How to use EMS(Emergency Message Service)

MCCS has a bundled product called EMS(Emergency Message service) that automatically sends SMS to the defined admin members in charge of critical events.
In addition, since console is web-based management, whenever an error or fault occurs, it can be managed anywhere that has internet service. Plus, Failures records in the past, management, reporting are all very easy to use.
Please refer to "EMS User Guide and EMS Agent Installation Guide" for more details about EMS system.

EMS Component

EMS Agent

It is a program installed in the server to connect with EMS server.

EMS Server

It is an installed server program from the product provider company of MCCS.

EMS Workflow

Save Log

EMS Agent saves logs.
EMS server can specify logs by its type using 'LogType' attribute as shown below.

H

It saves the logs related to HA (MCCS).
(It can only specify file monitor.)

A

It saves logs related to application.
(It can only specify file monitor.)

S

It saves event log of Windows system.
(It can only specify Windows event monitor.)

P

It saves log related to process.
(It can only monitor specified file.)

Log Analysis

EMS Server users can set failure level of the system that wants to receive EMS service.
EMS server uses failure level that is set to filter EMS Agent system of operating server and analysis log to determine if it is a failure

SMS Notification

After failure monitoring for given filter is checked, EMS will send the SMS to the system operator and MCCS server operator so that it can be dealt quickly.

After connecting to EMS server, analysis cause of failure

System operator and MCCS service operator can access to the EMS server where anywhere with internet connection to check on the log and analyze the cause.
In addition, in case of manufacturing customer, it provides a centered monitoring system for all the servers in the factory and also provides a statistic of periodical failure type and trouble-shooting solutions.
The following graph is the workflow if EMS system.

[Figure] Workflow of EMS System

Control Monitoring of EMS Server Consolidated Web-based dashboard of EMS Server

Following is a part of consolidated web-based dashboard of EMS Server.
Servers with failures are shown in red, servers that had failure and had notified to the server operators are shown in yellow, and servers that operate normally are shown in blue.
Users registered in EMS server are the only ones that can monitor the dashboard. 

[Figure] Redundant server monitoring view of EMS system

[Figure] Statistic view of EMS system

Server Failure

This is the case of system being rebooting or shut down because of conflicts of each device (NIC, Raid Controller), kernel driver problem of other application.

Active Server Failure

1. 서버의 정상 혹은 비정상 종료에 따른 MCCS의 역할에는 차이점이 없습니다. MCCS는 운영 서버에서 장애가 발생하면 대기 서버로 페일오버를 진행합니다.
   화면의 오른쪽에 있는 노드 관리에서 해당 서버를 선택하면 '리소스 상태' 및 '리소스 의존성' 화면을 통하여 장애를 확인할 수 있습니다.
   • Normal Termination of a system
     This is a case where user selected 'system shutdown' in operating systems.
   • Abnormal Termination of a system 
     This is a case where system is terminated or rebooted due to an unexpected situation or blue screen.
   
   [ Figure] Failure in Active Server
   
   
2. Since data cannot be replicated due to the server failure, will be shown in the mirror disk resource.
3. Server operators check on the failure and put the server back to normal.
4. After checking on the mirror role of two servers when server with the failure is rebooted, switch the server with the failure as replication target and proceed partial resync.

Standby Server Failure

1. MCCS will show the failure when failure occurs in standby server.
   
2. Data replication will be paused until standby server is back to normal.
   
   [ Figure] Failure in Standby Server
   
   
3. If I/O keep happens, data is impossible to replicate and mirror disk will be shown as 'Paused'(change of icon)
4. If there is no I/O, icon of mirror disk has no change but failure messages related mirror disk exists in MCCS log.
   
5. 대기 서버에서 장애가 발생하면 운영상에는 문제가 없지만 페일오버할 대상이 없으므로 서버 운영자는 반드시 MCCS 웹 콘솔을 통하여 장애를 확인하고 대기 서버를 정상화 시켜야 합니다.
6. When standby server is back to normal, it will recover from 'Paused' to 'Normal' and  icon will be disappeared.

Application, Process and Window Service Failure

Active application, process and window service resources are operated by 4 elements below.

