Enhancements

• Networking: Upgrade to Netty 3.9.1 #6331
• Cluster: have a dedicated join timeout #6342

Bug fixes

• Aggregations: Disable circuit break for aggregations #6381
• Aggregations: The reverse nested  aggregator now computes parent documents correctly #6278
• Indexing: Lower translog flush trigger #6363
• Searching: Search template does not correctly replace a parameter after an initial failure #6318
• Searching: Fixed issue with nested queries not working when filter cache is disabled #6279
• Searching: The filter cache setting is now handled correctly when above 32 GB in size #6268

Regression

• Routing: Restore shard routing #6393
• Mapping: MapperParsingException with include_in_all #6304