Envoy Access Log Service (ALS) provides full logs about RPC routed, including HTTP and TCP.
The solution was initialized and firstly implemented by Sheng Wu, Hongtao Gao, Lizan Zhou, and Dhi Aurrahman at 17 May. 2019, and was presented on KubeCon China 2019. Here is the recorded video.
SkyWalking is the first open source project introducing this ALS based solution to the world. This provides a new way with very low payload to service mesh, but the same observability.
You need the following steps to set up ALS.
Enable envoyAccessLogService
in ProxyConfig and set the ALS address to where SkyWalking OAP listens. On Istio version 1.6.0+, if Istio is installed with demo
profile, you can enable ALS with command:
istioctl manifest apply \ --set profile=demo \ --set meshConfig.enableEnvoyAccessLogService=true \ --set meshConfig.defaultConfig.envoyAccessLogService.address=<skywalking-oap.skywalking.svc:11800>
Note: Replace <skywalking-oap.skywalking.svc:11800>
with the real address where SkyWalking OAP is deployed.
Activate SkyWalking Envoy Receiver. This is activated by default.
Choose an ALS analyzer. There are two available analyzers, k8s-mesh
and mx-mesh
. Set the system environment variable SW_ENVOY_METRIC_ALS_HTTP_ANALYSIS such as SW_ENVOY_METRIC_ALS_HTTP_ANALYSIS=k8s-mesh
or in the application.yaml
to activate the analyzer. For more about the analyzers, see SkyWalking ALS Analyzers
envoy-metric: selector: ${SW_ENVOY_METRIC:default} default: acceptMetricsService: ${SW_ENVOY_METRIC_SERVICE:true} alsHTTPAnalysis: ${SW_ENVOY_METRIC_ALS_HTTP_ANALYSIS:""} # Setting the system env variable would override this.
To use multiple analyzers as a fallbackļ¼please use ,
to concatenate.
Here's an example to install Istio and deploy SkyWalking by Helm chart.
istioctl install \ --set profile=demo \ --set meshConfig.enableEnvoyAccessLogService=true \ --set meshConfig.defaultConfig.envoyAccessLogService.address=skywalking-oap.istio-system:11800 git clone https://github.com/apache/skywalking-kubernetes.git cd skywalking-kubernetes/chart helm repo add elastic https://helm.elastic.co helm dep up skywalking helm install 8.1.0 skywalking -n istio-system \ --set oap.env.SW_ENVOY_METRIC_ALS_HTTP_ANALYSIS=k8s-mesh \ --set fullnameOverride=skywalking \ --set oap.envoy.als.enabled=true
You can use kubectl -n istio-system logs -l app=skywalking | grep "K8sALSServiceMeshHTTPAnalysis"
to ensure OAP ALS k8s-mesh
analyzer has been activated.
There are two available analyzers, k8s-mesh
and mx-mesh
, you can specify one or more analyzers to analyze the access logs. When multiple analyzers are specified, it acts as a fast-success mechanism: SkyWalking loops over the analyzers and use it to analyze the logs, once there is an analyzer that is able to produce a result, it stops the loop.
k8s-mesh
k8s-mesh
uses the metadata from Kubernetes cluster, hence in this analyzer OAP needs access roles to Pod
, Service
, and Endpoints
.
The blog illustrates the detail of how it works, and a step-by-step tutorial to apply it into the bookinfo
application.
mx-mesh
mx-mesh
uses the Envoy metadata exchange mechanism to get the service name, etc., this analyzer requires Istio to enable the metadata exchange plugin (you can enable it by --set values.telemetry.v2.enabled=true
, or if you're using Istio 1.7+ and installing it with profile demo
/preview
, it should be enabled then).