• MonitorInterval
  Monitors the resource with interval set value. (Default Value=10sec)
• MonitorTimeout
  If there is no reply as much as the set value, it is considered as a failure. (Default Value=10sec)
• RestartLimit
  It will restart the application resource as the set value. (Default Value=0)
• OnlieTrustTime
  It re-sets the time of number of resource restarting number.It is the time to reset the frequency of the resource to restart. (Default Value=600sec)
  Attributes above are the set value of the registered being added the resource, and users can check or change the values through Resource Attribute view of MCCS console. 
  
  [Figure] Resource attribute value Edit
  
  

1. MCCS periodically monitors the resources referring  'MonitorInterval'.
2. If there is no response as the time set in 'MonitorTimeout', it is considered as a failure.
   
3. If there are no response after sending the command as the number set in 'RestartLimit', MCCS will failover the group which resource belongs to.
4. If the resource stays in normal state within the time limit set by 'OnlineTrustTime'. MCCS will initialize the attribute value of 'RestartLimit'. This is to ensure restart number when failure occurs in a resource.
   
5. If there is a failover due to a failure in the resource, server operator checks on the problem and put it back to normal.
   
6. 장애가 발생한 부분은 MCCS 웹 콘솔에서 확인할 수 있으며, 장애가 발생한 부분을 사용자가 확인한 후에 장애 표시를 제거해 주어야 다시 페일오버 기능이 활성화됩니다. 
   자동으로 장애 표시를 제거하고자 할 경우에는 그룹 속성의 AutoFaultClearTime에 0보다 큰 값을 설정하면 됩니다. 
7. After checking on the mirror role of two servers when server with the failure is rebooted, switch the server with the failure as replication target and proceed partial resync.
   
   
   [Figure] Failure in Resource Clear
   
   

Network Failure

Network failure happens when network connection has problem, such as network switch or network interface card is broken or disconnection in network cable, or ping timeout of some network and so on.

• Service Network Failure

  If failure occurs in service network of active server, the fault mark will be shown on the network interface card resource or IP address of the node in MCCS UI, and will failover to the standby server.

  
  [Figure] Failure in Network Interface Card

  
  

1. 서비스 네트워크 장애는 장애가 발생한 부분을 MCCS 웹 콘솔에서 확인할 수 있습니다.
2. MCCS checks network cable disconnection of server where network failure occurred, and whether ping timeout occurs from network.
   
3. If IP address resource is the cause of the failure, user should check on the network switch or network interface card.
   When physical parts related to network is back to normal, select 'Clear Fault' from the MCCS console and remove fault mark in order to re-enable the failover function. 
   
4. 자동으로 장애 표시를 제거하려면 그룹 속성의 AutoFaultClearTime에 0보다 큰 값을 설정하면 됩니다. 
   
   

• Heartbeat Network Fault

  핫빗은 노드 상호간의 상태를 동기화하고 장애 상태를 결정하는 중요한 역할을 하기 때문에 반드시 이중화되어 있어야 합니다. 이중화된 핫빗 네트워크 중에서 어느 하나라도 장애가 발생하면 장애 내용은 로그창에 표시 됩니다. 
  하지만 MCCS 웹 콘솔 에는 아무런 변화가 나타나지 않습니다. 이것은 운영 서버와 대기 서버에는 아무런 문제가 없다는 것을 뜻합니다. 

  At this point, when failure occurs in active server and needs to failover to the standby server, MCCS will use redundant normal heartbeat network to failover.
  If all the redundant heartbeat is disconnected, MCCS will use the service network as heartbeat line.

          [Figure] Failure in Heartbeat

1. Heartbeat failure can be checked on MCCS log, Window System log. If failure occurs in heartbeat line, server operator should check on the TCP/IP of server, physical connection check on the heartbeat through ping test.
2. If it is an abnormal situation, check on card, cable connection or cable disconnection and clear the cause of the failure.
   
   

• Replication (Mirroring) Network Failure

  When failure occurs in replication network, data cannot be replicated and it will be shown as 'Paused' in mirror disk resource of MCCS console.

  
  [Figure] Failure in Replicated Network

  
  

1. Replication network failure can be checked on MCCS log, Window System log. If failure occurs in replication network, server operator should check on the TCP/IP of server, physical connection check on the replication network through ping test.
2. If it is an abnormal situation, check on card, cable connection or cable disconnection and clear the cause of the failure.
   
   

• Single Network Switch Fault

  When failure occurs in network switch connected to Public Network where it is configured by single network switch, all the resources in active and standby server will be taken offline, resources where failure occurs will show as 'fault'.

