- Switch from Jannson to RapidJSON for our JSON library (allowing for a configuration schema in 1.2.0).
- Upgrade :ref:`recommended version <install_requirements>` of various other libraries.
- Configurable DNS refresh rate for DNS service discovery types.
- Upstream circuit breaker configuration can be :ref:`overridden via runtime <config_cluster_manager_cluster_runtime>`.
- :ref:`Zone aware routing support <arch_overview_load_balancing_zone_aware_routing>`.
- Generic header matching routing rule.
- HTTP/2 graceful connection draining (double GOAWAY).
- DynamoDB filter :ref:`per shard statistics <config_http_filters_dynamo>` (pre-release AWS feature).
- Initial release of the :ref:`fault injection HTTP filter <config_http_filters_fault_injection>`.
- HTTP :ref:`rate limit filter <config_http_filters_rate_limit>` enhancements (note that the configuration for HTTP rate limiting is going to be overhauled in 1.2.0).
- Added :ref:`refused-stream retry policy <config_http_filters_router_x-envoy-retry-on>`.
- Multiple :ref:`priority queues <arch_overview_http_routing_priority>` for upstream clusters (configurable on a per route basis, with separate connection pools, circuit breakers, etc.).
- Added max connection circuit breaking to the :ref:`TCP proxy filter <arch_overview_tcp_proxy>`.
- Added :ref:`CLI <operations_cli>` options for setting the logging file flush interval as well as the drain/shutdown time during hot restart.
- A very large number of performance enhancements for core HTTP/TCP proxy flows as well as a few new configuration flags to allow disabling expensive features if they are not needed (specifically request ID generation and dynamic response code stats).
- Support Mongo 3.2 in the :ref:`Mongo sniffing filter <config_network_filters_mongo_proxy>`.
- Lots of other small fixes and enhancements not listed.