@@ -64,4 +64,37 @@ ];
   systemd.services.caddy.serviceConfig = {
     ReadWritePaths = [ "/run/web" ];
   };
+
+  boot.kernel.sysctl =
+    let
+      buffer_size = 16 * 1024 * 1024;
+      server_count = 2;
+      max_clients = 100;
+      page_size = 4096;
+      # This server might have 100 clients simultaneously, so:
+      #   max(tcp_wmem) * 2 * 100 / 4096
+      mem = toString (buffer_size * server_count * max_clients / page_size);
+    in
+    {
+      # Provide adequate buffer memory.
+      # rmem_max and wmem_max are TCP max buffer size
+      # settable with setsockopt(), in bytes
+      # tcp_rmem and tcp_wmem are per socket in bytes.
+      # tcp_mem is for all TCP streams, in 4096-byte pages.
+      # The following are suggested on IBM's
+      # High Performance Computing page
+      "net.core.rmem_max" = buffer_size;
+      "net.core.wmem_max" = buffer_size;
+      "net.core.rmem_default" = buffer_size;
+      "net.core.wmem_default" = buffer_size;
+      "net.ipv4.tcp_rmem" = "4096 87380 ${toString buffer_size}";
+      "net.ipv4.tcp_wmem" = "4096 87380 ${toString buffer_size}";
+      "net.ipv4.tcp_mem" = "${mem} ${mem} ${mem}";
+
+      "net.ipv4.tcp_sack" = false;
+      "net.ipv4.tcp_dsack" = false;
+
+      "net.ipv4.tcp_slow_start_after_idle" = false;
+    };
+
 }