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.
logstash - logstash is a tool for managing events and logs.
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.
rsyslog - Rsyslog is an enhanced syslogd supporting, among others, MySQL, PostgreSQL, failover log...
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Graylog - Graylog is an open source log management platform for collecting, indexing, and analyzing both structured and unstructured data.