Rsyslog 8.1 Elasticsearch Output Performance
Video: Using Solr for Logs with Rsyslog, Flume, Fluentd and Logstash
Presentation: Introduction to Elasticsearch
Logstash Performance Monitoring (1.2.2 vs 1.2.1)
Video Presentation: On Centralizing Logs
On Centralizing Logs at Monitorama EU
Book: Elasticsearch in Action
Elasticsearch Refresh Interval vs Indexing Performance