MongoDB

参考文档：

http://grokbase.com/p/gg/mongodb-user/133v56br4v/mongodb-2-4-high-rate-of-user-asserts

https://support.serverdensity.com/hc/en-us/articles/212544257-Monitoring-MongoDB

https://www.datadoghq.com/blog/monitoring-mongodb-performance-metrics-mmap/#errors

http://blog.cloud.mongodb.com/post/78650784046/learn-about-lock-percentage-concurrency-in