.. _config_overload_manager: Overload manager ================ The :ref:`overload manager ` is configured in the Bootstrap :ref:`overload_manager ` field. An example configuration of the overload manager is shown below. It shows a configuration to disable HTTP/1.x keepalive when heap memory usage reaches 95% and to stop accepting requests when heap memory usage reaches 99%. .. code-block:: yaml refresh_interval: seconds: 0 nanos: 250000000 resource_monitors: - name: "envoy.resource_monitors.fixed_heap" typed_config: "@type": type.googleapis.com/envoy.config.resource_monitor.fixed_heap.v2alpha.FixedHeapConfig max_heap_size_bytes: 2147483648 actions: - name: "envoy.overload_actions.disable_http_keepalive" triggers: - name: "envoy.resource_monitors.fixed_heap" threshold: value: 0.95 - name: "envoy.overload_actions.stop_accepting_requests" triggers: - name: "envoy.resource_monitors.fixed_heap" threshold: value: 0.99 Resource monitors ----------------- The overload manager uses Envoy's :ref:`extension ` framework for defining resource monitors. Envoy's builtin resource monitors are listed :ref:`here `. Overload actions ---------------- The following overload actions are supported: .. csv-table:: :header: Name, Description :widths: 1, 2 envoy.overload_actions.stop_accepting_requests, Envoy will immediately respond with a 503 response code to new requests envoy.overload_actions.disable_http_keepalive, Envoy will disable keepalive on HTTP/1.x responses envoy.overload_actions.stop_accepting_connections, Envoy will stop accepting new network connections on its configured listeners envoy.overload_actions.shrink_heap, Envoy will periodically try to shrink the heap by releasing free memory to the system Statistics ---------- Each configured resource monitor has a statistics tree rooted at *overload..* with the following statistics: .. csv-table:: :header: Name, Type, Description :widths: 1, 1, 2 pressure, Gauge, Resource pressure as a percent failed_updates, Counter, Total failed attempts to update the resource pressure skipped_updates, Counter, Total skipped attempts to update the resource pressure due to a pending update Each configured overload action has a statistics tree rooted at *overload..* with the following statistics: .. csv-table:: :header: Name, Type, Description :widths: 1, 1, 2 active, Gauge, "Active state of the action (0=inactive, 1=active)"