Configure SLOs and alerting rules for applications - Alibaba Cloud Service Mesh - Alibaba Cloud - Alibaba Cloud Service Mesh

This topic describes how to define application Service Level Objectives (SLOs) by using ASM.

Prerequisites

The cluster is added to the ASM instance. of version 1.15.3 or later.
An ingress gateway is deployed.
Auto-injection is enabled. For more information, see Configure a sidecar injection policy.

Background

A Service Level Objective (SLO) is a target value or range of values for a service level, measured by one or more Service Level Indicators (SLIs). You can manually define SLOs based on Prometheus metrics, but the process can be complex. ASM simplifies this process by allowing you to generate SLOs and corresponding alert rules from the ASM console. For more information, see Service Level Objective (SLO) overview and SLO CRD field reference.

Preparations

Deploy the httpbin application in an ACK cluster and configure its virtual service and gateway rules.

Deploy httpbin in an ACK cluster

Create the httpbin.yaml file with the following content.

##################################################################################################
# httpbin service
##################################################################################################
apiVersion: v1
kind: ServiceAccount
metadata:
  name: httpbin
---
apiVersion: v1
kind: Service
metadata:
  name: httpbin
  labels:
    app: httpbin
    service: httpbin
spec:
  ports:
  - name: http
    port: 8000
    targetPort: 80
  selector:
    app: httpbin
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpbin
spec:
  replicas: 1
  selector:
    matchLabels:
      app: httpbin
      version: v1
  template:
    metadata:
      labels:
        app: httpbin
        version: v1
    spec:
      serviceAccountName: httpbin
      containers:
      - image: docker.io/kennethreitz/httpbin
        imagePullPolicy: IfNotPresent
        name: httpbin
        ports:
        - containerPort: 80

Connect to the ACK cluster by using kubectl to manage your cluster and its applications. For more information, see Connect to a cluster by using kubectl.
Run the following command to deploy httpbin in the ACK cluster.
```
kubectl apply -f httpbin.yaml
```

Configure virtual service and gateway rules

Create the httpbin-gateway.yaml file with the following content.

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: httpbin-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: httpbin
spec:
  hosts:
  - "*"
  gateways:
  - httpbin-gateway
  http:
  - route:
    - destination:
        host: httpbin
        port:
          number: 8000

Connect to the ASM instance by using kubectl to manage the instance. For more information, see Use kubectl on the control plane to access Istio resources.
Run the following command to deploy the virtual service and gateway rules.
```
kubectl apply -f httpbin-gateway.yaml
```
In the address bar of your browser, enter http://{IP address of the ingress gateway service}.
The httpbin application page appears, indicating a successful deployment.

Define SLO configuration

This section shows how to create a service availability SLO for the httpbin service in the default namespace with a target value of 99%, a 30-day duration, and two alert levels: Page and Ticket.

Log on to the ASM console. In the left-side navigation pane, choose Service Mesh > Mesh Management.
On the Mesh Management page, click the name of the ASM instance. In the left-side navigation pane, choose Observability Management Center > SLO Configuration.
On the SLO Configuration page, select the Namespace where the target service is located. In this example, the namespace is default. In the row for the httpbin service, click Create.
On the Create page, in the Basic Information section, select 30 days for Duration.
Click the SLO Rule tab. Set Name to asm-slo, Target to 99, and Plugin Type to availability. Turn on the Enable Alert Rule switch, set Alert Rule Name to asm-alert, and then turn on the Enable Page-level Alert Rule and Enable Ticket-level Alert Rule switches. In the Basic Information section, select default for Namespace, enter httpbin for , and set to .
Optional: At the bottom of the page, click Preview to review the configuration. After confirming the information is correct, click Confirm.
For more information about the fields in the configuration file, see SLO CRD field reference.
When you are finished, click Create at the bottom of the page.

Automatically generated Prometheus rules

After the SLO is configured, return to the SLO Configuration page. In the row for the httpbin service, click View Prometheus Rule in the Actions column to view the generated rules.

