Update logs metrics (#1568)

* update docs

* change subtitile

* fix image

* fix image

* address comment

docs/serving/accessing-logs.md

@@ -28,7 +28,7 @@ up the necessary components first.
 
   The Discover tab of the Kibana UI looks like this:
 
-  ![Kibana UI Discover tab](../images/kibana-discover-tab-annotated.png)
+  ![Kibana UI Discover tab](./images/kibana-discover-tab-annotated.png)
 
   You can change the time frame of logs Kibana displays in the upper right
   corner of the screen. The main search bar is across the top of the Discover
@@ -50,12 +50,32 @@ To find the logs sent to `stdout/stderr` from your application in the Kibana UI:
 
 ### Accessing request logs
 
-To find the request logs of your application in the Kibana UI :
+To access the request logs (if enabled), enter the following search in Kibana:
 
-1. Click `Discover` on the left side bar.
+```text
-1. Choose `logstash-*` index pattern on the left top.
+_exists_:"httpRequest.requestUrl"
-1. Input `tag: "requestlog.logentry.istio-system"` in the top search bar then
+```
-   search.
+
+Request logs contain customized details about requests served by the revision.
+Below is a sample request log:
+
+```text
+@timestamp                                            July 10th 2018, 10:09:28.000
+kubernetes.labels.serving_knative_dev/configuration   helloworld-go
+kubernetes.labels.serving_knative_dev/revision	      helloworld-go-6vf4x
+kubernetes.labels.serving_knative_dev/service         helloworld-go
+httpRequest.protocol                                  HTTP/1.1
+httpRequest.referer
+httpRequest.remoteIp                                  10.32.0.2:46866
+httpRequest.requestMethod                             GET
+httpRequest.requestSize                               0
+httpRequest.requestUrl                                /
+httpRequest.responseSize                              20
+httpRequest.serverIp                                  10.32.1.36
+httpRequest.status                                    200
+httpRequest.userAgent                                 curl/7.60.0
+traceId                                               0def9abf835ad90e9d824f7a492e2dcb
+```
 
 ### Accessing configuration and revision logs
 
@@ -112,40 +132,6 @@ To access logs for a [Knative Build](../build/README.md):
 kubernetes.labels.build\-name: <BUILD_NAME>
 ```
 
-### Accessing request logs
-
-To access the request logs, enter the following search in Kibana:
-
-```text
-tag: "requestlog.logentry.istio-system"
-```
-
-Request logs contain details about requests served by the revision. Below is a
-sample request log:
-
-```text
-@timestamp                   July 10th 2018, 10:09:28.000
-destinationConfiguration     configuration-example
-destinationNamespace         default
-destinationRevision          configuration-example-00001
-destinationService           configuration-example-00001-service.default.svc.cluster.local
-latency                      1.232902ms
-method                       GET
-protocol                     http
-referer                      unknown
-requestHost                  route-example.default.example.com
-requestSize                  0
-responseCode                 200
-responseSize                 36
-severity                     Info
-sourceNamespace              istio-system
-sourceService                unknown
-tag                          requestlog.logentry.istio-system
-traceId                      986d6faa02d49533
-url                          /
-userAgent                    curl/7.60.0
-```
-
 ### Accessing end to end request traces
 
 See [Accessing Traces](./accessing-traces.md) page for details.

docs/serving/installing-logging-metrics-traces.md

@@ -17,6 +17,17 @@ sections to do so now.
 
 ## Metrics
 
+1. Run the following command and follow the instructions below to enable request
+   metrics if they are wanted:
+
+   ```
+   kubectl edit cm -n knative-serving config-observability
+   ```
+
+   Add `metrics.request-metrics-backend-destination: prometheus` to `data`
+   field. You can find detailed information in `data._example` field in the
+   `ConfigMap` you are editing.
+
 1. Run the following command to install Prometheus and Grafana:
 
    ```shell
@@ -52,6 +63,22 @@ in Knative.
 
 ## Logs
 
+### Enable Request Logs
+
+Run the following command and follow the instructions below to enable request
+logs if they are wanted:
+
+
+```
+kubectl edit cm -n knative-serving config-observability
+```
+
+Copy `logging.request-log-template` from `data._example` field to`data`
+field in the `ConfigMap` you are editing.. You can find detailed information in
+`data._example` field to customize the request log format.
+
+### Choose One Logging Backend
+
 Knative offers three different setups for collecting logs. Choose one to
 install:
 
@@ -59,7 +86,7 @@ install:
 1. [Stackdriver](#stackdriver)
 1. [Custom logging plugin](./setting-up-a-logging-plugin.md)
 
-### Elasticsearch and Kibana
+#### Elasticsearch and Kibana
 
 1. Run the following command to install an ELK stack:
 
@@ -116,7 +143,7 @@ install:
 1. When the installation is complete and all the resources are running, you can
    continue to the next section and begin creating your Elasticsearch indices.
 
-#### Create Elasticsearch Indices
+##### Create Elasticsearch Indices
 
 To visualize logs with Kibana, you need to set which Elasticsearch indices to
 explore.
@@ -140,12 +167,12 @@ explore.
   `Index pattern` and select `@timestamp` from `Time Filter field name` and
   click on `Create` button.
 
-![Create logstash-* index](../images/kibana-landing-page-configure-index.png)
+![Create logstash-* index](./images/kibana-landing-page-configure-index.png)
 
 See [Accessing Logs](./accessing-logs.md) for more information about logs in
 Knative.
 
-### Stackdriver
+#### Stackdriver
 
 To configure and setup monitoring: