check_mk
Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server. It comes with a set of system checks, a mod_python and JavaScript based web user interface, and a module that allows fast access to the Nagios core. On top of Nagios it also adds additional features
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Nagios Core
Nagios Core network monitoring software is a powerful, enterprise-class host, server, application, monitoring and alerting tool
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Ngrok
Ngrok provides secure, encrypted tunnels to local services with out the requirement for port forwarding.
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ntopng
'ntopng' provides an easy to understand, intuitive interface with a world of options and features to monitor your network.
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NXLog Enterprise and Community Editions
A multi-platform log collection suite to collect, parse, convert and send logs. Integrate with a wide range of products including SIEMs, log analytics dashboards, cloud services, databases, and more.
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Snitch
SaaS SSL monitoring and alerting. Snitch audits for revocation, expiration, changes to the certificate, known security vulnerabilities, and best practices. Snitch worries about your SSL/TLS certificate so you don't have to
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Splunk
Splunk captures, indexes and correlates data (usually logs) in a searchable repository from which it can generate graphs, reports, alerts, dashboards and visualizations. Splunk provides searching time field parsing, so users can index any clear text data into splunk and extract the reqired fields later when needed.
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