Why my site is down sometimes after using illustrator?

Hello,

I have been using Illustrator recently in my site. But my site server went down sometimes. I installed some plugins like cache clear plugins. But that's not working. Why my site's server is down sometimes after I am using Illustrator recently?

Here is the Configuration:

Website: Techclicky

Name Server 1: ns1.cp-36.bigrockservers.com

Name Server 2: ns2.cp-36.bigrockservers.com

Theme: Newspaper