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4. Node

4. Node

2017/11/08

Node is a physical or virtual host composes a cluster.
If two nodes are used to compose a cluster, it is called a two node cluster. If one node is used, it is called a single node cluster.
Current version of MCCS support max two nodes in a cluster.

Table of Contents

Node Attribute

Node attribute can be identified from NodeAttributes view of MCCS console.
From the node management view of MCCS console, select node, then select the ‘Node Attributes’ tab located on right top of detailed information panel.
The values of gray colored are for read only. They just contain and show the information of node state. The values of white colored are configurable by user definition. Below is description of some of them.

[Figure] Node Attribute View

 

Attribute

Description

Type

Default

Edit

Note

BootMode

It is value that indicate whether or not to been started according to the bootMode value setting when MCCS service starts.

BOOLEAN

 

X

 

ExpirationDate

It shows expiration date of license key.

STRING

 

 

 

HostID

It shows host ID of the node.

STRING

 

X

 

IsolationTestAddresses

It enters the IP address to test Isolation at split-brain event. It is recommended the reliable IP address.
If two or more IPs are entered, they will be separated by ",".
If no IP address is entered, MCCS cannot identify the isolated node in the case split-brain.

 

IP ADDRESS

 

O

 

LicenseType

It shows license type of the node.

STRING

 

X

 

NodeName

It show the name of the node.

You can use an actual host name or nickname. 
In any case, it should be a unique name within a cluster.

NAME

 

X

 

NodeState

It shows the state of the node.

STRING

 

X

 

PrimaryHB1

It shows an IP address of the Primary Heartbeat1 defined in the MCCS server.

IP ADDRESS

 

X

 

PrimaryHB1Status

It shows state of primary heartbeat1.

IP ADDRESS

 

X

 

PrimaryHB2

It shows an IP address of the Primary Heartbeat2 defined in the MCCS server.

IP ADDRESS

 

X

 

PrimaryHB2Status

It shows state of primary heartbeat2.

IP ADDRESS

 

X

 

SecondaryHB

It shows an IP address of the Secondary Heartbeat defined in the MCCS server.

IP ADDRESS

 

X

 

SecondaryHBStatus

It shows state of secondary heartbeat.

IP ADDRESS

 

X

 

BootDiskMonitor

부트 디스크 장애 모니터링 유무를 나타냅니다.

BOOLEAN

false

O

 

BootDiskMonitorInterval

부트 디스크 모니터 할 때, 다음 모니터링까지의 시간 간격을 나타냅니다.

INTEGER

10

O

 

BootDiskMonitorRetryLimit

부트 디스크 I/O 테스트 실패할 경우 재시도 횟수를 지정한다.

INTEGER

0

O

 

MCCS 는 사용자의 입력필드에 대한 입력값 제한 기능이 존재하며, 사용자가 잘못 입력한 데이터에 대해 자동 점검기능을 제공합니다.

 

How MCCS Works

MCCS connects nodes as a cluster through heartbeat connection. 
Action of the cluster is decided by the state and role of the node, and node states are decided not only by the system state but also the state of heartbeat connection.
Following are node states for Cluster Mode. 

Node states of the Cluster Mode

State

Description

State

Description

EXITED

This is a state where MCCS engine is terminated.

INITING

This is a state before configuring the heartbeat after starting the engine.
This is initial state before both nodes communicate each other through heartbeat network and collect mutual status of node state after MCCS engine is started.
This state is normally changed to the LOCAL_BUILD or REMOTE_BUILD state, but if there is a problem with the configuration or physical environment, it remains in the INITING state, or is automatically terminated to the EXITED state.

LOCAL_BUILD

When every node in the cluster is in the INITING state, the node with the highest priority at establishing of heartbeat communication is changed to the LOCAL_BUILD state, and the node in this state forms a cluster database from the local configuration file(%MCCS_HOME%\config\main.json).
Only one node within the cluster goes through this state to the RUNNING state, and other nodes undergo the REMOTE_BUILD state that receives information from that node.

REMOTE_BUILD

When a node in the INITING state detects a node in the RUNNING state through heartbeat communication, it establishes by downloading the configuration.

RUNNING

This is the state when establishing a configuration database through the LOCAL_BUILD or REMOTE_BUILD is completed, and starts agents and group administrators of all the resources defined at this state.

FAULTED

When all the heartbeats with the node in the RUNNING state are disconnected, the node is FAULTED.