{"id":2710,"date":"2025-09-07T12:23:09","date_gmt":"2025-09-07T08:53:09","guid":{"rendered":"https:\/\/spadserver.com\/blog\/?p=2710"},"modified":"2025-09-07T12:23:09","modified_gmt":"2025-09-07T08:53:09","slug":"%d8%ae%d8%b7%d8%a7%db%8c-503-backend-fetch-failed-%d8%af%d8%b1-nginx-apache-%d8%a8%d8%a7-varnish","status":"publish","type":"post","link":"https:\/\/spadserver.com\/blog\/%d8%ae%d8%b7%d8%a7%db%8c-503-backend-fetch-failed-%d8%af%d8%b1-nginx-apache-%d8%a8%d8%a7-varnish\/","title":{"rendered":"\u06f5\u06f0\u06f3 Backend Fetch Failed \u062f\u0631 Nginx\/Apache \u0628\u0627 Varnish"},"content":{"rendered":"

\u062e\u0637\u0627\u06cc \u06f5\u06f0\u06f3 Backend Fetch Failed \u06cc\u06a9\u06cc \u0627\u0632 \u0631\u0627\u06cc\u062c \u062a\u0631\u06cc\u0646 \u0627\u0631\u0648\u0631\u0647\u0627 \u0627\u0633\u062a. \u0628\u0647 \u062e\u0635\u0648\u0635 \u06a9\u0647 \u0647\u0646\u06af\u0627\u0645\u06cc \u06a9\u0647 Varnish Cache \u062f\u0631 \u06a9\u0646\u0627\u0631 \u0648\u0628 \u0633\u0631\u0648\u0631\u0647\u0627\u06cc\u06cc \u0645\u0627\u0646\u0646\u062f Nginx \u06cc\u0627 Apache \u0645\u06cc \u0628\u06cc\u0646\u06cc\u062f. \u0627\u06cc\u0646 \u062e\u0637\u0627 \u0645\u0639\u0645\u0648\u0644\u0627 \u0648\u0642\u062a\u06cc \u06a9\u0647 Varnish \u0642\u0627\u062f\u0631 \u0628\u0647 \u062f\u0631\u06cc\u0627\u0641\u062a \u067e\u0627\u0633\u062e\u06cc \u0645\u0639\u062a\u0628\u0631 \u0627\u0632 \u0633\u0631\u0648\u0631 \u0628\u06a9 \u0627\u0646\u062f (Backend Server) \u0646\u0628\u0627\u0634\u062f. \u062f\u0631 \u0627\u06cc\u0646 \u0645\u0642\u0627\u0644\u0647 \u0627\u0633\u067e\u0627\u062f \u0633\u0631\u0648\u0631<\/a><\/strong><\/span> \u0628\u0647 \u0637\u0648\u0631 \u06a9\u0627\u0645\u0644 \u0639\u0644\u062a \u0628\u0631\u0648\u0632 \u0627\u06cc\u0646 \u062e\u0637\u0627\u060c \u0631\u0648\u0634 \u0647\u0627\u06cc \u0634\u0646\u0627\u0633\u0627\u06cc\u06cc\u060c \u0648 \u0631\u0627\u0647\u06a9\u0627\u0631\u0647\u0627\u06cc \u0631\u0641\u0639 \u0622\u0646 \u0631\u0627 \u0628\u0631\u0631\u0633\u06cc \u0645\u06cc \u06a9\u0646\u06cc\u0645. \u0647\u0645\u0686\u0646\u06cc\u0646 \u0646\u062d\u0648\u0647 \u067e\u06cc\u06a9\u0631\u0628\u0646\u062f\u06cc \u0635\u062d\u06cc\u062d cache<\/strong> \u0648 \u062a\u0646\u0638\u06cc\u0645\u0627\u062a backend connection<\/strong> \u0631\u0627 \u06af\u0627\u0645 \u0628\u0647 \u06af\u0627\u0645 \u062a\u0648\u0636\u06cc\u062d \u062e\u0648\u0627\u0647\u06cc\u0645 \u062f\u0627\u062f.<\/p>\n

\u062e\u0637\u0627\u06cc \u06f5\u06f0\u06f3<\/strong> Backend Fetch Failed \u0686\u06cc\u0633\u062a\u061f<\/strong><\/h2>\n