  
  [Figure] Failure in Network Switch

  
  

1. Network switch failure can be checked on MCCS log, Window System log. If failure occurs in service network connection, server operator should check on the TCP/IP of server, physical connection check on the service network through ping test.
   
2. 자동으로 장애 표시를 제거하려면 그룹 속성의 AutoFaultClearTime에 0보다 큰 값을 설정하면 됩니다.
3. Please get the supports regarding the recovery of Network switch failure through manufacturer.
   
   

Disk Failure

Source Disk Failure

• 소스 디스크 장애 

  If failure occurs in disk resource of active server, MCCS GUI will show the failure. MCCS will failover to the standby server since it is impossible to Read/Write in the disk.

   

  [Figure] Failure in Mirror Disk

  
  

1. Availability of disk monitoring of MCCS are as below.
   • Periodic read/write test on the disk.
   • Determines whether drive letter exists in the disk.
     
     
2. 디스크 장애 발생 요인은 다음과 같은 경우가 있을 수 있습니다. 위의 문제가 해결 된 후에 운영 체제는 변경된 디스크를 다시 인식합니다.이후 DataKeeper에서 동기화를 진행합니다.
   • 디스크 컨트롤러 문제 하드웨어 자체의 문제는 해당 업체에서 해결해야 합니다.
   • 물리적인 디스크 문제 하드웨어 자체의 문제는 해당 업체에서 해결해야 합니다.
     
     
3. 미러 리소스에서 에서 동기화가 진행되지 않으면 미러디스크 리소스를 삭제한 후에 다시 생성해야 합니다. 단, 삭제시 리소스만 삭제가 아니라 생성된 미러까지 삭제 하고 다시 생성해야 합니다. 
   
   

• Target Disk Failure

  If failure occurs in disk resource of active server, MCCS UI will show as 'Paused'. It does not affect the operating service of active server.

  
  [Figure] Failure in Target Disk

  
  

1. MCCS에서 타깃 디스크에 대한 장애 감지는 해당 디스크의 드라이브 문자가 있는지 없는지 만을 판단합니다.
2. 디스크 장애 발생 요인은 다음과 같은 경우가 있을 수 있습니다.위의 문제가 해결 된 후에 운영 체제는 변경된 디스크를 다시 인식합니다.이후 DataKeeper에서 동기화를 진행합니다.
   • 디스크 컨트롤러 문제 하드웨어 자체 문제는 해당 업체에서 해결해야 합니다.
   • 물리적인 디스크 문제 하드웨어 자체 문제는 해당 업체에서 해결해야 합니다.
3. 미러 리소스에서 에서 동기화가 진행되지 않으면 미러디스크 리소스를 삭제한 후에 다시 생성시도합니다. 단, 삭제시 리소스만 삭제가 아니라 생성된 미러까지 삭제 하고 다시 생성해야 합니다.  
   
   

• Split Brain of Mirror Disk Resource 

  This happens rarely but mirror disks identifies as source on both servers. This happens in the process of changing from existing source cannot be changed to target source.
  Both servers will try to synchronize the data and that cause the split brain. Split brain occurs in the situation as shown below.

1. Failover happens due to a failure in source server (A).
   
2. MCCS sends a 'SWITCHOVERVOLUME' command.
   
3. Without deleting the existing source volume, target source (B) has switched to source.
4. Reboot the original source server(A).
5. After booting the original source server(A), check in the role of target server(B).
6. If target server(B) is source, it determines itself that failover happened normally and MCCS tries to switch the original server (Node A) to target.
7. Role cannot be checked due to the problem in mirror network or other errors. (Process of 5 and 6 get failed)
8. Mirror role of both servers become source.
   
   

   In this case, icon of mirror disk resource is shown as put on one another in MCCS Console and attribute value of 'MirrorRole' on both servers are 'Source'.
   When this happens, role of mirror disk should be changed manually, and after the change, re-synchronization process happens.
   There is a way to change the role of mirror disk, using MCCS Console.

•  MCCS 웹 콘솔을 사용해서 스플릿브레인을 해결하는 방법

1. 리소스 속성창을 확인합니다.
   
   [Figure] Verify SplitBrain of MirrorDisk

   
   

2. 미러관리 창을 확인합니다.

