diff --git a/src/Server.php b/src/Server.php
index e46525b4c..f40667786 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -537,8 +537,12 @@ class Server{
 		if(!$ev->isCancelled()){
 			Timings::$syncPlayerDataSave->time(function() use ($name, $ev) : void{
 				$nbt = new BigEndianNbtSerializer();
+				$contents = zlib_encode($nbt->write(new TreeRoot($ev->getSaveData())), ZLIB_ENCODING_GZIP);
+				if($contents === false){
+					throw new AssumptionFailedError("zlib_encode() failed unexpectedly");
+				}
 				try{
-					Filesystem::safeFilePutContents($this->getPlayerDataPath($name), zlib_encode($nbt->write(new TreeRoot($ev->getSaveData())), ZLIB_ENCODING_GZIP));
+					Filesystem::safeFilePutContents($this->getPlayerDataPath($name), $contents);
 				}catch(\RuntimeException | \ErrorException $e){
 					$this->logger->critical($this->getLanguage()->translate(KnownTranslationFactory::pocketmine_data_saveError($name, $e->getMessage())));
 					$this->logger->logException($e);
diff --git a/tools/ping-server.php b/tools/ping-server.php
new file mode 100644
index 000000000..912119d5c
--- /dev/null
+++ b/tools/ping-server.php
@@ -0,0 +1,152 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\tools\ping_server;
+
+use pocketmine\utils\AssumptionFailedError;
+use raklib\protocol\MessageIdentifiers;
+use raklib\protocol\PacketSerializer;
+use raklib\protocol\UnconnectedPing;
+use raklib\protocol\UnconnectedPong;
+use function bin2hex;
+use function count;
+use function fgets;
+use function gethostbynamel;
+use function hrtime;
+use function intdiv;
+use function mt_rand;
+use function ord;
+use function sleep;
+use function socket_bind;
+use function socket_close;
+use function socket_create;
+use function socket_getsockname;
+use function socket_last_error;
+use function socket_recvfrom;
+use function socket_select;
+use function socket_sendto;
+use function socket_strerror;
+use function strlen;
+use function time;
+use function trim;
+use const MSG_DONTROUTE;
+use const PHP_BINARY;
+use const PHP_INT_MAX;
+
+require_once 'vendor/autoload.php';
+
+function hrtime_ms() : int{
+	return intdiv(hrtime(true), 1_000_000);
+}
+
+function read_stdin(string $prompt) : string{
+	echo $prompt . ": ";
+	$input = fgets(STDIN);
+	if($input === false){
+		exit(1); //this probably means the user pressed ctrl+c
+	}
+	return trim($input);
+}
+
+function ping_server(\Socket $socket, string $serverIp, int $serverPort, int $timeoutSeconds, int $rakNetClientId) : bool{
+	$ping = new UnconnectedPing();
+	$ping->sendPingTime = hrtime_ms();
+	$ping->clientId = $rakNetClientId;
+	$serializer = new PacketSerializer();
+	$ping->encode($serializer);
+	if(@socket_sendto($socket, $serializer->getBuffer(), strlen($serializer->getBuffer()), MSG_DONTROUTE, $serverIp, $serverPort) === false){
+		\GlobalLogger::get()->error("Failed to send ping: " . socket_strerror(socket_last_error($socket)));
+		return false;
+	}
+	\GlobalLogger::get()->info("Ping sent to $serverIp on port $serverPort, waiting for response (press CTRL+C to abort)");
+
+	$r = [$socket];
+	$w = $e = null;
+	if(socket_select($r, $w, $e, $timeoutSeconds) === 1){
+		$response = @socket_recvfrom($socket, $recvBuffer, 65535, 0, $recvAddr, $recvPort);
+		if($response === false){
+			\GlobalLogger::get()->error("Error reading from socket: " . socket_strerror(socket_last_error($socket)));
+			return false;
+		}
+		if($recvAddr === $serverIp and $recvPort === $serverPort and $recvBuffer !== "" and ord($recvBuffer[0]) === MessageIdentifiers::ID_UNCONNECTED_PONG){
+			$pong = new UnconnectedPong();
+			$pong->decode(new PacketSerializer($recvBuffer));
+			\GlobalLogger::get()->info("--- Response received ---");
+			\GlobalLogger::get()->info("Payload: $pong->serverName");
+			\GlobalLogger::get()->info("Response time: " . (hrtime_ms() - $pong->sendPingTime) . " ms");
+			return true;
+		}else{
+			\GlobalLogger::get()->debug("Garbage packet from $recvAddr $recvPort: " . bin2hex($recvBuffer));
+		}
+	}
+
+	\GlobalLogger::get()->info("No ping response after $timeoutSeconds seconds");
+	return false;
+}
+
+if(count($argv) > 3){
+	echo "Usage: " . PHP_BINARY . " " . __FILE__ . " [server IP] [server port]\n";
+	exit(1);
+}
+
+if(count($argv) > 1){
+	$hostName = $argv[1];
+}else{
+	do{
+		$hostName = read_stdin("Server address");
+	}while($hostName === "");
+}
+
+$serverIps = gethostbynamel($hostName);
+if($serverIps === false){
+	\GlobalLogger::get()->critical("Unable to resolve hostname $hostName to an IP address");
+	exit(1);
+}
+if(count($serverIps) > 1){
+	\GlobalLogger::get()->warning("Multiple IP addresses found for hostname $hostName, using the first one: " . $serverIps[0]);
+}
+$server = $serverIps[0];
+\GlobalLogger::get()->info("Resolved hostname to $server");
+
+if(count($argv) > 2){
+	$port = (int) $argv[2];
+}elseif(count($argv) > 1){
+	$port = 19132;
+}else{
+	$portRaw = read_stdin("Server port (empty for 19132)");
+	$port = $portRaw === "" ? 19132 : (int) $portRaw;
+}
+
+$sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
+if($sock === false) throw new AssumptionFailedError();
+
+socket_bind($sock, "0.0.0.0");
+socket_getsockname($sock, $bindAddr, $bindPort);
+\GlobalLogger::get()->info("Bound to $bindAddr on port $bindPort");
+
+$start = time();
+while(time() < $start + 60_000 && !ping_server($sock, $server, $port, 5, mt_rand(0, PHP_INT_MAX))){
+	sleep(1);
+}
+
+socket_close($sock);