Using CloudWatch Logs

AWS CloudWatch Logs helps you store, monitor, and analyze your application, system and custom logs, centrally. Using CloudWatch Logs you can monitor your logs in near real time for specific errors and exceptions in your application. For example, you might want to monitor exceptions such as NullPointerException, ArrayIndexOutOfBounds, and ArithmeticException in your Java application.

We will need to aggregate the logs from multiple hosts in an environment where instances are added and deleted, dynamically. AWS CloudWatch is not restricted to work with EC2 instances only, it can also be used for on-premise servers and servers hosted on other public clouds. You can analyze your logs and archive them for access later.

You can extract metrics from logs as they come into AWS CloudWatch using the metric filter. For example, you may want to monitor your web server logs for 4xx and 5xx status codes or monitor your server's log files for OS specific error conditions. In addition...