\u0627\u06cc\u0646 \u06cc\u0639\u0646\u06cc \u0627\u06cc\u0646 \u06a9\u0647 Varnish \u062a\u0644\u0627\u0634 \u06a9\u0631\u062f\u0647. \u0648 \u0645\u062d\u062a\u0648\u0627\u06cc\u06cc \u0631\u0627 \u0627\u0632 \u0633\u0631\u0648\u0631<\/a> \u0627\u0635\u0644\u06cc (Backend) \u062f\u0631\u06cc\u0627\u0641\u062a \u06a9\u0646\u062f. \u0627\u0645\u0627 \u0628\u0647 \u062f\u0644\u06cc\u0644 \u0645\u0634\u06a9\u0644\u0627\u062a \u0645\u062e\u062a\u0644\u0641 \u0645\u0648\u0641\u0642 \u0628\u0647 \u0627\u06cc\u0646 \u06a9\u0627\u0631 \u0646\u0634\u062f\u0647. \u062f\u0631 \u0646\u062a\u06cc\u062c\u0647\u060c Varnish \u06cc\u06a9 \u067e\u0627\u0633\u062e \u06f5\u06f0\u06f3 Service Unavailable<\/strong> \u0628\u0647 \u06a9\u0627\u0631\u0628\u0631 \u0628\u0631\u0645\u06cc \u06af\u0631\u062f\u0627\u0646\u062f.<\/p>\n

\u0646\u0645\u0648\u0646\u0647 \u067e\u06cc\u0627\u0645 \u062e\u0637\u0627<\/strong>:<\/strong><\/p>\n

Error 503 Backend Fetch Failed<\/p>\n

Backend Fetch Failed<\/p>\n

Guru Meditation:<\/p>\n

XID: 123456<\/p>\n

\u062f\u0644\u0627\u06cc\u0644 \u0627\u0635\u0644\u06cc \u0628\u0631\u0648\u0632 \u062e\u0637\u0627\u06cc \u06f5\u06f0\u06f3 \u062f\u0631<\/strong> Varnish<\/h2>\n

\u0628\u0631\u0627\u06cc \u0631\u0641\u0639 \u0645\u0634\u06a9\u0644 \u0628\u0627\u06cc\u062f \u0627\u0628\u062a\u062f\u0627 \u062f\u0644\u06cc\u0644 \u0628\u0631\u0648\u0632 \u0622\u0646 \u0631\u0627 \u0634\u0646\u0627\u0633\u0627\u06cc\u06cc \u06a9\u0646\u06cc\u0645. \u0645\u0647\u0645 \u062a\u0631\u06cc\u0646 \u0639\u0644\u0644 \u0639\u0628\u0627\u0631\u062a\u0646\u062f \u0627\u0632:<\/p>\n

