- :ref:`Cluster discovery service (CDS) API <config_cluster_manager_cds>`.
- :ref:`Outlier detection <arch_overview_outlier_detection>` (passive health checking).
- Envoy configuration is now checked against a JSON schema.
- :ref:`Ring hash <arch_overview_load_balancing_types>` consistent load balancer, as well as HTTP consistent hash routing based on a policy.
- Vastly :ref:`enhanced global rate limit configuration <arch_overview_global_rate_limit>` via the HTTP rate limiting filter.
- HTTP routing to a cluster retrieved from a header.
- Weighted cluster HTTP routing.
- Auto host rewrite during HTTP routing.
- Regex header matching during HTTP routing.
- HTTP access log runtime filter.
- LightStep tracer :ref:`parent/child span association <arch_overview_tracing>`.
- :ref:`Route discovery service (RDS) API <config_http_conn_man_rds>`.
- HTTP router :ref:`x-envoy-upstream-rq-timeout-alt-response header <config_http_filters_router_x-envoy-upstream-rq-timeout-alt-response>` support.
- use_original_dst and bind_to_port :ref:`listener options <config_listeners>` (useful for iptables based transparent proxy support).
- TCP proxy filter :ref:`route table support <config_network_filters_tcp_proxy>`.
- Configurable stats flush interval.
- Various :ref:`third party library upgrades <install_requirements>`, including using BoringSSL as the default SSL provider.
- No longer maintain closed HTTP/2 streams for priority calculations. Leads to substantial memory savings for large meshes.
- Numerous small changes and fixes not listed here.