Wordpress Wordpress keep crashing randomly- few times in an hour

My WordPress keep crashing randomly today. It never happens before.

Now I keep getting this error - "404 not found", few times in an hour.
https://prnt.sc/mm9yhq

---

How do i troubleshoot this issue and find out the root cause?

 

Hi eva,

/usr/local/nginx/conf/conf.d/newdomain.com.ssl.conf

Code:

#x# HTTPS-DEFAULT
 server {
  
   server_name techrakyat.com www.techrakyat.com;
   return 302 https://techrakyat.com$request_uri;
   include /usr/local/nginx/conf/staticfiles.conf;
 }

server {
  listen 443 ssl http2 reuseport;
  server_name techrakyat.com www.techrakyat.com;

  include /usr/local/nginx/conf/ssl/techrakyat.com/techrakyat.com.crt.key.conf;
  include /usr/local/nginx/conf/ssl_include.conf;

  # cloudflare authenticated origin pull cert community.centminmod.com/threads/13847/
  #ssl_client_certificate /usr/local/nginx/conf/ssl/cloudflare/techrakyat.com/origin.crt;
  #ssl_verify_client on;
  http2_max_field_size 16k;
  http2_max_header_size 32k;
  # mozilla recommended
  ssl_ciphers TLS13-AES-128-GCM-SHA256:TLS13-AES-256-GCM-SHA384:TLS13-CHACHA20-POLY1305-SHA256:TLS13-AES-128-CCM-8-SHA256:TLS13-AES-128-CCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS;
  ssl_prefer_server_ciphers   on;
  #add_header Alternate-Protocol  443:npn-spdy/3;

  # before enabling HSTS line below read centminmod.com/nginx_domain_dns_setup.html#hsts
  #add_header Strict-Transport-Security "max-age=31536000; includeSubdomains;";
  #add_header X-Frame-Options SAMEORIGIN;
  add_header X-Xss-Protection "1; mode=block" always;
  add_header X-Content-Type-Options "nosniff" always;
  #add_header Referrer-Policy "strict-origin-when-cross-origin";
  #spdy_headers_comp 5;
  ssl_buffer_size 1369;
  ssl_session_tickets on;
 
  # enable ocsp stapling
  resolver 8.8.8.8 8.8.4.4 valid=10m;
  resolver_timeout 10s;
  ssl_stapling on;
  ssl_stapling_verify on;

# ngx_pagespeed & ngx_pagespeed handler
#include /usr/local/nginx/conf/pagespeed.conf;
#include /usr/local/nginx/conf/pagespeedhandler.conf;
#include /usr/local/nginx/conf/pagespeedstatslog.conf;

  # limit_conn limit_per_ip 16;
  # ssi  on;

  access_log /home/nginx/domains/techrakyat.com/log/access.log combined buffer=256k flush=5m;
  error_log /home/nginx/domains/techrakyat.com/log/error.log;

  include /usr/local/nginx/conf/autoprotect/techrakyat.com/autoprotect-techrakyat.com.conf;
  root /home/nginx/domains/techrakyat.com/public;
  # uncomment cloudflare.conf include if using cloudflare for
  # server and/or vhost site
  #include /usr/local/nginx/conf/cloudflare.conf;
  include /usr/local/nginx/conf/503include-main.conf;

  #include /usr/local/nginx/conf/wpincludes/techrakyat.com/wpcacheenabler_techrakyat.com.conf;
  #include /usr/local/nginx/conf/wpincludes/techrakyat.com/wpsupercache_techrakyat.com.conf;
  # https://community.centminmod.com/posts/18828/
  include /usr/local/nginx/conf/wpincludes/techrakyat.com/rediscache_techrakyat.com.conf; 

  location / {
  include /usr/local/nginx/conf/503include-only.conf;
 

  # Enables directory listings when index file not found
  #autoindex  on;

  # for wordpress super cache plugin
  #try_files /wp-content/cache/supercache/$http_host/$cache_uri/index.html $uri $uri/ /index.php?q=$uri&$args;

