diff --git a/src/backend/access/external/url_execute.c b/src/backend/access/external/url_execute.c
index 0205004dd3d3..1bae6ce7026e 100644
--- a/src/backend/access/external/url_execute.c
+++ b/src/backend/access/external/url_execute.c
@@ -23,6 +23,7 @@
 #include "cdb/cdbtimer.h"
 #include "cdb/cdbvars.h"
 #include "libpq/pqsignal.h"
+#include "mb/pg_wchar.h"
 #include "utils/resowner.h"
 
 #define EXEC_DATA_P 0 /* index to data pipe */
@@ -484,7 +485,12 @@ interpretError(int rc, char *buf, size_t buflen, char *err, size_t errlen)
 			/* Exit codes from commands rarely map to strerror() strings. In here
 			 * we show the error string returned from pclose, and omit the non
 			 * friendly exit code interpretation */
-			snprintf(buf, buflen, "error. %s", err);
+			int len = snprintf(buf, buflen, "error. %s", err);
+
+			if (len >= buflen)
+			{
+				buf[pg_mbcliplen(buf, len, buflen - 1)] = '\0';
+			}
 		}
 	}
 	else if (WIFSIGNALED(rc))
diff --git a/src/backend/cdb/cdbthreadlog.c b/src/backend/cdb/cdbthreadlog.c
index 700258436560..297d469bbeef 100644
--- a/src/backend/cdb/cdbthreadlog.c
+++ b/src/backend/cdb/cdbthreadlog.c
@@ -117,7 +117,12 @@ write_log(const char *fmt,...)
 	{
 		char		errbuf[2048];	/* Arbitrary size? */
 
-		vsnprintf(errbuf, sizeof(errbuf), fmt, ap);
+		int len = vsnprintf(errbuf, sizeof(errbuf), fmt, ap);
+
+		if (len >= sizeof(errbuf))
+		{
+			errbuf[pg_mbcliplen(errbuf, len, sizeof(errbuf) - 1)] = '\0';
+		}
 
 		/* Write the message in the CSV format */
 		write_message_to_server_log(LOG,
diff --git a/src/test/regress/input/external_table.source b/src/test/regress/input/external_table.source
index dab9b775638a..3f6d94ae2da4 100644
--- a/src/test/regress/input/external_table.source
+++ b/src/test/regress/input/external_table.source
@@ -135,6 +135,15 @@ FETCH FORWARD 1 FROM _psql_cursor;
 CLOSE _psql_cursor;
 COMMIT;
 
+-- ensure correct truncate error log according to database encoding
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 500 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && false $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+DROP EXTERNAL TABLE IF EXISTS table_test;
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 2006 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && true $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+SELECT logseverity FROM gp_toolkit.gp_log_system WHERE logmessage LIKE 'read err msg from pipe%' AND logdatabase = current_database() LIMIT 1;
+DROP EXTERNAL TABLE IF EXISTS table_test;
+
 -- echo will behave differently on different platforms, force to use bash with -E option
 CREATE EXTERNAL WEB TABLE table_qry (val TEXT)
   EXECUTE E'/usr/bin/env bash -c ''echo -E "$GP_QUERY_STRING"''' ON SEGMENT 0
diff --git a/src/test/regress/output/external_table.source b/src/test/regress/output/external_table.source
index 8438693ca229..d32b4bd6c8df 100644
--- a/src/test/regress/output/external_table.source
+++ b/src/test/regress/output/external_table.source
@@ -166,6 +166,25 @@ FETCH FORWARD 1 FROM _psql_cursor;
 
 CLOSE _psql_cursor;
 COMMIT;
+-- ensure correct truncate error log according to database encoding
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 500 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && false $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+ERROR:  external table table_test command ended with error. ‘12345678911111111112222222222333333333344444444445555555555666666666677777777778888888888999999999911111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111112222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333344444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444445  (seg0 slice1 172.19.0.4:6434 pid=107133)
+DETAIL:  Command: execute: (echo -n ‘ && seq 1 500 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && false
+DROP EXTERNAL TABLE IF EXISTS table_test;
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 2006 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && true $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+ bool 
+------
+(0 rows)
+
+SELECT logseverity FROM gp_toolkit.gp_log_system WHERE logmessage LIKE 'read err msg from pipe%' AND logdatabase = current_database() LIMIT 1;
+ logseverity 
+-------------
+ LOG
+(1 row)
+
+DROP EXTERNAL TABLE IF EXISTS table_test;
 -- echo will behave differently on different platforms, force to use bash with -E option
 CREATE EXTERNAL WEB TABLE table_qry (val TEXT)
   EXECUTE E'/usr/bin/env bash -c ''echo -E "$GP_QUERY_STRING"''' ON SEGMENT 0
diff --git a/src/test/regress/output/external_table_optimizer.source b/src/test/regress/output/external_table_optimizer.source
index 63c99689d4d2..782c62fc2c90 100644
--- a/src/test/regress/output/external_table_optimizer.source
+++ b/src/test/regress/output/external_table_optimizer.source
@@ -166,6 +166,25 @@ FETCH FORWARD 1 FROM _psql_cursor;
 
 CLOSE _psql_cursor;
 COMMIT;
+-- ensure correct truncate error log according to database encoding
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 500 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && false $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+ERROR:  external table table_test command ended with error. ‘12345678911111111112222222222333333333344444444445555555555666666666677777777778888888888999999999911111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111112222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222222333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333344444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444445  (seg0 slice1 172.19.0.4:6434 pid=107133)
+DETAIL:  Command: execute: (echo -n ‘ && seq 1 500 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && false
+DROP EXTERNAL TABLE IF EXISTS table_test;
+CREATE EXTERNAL WEB TABLE table_test (text text) EXECUTE $$ (echo -n ‘ && seq 1 2006 | cut -b1 | tr -d '\n' && echo -n ’) >/dev/stderr && true $$ ON ALL FORMAT 'CSV';
+SELECT true FROM table_test;
+ bool 
+------
+(0 rows)
+
+SELECT logseverity FROM gp_toolkit.gp_log_system WHERE logmessage LIKE 'read err msg from pipe%' AND logdatabase = current_database() LIMIT 1;
+ logseverity 
+-------------
+ LOG
+(1 row)
+
+DROP EXTERNAL TABLE IF EXISTS table_test;
 -- echo will behave differently on different platforms, force to use bash with -E option
 CREATE EXTERNAL WEB TABLE table_qry (val TEXT)
   EXECUTE E'/usr/bin/env bash -c ''echo -E "$GP_QUERY_STRING"''' ON SEGMENT 0