logstash - logstash is a tool for managing events and logs.
Graylog - Graylog is an open source log management platform for collecting, indexing, and analyzing both structured and unstructured data.
Wazuh - Open Source Host and Endpoint Security
Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.
Kafka - Apache Kafka is publish-subscribe messaging rethought as a distributed commit log.
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.