{"id":5389,"date":"2017-03-04T15:01:06","date_gmt":"2017-03-04T20:01:06","guid":{"rendered":"https:\/\/www.tecklyfe.com\/?p=5389"},"modified":"2017-03-04T15:01:06","modified_gmt":"2017-03-04T20:01:06","slug":"adjusting-child-processes-php-fpm-nginx-fix-server-reached-pm-max_children-setting","status":"publish","type":"post","link":"https:\/\/www.tecklyfe.com\/adjusting-child-processes-php-fpm-nginx-fix-server-reached-pm-max_children-setting\/","title":{"rendered":"Adjusting Child Processes For PHP-FPM Nginx &#8211; Fix Server Reached pm.max_children Setting"},"content":{"rendered":"<p><img decoding=\"async\" src=\"data:image\/gif,GIF89a%01%00%01%00%80%00%00%00%00%00%FF%FF%FF%21%F9%04%01%00%00%00%00%2C%00%00%00%00%01%00%01%00%00%02%01D%00%3B\" data-layzr=\"https:\/\/www.tecklyfe.com\/wp-content\/uploads\/2017\/03\/php-nginx.jpg\" alt=\"\" width=\"350\" height=\"200\" class=\"alignright size-full wp-image-5390\" title=\"\">As an addition to my previous <a href=\"https:\/\/www.tecklyfe.com\/tag\/nginx\/\" target=\"_blank\">NGINX articles<\/a>, today we&#8217;ll discuss how to adjust the number of child processes for PHP-FPM to fix the common error of &#8220;server reached pm.max_children&#8221; in the logs.  This is a follow-up to the <a href=\"https:\/\/www.tecklyfe.com\/lemp-install-nginx-php7-mysql-ubuntu-16-04-server\/\" target=\"_blank\">LEMP Install NGINX PHP7 MySQL on Ubuntu 16.04 Server<\/a> or <a href=\"https:\/\/www.tecklyfe.com\/lemp-install-nginx-php7-mysql-centos-7-rhel-fedora\/\" target=\"_blank\">LEMP Install NGINX PHP7 MySQL on CentOS 7 \/ RHEL \/ Fedora<\/a> articles.  By default, the pm.max_children is set to 5 when using PHP-FPM.<\/p>\n<h2>Reasons Why You Reach max_children<\/h2>\n<p>The most common reasons why your PHP-FPM would reach the max_children are:<\/p>\n<ul>\n<li>A lot of concurrent site visitors<\/li>\n<li>Slow execution of the PHP scripts due to server resources or buggy scripts<\/li>\n<li>Very low setting of max_children setting in php-fpm config<\/li>\n<\/ul>\n<p>Depending on where your PHP-FPM logs are stored, try running one of the following commands:<\/p>\n<blockquote><p><code>tail -f \/var\/log\/php-fpm\/error.log<br \/>\ntail -f \/var\/log\/php7.0-fpm.log<\/code><\/p><\/blockquote>\n<p>If you see any lines like the one below, then you&#8217;ll want to adjust some of these settings:<\/p>\n<blockquote><p><code>server reached max_children setting (5), consider raising<\/code><\/p><\/blockquote>\n<h2>Adjusting The max_children Setting<\/h2>\n<p>To adjust the settings, you&#8217;ll need to find your <strong>php-fpm.conf<\/strong> or <strong>www.conf<\/strong> depending on what version of PHP-FPM you have installed.  In my case, I had to edit <strong>\/etc\/php\/7.0\/fpm\/pool.d\/www.conf<\/strong>.  You&#8217;ll want to look for the following settings and make adjustments based on your server specs:<\/p>\n<blockquote><p><code>[php-fpm-pool-settings]<br \/>\npm = dynamic<br \/>\npm.max_children = 25<br \/>\npm.start_servers = 10<br \/>\npm.min_spare_servers = 5<br \/>\npm.max_spare_servers = 20<br \/>\npm.max_requests = 500<\/code><\/p><\/blockquote>\n<p>A few of these settings are the default, like pm=dymanic.  For the pm.max_requests, the setting should be there but commented out with a ; in front of the line.  Delete the ; to uncomment the setting.<\/p>\n<p>To get an idea of what to use for the pm.max_children, you can use this calculation:  <code>pm.max_children = Total RAM dedicated to the web server \/ Max child process size<\/code>.  Remember to leave some RAM for extra services you have running on your system.<\/p>\n<p>Also remember, higher isn&#8217;t always better.  If you have a bad PHP script, these settings won&#8217;t resolve your issues.  Tweak these settings and see what works best on your server.  After you make the changes, you need to restart your PHP-FPM service.  Depending on the name of your service, you can try on of the following:<\/p>\n<blockquote><p><code>sudo systemctl restart php-fpm<br \/>\nsudo systemctl restart php7.0-fpm<\/code><\/p><\/blockquote>\n<h2>Final Thoughts<\/h2>\n<p>Have you run into these errors in your logs?  If so, what are your server specs and what settings worked best for you?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>As an addition to my previous NGINX articles, today we&#8217;ll discuss how to adjust the number of child processes for PHP-FPM to fix the common error of &#8220;server reached pm.max_children&#8221; in the logs. This is a follow-up to the LEMP Install NGINX PHP7 MySQL on Ubuntu 16.04 Server or LEMP Install NGINX PHP7 MySQL on CentOS 7 \/ RHEL \/ Fedora articles. By default, the pm.max_children is set to 5 when using PHP-FPM. Reasons Why You Reach max_children The most common reasons why your PHP-FPM would reach the max_children are: A lot of concurrent site visitors Slow execution of the <\/p>\n","protected":false},"author":1,"featured_media":5390,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1339,1078],"tags":[375,1079,1516,1814,1521,1815,1819,1818,1817,1816],"_links":{"self":[{"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/posts\/5389"}],"collection":[{"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/comments?post=5389"}],"version-history":[{"count":0,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/posts\/5389\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/media\/5390"}],"wp:attachment":[{"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/media?parent=5389"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/categories?post=5389"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tecklyfe.com\/wp-json\/wp\/v2\/tags?post=5389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}