Sentry is an open source web application that can log application events and aggregate them in realtime.
The ability to monitor events is very useful considering it is possible to know any issues when they happen.
Also, using Sentry, we can easily see the trends of events (errors, warnings, 404, etc.) which is also nice to have a strong opinion about their frequency.
The application supports adding multiple projects and users (with each user having their own custom rights).
With over 70% of all attacks now carried out over the web application level.
Web application firewalls are used to create an external security layer to improve security, detection, and prevention of attacks before they hit web applications.
Web servers are well-equipped to log traffic for marketing analyses, but they are not good when it comes to logging of traffic to web applications.
ModSecurity is a web application firewall for Apache which makes full HTTP transaction logging possible, allowing complete requests and responses to be logged.
This web application firewall has an easy to use rule engine which creates the core of the system.
ModSecurity can monitor the HTTP traffic in real time, has other features like parallel text matching, Geo IP resolution, credit card number detection, support for content injection, automated rule updates, scripting & more.