diff --git a/src/common/backend/utils/error/elog.cpp b/src/common/backend/utils/error/elog.cpp
index 4c490dc88110e42cdc58010118d7d7544f76beef..ce384cc17b428d5f20ce6507136eb2eda9eb6e20 100644
--- a/src/common/backend/utils/error/elog.cpp
+++ b/src/common/backend/utils/error/elog.cpp
@@ -252,7 +252,7 @@ bool errstart(int elevel, const char* filename, int lineno, const char* funcname
      * Check some cases in which we want to promote an error into a more
      * severe error.  None of this logic applies for non-error messages.
      */
-    if (elevel >= ERROR) {
+    if (elevel >= ERROR && u_sess != NULL) {
         /*
          * If we are inside a critical section, all errors become PANIC
          * errors.	See miscadmin.h.
@@ -316,7 +316,15 @@ bool errstart(int elevel, const char* filename, int lineno, const char* funcname
             elevel = ERROR;
         }
     }
-
+    if (u_sess == NULL && (g_instance.role == VUNKNOWN || t_thrd.role == MASTER_THREAD)) {
+        // there out of memory in startup, we exit directly.
+        /* Ooops, hard crash time; very little we can do safely here */
+        write_stderr("error occurred at %s:%d before error message processing is available\n"
+                     " u_sess is NULL! gaussdb is exit now.\n",
+            filename ? filename : "(unknown file)",
+            lineno);
+        _exit(-1);
+    }
     /*
      * Now decide whether we need to process this report at all; if it's
      * warning or less and not enabled for logging, just return FALSE without