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Introducing the Function of EXPRESSCLUSTER: Specify Service Startup Delay Time

EXPRESSCLUSTER Official Blog

August 26th, 2022

Machine translation is used partially for this article. See the Japanese version for the original article.

Introduction

We have released EXPRESSCLUSTER X 5.0, the latest version of EXPRESSCLUSTER X, on April 22nd, 2022.
In EXPRESSCLUSTER X 5.0, we have further enhanced the supported functions for the various clouds and add the functions that allow you to build a cluster system easier. For other enhancements of EXPRESSCLUSTER X 5.0, please refer to popupthe EXPRESSCLUSTER X 5.0 New Enhancement document.

This time, we will introduce the function to specify the Service Startup Delay Time of EXPRESSCLUSTER X, which is one of the new enhancements of EXPRESSCLUSTER X 5.0.

Contents

1. Why Do We Need to Delay the Service Startup of EXPRESSCLUSTER?

For using EXPRESSCLUSTER X, we must set the time, which is from powering on each server for the HA cluster system to starting the service of EXPRESSCLUSTER X, to be longer than the following two points. 


  • The time from power-on of the shared disk to the point they become available.
    * For using the shared disk

  • Heartbeat timeout time
    * Default values for heartbeat timeout time (Windows: 30 seconds, Linux: 90 seconds)
    * When using the forced stop resource, we must set the heartbeat timeout time to satisfy the following calculation formula.
The time to complete the service startup of EXPRESSCLUSTER X ≧ the heartbeat timeout time + the time to wait for stop to be completed of forced stop resource

For more information about the forced stop resource, refer to the Reference Guide.

[Reference]
  • EXPRESSCLUSTER X 5.0 > EXPRESSCLUSTER X 5.0 for Windows > Reference Guide

  • 7 Forced stop resource details

  • EXPRESSCLUSTER X 5.0 > EXPRESSCLUSTER X 5.0 for Linux > Reference Guide

  • 7 Forced stop resource details

This is to avoid the following issues:


  • When we power on the shared disk and the servers for HA cluster as the same time to start the HA cluster system, the completion of the shared disk startup time may take longer than the service startup of EXPRESSCLUTER X. In this case, due to the state of the servers for the HA cluster which cannot recognize the shared disk, the activation of the disk resource will be failed. 

  • In the case that we want to cause a failover triggered by the active server restart, if the service startup of EXPRESSCLUSTER X of the restarted server completes within the heartbeat timeout time, the other servers consider the heartbeat to continue, and a failover does not occur.
For the EXPRESSCLUSTER X-specific terms such as heartbeat, refer to this popuparticle.

In EXPRESSCLUSTER X 4.3 and earlier, to adjust the service startup time of EXPRESSCLUSTER X, we had to delay the time until the OS started, or, for windows, use the armdelay command.

However, if you delay the time until the OS starts, there is a disadvantage that the startup of services that are not clustered by EXPRESSCLUSTER X will also be delayed.
In EXPRESSCLUSTER X 5.0, the function was added to delay the time until the service startup time of EXPRESSCLUSTER X after the OS start. This function allows you to delay only the service startup of EXPRESSCLUSTER X without delaying the time until the OS starts.

* For more information about the function of the Service Startup Delay Time and the adjustment the OS startup time, refer to the Installing and Configuration Guide.

[Reference]
  • EXPRESSCLUSTER X 5.0 > EXPRESSCLUSTER X 5.0 for Windows > Installation and Configuration Guide

  • 2 Determining a system configuration
  • 2.6 Settings after configuring hardware
  • 2.6.3 Adjustment of the operating system startup time (Required)

  • EXPRESSCLUSTER X 5.0 > EXPRESSCLUSTER X 5.0 for Linux > Installation and Configuration Guide

  • 2 Determining a system configuration
  • 2.8 Settings after configuring hardware
  • 2.8.5. Adjustment of the operating system startup time (Required)

2. Specify the Service Startup Delay Time

We can specify the Service Startup Delay Time with the Cluster WebUI.
Start the Cluster WebUI, from "Config Mode", select the "Timeout" tab in the "Cluster properties", and enter the number of seconds you want to delay the service startup of EXPRESSCLUSTER to "Service Startup Delay Time" in the range 0 to 9999 seconds. The following is for the Windows version, but it is also possible to set the "Service Startup Delay Time" from the same "Timeout" tab in the Linux version.

Timeout tab

3. Checking the Operation

Verify starting the service of EXPRESSCLUSTER in the seconds set to the Service Startup Delay Time after starting the OS. 
For this verification, we use EXPRESSCLUSTER X 5.0 (Internal Ver. Windows: 13.00, Linux: 5.0.0-1), and the Service Startup Delay Time is set to "300 seconds".

After restarting the OS, verify the time the OS started and the time the service of EXPRESSCLUSTER started.
The steps to verify for Windows and Linux are different, so we will describe each one.

3.1 Windows

For Windows, we can verify the server startup time from the "System" in the event log.

Next, in the "Application" of the event log, verify the message that the cluster service has started and the time when it occurred.

Verify the following log:
"Cluster service has been started properly."

This time, we can verify that the cluster service startup is completed after 5 min 34 seconds (334 seconds) from the time the OS started,.
* There is a slight error in the time it is logged.

3.2 Linux

For Linux, we can verify the server startup time by running the following command:

# last reboot

Next, run the following command to verify when the service of EXPRESSCLUSTER X started.

# cat /var/log/messages | grep "Starting the cluster daemon"

This time, we can verify that the service startup of EXPRESSCLUSTER X is completed after more than 5 minutes (300 seconds) from the time the OS started.

* Note that the characters you search for in the command are case-sensitive.
* There is a slight error in the time it is logged.

Conclusion

This time, we introduced the function to specify the Service Startup Delay Time of EXPRESSCLUSTER X, which is one of the new enhancements of EXPRESSCLUSTER X 5.0.
Without delaying the time until the OS starts, we can easily set the service startup delay of EXPRESSCLUSTER X with Cluster WebUI.

If you consider introducing the configurations described in this article, you can perform a validation with the popuptrial module of EXPRESSCLUSTER. Please do not hesitate to contact us if you have any questions.