Fluentd - Fluentd is a cross platform open source data collection solution originally developed at Treasure Data.
InfluxData - Scalable datastore for metrics, events, and real-time analytics.
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.
TimescaleDB - TimescaleDB is a time-series SQL database providing fast analytics, scalability, with automated data management on a proven storage engine.
Splunk - Splunk's operational intelligence platform helps unearth intelligent insights from machine data.
Prometheus - An open-source systems monitoring and alerting toolkit.