1. Overview

1.1. Introduction

This guide aims to explain Kubernetes, a container operation management tool usable by the Exastro system.

1.2. Features

The Exastro system operates on multiple containers. By using Kubernetes, userse can achieve a system architecture with higher availability amd services levels.

1.3. Availability

1.3.1. Automatic restoring

In the Exastro system, we can automatically restore the container by using Probe, the Kubernetes health-check function.

By configuring Probe, the container status will be checked. We can then automatically reboot the system when a backup occurs.

Probe are configured to the following front-end type containers.

• platform-auth

• platform-api

• platform-web

• ita-api-admin

• ita-api-organization

• ita-api-oase-receiver

• ita-web-server

As Probe is a Kubernetes function, it can only be used if Exastro is installed using Kubernetes.

There are 3 types of Probes, Startup Probe, Liveness Probe and Readiness Probe.

Each container runs HTTP GET request to their own endpoint every 10 seconds to health-check themselves.

At initial startup, the container will restart if the Startup Probe fails 30 times. After that, the container will restart if the Liveness Probe fails 3 times.

表 1.1 Probe types

Probe	Description
Startup Probe	The Liveness Probe and Readiness Probe checks are deactivated until the Startup Probe succeeds.
Liveness Probe	Checks whether to reboot the container or not.
Readiness Probe	Checks if the Container is in a state to recieve traffic or not.

表 1.2 Startup Probe setting value

Parameter	Description	Setting value
httpGet.path	Specifies path with HTTP GET request.	(Path for health-checks)
httpGet.port	Specifies port with HTTP GET request.	port-http
timeoutSeconds	Specifies Probe timeout(seconds).	30
periodSeconds	Specifies Probe interval time(seconds).	10
successThreshold	Specifies smallest number for Probe success.	1
failureThreshold	Specifies smallest number for Probe failure.	30

表 1.3 Liveness Probe setting value

Parameter	Description	Setting value
httpGet.path	Specifies path with HTTP GET request.	(Path for health-checks)
httpGet.port	Specifies port with HTTP GET request.	port-http
timeoutSeconds	Specifies Probe timeout(seconds).	30
periodSeconds	Specifies Probe interval time(seconds).	10
successThreshold	Specifies smallest number for Probe success.	1
failureThreshold	Specifies smallest number for Probe failure.	3

表 1.4 Readiness Probe setting value

Parameter	Description	Setting value
httpGet.path	Specifies path with HTTP GET request.	(Path for health-checks)
httpGet.port	Specifies port with HTTP GET request.	port-http
timeoutSeconds	Specifies Probe timeout(seconds).	30
periodSeconds	Specifies Probe interval time(seconds).	10
successThreshold	Specifies smallest number for Probe success.	1
failureThreshold	Specifies smallest number for Probe failure.	3