A cluster is a set of nodes composited of multiple resource groups such as failover or parallel groups.
A cluster is at the top layer of MCCS configuration and contains single or multiple groups in there. This manages HA configuration.

Table of Contents

Cluster Configuration

Two Node Clsuter

Support Failover Group

A failover group is a group that contains the resource that can be run at a single node at a time.
A failover group switches to the standby node when the managed resource is failed. The resource in this group only runs at the available nodes.
For instance, a virtual IP address cannot be used at the active node and the standby node at the same time. In addition, if a virtual IP address causes troubles, it will failover the group to the standby node.

Support Parallel Group

A parallel group is a group composed of the resources that can be run at more than one node at the same time.
A parallel group does not failover.In general, the resource containing applications made of cluster is online at the active node and offline at the standby node.
However, if you use a parallel group, you can start, monitor and stop the designated application at the both nodes.
For instance, if the both nodes operate the backup software and you register it as the resource managed in a cluster, you can run the backup software at the both nodes at the same time. (But, the application should be run at multiple nodes in parallel.)

Support Single Node Group

A single node group is a group of resources that can be run at a single node.
A single node group does not failover. When the included resource experiences troubles, a single node group will try to be online as many times as designated.

싱글노드 클러스터

한 개의 노드에서 실행될 수 있는 리소스로 구성된 클러스터를 싱글 노드 클러스터라고 합니다. 싱글노드 클러스터는 페일오버 를하지 않습니다.
싱글노드 클러스터에서는 오직 싱글노드 그룹만 지원합니다.

Cluster Attribute

Cluster attributes can be checked in the cluster attribute view.
In the group management view of the MCCS web console, select a cluster and press the 'Cluster Attribute value' tab on the right to view the detailed information.
The grey values are for reading only. These values represent the group status. The white colored values are defined by a user and they can be modified.
The below table explains some attributes.

[Figure] Cluster Attribute View

Attribute	Description	Type	Defaults	Edit	Note
ClusterName	It is the name of the cluster. It is defined during the first time configuring the heartbeat.	NAME		X
GroupLimit	It is a maximum number of groups that can be added.	INTEGER	32ea	X
HBInterval	It is an interval for checking whether to receive heartbeat signal, Heartbeat signal is transferred at an interval 1/10 of this time.	INTEGER	2000ms	O
HBPort	It is the heartbeat service port number.	PORT	14321	X
HBTimeout	It is ICMP test timeout for heartbeat network. If heartbeat data is disconnected, Timeout will take place, and the ICMP test will be conducted.	INTEGER	3sec	O
IsolationTestTmeout	It sets up the ICMP test timeout during the node isolation (SPLIT) test. For the test IP address, please refer to 'Isolation TestAddress' from Node Attribute of this chapter.	INTEGER	3sec	O
LogBackupCount	It is the limit of backuped log file count.	INTEGER	3ea	O
LogFileSize	It is the size of the log file. Minimum size is 64KB. while the maximum size is 10,000MB. If the size of the log file is greater than this, it will be backed up to mccs.log.1	INTEGER	1000Kb	O
LogLevel	It is the standard level of the log recorded in the log file. The log levels include DEBUG, INFO, WARN, ERROR and FATAL, and only those logs above this level will be recorded in the file.	LOG LEVEL	Info	O
NodeFaultDetectionTime	It is the time for detecting node failures. If the time from the last hearbeat disconnection to the disconnection of the second behind heartbeats exceeds this time, it will be regarded as SPLIT, and if smaller, it will be considered a node failure.	INTEGER	30sec	O
PingRetryTime	Time to determine ping test failure. If the heartbeat data disconnects, it will try to ping during this time. If ping does not work after the time is exceed, it is determine as failure.	INTEGER	0sec	O
ResourceLimit	It is a maximum number of resources that can be added.	INTEGER	500ea	X
RMIConnectionTimeout	It is RMI connection timeout.	INTEGER	2sec	O
RuntimeExcuteTimeout	OS Command 연결 시간 제한을 입력합니다.	INTEGER	10초	O
SingleNodeCluster	It is a cluster consist of a node.	BOOLEAN	false	X
SysLogLevel	It indicated the log level to be recorded in the Windows system log. Only those logs above this level will be recorded in the system log.	LOG LEVEL	Error	O

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

로그레벨은 다음과 같이 정의되어 있습니다.

로그레벨	설명
DEBUG	그룹, 리소스 등의 세부 속성값, 세부상태 변경등에 대한 정보, 백업파일 생성에 대한 정보
INFO	그룹, 리소스 등의 최종 값 변경 및 최종 상태 변경등에 대한 정보
WARN	핫빗 상태변경, 엔진상태 변경등의 경고성 정보
ERROR	리소스 장애(FAULTED 상태), 배치 스크립트 실행실패, 잘못된 배치 스크립트 위치 등의 오류성 정보
FATAL	잘못된 설정파일로 인한 MCCS 구동 실패등의 정보

CLI Use (mccluster command)

Used to modify the attribute values of an MCCS cluster. Using this CLI, a user can modify the desired attributes values.

When you install MCCS, the initial user account is set to 'admin' and the password is set to 'password'.
When you run the CLI command, you need to enter the account and the password. Otherwise, the above initial account and password will be used.
Thus, when you change the account and password, you must enter the account/password in the CLI command as options.

Syntax

mccluster [-u userid -pw password] [-c clusterName] [-a attribute] attribute_value

Options

Option	Description
-h	Display Help.
-u	Enter the user account.
-pw	Enter the password.
-c	Designate a cluster to be accessed to run the command.
-a	Designate the attribute name to be modified.

Example

modify

Modify the cluster attributes of testCluster.

mccluster -u admin -pw password -modify -c testCluster -a attribute attribute_value

list

Display the cluster condition.

mccluster -u admin -pw password -list

3. Cluster.