isotope

README

Isotope

Isotope (istio topology performance) benchmarks Istio against various service graph topologies.

Repository Structure

Item	Role
example-topologies/	Examples of topology configurations
convert/	Go command to convert topologies to other formats
service/	Go command to run as a node in the service graph
run_tests.py	CLI to run tests against topologies
runner/	Python module used by run_tests.py
create_tree_topology.py	Python script to create a hierarchical topology

Prometheus Metrics

The system deploys a Prometheus instance to collect and label metrics throughout the tests. The current implementation connects it to a Persistent Volume to write to a Persistent Disk. This ensures the data is not lost when the Prometheus instance is deleted.

However, so long as you adhere to calling the "/metrics" HTTP endpoints, metrics could be collected by other means.

service-graph.yaml

Describes a service graph to be tested which mocks a real world service-oriented architecture.

Full example

apiVersion: v1alpha1
kind: MockServiceGraph
defaults:
  type: grpc
  requestSize: 1 KB
  responseSize: 16 KB
services:
- name: a
  errorRate: 0.01%
  script:
  - sleep: 100ms
- name: b
  type: grpc
- name: c
  script:
  - call:
      service: a
      size: 10K
  - call: b
- name: d
  script:
  - - call: a
    - call: c
  - sleep: 10ms
  - call: b

Represents a service graph like:

Generates a Kubernetes manifest like:

apiVersion: v1
kind: ConfigMap
metadata:
  name: scripts
data:
  a: |
    errorRate: 0.0001
    name: a
    responseSize: 16KiB
    script:
    - sleep: 100ms
    type: http
  b: |
    name: b
    responseSize: 16KiB
    type: grpc
  c: |
    name: c
    responseSize: 16KiB
    script:
    - call:
        service: a
        size: 10KiB
    - call:
        service: b
        size: 1KiB
    type: http
  d: |
    name: d
    responseSize: 16KiB
    script:
    - - call:
          service: a
          size: 1KiB
      - call:
          service: c
          size: 1KiB
    - sleep: 10ms
    - call:
        service: b
        size: 1KiB
    type: http
---
apiVersion: v1
kind: Service
metadata:
  name: a
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: a
spec:
  template:
    spec:
      containers:
      - name: performance-test
        image: istio.gcr.io/performance-test
---
apiVersion: v1
kind: Service
metadata:
  name: b
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: b
spec:
  template:
    spec:
      containers:
      - name: performance-test
        image: istio.gcr.io/performance-test
---
apiVersion: v1
kind: Service
metadata:
  name: c
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: c
spec:
  template:
    spec:
      containers:
      - name: performance-test
        image: istio.gcr.io/performance-test
---
apiVersion: v1
kind: Service
metadata:
  name: d
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: d
spec:
  template:
    spec:
      containers:
      - name: performance-test
        image: istio.gcr.io/performance-test
---

Specification

apiVersion: {{ Version }} # Required. K8s-like API version.
kind: MockServiceGraph
default: # Optional. Default to empty map.
  type: {{ "http" | "grpc" }} # Optional. Default "http".
  errorRate: {{ Percentage }} # Optional. Default 0%.
  requestSize: {{ ByteSize }} # Optional. Default 0.
  responseSize: {{ ByteSize }} # Optional. Default 0.
  script: {{ Script }} # Optional. See below for spec.
services: # Required. List of services in the graph.
- name: {{ ServiceName }}: # Required. Name of the service.
  type: {{ "http" | "grpc" }} # Optional. Default "http".
  responseSize: {{ ByteSize }} # Optional. Default 0.
  errorRate: {{ Percentage }} # Optional. Overrides default.
  script: {{ Script }} # Optional. See below for spec.

Default

At the global scope a default map may be placed to indicate settings which should hold for omitted settings for its current and nested scopes.

Default-able settings include type, script, responseSize, requestSize, and errorRate.

Example

apiVersion: v1alpha1
default:
  errorRate: 0.1%
  requestSize: 100KB
  # responseSize: 0 # Inherited from default.
  # type: "http" # Inherited from default.
  # script: [] # Inherited from default (acts like an echo server).
services:
- name: a
  memoryUsage: 80%
  script:
  - call: b # payloadSize: 100KB # Inherited from default.
  - call:
      service: b
      payloadSize: 80B
  # computeUsage: 10% # Inherited from default.
  # errorRate: 10% # Inherited from default.
- name: b
  errorRate: 5%
  # computeUsage: 10% # Inherited from default.
  # memoryUsage: 0% # Inherited from default.
  # script: [] # Inherited from default.

Script

script is a list of high level steps which run when the service is called.

Each step is executed sequentially and may contain either a single command or a list of commands. If the step is a list of commands, each command in that sub-list is executed concurrently (this effect is not recursive; there may only be one level of nested lists).

The script is always started when the service is called and ends by responding to the calling service.

Commands

Each step in the script includes a command.

Sleep

sleep: Pauses for a duration. Useful for simulating processing time.

sleep: {{ Duration }}

Send Request

call: Sends a HTTP/gRPC request (depending on the receiving service's type) to another service.

call: {{ ServiceName }}

OR

call:
  service: {{ ServiceName }}
  payloadSize: {{ ByteSize (e.g. 1 KB) }}

Examples

Call A, then call B sequentially:

script:
- call: A
- call: B

Call A, B, and C concurrently, sleep to simulate work, and finally call D:

script:
- - call: A
  - call: B
  - call: C
- sleep: 10ms
- call: D

Pipeline

1. Create GKE cluster

   gcloud container clusters create isotope-cluster
   gcloud container clusters get-credentials isotope-cluster
   kubectl create clusterrolebinding cluster-admin-binding --clusterrole cluster-admin --user "$(gcloud config get-value account)"
   

2. Install Prometheus Operator using a Persistent Volume connected to a GCE PD.

   kubectl create -f persistent-volume.yaml
   kubectl create -f helm-service-account.yaml
   helm init --service-account tiller --wait
   helm repo add coreos https://s3-eu-west-1.amazonaws.com/coreos-charts/stable
   helm install coreos/prometheus-operator --name prometheus-operator --namespace monitoring
   helm install coreos/prometheus --name prometheus --namespace monitoring --values values-prometheus.yaml
   

3. Run the test on a topology - ./runner/run_tests.py ...