[Enhancement] validate loop_count_wait_fragments_finish config value …

…(backport #54395) (#54466)

Co-authored-by: Kevin Cai <[email protected]>

be/src/common/config.h

@@ -1065,7 +1065,7 @@ CONF_String(dependency_librdkafka_debug, "all");
 // DEBUG: 0, INFO: 1, WARN: 2, ERROR: 3, WARN by default
 CONF_mInt16(pulsar_client_log_level, "2");
 
-// max loop count when be waiting its fragments finish
+// max loop count when be waiting its fragments finish. It has no effect if the var is configured with value <= 0.
 CONF_Int64(loop_count_wait_fragments_finish, "0");
 
 // the maximum number of connections in the connection pool for a single jdbc url

be/src/runtime/exec_env.cpp

@@ -723,6 +723,11 @@ void ExecEnv::destroy() {
 }
 
 void ExecEnv::_wait_for_fragments_finish() {
+    if (config::loop_count_wait_fragments_finish < 0) {
+        LOG(WARNING) << "'config::loop_count_wait_fragments_finish' is set to a negative integer, ignore it.";
+        return;
+    }
+
     size_t max_loop_secs = config::loop_count_wait_fragments_finish * 10;
     if (max_loop_secs == 0) {
         return;