   
   [그림] 미러디스크 스플릿 브레인 확인

    

   Warning

   1)양노드의 MirrorRole은 Source, MirrorState은 MIRROR_PAUSED 상태가 됩니다. 2) 미러디스크의 TimeAquiredSourceRole을 확인합니다. (TimeAquiredSourceRole은 시스템의 시간이므로 최신 데이터의 유무를 결정할 수 있는 절대값은 아닙니다) 3) 스플릿 브레인이 발생했을 때 발생하는 로그가 출력됩니다.  (윈도우즈 이벤트 오류: An invalid attempt to establish a mirror occurred. Both systems were found to be Source.  Local Volume: F Remote system: 200.200.124.49 Remote Volume: F The mirror has been paused, or left in its current non-mirroring state.  Use the DataKeeper User Inteface to resolve this Split Brain condition.) 4) 미러관리 창에서 미러 상태가 'SPLIT' 상태 입니다.

3. In the Group tab of the configuration tree, right click mirrordisk resource and you can select the source node when you place the cursor on the "Resolve Split Brain".
   
   [그림] 스플릿 브레인 해결  선택
   
   
4. 스플릿브레인에 대한 설명창이 출력됩니다.
    
   [그림] 소스 노드 선택에 대한 내용 확인
   
   
5. 소스노드를 선택합니다.
   
   [그림] 소스 롤 노드 선택
   
   
6. 선택한 소스노드에 대해 다시 한번 확인합니다.
   
   [그림] 소스 노드 선택 다시 확인
   
   
7. 스플릿해결 중인 화면입니다.
   
   [그림] 스플릿 브레인 해결 화면
   
   
8. 스플릿해결 완료 화면입니다.
   
   [그림] 스플릿 브레인 해결 완료 화면
   
   

9. 선택한 노드가 소스노드가 되고 미러디스크의 상태는 MIRRORING 상태로 바뀌게 됩니다. 
   
   [그림] 스플릿 브레인 해결
   
   

   Warning
   노드 B 의 변경된 정보는 모두 덮어써지게 됩니다

    

External Storage Failure

외장 디스크의 연결 경로 및 디스크에 장애가 발생하면 해당 디스크의 Read/Write가 불가능하므로 MCCS는 장애를 표시하고 페일오버를 진행합니다.

[Figure] Failure in Shared Disk

1. External storage failure can be checked through MCCS log, System log.

2. If there is a problem in external storage, service is stopped until the storage recovers. Therefore, storage should be recovered in a short period of time or it should be replaced to other one (back up storage).

3. Problems related to the external storage should be dealt with the vendor.

4. When the server of external storage connection and disk where failure occurs is back to normal, Server should be rebooted so that MCCS Kernel Driver can identify the recovered environment.

5. Also, redundancy measures should be solved from storage vendor.
   

NetBIOS 장애

Use Direct-Hosted SMB

SMB which is supported on Windows 2000 or later uses Direct-Hosted. This feature is support directly file sharing service without NetBIOS interface.
To resolve name resolution for an IP address, DNS lookup occurs and not used NetBIOS name resolution.

Transmit and receive operation

• Basically redirector(WorkStation Service) is transmit call to NetBIOS devices and SMB devices, file server receive call about NetBIOS devices and SMB devices.
• File server SMB device is waiting to receive call TCP port 445 preferentially not in TCP over NetBIOS 139.
• If SMB session fails to listen TCP port 445, use TCP over 139(NetBT). If both of TCP port 445 and TCP over 139(NetBT) are failed, session will be failed.

Namely, if you want to work with the DNS server while using NetBIOS agent, most of clients are connected by Direct-Hosted SMB.

Related Cache Flush

When verify agent action, related cache will be flushed.

Flush a NetBIOS table cache

netbtstat -R

Flush A DNS cache

ipconfig /flushdns

Flush an ARP cache

arp -d

Turn off firewall settings

Turn off NetBIOS communication related are : the destination port number.

Turn off DNS Server update, WINS Server update communication related are : the destination port number.

Considerations when Workstation Service is stopped

The Workstation Service on Windows Services creates and maintains client connection for the remote server using SMB protocol.
If this service is stopped, cannot keep the connections. if this service is disabled, then this connection explicitly using the service cannot be started.
When the workstation service is stopped, you must be careful.

