Issue recv() failed (104: Connection reset by peer) while reading response header from upstream

[doubledeckcafe]

Hi we are getting this error a couple of times since we moved our client's website to a new server.

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Source:
nginx error

Message:
11335#0: *5300222 recv() failed (104: Connection reset by peer) while reading response header from upstream ngi
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I would like to know what is exactly happening and what we can do to prevent this error.

For your information the PHP settings are:
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PHP version : 5.6.30 run PHP as FPM application served by nginx
memory limit 128M
max_execution_time 60 (It was 30 this morning but since this error we have changed to 60)
max_input_time : 60
pos_max_size : 8M
upload_max_filesize 2M
opcache.enable on
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Thanks in advance

 

[Bitpalast]

Please check the Apache error_log file at the same time when the error is recorded in the nginx log file. There should be a PHP error logged. The most likely problem is that a PHP script does not produce any output, so that the connection to the backend times out. The second likely reason is that 127.0.0.1 and the public IPv4 address were not whitelisted in the Plesk Fail2Ban configuration, so that randomly an IP block for localhost or the server's own IPv4 is triggered.