How to: Enable SharePoint 2013 Central Administration when it displays “HTTP Error 503. The service is unavailable.”

So this issue threw me off at the beginning as I had just freshly installed a SharePoint 2013 server and who would possibly expect that right out of the box the thing won’t work. Regardless, after doing some digging in the event logs and on IIS it turns out the SharePoint application pools were stopped as the domain user I had provided for some reason didn’t have enough permissions to run as a service / batch job. As you can imagine, all you need to do at this point is give that user the right permissions and you are good to go. Be sure to check you have the right username/password and that the account is not locked too!

• Open the “Local Security Policy” however you can (Windows 2012 you can just hit the Windows key and type that or for older versions go to: Control Panel >> Administrative Tools >> Local Security Policy)
• Go to Security Settings
• Then Local Policies
• Finally User Rights Assignment
• There you will find “Log on as a batch job”. Go in there and add the user you set up on your SharePoint 2013 installation!

Rumor has it this issue appears on SharePoint 2010 as well and the steps to resolve it are the same.

How to disable the process termination by IIS when debugging

When you are writing code for your SharePoint solution, you’ll probably be testing and debugging that code as well. You deploy your solution, attach Visual Studio to the worker process and when the debugger hits the break-point, you examine what happens and read the values of your variables at that moment. And before you know it, you get the message that IIS has terminates the process that was being debugged.

The Windows Process Activation Service (WAS) pings an application pool’s worker process at set intervals for monitoring. If a worker process is non-responsive, WAS can shut it down. This WAS pinging is enabled by default and the interval is set to 90 seconds.

To avoid this you can either disable the Ping Enabled setting of the application pool of your web application or increase the Ping Maximum Response Time. From the Administrative Tools menu, start the Internet Information Services (IIS) Manager and expand your server. Select the Application Pools node. In the Application Pools list select your application of your web application and click on the Advanced Settings link.

Now set Ping Enabled to false (or increase Ping Maximum Response Time to 900) and save your settings by clicking the OK button.

Reference : Blog by Octavie