    \n
  1. Timeout <\/strong>\u062f\u0631 \u0627\u0631\u062a\u0628\u0627\u0637 \u0628\u0627 \u0628\u06a9 \u0627\u0646\u062f<\/strong>
    \n\u0648\u0642\u062a\u06cc \u067e\u0627\u0633\u062e \u062f\u0647\u06cc     \u0633\u0631\u0648\u0631<\/a> \u0628\u06a9 \u0627\u0646\u062f \u0628\u06cc\u0634\u062a\u0631 \u0627\u0632 \u0645\u0642\u062f\u0627\u0631 \u062a\u0639\u0631\u06cc\u0641 \u0634\u062f\u0647 \u062f\u0631 Varnish<\/a> \u0637\u0648\u0644 \u0628\u06a9\u0634\u062f. \u0648 \u062f\u0631\u062e\u0648\u0627\u0633\u062a \u0634\u06a9\u0633\u062a \u0645\u06cc \u062e\u0648\u0631\u062f.<\/li>\n
  2. \u067e\u06cc\u06a9\u0631\u0628\u0646\u062f\u06cc \u0646\u0627\u062f\u0631\u0633\u062a \u0622\u062f\u0631\u0633 \u0628\u06a9 \u0627\u0646\u062f \u062f\u0631<\/strong> Varnish<\/strong>
    \n\u0627\u0633\u062a\u0641\u0627\u062f\u0647 \u0627\u0632 IP \u06cc\u0627 \u0646\u0627\u0645 \u062f\u0627\u0645\u0646\u0647 \u0627\u0634\u062a\u0628\u0627\u0647 \u062f\u0631 backend \u0628\u0627\u0639\u062b \u0627\u06cc\u062c\u0627\u062f \u0627\u06cc\u0646 \u062e\u0637\u0627 \u0645\u06cc \u0634\u0648\u062f.<\/li>\n
  3. \u0645\u0634\u06a9\u0644\u0627\u062a \u0645\u0646\u0627\u0628\u0639 \u0633\u0631\u0648\u0631 \u0628\u06a9 \u0627\u0646\u062f<\/strong>
    \n\u0627\u06af\u0631 CPU \u06cc\u0627 RAM \u0633\u0631\u0648\u0631 \u0628\u06a9 \u0627\u0646\u062f \u067e\u0631 \u0634\u062f\u0647 \u0628\u0627\u0634\u062f\u060c \u0645\u0645\u06a9\u0646 \u0627\u0633\u062a \u0646\u062a\u0648\u0627\u0646\u062f \u0628\u0647 \u062f\u0631\u062e\u0648\u0627\u0633\u062a \u0647\u0627\u06cc Varnish \u067e\u0627\u0633\u062e \u062f\u0647\u062f.<\/li>\n
  4. \u0641\u06cc\u0644\u062a\u0631 \u0634\u062f\u0646 \u062a\u0631\u0627\u0641\u06cc\u06a9 \u062a\u0648\u0633\u0637 \u0641\u0627\u06cc\u0631\u0648\u0627\u0644 \u06cc\u0627 \u062a\u0646\u0638\u06cc\u0645\u0627\u062a \u0627\u0645\u0646\u06cc\u062a\u06cc<\/strong>
    \n\u0628\u0631\u062e\u06cc \u0641\u0627\u06cc\u0631\u0648\u0627\u0644 \u0647\u0627 \u06cc\u0627 \u0645\u0627\u0698\u0648\u0644 \u0647\u0627\u06cc \u0627\u0645\u0646\u06cc\u062a\u06cc \u0645\u0627\u0646\u0646\u062f mod_security<\/strong> \u0645\u0645\u06a9\u0646 \u0627\u0633\u062a \u062a\u0631\u0627\u0641\u06cc\u06a9 Varnish \u0631\u0627 \u0628\u0644\u0627\u06a9 \u06a9\u0646\u0646\u062f.<\/li>\n
  5. \u0628\u0633\u062a\u0647 \u0628\u0648\u062f\u0646 \u067e\u0648\u0631\u062a \u0627\u0631\u062a\u0628\u0627\u0637\u06cc \u0628\u06a9 \u0627\u0646\u062f<\/strong>
    \n\u0627\u06af\u0631 \u067e\u0648\u0631\u062a \u062a\u0639\u0631\u06cc\u0641 \u0634\u062f\u0647 \u062f\u0631 Varnish \u0628\u0631\u0627\u06cc \u062f\u0633\u062a\u0631\u0633\u06cc \u0628\u0647 \u0628\u06a9 \u0627\u0646\u062f \u0628\u0627\u0632 \u0646\u0628\u0627\u0634\u062f\u060c \u0627\u0631\u062a\u0628\u0627\u0637 \u0642\u0637\u0639 \u0645\u06cc \u0634\u0648\u062f.<\/li>\n<\/ol>\n

    \u0627\u06af\u0631 \u0646\u06cc\u0627\u0632 \u0628\u0647 \u0631\u0627\u0647\u0646\u0645\u0627\u06cc\u06cc \u0628\u0631\u0627\u06cc \u062e\u0631\u06cc\u062f \u0647\u0627\u0633\u062a \u0627\u0642\u062a\u0635\u0627\u062f\u06cc \u0648 \u062f\u0627\u0645\u0646\u0647 \u0648 \u0633\u0631\u0648\u0631 \u0645\u062c\u0627\u0632\u06cc \u062f\u0627\u0631\u06cc\u062f\u060c \u0645\u062a\u062e\u0635\u0635\u0627\u0646 \u0628\u0627 \u062a\u062c\u0631\u0628\u0647 \u0627\u0633\u067e\u0627\u062f \u0633\u0631\u0648\u0631 \u0622\u0645\u0627\u062f\u0647 \u062e\u062f\u0645\u062a \u0628\u0647 \u0634\u0645\u0627 \u0647\u0633\u062a\u0646\u062f. \u0628\u0631\u0627\u06cc \u062a\u0645\u0627\u0633 \u0628\u0627 \u0645\u0627\u060c \u0631\u0648\u06cc \u201c\u062a\u0645\u0627\u0633 \u0628\u0627 \u0627\u0633\u067e\u0627\u062f \u0633\u0631\u0648\u0631<\/a><\/span>\u201d \u06a9\u0644\u06cc\u06a9 \u06a9\u0646\u06cc\u062f.<\/strong><\/span><\/p>\n

