diff --git a/2.1.x/multi/multi__global_filters.html b/2.1.x/multi/multi__global_filters.html
index 7640129f..795df6d5 100644
--- a/2.1.x/multi/multi__global_filters.html
+++ b/2.1.x/multi/multi__global_filters.html
@@ -34,7 +34,31 @@ the scheme specified in the request made to the Gateway. For example, if the re
but the ServiceInstance indicates it is not secure, then the downstream request will be made over
HTTP. The opposite situation can also apply. However if GATEWAY_SCHEME_PREFIX_ATTR is specified for the
route in the Gateway configuration, the prefix will be stripped and the resulting scheme from the
-route URL will override the ServiceInstance configuration.The Netty Routing Filter runs if the url located in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute has a http or https scheme. It uses the Netty HttpClient to make the downstream proxy request. The response is put in the ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR exchange attribute for use in a later filter. (There is an experimental WebClientHttpRoutingFilter that performs the same function, but does not require netty)
6.5 Netty Write Response Filter
The NettyWriteResponseFilter runs if there is a Netty HttpClientResponse in the ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR exchange attribute. It is run after all other filters have completed and writes the proxy response back to the gateway client response. (There is an experimental WebClientWriteResponseFilter that performs the same function, but does not require netty)
6.6 RouteToRequestUrl Filter
The RouteToRequestUrlFilter runs if there is a Route object in the ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR exchange attribute. It creates a new URI, based off of the request URI, but updated with the URI attribute of the Route object. The new URI is placed in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute`.
If the URI has a scheme prefix, such as lb:ws://serviceid, the lb scheme is stripped from the URI and placed in the ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR for use later in the filter chain.
6.7 Websocket Routing Filter
The Websocket Routing Filter runs if the url located in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute has a ws or wss scheme. It uses the Spring Web Socket infrastructure to forward the Websocket request downstream.
Websockets may be load-balanced by prefixing the URI with lb, such as lb:ws://serviceid.
![[Note]](images/note.png) | Note |
|---|
If you are using SockJS as a fallback over normal http, you should configure a normal HTTP route as well as the Websocket Route. |
application.yml.
+route URL will override the ServiceInstance configuration.
![[Warning]](images/warning.png) | Warning |
|---|
LoadBalancerClientFilter uses a blocking Ribbon LoadBalancerClient under the hood.
+We suggest you use ReactiveLoadBalancerClientFilter instead.
+You can switch to using it by adding org.springframework.cloud:spring-cloud-loadbalancer dependency to your project
+and setting the value of the spring.cloud.loadbalancer.ribbon.enabled to false.
|
6.4 ReactiveLoadBalancerClientFilter
The ReactiveLoadBalancerClientFilter looks for a URI in the exchange attribute
+ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR. If the url has a lb scheme (ie lb://myservice),
+it will use the Spring Cloud ReactorLoadBalancer to resolve the name (myservice in the previous example)
+to an actual host and port and replace the URI in the same attribute. The unmodified
+original url is appended to the list in the ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR attribute.
+The filter will also look in the ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR attribute to see if it equals
+lb and then the same rules apply.
application.yml.
+
spring:
+ cloud:
+ gateway:
+ routes:
+ - id: myRoute
+ uri: lb://service
+ predicates:
+ - Path=/service/**
+
| Note |
|---|
By default when a service instance cannot be found by the ReactorLoadBalancer, a 503 will be returned.
