             return client_state_;