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 mode when the main resource is failed. The resource in this group only operates at the operating nodes.
For instance, a virtual IP address cannot be used at the operating node and the standby node at the same time. In addition, if a virtual IP address causes troubles, it will switch service 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 operating node and offline at the standby node. However, if you use a parallel group, you can start, monitor or terminate 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. | 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. | 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. | INTEGER | 30sec | O | |
| PingRetryTime | Time to determine ping test 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 | 10sec | 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 |
MCCS 의 로그를 시스템로그에 추가하려면 다음의 추가 설정이 필요합니다.
/etc/rsyslog.conf 의 다음 두 라인의 주석을 해제 합니다.
... #$ModLoad imudp #$UDPServerRun 514 ...
... $ModLoad imudp $UDPServerRun 514 ...
설정이 완료되면 다음의 명령으로 rsyslog 서비스를 재 시작합니다.
# service rsyslog restart 또는 # systemctl restart rsyslog
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