    \"503<\/a>

    \u06f5\u06f0\u06f3 Backend Fetch Failed<\/p><\/div>\n

    \u0628\u0631\u0631\u0633\u06cc \u0648 \u0631\u0641\u0639 \u0645\u0634\u06a9\u0644 \u0645\u0631\u062d\u0644\u0647 \u0628\u0647 \u0645\u0631\u062d\u0644\u0647<\/strong><\/h2>\n

    \u062f\u0631 \u0627\u062f\u0627\u0645\u0647 \u0628\u0647 \u0628\u0631\u0631\u0633\u06cc \u0645\u0631\u062d\u0644\u0647 \u0628\u0647 \u0645\u0631\u062d\u0644\u0647 \u0631\u0641\u0639 \u062e\u0637\u0627\u06cc \u06f5\u06f0\u06f3 Backend Fetch Failed \u062f\u0631 Nginx\/Apache \u0628\u0627 Varnish \u0645\u06cc \u067e\u0631\u062f\u0627\u0632\u06cc\u0645.<\/p>\n

    \u06f1. \u0628\u0631\u0631\u0633\u06cc \u0644\u0627\u06af \u0647\u0627 \u0628\u0631\u0627\u06cc \u0631\u0641\u0639 \u062e\u0637\u0627\u06cc \u06f5\u06f0\u06f3 Backend Fetch Failed<\/strong><\/h3>\n

    \u0627\u0648\u0644\u06cc\u0646 \u0642\u062f\u0645 \u0628\u0631\u0627\u06cc \u0631\u0641\u0639 \u0627\u06cc\u0646 \u062e\u0637\u0627\u060c \u0628\u0631\u0631\u0633\u06cc \u0644\u0627\u06af \u0647\u0627\u06cc Varnish \u0648 \u0648\u0628 \u0633\u0631\u0648\u0631 \u0627\u0633\u062a.<\/p>\n

    # \u0645\u0634\u0627\u0647\u062f\u0647 \u0644\u0627\u06af \u0647\u0627\u06cc Varnish<\/p>\n

    varnishlog<\/p>\n

    # \u0645\u0634\u0627\u0647\u062f\u0647 \u0644\u0627\u06af \u0647\u0627\u06cc Nginx<\/p>\n

    tail -f \/var\/log\/nginx\/error.log<\/p>\n

     <\/p>\n

    # \u0645\u0634\u0627\u0647\u062f\u0647 \u0644\u0627\u06af \u0647\u0627\u06cc Apache<\/p>\n

    tail -f \/var\/log\/apache2\/error.log<\/p>\n

    \u0628\u0627 \u0628\u0631\u0631\u0633\u06cc \u0627\u06cc\u0646 \u0644\u0627\u06af \u0647\u0627 \u0645\u06cc \u062a\u0648\u0627\u0646\u06cc\u062f \u0645\u062a\u0648\u062c\u0647 \u0634\u0648\u06cc\u062f \u06a9\u0647 \u062e\u0637\u0627 \u062f\u0631 \u06a9\u062f\u0627\u0645 \u0628\u062e\u0634 \u0631\u062e \u062f\u0627\u062f\u0647 \u0627\u0633\u062a.<\/p>\n

    \u06f2. \u0628\u0631\u0631\u0633\u06cc \u067e\u06cc\u06a9\u0631\u0628\u0646\u062f\u06cc<\/strong> Backend \u062f\u0631<\/strong> Varnish<\/h3>\n

    \u062f\u0631 \u0641\u0627\u06cc\u0644 \u067e\u06cc\u06a9\u0631\u0628\u0646\u062f\u06cc Varnish (\u0645\u0639\u0645\u0648\u0644\u0627 \/etc\/varnish\/default.vcl) \u0628\u062e\u0634 backend \u0631\u0627 \u0686\u06a9 \u06a9\u0646\u06cc\u062f:<\/p>\n

    backend default {<\/p>\n

    .host = “127.0.0.1”;<\/p>\n

    .port = “8080”;<\/p>\n

    .first_byte_timeout = 300s;<\/p>\n

    .connect_timeout = 60s;<\/p>\n

    .between_bytes_timeout = 60s;<\/p>\n

    }<\/p>\n