Reduce spam log messages at server under high memory pressure (#29470)

* Reduce spam log messages at server under high memory pressure

* change atomic usage

* minor fix

* minor fix

src/core/lib/iomgr/tcp_server_posix.cc

@@ -29,6 +29,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <string.h>
@@ -61,6 +62,8 @@
 #include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/resource_quota/api.h"
 
+static std::atomic<int64_t> num_dropped_connections{0};
+
 static grpc_error_handle tcp_server_create(grpc_closure* shutdown_complete,
                                            const grpc_channel_args* args,
                                            grpc_tcp_server** server) {
@@ -221,7 +224,14 @@ static void on_read(void* arg, grpc_error_handle err) {
     }
 
     if (sp->server->memory_quota->IsMemoryPressureHigh()) {
-      gpr_log(GPR_INFO, "Drop incoming connection: high memory pressure");
+      int64_t dropped_connections_count =
+          num_dropped_connections.fetch_add(1, std::memory_order_relaxed) + 1;
+      if (dropped_connections_count % 1000 == 1) {
+        gpr_log(GPR_INFO,
+                "Dropped >= %" PRId64
+                " new connection attempts due to high memory pressure",
+                dropped_connections_count);
+      }
       close(fd);
       continue;
     }