Question

我已经实现了Play！应用程序在我的服务器中有两个不同的实例（比如％inst1和％inst2），以避免在使用任何更新进行预编译时的停机时间。我已经配置了nginx以获得负载均衡器。对于每个实例，我都有自己的子目录，并且我已正确配置文件application.conf以获取％inst1和％inst2的不同端口。 nginx的配置文件是这样的：

upstream myapp {
  server localhost:9031;
  server localhost:9032;
}

server {
  server_name www.example.com;

  access_log /var/log/nginx/myapp.access.log;

  location / {
    proxy_pass              http://myapp;
    proxy_set_header        X-Real-IP $remote_addr;
    proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header        Host $http_host;
  }
}

当我在开发模式下尝试此配置时，它可以正常工作。我执行这两个实例，每当我为了更新它而停止其中一个实例时，所有流量都会转到另一个实例而不会出现任何停机。当我再次重新启动应用程序并重新加载nginx时，两个实例都运行良好。

当我为生产模式配置实例时出现问题。我只从：

更改application.conf

%inst1.application.mode=dev
%inst2.application.mode=dev

为：

%inst1.application.mode=prod
%inst2.application.mode=prod

然后我无法让两个实例同时工作两次。每当我启动第二个时，我都会收到502 Bad Gateway错误。然后我检查第一个实例的状态，我得到以下错误：

$ play status --%inst1
~        _            _ 
~  _ __ | | __ _ _  _| |
~ | '_ \| |/ _' | || |_|
~ |  __/|_|\____|\__ (_)
~ |_|            |__/   
~
~ play! 1.2.4, http://www.playframework.org
~ framework ID is inst1
~
~ Cannot contact the application...
~

另外，我不能用这样的错误启动它：

Oops. /usr/share/apps/klingstore1 is already started! (or delete /usr/share/apps/klingstore1/server.pid)

也不要阻止它：

Play was not running (Process id 11657 not found)

