Cause of 503 Service Unavailable Errors
The 503 Service Unavailable error is an HTTP status code that means the web site’s server is simply not available right now. Most of the time this is because the server is too busy or because there’s maintenance being performed on it. It can also mean that a backend process like Tomcat has become unavailable.
1) Retry the URL from the address bar again by clicking the reload/refresh button or pressing F5.
Note: If the 503 Service Unavailable error message appears while paying for an online purchase, be aware that multiple attempts to checkout may end up creating multiple orders – and multiple charges! Most payment systems, and some credit card companies, have protections from this kind of thing but it’s still something to be aware of.
2) Come back later. The 503 Service Unavailable error is a common error message on very popular websites when a huge increase in traffic by visitors (that’s you!) is overwhelming the servers. As more and more visitors leave the website, the chances of a successful page load for you increases.
3) Restart your router and then your computer, especially if you’re seeing the “Service Unavailable – DNS Failure” error. While the 503 error is still most likely the fault of the web site you’re visiting, it’s possible that there’s an issue with your computer’s or router’s DNS server configurations and a simple restart of both might fix the problem.
