Availability is the amount of time when the condition of the element is not below a specified threshold. It is expressed as the percentage of uptime in comparison to total time as follows:
Availability = (total time downtime)/total time x 100
Disabled objectives have no impact on availability calculations. Availability is rounded so it is possible for the report to show 100% availability when it is actually between 99% and 100%. There is an option in the reports to indicate this negligible impact and if this option is used, when availability is less than 100% but not exactly 100%, the availability displays as <100% (with a down arrow).
Availability based on objectives is available in the following reports:
SLA Status Report
SLA Compliance Report
For availability based on an objective, as of the first day the availability is 100% and declines over the interval specified.
Run the SLA reports only for elements that have an SLA defined. If the element does not have an SLA defined for it, no data appears in the report.
The SLA Status and SLA Compliance reports have options for calculating downtime. The downtime calculation impacts how availability is calculated. Downtime can be calculated using the element outages, outages for a specified threshold and duration, or outages as defined in an objective or SLA.
The SLA Status Report shows a summary overview of availability. They show the condition as well as the availability percentage. From within these reports click a specific piece of data and obtain more detailed information, which is the same as the SLA Compliance Report.
The SLA Compliance Report shows availability on a chart and include summary information, such as averages or first, last, highest, and lowest data. They also show data availability and data relevance, which are defined as follows:
Data Available: Amount of data available for the measured period of time as measured in a range of the following values:
0%
0.1%–33%
33.1%–65.9%
66%–99.9%
100%
Data Relevance: Relevancy of data to the reported period of time. For example, there can be data available but it is not considered (not relevant) if the associated time category is filtered out. It is indicated by the following range:
0%
0.1%–33%
33.1%–65.9%
66%–99.9%
100%
The availability and downtime data values are filtered out based on the selected time categories. Filtering of time categories is independent of any agreement or objective, thereby allowing IT to assess what availability and downtime are during specific time categories, such as peak hours. For example, Blackout periods (and other time categories) could be included in an internal IT report in order to analyze whether service outages are occurring during scheduled maintenance periods, for example. Thus, Internal IT might decide to include/exclude Blackout periods from the availability report.
The Data Relevance shows an empty square icon with a value of 0 when a time period is not included in the availability and downtime metrics. In addition, an NA appears in the time periods that are filtered out of the report. Note that outage counts and durations, and the actual outage alarms are still visible in the Outage tab (if the display options are set to show this data) to illustrate when outages did occur. However, these outages are not affecting the availability and downtime data.
For all availability reports, select the following time-related options:
Calendar: Defines when data is collected for the availability calculation.
Time Categories: Defines the periods in the calendar for which data is collected for the availability calculation.
Time Control: For either an interval or date range, further defines when data is collected for the availability calculation and the time period displayed in the report.
The ability to apply a calendar at report time allows:
Reporting: Reporting on downtime for an element using any calendar and time category definition.
Viewing: Viewing downtime that was excluded from an SLA based on the SLA calendar and specified objective time categories.
Downtime is not calculated during periods on the calendar when an outage is scheduled to occur (such as blackout periods).
If you specify a different calendar when viewing downtime and availability than that used by an SLA, the downtime and availability results might differ from those used to perform the SLA calculations. Outages also respect the SLA calendar, so you might see zero outages but also see downtime if you specify a different calendar. Therefore, be consistent when specifying the calendar to use for your report so that you do not see availability and downtime numbers that do not coincide with the SLA outage and health calculations.
Table 7-6 lists some uses of the calendar options.
Table 7-6 Implementing Scenarios for SLA Reporting
|
Requirement |
Then… |
|---|---|
|
Ignore all blackout calendars and dialog boxes in reports |
When selecting the calendar to use for the availability reports, do not select the Include Blackout option for time categories. |
|
Include all blackout calendars and dialog boxes in reports |
When specifying the calendar for the availability reports, be sure to select the Blackout option for time categories. Element blackout calendars are applied, as well as the specified report calendar. |
|
Ignore a scheduled maintenance dialog box in availability and downtime reports |
Create a new calendar that matches the agreement calendar but doesn’t include the maintenance dialog box, then configure the report to use the new calendar for availability. Be sure to select the time categories to report on. Element blackout calendars are applied, as well as the specified report calendar. |
|
Ignore an outage in reports |
Do one of the following:
|