  # for wp cache enabler plugin
  #try_files $cache_enabler_uri $uri $uri/ $custom_subdir/index.php?$args; 

  # Wordpress Permalinks
  #try_files $uri $uri/ /index.php?q=$uri&$args;

  # Nginx level redis Wordpress
  # https://community.centminmod.com/posts/18828/
  try_files $uri $uri/ /index.php?$args;

  }

location ~* /(wp-login\.php) {
    limit_req zone=xwplogin burst=1 nodelay;
    #limit_conn xwpconlimit 30;
    #auth_basic "Private";
    #auth_basic_user_file /home/nginx/domains/techrakyat.com/htpasswd_wplogin;   
    #include /usr/local/nginx/conf/php-wpsc.conf;
    
    # https://community.centminmod.com/posts/18828/
    include /usr/local/nginx/conf/php-rediscache.conf;
}

location ~* /(xmlrpc\.php) {
    limit_req zone=xwprpc burst=45 nodelay;
    #limit_conn xwpconlimit 30;
    #include /usr/local/nginx/conf/php-wpsc.conf;
    
    # https://community.centminmod.com/posts/18828/
    include /usr/local/nginx/conf/php-rediscache.conf;
}

location ~* /wp-admin/(load-scripts\.php) {
    limit_req zone=xwprpc burst=5 nodelay;
    #limit_conn xwpconlimit 30;
    #include /usr/local/nginx/conf/php-wpsc.conf;
    
    # https://community.centminmod.com/posts/18828/
    include /usr/local/nginx/conf/php-rediscache.conf;
}

location ~* /wp-admin/(load-styles\.php) {
    limit_req zone=xwprpc burst=5 nodelay;
    #limit_conn xwpconlimit 30;
    #include /usr/local/nginx/conf/php-wpsc.conf;
    
    # https://community.centminmod.com/posts/18828/
    include /usr/local/nginx/conf/php-rediscache.conf;
}

  include /usr/local/nginx/conf/wpincludes/techrakyat.com/wpsecure_techrakyat.com.conf;
  #include /usr/local/nginx/conf/php-wpsc.conf;
 
  # https://community.centminmod.com/posts/18828/
  include /usr/local/nginx/conf/php-rediscache.conf;
  include /usr/local/nginx/conf/pre-staticfiles-local-techrakyat.com.conf;
  include /usr/local/nginx/conf/pre-staticfiles-global.conf;
  include /usr/local/nginx/conf/staticfiles.conf;
  include /usr/local/nginx/conf/drop.conf;
  #include /usr/local/nginx/conf/errorpage.conf;
  include /usr/local/nginx/conf/vts_server.conf;
}

curl output as below

Code:

Date: Mon, 18 Feb 2019 04:40:05 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive
Set-Cookie: __cfduid=d9dcd64efe5422beb024925eafe4944c31550464804; expires=Tue, 18-Feb-20 04:40:04 GMT; path=/; domain=.techrakyat.com; HttpOnly
Vary: Accept-Encoding
Set-Cookie: PHPSESSID=t650r4au6aoblf5kj0hs75hgbl; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate
Pragma: no-cache
X-Pingback: https://techrakyat.com/xmlrpc.php
Link: <https://techrakyat.com/wp-json/>; rel="https://api.w.org/"
Link: <https://techrakyat.com/>; rel=shortlink
X-Powered-By: centminmod
X-Cache: MISS
X-Cache-2: BYPASS
X-Xss-Protection: 1; mode=block
X-Content-Type-Options: nosniff
Expect-CT: max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
Server: cloudflare
CF-RAY: 4aadd0469f6099c1-LAX

When site shows 404, I can still ping my server which hosted on upcloud.com. But I cannot log in using putty. so, the curl output is what i get when the site is still functioning. The downtime usually very short and only last few minutes, but it happens randomly

 

Here is the email notification i got from uptime robot. See if it gives you any clues on what causes the crash?

It's been working well all the while, yesterday it suddenly starts malfunctioning after some server downtime on upcloud -singapore server.

https://prnt.sc/mmi0rh