The number of hosts will be calculated as follows.

• The number of hosts will be calculated using the average of the past month.
  • It is the average number of hosts, not the maximum number of concurrent active hosts or the total number of hosts.
  • For example, even if there is a temporary increase in the number of servers due to high-load countermeasures, the usage fee will not increase significantly.
  • Any decimal points calculated in the average will be rounded up.
    • For example, in the case of 3.2 hosts, the number will be rounded up to 4 and charges will be made accordingly.
  • For the first month of your contract, you will be billed for usage from the date you sign up for a paid plan until the end of the month.
    • Example: If you are using 5 Standard Hosts and signed up for the Standard Plan on the 15th of a month ending on the 31st, the number of Standard Hosts you will be using will be approximately 3 (rounded up).
    • The formula: 5 standard hosts * (31 days - 15 days)/31 days = 2.58...
• The number of active hosts will be counted periodically in time intervals of about 1 hour.

  • The number of unique hosts that have accessed the metric posting API will be included regardless of those hosts’ statuses.

    • Hosts with metric posts are counted as active hosts even if the host status is poweroff.

  • Normally this number will equal the number of mackerel-agents being run.  * Hosts with a “retired” status / hosts with no metric posts will not be counted as active hosts.

• If you are using a paid plan, even if you have 0 active Standard Hosts, you will be charged for features that are subject to billing by Mackerel, such as metric posting and external monitoring. For more details, please refer to the How usage fees are calculated.