We started noticing a really weird pattern with our web page. Exactly every 30 minutes we are seeing a huge drop in requests in our server. We go from about 2,000 requests per minute down to 500-800 requests per minute. Our web site slows down completely and takes almost a minute to open. The pattern is shown on the following graph (taken from probe):
As you can see exactly at the same time, we get a drop in requests for about 3 minutes followed by a huge peak of requests. You can also notice an increase in errors just when this happens. We have noticed this pattern for the last 2 days and have no idea what it could be. We have already increased the memory usage for tomcat with no success in stopping this issue.
All websites running on tomcat experience a huge slowdown, not just our main site. Also our server sees no changes whatsover in performance, so we are pretty sure that our server is not the bottleneck.
Any help or ideas on what this could be will be greatly appreciated.