Considerations of Server Service stop

Windows Server service supports sharing the file, print, and named pipe over the network for this computer. If this service is stopped, cannot use these features. If this is disabled, the following services have a dependency on this service will not be able to start.

When the server service is stopped, you must be careful.

When file sharing is not working

At first, please verify file sharing is working as original NetBIOS computer name except virtual name.
On the client, please verify that access to node file on a regular basis is working using command like dir, start, explorer or net view.
Please verify as DIR command.
DIR command is run by following syntax.

dir \\virtual_name\shared_folder 

Please verify as START command.
START command is run by following syntax.

start \\virtual_name

Please verify as EXPLORER command.
EXPLORER command is run by following syntax.

explorer \\virtual_name

Please verify as NET VIEW command.
NET VIEW command is run by following syntax.

net view virtual_name

Your computer's file and print sharing lists are created. On the specified computer, there are no file or print shares available, "there are no entries in the list" message.
When the client isn't refreshed the mapping information between virtual name and real IP address after failover occurs, the client's NetBIOS cache is not communication for a few minutes until flushed.
This case will be happened when you use WINS server. Therefore the clients program is needed to be cluster aware in this case.

SCSI Lock Failure

When interlock with volume manager using SCSI3-PR

Volume Manager (Ex: something like SFW of Symantec that has SCSI3-PR reservation function) can be used with SCSI Lock agent.

When check if SCSI-PR is supported

To check of the disk supports SCSI-3PR function, PR type can be checked using scsicmd.cmd command.

When cannot find sg_scan.exe or sg_persist.exe pass

Check if the command exist in %MCCS_HOME%/bin.

When interlock with shared disk

When interlock shared disk agent and SCSI Lock agent, check if the shared disk agent works normally and then register SCSI Lock agent.
The purpose of disk of SCSI Lock agent is to use as a LOCK device in hardware perspective, not the contents of the disk. Therefore, size of disk can be small and it is not protected.

When registration key error occurs

Remove Reservation key and registration key using scsicmd.cmd-c command and re-set. Before registering resource, check if there is any registered key and if there is, remove the key first before registering.
Note that the current key is se automatically by its MAC address. It uses the first adapter among the network adapters. This key is automatically recorded in setting file. If key does not exist in setting file then new key is not created.

When various letters exist in one disk and when register one letter, other letters cannot access

SCSI Lock disk supports basic disk and single letter. Please do not use the disk that uses dynamic disk or multiple volume(use one LUN to configure various partition).

When maintaining the state where DUID is not solved after registering agent

레터를 정의하고 활성화를 요청해야 main.json에 해당 레터에 연결된 DUID 정보가 기록됩니다.

When delete agent

SCSI Lock 에이전트가 삭제될때 예약을 해제합니다. 따라서 예약대상 공유디스크가 상대 노드에서 사용될 가능성을 염두에 두고 삭제를 해야 합니다. 즉 삭제할 경우에는 상대 노드를 다운시킨 후 작업하십시요.

Ways to collect support files

When problems occur in MCCS, support file must be collected to collect log and preference information.
There are 2 ways to collect support file.

웹 콘솔 통해서 수집하는 방법

1. MCCS 웹 콘솔에서 메뉴바의 '파일'을 클릭하여 서포트 파일을 수집할 수 있습니다.
   
   [Figure] Support file Collect Icon 1
   
   
2. Support files can be collected by clicking the toolbar shown in the figure below.
   
   [Figure] Support File collect icon 2
   
   
3. 서포트 파일을 수집할 노드의 선택과 이전에 받은 서포트파일을 다시 받을 수 있습니다.
   
   [그림] 서포트 파일 노드 선택 및 이전 서포트 파일 선택 여부
   
   

4. Click 'OK' button and support file is collected.
   
   [그림] 서포트 파일 수집 중 화면

    

   Info
   로그파일의 용량과 네트워크의 상태에 따라서 몇 분이 걸릴수도 있습니다.

5. 아래와 같이 다운로드 창이 열리게 되고 다운받으시면 됩니다.
   
   
   
   [그림] 서포트 파일 수집 확인
   
   
   
   

Collecting file using script files

Script file is located as below:

%MCCS_HOME%\bin\Support\support.cmd

Collected support file is created in the following directory.

%MCCS_HOME%\support-%COMPUTERNAME%\%COMPUTERNAME.zip