overload: scale http stream idle timeout (#14155)

The connection timeout applies to the idle timeout in the common HTTP
protocol options message in the HttpConnectionManager, not to the
RouteAction idle timeout.

Signed-off-by: Alex Konradi <akonradi@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 6246920219ac0ba215bfd0b5462ef78036363b75

envoy/config/core/v3/protocol.proto

@@ -77,6 +77,10 @@ message HttpProtocolOptions {
   // .. warning::
   //   Disabling this timeout has a highly likelihood of yielding connection leaks due to lost TCP
   //   FIN packets, etc.
+  //
+  // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
+  // is configured, this timeout is scaled for downstream connections according to the value for
+  // :ref:`HTTP_DOWNSTREAM_CONNECTION_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_CONNECTION_IDLE>`.
   google.protobuf.Duration idle_timeout = 1;
 
   // The maximum duration of a connection. The duration is defined as a period since a connection

envoy/config/core/v4alpha/protocol.proto

@@ -77,6 +77,10 @@ message HttpProtocolOptions {
   // .. warning::
   //   Disabling this timeout has a highly likelihood of yielding connection leaks due to lost TCP
   //   FIN packets, etc.
+  //
+  // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
+  // is configured, this timeout is scaled for downstream connections according to the value for
+  // :ref:`HTTP_DOWNSTREAM_CONNECTION_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_CONNECTION_IDLE>`.
   google.protobuf.Duration idle_timeout = 1;
 
   // The maximum duration of a connection. The duration is defined as a period since a connection

envoy/config/overload/v3/overload.proto

@@ -91,8 +91,15 @@ message ScaleTimersOverloadActionConfig {
     UNSPECIFIED = 0;
 
     // Adjusts the idle timer for downstream HTTP connections that takes effect when there are no active streams.
-    // This affects the value of :ref:`RouteAction.idle_timeout <envoy_v3_api_field_config.route.v3.RouteAction.idle_timeout>`.
+    // This affects the value of :ref:`HttpConnectionManager.common_http_protocol_options.idle_timeout
+    // <envoy_v3_api_field_config.core.v3.HttpProtocolOptions.idle_timeout>`
     HTTP_DOWNSTREAM_CONNECTION_IDLE = 1;
+
+    // Adjusts the idle timer for HTTP streams initiated by downstream clients.
+    // This affects the value of :ref:`RouteAction.idle_timeout <envoy_v3_api_field_config.route.v3.RouteAction.idle_timeout>` and
+    // :ref:`HttpConnectionManager.stream_idle_timeout
+    // <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.stream_idle_timeout>`
+    HTTP_DOWNSTREAM_STREAM_IDLE = 2;
   }
 
   message ScaleTimer {

envoy/config/route/v3/route_components.proto

@@ -980,7 +980,7 @@ message RouteAction {
   //
   // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
   // is configured, this timeout is scaled according to the value for
-  // :ref:`HTTP_DOWNSTREAM_CONNECTION_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_CONNECTION_IDLE>`.
+  // :ref:`HTTP_DOWNSTREAM_STREAM_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_STREAM_IDLE>`.
   google.protobuf.Duration idle_timeout = 24;
 
   // Indicates that the route has a retry policy. Note that if this is set,

envoy/config/route/v4alpha/route_components.proto

@@ -980,7 +980,7 @@ message RouteAction {
   //
   // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
   // is configured, this timeout is scaled according to the value for
-  // :ref:`HTTP_DOWNSTREAM_CONNECTION_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_CONNECTION_IDLE>`.
+  // :ref:`HTTP_DOWNSTREAM_STREAM_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_STREAM_IDLE>`.
   google.protobuf.Duration idle_timeout = 24;
 
   // Indicates that the route has a retry policy. Note that if this is set,

envoy/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto

@@ -340,6 +340,10 @@ message HttpConnectionManager {
   // <envoy_api_field_config.core.v3.HttpProtocolOptions.max_stream_duration>` does not apply to
   // this corner case.
   //
+  // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
+  // is configured, this timeout is scaled according to the value for
+  // :ref:`HTTP_DOWNSTREAM_STREAM_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_STREAM_IDLE>`.
+  //
   // Note that it is possible to idle timeout even if the wire traffic for a stream is non-idle, due
   // to the granularity of events presented to the connection manager. For example, while receiving
   // very large request headers, it may be the case that there is traffic regularly arriving on the

envoy/extensions/filters/network/http_connection_manager/v4alpha/http_connection_manager.proto

@@ -339,6 +339,10 @@ message HttpConnectionManager {
   // <envoy_api_field_config.core.v4alpha.HttpProtocolOptions.max_stream_duration>` does not apply to
   // this corner case.
   //
+  // If the :ref:`overload action <config_overload_manager_overload_actions>` "envoy.overload_actions.reduce_timeouts"
+  // is configured, this timeout is scaled according to the value for
+  // :ref:`HTTP_DOWNSTREAM_STREAM_IDLE <envoy_api_enum_value_config.overload.v3.ScaleTimersOverloadActionConfig.TimerType.HTTP_DOWNSTREAM_STREAM_IDLE>`.
+  //
   // Note that it is possible to idle timeout even if the wire traffic for a stream is non-idle, due
   // to the granularity of events presented to the connection manager. For example, while receiving
   // very large request headers, it may be the case that there is traffic regularly arriving on the