+You can configure the Gateway to return a 404 by setting spring.cloud.gateway.loadbalancer.use404=true. |
| Note |
|---|
The isSecure value of the ServiceInstance returned from the ReactiveLoadBalancerClientFilter will override
+the scheme specified in the request made to the Gateway. For example, if the request comes into the Gateway over HTTPS
+but the ServiceInstance indicates it is not secure, then the downstream request will be made over
+HTTP. The opposite situation can also apply. However if GATEWAY_SCHEME_PREFIX_ATTR is specified for the
+route in the Gateway configuration, the prefix will be stripped and the resulting scheme from the
+route URL will override the ServiceInstance configuration. |
The Netty Routing Filter runs if the url located in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute has a http or https scheme. It uses the Netty HttpClient to make the downstream proxy request. The response is put in the ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR exchange attribute for use in a later filter. (There is an experimental WebClientHttpRoutingFilter that performs the same function, but does not require netty)
6.6 Netty Write Response Filter
The NettyWriteResponseFilter runs if there is a Netty HttpClientResponse in the ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR exchange attribute. It is run after all other filters have completed and writes the proxy response back to the gateway client response. (There is an experimental WebClientWriteResponseFilter that performs the same function, but does not require netty)
6.7 RouteToRequestUrl Filter
The RouteToRequestUrlFilter runs if there is a Route object in the ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR exchange attribute. It creates a new URI, based off of the request URI, but updated with the URI attribute of the Route object. The new URI is placed in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute`.
If the URI has a scheme prefix, such as lb:ws://serviceid, the lb scheme is stripped from the URI and placed in the ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR for use later in the filter chain.
6.8 Websocket Routing Filter
The Websocket Routing Filter runs if the url located in the ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR exchange attribute has a ws or wss scheme. It uses the Spring Web Socket infrastructure to forward the Websocket request downstream.
Websockets may be load-balanced by prefixing the URI with lb, such as lb:ws://serviceid.
| Note |
|---|
If you are using SockJS as a fallback over normal http, you should configure a normal HTTP route as well as the Websocket Route. |
application.yml.
spring:
cloud:
gateway:
@@ -49,7 +73,7 @@ route URL will override the ServiceInstance configu
uri: ws://localhost:3001
predicates:
- Path=/websocket/**
-
6.8 Gateway Metrics Filter
To enable Gateway Metrics add spring-boot-starter-actuator as a project dependency. Then, by default, the Gateway Metrics Filter runs as long as the property spring.cloud.gateway.metrics.enabled is not set to false. This filter adds a timer metric named "gateway.requests" with the following tags:
routeId: The route idrouteUri: The URI that the API will be routed tooutcome: Outcome as classified by HttpStatus.Seriesstatus: Http Status of the request returned to the clienthttpStatusCode: Http Status of the request returned to the clienthttpMethod: The Http method used for the request
These metrics are then available to be scraped from /actuator/metrics/gateway.requests and can be easily integrated with Prometheus to create a Grafana dashboard.
| Note |
|---|
To enable the prometheus endpoint add micrometer-registry-prometheus as a project dependency. |
6.9 Marking An Exchange As Routed
After the Gateway has routed a ServerWebExchange it will mark that exchange as "routed" by adding gatewayAlreadyRouted
+
6.9 Gateway Metrics Filter
To enable Gateway Metrics add spring-boot-starter-actuator as a project dependency. Then, by default, the Gateway Metrics Filter runs as long as the property spring.cloud.gateway.metrics.enabled is not set to false. This filter adds a timer metric named "gateway.requests" with the following tags:
routeId: The route idrouteUri: The URI that the API will be routed tooutcome: Outcome as classified by HttpStatus.Seriesstatus: Http Status of the request returned to the clienthttpStatusCode: Http Status of the request returned to the clienthttpMethod: The Http method used for the request
These metrics are then available to be scraped from /actuator/metrics/gateway.requests and can be easily integrated with Prometheus to create a Grafana dashboard.
| Note |
|---|
To enable the prometheus endpoint add micrometer-registry-prometheus as a project dependency. |
6.10 Marking An Exchange As Routed
After the Gateway has routed a ServerWebExchange it will mark that exchange as "routed" by adding gatewayAlreadyRouted
to the exchange attributes. Once a request has been marked as routed, other routing filters will not route the request again,
essentially skipping the filter. There are convenience methods that you can use to mark an exchange as routed
or check if an exchange has already been routed.
ServerWebExchangeUtils.isAlreadyRouted takes a ServerWebExchange object and checks if it has been "routed"ServerWebExchangeUtils.setAlreadyRouted takes a ServerWebExchange object and marks it as "routed"