我必须手动删除server.pid。然后我再次启动它，它又与另一个实例一起发生。

你有任何线索吗？

谢谢！

解决：

最后，它似乎只是RAM的一个问题。实例使用相同的Play配置正常工作！和Nginx在不同的日子里没有问题。

Answer 1

您应该检查您的logs / system.log文件，看看是否有一些例外情况阻止您的播放应用启动

Answer 2

这更像是你nginx.conf的补充，而不是答案，但我认为这是对这个问题的有用补充。

如果两个实例都在编译，则用户会收到502错误。更好的消息是“APPLICATION_NAME正在更新”。这可以通过设置custon 502错误页面来完成：

<强> nginx.conf：

error_page 502 /502.html;
location /502.html {
    index $uri;
}

<强> 502.html：

<!DOCTYPE html>
<html><head><title>Kleiderliebe wird aktualisiert</title>
<style>body {margin: 0;padding: 0;background-color: #fff;color: #000;
        font-family: Arial,sans-serif;font-size: 14px;}
    #container {text-align: center;margin: 0 auto;padding: 20% 0;}</style>
<meta http-equiv="refresh" content="10"></head>
<body><div id="container">
<img src="data:image/gif;base64,R0lGODlhHwAfAPUAAP///wAAAOjo6NLS0ry8vK6urqKiotzc3Li4uJqamuTk5NjY2KqqqqCgoLCwsMzMzPb29qioqNTU1Obm5jY2NiYmJlBQUMTExHBwcJKSklZWVvr6+mhoaEZGRsbGxvj4+EhISDIyMgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH/C05FVFNDQVBFMi4wAwEAAAAh/hpDcmVhdGVkIHdpdGggYWpheGxvYWQuaW5mbwAh+QQJCgAAACwAAAAAHwAfAAAG/0CAcEgUDAgFA4BiwSQexKh0eEAkrldAZbvlOD5TqYKALWu5XIwnPFwwymY0GsRgAxrwuJwbCi8aAHlYZ3sVdwtRCm8JgVgODwoQAAIXGRpojQwKRGSDCRESYRsGHYZlBFR5AJt2a3kHQlZlERN2QxMRcAiTeaG2QxJ5RnAOv1EOcEdwUMZDD3BIcKzNq3BJcJLUABBwStrNBtjf3GUGBdLfCtadWMzUz6cDxN/IZQMCvdTBcAIAsli0jOHSJeSAqmlhNr0awo7RJ19TJORqdAXVEEVZyjyKtE3Bg3oZE2iK8oeiKkFZGiCaggelSTiA2LhxiZLBSjZjBL2siNBOFQ84LxHA+mYEiRJzBO7ZCQIAIfkECQoAAAAsAAAAAB8AHwAABv9AgHBIFAwIBQPAUCAMBMSodHhAJK5XAPaKOEynCsIWqx0nCIrvcMEwZ90JxkINaMATZXfju9jf82YAIQxRCm14Ww4PChAAEAoPDlsAFRUgHkRiZAkREmoSEXiVlRgfQgeBaXRpo6MOQlZbERN0Qx4drRUcAAJmnrVDBrkVDwNjr8BDGxq5Z2MPyUQZuRgFY6rRABe5FgZjjdm8uRTh2d5b4NkQY0zX5QpjTc/lD2NOx+WSW0++2RJmUGJhmZVsQqgtCE6lqpXGjBchmt50+hQKEAEiht5gUcTIESR9GhlgE9IH0BiTkxrMmWIHDkose9SwcQlHDsOIk9ygiVbl5JgMLuV4HUmypMkTOkEAACH5BAkKAAAALAAAAAAfAB8AAAb/QIBwSBQMCAUDwFAgDATEqHR4QCSuVwD2ijhMpwrCFqsdJwiK73DBMGfdCcZCDWjAE2V347vY3/NmdXNECm14Ww4PChAAEAoPDltlDGlDYmQJERJqEhGHWARUgZVqaWZeAFZbERN0QxOeWwgAAmabrkMSZkZjDrhRkVtHYw+/RA9jSGOkxgpjSWOMxkIQY0rT0wbR2LQV3t4UBcvcF9/eFpdYxdgZ5hUYA73YGxruCbVjt78G7hXFqlhY/fLQwR0HIQdGuUrTz5eQdIc0cfIEwByGD0MKvcGSaFGjR8GyeAPhIUofQGNQSgrB4IsdOCqx7FHDBiYcOQshYjKDxliVDpRjunCjdSTJkiZP6AQBACH5BAkKAAAALAAAAAAfAB8AAAb/QIBwSBQMCAUDwFAgDATEqHR4QCSuVwD2ijhMpwrCFqsdJwiK73DBMGfdCcZCDWjAE2V347vY3/NmdXNECm14Ww4PChAAEAoPDltlDGlDYmQJERJqEhGHWARUgZVqaWZeAFZbERN0QxOeWwgAAmabrkMSZkZjDrhRkVtHYw+/RA9jSGOkxgpjSWOMxkIQY0rT0wbR2I3WBcvczltNxNzIW0693MFYT7bTumNQqlisv7BjswAHo64egFdQAbj0RtOXDQY6VAAUakihN1gSLaJ1IYOGChgXXqEUpQ9ASRlDYhT0xQ4cACJDhqDD5mRKjCAYuArjBmVKDP9+VRljMyMHDwcfuBlBooSCBQwJiqkJAgAh+QQJCgAAACwAAAAAHwAfAAAG/0CAcEgUDAgFA8BQIAwExKh0eEAkrlcA9oo4TKcKwharHScIiu9wwTBn3QnGQg1owBNld+O72N/zZnVzRApteFsODwoQABAKDw5bZQxpQ2JkCRESahIRh1gEVIGVamlmXgBWWxETdEMTnlsIAAJmm65DEmZGYw64UZFbR2MPv0QPY0hjpMYKY0ljjMZCEGNK09MG0diN1gXL3M5bTcTcyFtOvdzBWE+207pjUKpYrL+wY7MAB4EerqZjUAG4lKVCBwMbvnT6dCXUkEIFK0jUkOECFEeQJF2hFKUPAIkgQwIaI+hLiJAoR27Zo4YBCJQgVW4cpMYDBpgVZKL59cEBhw+U+QROQ4bBAoUlTZ7QCQIAIfkECQoAAAAsAAAAAB8AHwAABv9AgHBIFAwIBQPAUCAMBMSodHhAJK5XAPaKOEynCsIWqx0nCIrvcMEwZ90JxkINaMATZXfju9jf82Z1c0QKbXhbDg8KEAAQCg8OW2UMaUNiZAkREmoSEYdYBFSBlWppZl4AVlsRE3RDE55bCAACZpuuQxJmRmMOuFGRW0djD79ED2NIY6TGCmNJY4zGQhBjStPTFBXb21DY1VsGFtzbF9gAzlsFGOQVGefIW2LtGhvYwVgDD+0V17+6Y6BwaNfBwy9YY2YBcMAPnStTY1B9YMdNiyZOngCFGuIBxDZAiRY1eoTvE6UoDEIAGrNSUoNBUuzAaYlljxo2M+HIeXiJpRsRNMaq+JSFCpsRJEqYOPH2JQgAIfkECQoAAAAsAAAAAB8AHwAABv9AgHBIFAwIBQPAUCAMBMSodHhAJK5XAPaKOEynCsIWqx0nCIrvcMEwZ90JxkINaMATZXfjywjlzX9jdXNEHiAVFX8ODwoQABAKDw5bZQxpQh8YiIhaERJqEhF4WwRDDpubAJdqaWZeAByoFR0edEMTolsIAA+yFUq2QxJmAgmyGhvBRJNbA5qoGcpED2MEFrIX0kMKYwUUslDaj2PA4soGY47iEOQFY6vS3FtNYw/m1KQDYw7mzFhPZj5JGzYGipUtESYowzVmF4ADgOCBCZTgFQAxZBJ4AiXqT6ltbUZhWdToUSR/Ii1FWbDnDkUyDQhJsQPn5ZU9atjUhCPHVhgTNy/RSKsiqKFFbUaQKGHiJNyXIAAh+QQJCgAAACwAAAAAHwAfAAAG/0CAcEh8JDAWCsBQIAwExKhU+HFwKlgsIMHlIg7TqQeTLW+7XYIiPGSAymY0mrFgA0LwuLzbCC/6eVlnewkADXVECgxcAGUaGRdQEAoPDmhnDGtDBJcVHQYbYRIRhWgEQwd7AB52AGt7YAAIchETrUITpGgIAAJ7ErdDEnsCA3IOwUSWaAOcaA/JQ0amBXKa0QpyBQZyENFCEHIG39HcaN7f4WhM1uTZaE1y0N/TacZoyN/LXU+/0cNyoMxCUytYLjm8AKSS46rVKzmxADhjlCACMFGkBiU4NUQRxS4OHijwNqnSJS6ZovzRyJAQo0NhGrgs5bIPmwWLCLHsQsfhxBWTe9QkOzCwC8sv5Ho127akyRM7QQAAOwAAAAAAAAAAAA==" border="0">
<br/>YOUR_APPLICATION is being updated.<br/><br/>
<small>If this page does not refresh automatically, <a href="/">please click here</a>.
</small></div></body></html>

（long data-URI是一个动画微调器）

玩！ 1.2.4 + Nginx负载均衡器 - 无法在PROD模式下使两个实例一起工作

2 个答案: