diff -Naur grpc-1.41.1/src/core/lib/debug/stats_data.cc third_party_grpc_sxy/src/core/lib/debug/stats_data.cc
--- grpc-1.41.1/src/core/lib/debug/stats_data.cc	2021-10-20 04:14:40.000000000 +0800
+++ third_party_grpc_sxy/src/core/lib/debug/stats_data.cc	2023-04-20 14:24:54.000000000 +0800
@@ -282,8 +282,8 @@
     "Number of streams terminated per TCP write",
     "Number of flow control updates written per TCP write",
     // NOLINTNEXTLINE(bugprone-suspicious-missing-comma)
-    "How many completion queues were checked looking for a CQ that had "
-    "requested the incoming call",
+    ("How many completion queues were checked looking for a CQ that had "
+    "requested the incoming call"),
 };
 const int grpc_stats_table_0[65] = {
     0,      1,      2,      3,      4,     5,     7,     9,     11,    14,
diff -Naur grpc-1.41.1/src/core/lib/debug/trace.cc third_party_grpc_sxy/src/core/lib/debug/trace.cc
--- grpc-1.41.1/src/core/lib/debug/trace.cc	2021-10-20 04:14:40.000000000 +0800
+++ third_party_grpc_sxy/src/core/lib/debug/trace.cc	2023-04-20 14:24:54.000000000 +0800
@@ -40,45 +40,51 @@
 TraceFlag* TraceFlagList::root_tracer_ = nullptr;
 
 bool TraceFlagList::Set(const char* name, bool enabled) {
-  TraceFlag* t;
-  if (0 == strcmp(name, "all")) {
-    for (t = root_tracer_; t; t = t->next_tracer_) {
+  if (0 == strlen(name)) {
+    gpr_log(GPR_DEBUG, "No trace flags are changed");
+  } else if (0 == strcmp(name, "all")) {
+    for (auto t = root_tracer_; t != nullptr; t = t->next_tracer_) {
       t->set_enabled(enabled);
     }
   } else if (0 == strcmp(name, "list_tracers")) {
     LogAllTracers();
   } else if (0 == strcmp(name, "refcount")) {
-    for (t = root_tracer_; t; t = t->next_tracer_) {
+    for (auto t = root_tracer_; t != nullptr; t = t->next_tracer_) {
       if (strstr(t->name_, "refcount") != nullptr) {
         t->set_enabled(enabled);
+        break;
       }
     }
   } else {
-    bool found = false;
-    for (t = root_tracer_; t; t = t->next_tracer_) {
+    for (auto t = root_tracer_; t != nullptr; t = t->next_tracer_) {
       if (0 == strcmp(name, t->name_)) {
         t->set_enabled(enabled);
-        found = true;
+        return true;
       }
     }
     // check for unknowns, but ignore "", to allow to GRPC_TRACE=
-    if (!found && 0 != strcmp(name, "")) {
-      gpr_log(GPR_ERROR, "Unknown trace var: '%s'", name);
-      return false; /* early return */
-    }
+    gpr_log(GPR_ERROR, "Unknown trace var: '%s'", name);
+    return false; /* early return */
   }
   return true;
 }
 
 void TraceFlagList::Add(TraceFlag* flag) {
+  gpr_log(GPR_DEBUG, "Add tracer:\t%s", flag->name_);
+  // prevent cycles at 'Add' flag to 'root_tracer_'
+  for (auto t = root_tracer_; t != nullptr; t = t->next_tracer_) {
+    // check if flag is already part of 'root_tracer_'
+    if (t == flag) {
+      return;
+    }
+  }
   flag->next_tracer_ = root_tracer_;
   root_tracer_ = flag;
 }
 
 void TraceFlagList::LogAllTracers() {
   gpr_log(GPR_DEBUG, "available tracers:");
-  TraceFlag* t;
-  for (t = root_tracer_; t != nullptr; t = t->next_tracer_) {
+  for (auto t = root_tracer_; t != nullptr; t = t->next_tracer_) {
     gpr_log(GPR_DEBUG, "\t%s", t->name_);
   }
 }