Manage SLA Items

Caution

You can only do this if you’re a PerformanceGuard administrator.

Many organizations use Service Level Agreements (SLAs) to define what they consider to be acceptable levels of IT service. PerformanceGuard helps you keep track of whether your organization’s IT services live up to the agreed service levels. It works this way:

1. You create SLA items. They define what to look out for, how often to look, and the thresholds that determine success or failure
2. PerformanceGuard then automatically runs the SLA items. In other words, PerformanceGuard automatically checks whether the defined services live up to the agreed service levels
3. You can then include the SLA item results in reports to management, service providers, consultants, etc. If you have external service providers, the ability to prove whether they live up to agreed service levels or not can in some environments have a big impact on the price that your organization must pay for the services.

Caution

There are three types of SLA items: One that looks at Monitor Availability, Latency and Response Times with Application Ping, one that looks at requests against specific server group and port group combinations, and one that looks at web requests defined through Web Applications. Thus, you must have set up at least some of those features before you can create SLA items.

Create SLA Items

Each SLA item consists of some threshold values, a calculation period and a target.

• The threshold values determines if the item fails or succeeds during the calculation period.
• The calculation period defines how often the SLA item should be calculated.
• The target determines what the SLA item should look at. See the following for details.

When you create a new SLA item (ADMINISTRATION > Reporting > SLA items, then select the New SLA item tab), you’ll find that the three types of SLA items share a number of parameters.

Basic Parameters

• Name: Specify a name for the SLA item.
• Period: Select how often the SLA item should be calculated. One set of SLA item values will be calculated for the selected period.
• Description: Optional textual description. If you later include the SLA item in a report, the description will be shown below the results for the SLA item in the report.

Target Value Parameters

• Availability target %: Availability in percent. If, for a period, the availability drops below the specified value, the SLA item will be marked as failed for that period.

Important

When is something considered to be available?

To answer this we need to look at response times: If response times are so long that use of a service, website, transaction or similar becomes impossible, PerformanceGuard considers the service, etc. to be unavailable. By default, PerformanceGuard loses its patience with a service, etc. if it hasn’t responded within 500,000 milliseconds (that’s a little more than eight minutes). Everything that’s not unavailable, is considered by PerformanceGuard to be available. So, if you see that a service has been 100% available during the last week, it means that it has not exceeded the acceptable response time limit during the last week.

Important

Do you measure availability of application pings (HTTP requests, ICMP ping and/or traceroutes)?

For Monitor Availability, Latency and Response Times with Application Ping, PerformanceGuard looks not only at acceptable response times, but also at whether a response is expected or not: If the response is unexpected, for example if the response has a response code of 404 Not Found, PerformanceGuard considers the service to be unavailable, even if the response was received within acceptable time.

Important

How does PerformanceGuard calculate the availability %?

PerformanceGuard looks at the ratio between failed requests and all requests in percent. In other words: (all requests − failed requests) / all requests × 100

Important

I just set up a new server. Nobody has used it yet. How can it be 100% available?

Bear in mind that PerformanceGuard looks at your new server based on how the PerformanceGuard agents experience it: If none of the computers with PerformanceGuard agents have used the new server, there have not been any unacceptably long response times, and the server has thus not been unavailable. Everything that’s not unavailable, is considered by PerformanceGuard to be available, and that explains the 100% availability, even though nobody has yet used your new server.

• Response target %: Percentage of response time measurements that must be at least equal to the specified response time target.
• Response time target [ms]: Required average response time in milliseconds. If the average response time exceeds the specified value, the SLA item will be marked as failed for that period.

SLA Item Type-Specific Parameters

These parameters depend on the type of SLA item you want to create:

Active (Application Ping)

Caution

You must have set up Monitor Availability, Latency and Response Times with Application Ping before you can create this type of SLA item.

An active SLA item looks at a single application ping of the type ICMP or HTTP Request.

Important

Why is this type called Active?

When you use application pings, selected PerformanceGuard agents contact specific servers at regular intervals to determine whether the servers are available and how long it takes to get a reply from them. A part of the PerformanceGuard solution thus actively does something in order to gather performance data.

• Agent group: Select the group of computers that you want to use for the SLA item
• Application ping: Select the required application ping the for the SLA item

Passive (Server/Port Group Combination)

Caution

You must have set up server groups and port groups before you can create this type of SLA item.

A passive SLA item looks at requests made against a specific server and port group combination.

Important

Why is this type called Passive?

PerformanceGuard passively waits for some computers to request something from the specified server/port combination. If computers don’t request anything, PerformanceGuard won’t measure anything.

• Agent group: Select the group of computers that you want to use for the SLA item
• Server group: Select required server group
• Port group: Select required port group

Transaction (Web Request)

Caution

Before you can create this type of SLA item, you must have set up at least one Web Applications and applied it to at least one agent configuration group. Also, the transaction filter must have caught some data before you can use it for an SLA item.

A transaction SLA item looks at a specific web request made by a group of computers. Transaction SLA items thus let you monitor the performance of websites and web applications as seen from specific groups of computers, for example computers at a specific office location.

• Agent group: Select the group of computers that you want to use for the SLA item.
• Transaction filter: Select the transaction filter that contains the required transaction.

Important

What's a transaction filter?

It’s a definition of things to look out for in a web request—for example images so that you can measure how long it takes before all images on a web page are available for the user to view in his or her browser. Transaction filters are very flexible: PerformanceGuard administrators can define more or less any element of a web request as a thing to look out for.

• Server & Port: Select the web server and port combination that you want the SLA item to cover. You can only select server/port combinations that have been caught by the selected transaction filter.
• Transaction: Select a transaction tag from the selected transaction filter.

Important

What's a transaction tag?

The PerformanceGuard agents installed on your organization’s computers look out for the things that your transaction filter specifies. When an agent detects one of those things, it generates a transaction tag and sends it to PerformanceGuard so that you are able to select it when you want to view a transaction graph or create SLA items. In other words, a transaction tag is a thing to look out for that one or more agents have positively found.

View SLA Item Results and Add them to Reports

To view the results of the calculations performed by your SLA items, select REPORTING > SLA. That’s also where you are able to include SLA items in reports.

Read more in SLA Item Results.