The system will temporarily shut down for scheduled maintenance on December 2nd (Wed.)

Thank you for choosing Mackerel.

In order to carry out scheduled maintenance, the system will temporarily shut down during the time designated below. We apologize for the inconvenience, and thank you for your understanding.

This maintenance was previously announced as the second of two operations and was originally scheduled for November, but has been moved back.

Scheduled date and time

  • December 2, 2020 (Wednesday) 1:00pm - 6:00pm (JST)
  • The system will be temporarily shut down within the above time period
  • This time period was set in anticipation of handling issues as they occur. If everything proceeds normally, this time period is expected to end earlier than scheduled

Maintenance subject

Areas affected during maintenance period

  • The scheduled time frame is the longest case scenario and will end as soon as the work has been completed
    • Once maintenance work has begun, the entire Mackerel system will shut down for a short period of time
  • Web access to Mackerel, data posting by the agent, API access (including the CLI tool), alert notifications, etc. will be unavailable during this time
  • As soon as the scheduled maintenance has been completed and working operation has been confirmed, the system shutdown will end and an announcement will be made
  • As for mackerel-agent metric posting, data will be buffered from mackerel-agent during the maintenance period and resent after maintenance has been completed
    • If resent properly, graphs during the maintenance period will also be displayed
    • Please note that if mackerel-agent is stopped or restarted before resending is complete, buffering data will be lost
    • Trying to start up mackerel-agent during maintenance will fail because communication with Mackerel cannot be made
    • Trying to transmit to mackerel during maintenance will fail and an error message will be output in the error log
    • If metric thresholds are exceeded during the maintenance time period, alerts will not be issued retroactively following maintenance completion
    • Check monitoring alerts will be issued for up to 6 hours for events detected during the maintenance time period
  • External monitoring and cloud integration graphs may be incomplete during the maintenance period

Why we chose this time schedule

Due to the fact that the Mackerel service is relied upon for system monitoring, we came to the conclusion that the best time for a temporary shutdown would be during the day when the majority of Mackerel users could be available to respond if necessary, rather than in the middle of the night. For this reason, we’ve scheduled the maintenance to take place during a weekday in Japan Standard Time.

On the other hand, we understand that it might be difficult to perform server operations and deploy applications during the daytime and we sincerely apologize for this inconvenience.

Consideration for our users is essential in determining an appropriate maintenance timeframe and something that we want to continue to improve. If you have any feedback, please let us know.


Situation reports will be made on the Mackerel status page (

We will also make periodical updates on our official Twitter account (

Related inquiries

Please send all inquiries regarding this matter to using the forms provided below.

Again, thank you for your understanding and cooperation.