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Support Portal Home » Pre-Sales & Policies » Rules & Terms of Service » Processes Limit

Processes Limit

What is the concurrent processes limitation?

Shared and Reseller plans are limited to 25 simultaneous processes per cPanel.

Dedicated servers and VPS plans allow an adjustable number of simultaneous processes with no enforced limit.

Note: Most sites will work perfectly with a 25 concurrent processes limit. Processes open and close so quickly that they hardly ever overlap.

There has been a feature added into the HostGator X3 theme (Hatchling, Baby, Business only). HostGator clients are now able to see which processes have been killed for resource usage. Most processes / MySQL queries will have a possible reason as to why they were disabled, and a few will have generic reasons if there is not yet a known cause.

If you are exceeding the limit, this could be caused by your mail client (Thunderbird, Mac mail, Outlook, etc.) checking for emails too many times in an hour. Per our mail policy, most of our servers have a limit of 30 POP3/IMAP checks per hour per IP address. Once this is hit, the server stores the check as a process to be handled after the 30 checks reset. However, more requests from your mail client keep coming. Therefore, more and more processes are stored until they hit the 25 process limit and thereafter brings your site down with a 500 error message.

Here is what you need to do:

  1. Close the mail client right away to see the site load back up. Closing the client will clear all the processes.
  2. Open the client again and look for the setting on how often it is checking the server for more emails. Set this to no less than 10 minutes apart.

Apple/Mac users: On most Apple devices there is a function called "push" and when it is enabled, it keeps the connection to our server open and continually checks mail. Consequently, this creates many IMAP processes and eventually will conflict with our Terms of Service.

If you are still hitting the process limit, you either have too much traffic for a shared server, or you need to optimize your database (for faster queries). Please email support@hostgator.com for a proper assessment.

What if my VPS is limiting me to 25 processes?

This number can be increased at your discretion. Make the changes in /usr/local/apache/conf/includes/pre_main_global.conf

The command line is RLimitNPROC 25 30. Change the first number to the new limit, then add 5 to get the second number, and finally restart Apache (Location: /etc/init.d/httpd Command: restart)

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Article Comments

Brad
Is there a way to limit how long a process can run?
Posted: April 21, 2010
HostGator
We generally kill processes running longer than 30 seconds.

You cannot set your processes to time-out, but you can manually kill any of your processes.
Posted: April 21, 2010
BareFeet
Hmm, that's quite disappointing. I evaluated several hosting services before settling on HostGator, but didn't realize that the process limit would bite me. Last night my wife said she couldn't get email, then today I discovered that all my php driven web pages were giving server errors. I had to kill several ghost imap connections just to get my web server to answer queries.

I am worries that if the imap server doesn't kill processes attached to clients that aren't responding, that my web server will cease to be functional. Also, if I happen to get a peak of web activity, most of my visitors a going to get a server error. I only have a couple of mail users, but we skip between devices. I have pretty low web affix but hope to get a peak when I announce a new product or similar. Dedicated hosting is overkill for me.

Is there any way to better handle the process limitation such as having zombie imap processes killed sooner by the server and dedicated a couple of processes to the web server so that web server errors never occur? Otherwise I'll have to go elsewhere.

Thanks.
Posted: October 29, 2010
HostGator
Make sure your iPad/iPhone and other Apple devices have "push" disabled.

Use POP3 plus "Leave copy of message on server" when possible to reduce the regular processes.

A VPS plan will allow you to increase the process limit.
Posted: October 29, 2010
Glenn
I solved the Apple imap issue by creating a cron job that kills imapd processes every couple minutes. Apple just happily opens a new connection when it tries to
check mail. The cron command is:

/usr/bin/pkill imapd
Posted: December 28, 2010
Gary Davis
The above command provided by Glenn did not work for me, but did lead me toward the solution.

Within the Cron jobs applet of the Advanced tab on cPanel I added a job that ran every 10 minutes using the command:

/usr/bin/kill imap

pkill did not seem to work, suggesting that the command was not available. As well, opening up the server statice I realized the service name was itself imap and not imapd.

If you are reading this as a solution keep in mind that my solution is correct for my server instance. Glenn's is obviously correct for his instance. You will need to validate the correct service name and command line for your instance however, it will likely be one of these two examples.
Posted: November 6, 2011
HostGator
Thank you for your comments. Just a quick reminder that the comments on this page are not monitored by technical support staff, and that for support issues, it is best to contact us by live chat, phone or email so we can assist you right away.

Although comments are not monitored by technical support staff, they are moderated and read by technical writers. Comments will need to be approved by a moderator before appearing.

Our technical writers do read the comments periodically for the purposes of updating the articles, and do appreciate your feedback, suggestions and corrections to the articles themselves, as well as any suggestions or tips for readers of this article. However, support questions posted here are not guaranteed to be replied to in a timely manner or at all. For support issues, it is best to contact our support staff instead by live chat, email or phone.

Posted: December 13, 2011 (Global Reply)
Your comments help us keep the knowledge base updated. This is not a medium for support. If you have questions or need help, please contact us via email, phone or live chat for fast assistance.

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