I am getting to many notifications from pingdom about Site Down. Down from multiple locations,Reason: Read time out or Connection Timeout. So everyday we are getting website down for 5/6 time or more. Its not false positive from pingdom. On checking, I got following error in the log file.
I was monitoring the server logs and I could see the same error is logged in the log file when the post scripts are executed. Below are the main reasons for the 400 Bad request error.
we are getting notifications from Pingdom too, however, the VPS is online the whole site so it's either related to Apache.
[Mon Apr 03 03:37:17.242252 2017] [php7:error] [pid 13527] [client 184.108.40.206:10542] Error while attempting to read POST data: 400, referer: https://www.mysite.com/ [Mon Apr 03 03:39:18.630654 2017] [http2:error] [pid 13529] (103)Software caused connection abort: [client 220.127.116.11:10545] AH02938: h2_stream(6-13): reading data [Mon Apr 03 03:52:15.069675 2017] [php7:error] [pid 15451] [client 18.104.22.168:45244] Error while attempting to read POST data: 400, referer: https://www.mysite.com/forums/breada.112/ [Mon Apr 03 03:52:28.103030 2017] [php7:error] [pid 15031] [client 22.214.171.124:8746] Error while attempting to read POST data: 400, referer: https://www.mysite.com/forums/self-written.114/
The 400 status code, or Bad Request error, means the HTTP request that was sent to the server has invalid syntax. Here are a few examples of when a 400 Bad Request error might occur: The user's cookie that is associated with the site is corrupt. Clearing the browser's cache and cookies could solve this issue Malformed request due to a faulty browser Malformed request due to human error when manually forming HTTP requests (e.g. using curl incorrectly)