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.

Zabbix - Track, record, alert and visualize performance and availability of IT resources

Logz.io - Logz.io provides log analysis software with alerts, role-based access, unlimited scalability and free ELK apps. Index, search & visualize your log data!

FastNetMon - FastNetMon is a very fast DDoS analyzer with sflow/netflow/mirror support.

Sumo Logic - Sumo Logic is a secure, purpose-built cloud-based machine data analytics service that leverages big data for real-time IT insights

Abusix - Abusix is a network security company that offers email threat protection and network abuse handling solutions to ISPs, Telcos, and Cloud/Hosting Providers to stop the rapidly growing problem of email-borne threats and other kinds of network abuse.