log4net - log4net is a tool to help the programmer output log statements to a variety of output targets.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
AWS CloudTrail - AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you.
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Logary - Professional logging metrics and analytics for your apps
Zabbix - Track, record, alert and visualize performance and availability of IT resources