Planning downtime

Adding downtime

Principle

Downtime is a period during which the notifications for a resource are disabled. Downtimes are used during a programmed maintenance operation. They save us from receiving false positive alerts.

It is important to select all the resources necessary to prevent false positives and false negatives. In addition, the time spent in this state is taken into account during the generation of the availability data.

There are two types of downtime:

• Fixed downtime: starts and stops at the planned time.
• Flexible downtime: starts during the planned time window as soon as an incident is detected and finishes when the planned time in seconds expires.

Practice

There are several ways to define downtime:

• From the Resources Status page
• From the detail sheets of a host or of the service
• From the real-time monitoring interface
• From the Downtime menu

Resources Status page

1. Go to Monitoring > Resources Status.

2. Use one of the following methods:

   • Select the object(s) that you want to define downtime on, and then click the Set Downtime button above the list of resources.

   • Hover over the resource you want to define downtime on, and then click the Set Downtime icon that appears on the left.

     

   The following window appears:

   

   • The From and To fields define the beginning and end date of the downtime. Downtime cannot start or end after December 31, 2099, 11:59 pm.

   • If the Fixed box is checked, the downtime is fixed. Otherwise, it is flexible.

   • If the downtime is flexible, the Duration field defines the length of the downtime.

   • The Comments field can be used to indicate why the downtime is defined.

Detailed sheet of an object

1. Access the detail page of an object

2. In the category: Commands, click Schedule downtime for this host/service

   The following window appears:

   

• The Host Name field defines the host concerned by the downtime
• The Service field defines the service concerned by the downtime
• If the Fixed box is checked, the downtime is fixed. Otherwise, it is flexible
• If the downtime is flexible, the Duration field defines the length of the downtime
• The Start Time and End Time fields define the beginning and end date of the downtime. Downtime cannot start or end after December 31, 2099, 11:59 pm.
• The Comments field can be used to indicate why the downtime is defined

Real time monitoring

1. Go into the Monitoring > Status Details > Hosts (or Services) menu

2. Select the(s) object(s) on which you want to program the downtime period

3. In the More actions… menu, click Hosts: Set Downtime or Services: Set Downtime

   The following window appears:

   

   • The Host Name field defines the host concerned by the downtime
   • The Service field defines the service concerned by the downtime
   • If the Fixed box is checked, the downtime is fixed. Otherwise, it is flexible
   • If the downtime is flexible, the Duration field defines the length of the downtime
   • The Start Time and End Time fields define the beginning and end date of the downtime. Downtime cannot start or end after December 31, 2099, 11:59 pm.
   • The Comments field can be used to indicate why the downtime is defined

Downtime menu

1. Go into the Monitoring > Downtimes > Downtimes menu

2. Click Add a service downtime or Add a host downtime

   The following window appears:

   

   • The Host Name field defines the host concerned by the downtime
   • The Service field defines the service concerned by the downtime
   • If the Fixed box is checked, the downtime is fixed. Otherwise, it is flexible
   • If the downtime is flexible, the Duration field defines the length of the downtime
   • The Start Time and End Time fields define the beginning and end date of the downtime. Downtime cannot start or end after December 31, 2099, 11:59 pm.
   • The Comments field can be used to indicate why the downtime is defined

Recurrent downtimes

Principle

Downtime is a period during which the notifications to a host or a service are disabled. Downtime periods are convenient during maintenance operations on a host or a service: they allow us to avoid receiving false positives.

Recurrent downtime periods are downtime periods that recur repetitively.

Example: A back-up of the virtual machines is performed every day from 8 PM to midnight. This type of back-up has a tendency to saturate the CPU use of all the virtual machines. It is necessary to program recurrent downtime periods on the services concerned to avoid receiving notifications from 8 PM to midnight.

Downtime periods are taken into account in the calculation of the availability ratio of the resource in the Dashboard.

Practice

There are two types of downtime:

• The fixed downtime period: This means that the downtime period takes place during exactly the time period defined.
• The flexible downtime period: This means that if, during the time period defined, the service or the host returns a Not-OK status, the downtime period lasts a certain number of seconds (to be defined in the form) from the moment when the host or the status returns a Not-OK status.

To add a recurrent downtime period, go into the Monitoring > Downtimes > Recurrent Downtimes menu and click Add.

Configuration of Downtime periods

• The Name and Description fields are used to give a name and describe the recurrent downtime period.
• The Enable field is used to enable or disable the downtime period.
• The Periods field is used to define one or more periods of recurrent downtime periods. To add a period, click the symbol .

It is possible to choose three types of period:

• Weekly: to choose the days of the week

• Monthly: to choose the days of the month

• Specific date: to choose specific dates

• The Days field defines the day(s) concerned.

• The Time period field contains the time period concerned (expressed in HH:MM - HH:MM).

• The Downtime type field defines the type of downtime period desired.

It is possible to combine several types of period within the same downtime.

Relations

• The Linked with Hosts list can be used to choose the host(s) concerned by the recurrent downtime period.
• If Linked with Host Groups is chosen with the list Linked with the host group, all the hosts belonging to this group are concerned by the recurrent downtime period.
• The Linked with Services list can be used to choose the service(s) concerned by the recurrent downtime period.
• If a service group is chosen with the list Linked with Service Groups, all the services belonging to this group are concerned by the recurrent downtime period.