---
# Code generated by Alibaba Cloud Service Mesh (ASM).
# DO NOT EDIT.

groups:
- name: asm-slo-sli-recordings-httpbin-asm-slo
  rules:
  - record: slo:sli_error:ratio_rate5m
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_naxxx\n      }[5m])) \n  /        \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destinaxxx\n      }[5m])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 5m
  - record: slo:sli_error:ratio_rate30m
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_naxxx\n      }[30m])) \n  /        \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destinaxxx\n      }[30m])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 30m
  - record: slo:sli_error:ratio_rate1h
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_naxxx\n      }[1h])) \n  /        \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destinaxxx\n      }[1h])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo

Expand to view an example of the Prometheus rules.

groups:
- name: asm-slo-sli-recordings-httpbin-asm-slo
  rules:
  - record: slo:sli_error:ratio_rate5m
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[5m])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[5m])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 5m
  - record: slo:sli_error:ratio_rate30m
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[30m])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[30m])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 30m
  - record: slo:sli_error:ratio_rate1h
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[1h])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[1h])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 1h
  - record: slo:sli_error:ratio_rate2h
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[2h])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[2h])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 2h
  - record: slo:sli_error:ratio_rate6h
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[6h])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[6h])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 6h
  - record: slo:sli_error:ratio_rate1d
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[1d])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[1d])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 1d
  - record: slo:sli_error:ratio_rate3d
    expr: "(\n(\n  sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\",response_code=~\"(5..|429)\"
      }[3d])) \n  /          \n  (sum(rate(istio_requests_total{ destination_service_name=\"httpbin\",destination_service_namespace=\"default\"
      }[3d])) > 0)\n) OR on() vector(0)\n)"
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
      slo_window: 3d
  - record: slo:sli_error:ratio_rate30d
    expr: |
      sum_over_time(slo:sli_error:ratio_rate5m{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}[30d])
      / ignoring (slo_window)
      count_over_time(slo:sli_error:ratio_rate5m{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}[30d])
    labels:
      slo_window: 30d
- name: asm-slo-meta-recordings-httpbin-asm-slo
  rules:
  - record: slo:objective:ratio
    expr: vector(0.99)
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: slo:error_budget:ratio
    expr: vector(1-0.99)
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: slo:time_period:days
    expr: vector(30)
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: slo:current_burn_rate:ratio
    expr: |
      slo:sli_error:ratio_rate5m{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}
      / on(slo_id, asm_slo, slo_service) group_left
      slo:error_budget:ratio{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: slo:period_burn_rate:ratio
    expr: |
      slo:sli_error:ratio_rate30d{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}
      / on(slo_id, asm_slo, slo_service) group_left
      slo:error_budget:ratio{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"}
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: slo:period_error_budget_remaining:ratio
    expr: 1 - slo:period_burn_rate:ratio{asm_slo="asm-slo", slo_id="httpbin-asm-slo",
      slo_service="httpbin"}
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_service: httpbin
  - record: asm_slo_info
    expr: vector(1)
    labels:
      asm_slo: asm-slo
      slo_id: httpbin-asm-slo
      slo_mode: cli-gen-prom
      slo_objective: "99"
      slo_service: httpbin
      slo_spec: prometheus/v1
      slo_version: dev
- name: asm-slo-alerts-httpbin-asm-slo
  rules:
  - alert: asm-alert
    expr: |
      (
          (slo:sli_error:ratio_rate5m{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (14.4 * 0.01))
          and ignoring (slo_window)
          (slo:sli_error:ratio_rate1h{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (14.4 * 0.01))
      )
      or ignoring (slo_window)
      (
          (slo:sli_error:ratio_rate30m{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (6 * 0.01))
          and ignoring (slo_window)
          (slo:sli_error:ratio_rate6h{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (6 * 0.01))
      )
    labels:
      slo_severity: page
    annotations:
      summary: '{{$labels.slo_service}} {{$labels.asm_slo}} SLO error budget burn
        rate is over expected.'
      title: (page) {{$labels.slo_service}} {{$labels.asm_slo}} SLO error budget burn
        rate is too fast.
  - alert: asm-alert
    expr: |
      (
          (slo:sli_error:ratio_rate2h{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (3 * 0.01))
          and ignoring (slo_window)
          (slo:sli_error:ratio_rate1d{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (3 * 0.01))
      )
      or ignoring (slo_window)
      (
          (slo:sli_error:ratio_rate6h{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (1 * 0.01))
          and ignoring (slo_window)
          (slo:sli_error:ratio_rate3d{asm_slo="asm-slo", slo_id="httpbin-asm-slo", slo_service="httpbin"} > (1 * 0.01))
      )
    labels:
      slo_severity: ticket
    annotations:
      summary: '{{$labels.slo_service}} {{$labels.asm_slo}} SLO error budget burn
        rate is over expected.'
      title: (ticket) {{$labels.slo_service}} {{$labels.asm_slo}} SLO error budget
        burn rate is too fast.

You can import these rules into Prometheus to apply the SLOs. For more information, see Import generated rules into Prometheus to implement SLOs.