Chapter 8. Graphs

Table of Contents

New Graph Wizard
Selecting the Aquirer Type
Specifying Info required by the Aquirer
PerfMon
SNMP
Script and Script-Remote
Specifying Graph Related Info
Naming the Target, Refresh Rate and Timeout
Adding another target or Finishing off by naming the Graph
Graph Settings
Active Refresh Rate and History Size
Graph Mark (Line/Bar)
Graph Type (Counter/Gauge)
Value Type
Consolidation Method
Scales ('Max Value' and 'Graph Axis Scales')
YMax / YMin
Graph Colors and Headers (Graph Has Title, Graph Win Color, Graph Back Color, Graph Title, Graph Font Color)
Multiplier and Offset

Graphs are used to plot some parameter over time. Perhaps one of the most useful things to plot is the amount of traffic on a WAN interface. All graphs have an X-Scale of time. The Y-Scale shows the values of the recording. Targets are used to get the values. A graph can show up to 4 Targets. One graph can be selected to be displayed as the Desktop Band. Right clicking on the graph will show this option.

Also See: Chapter 19, Desktop Band

New Graph Wizard

There are two ways to create a new graph. The first is using the New Graph Wizard, and the second is to copy and paste a graph. Once Pasted the settings for the graph can be edited to what is required. The other alternative is to use the Workspace Wizard as described above.

Also See: the section called “Workspace Wizard”

To launch the New Graph Wizard you could:

  • right click on an empty section of Workspace
  • use the menu bar, Edit->Insert->Add Graph
  • use the tool bar.

In broad terms the wizard steps are as follows:

  • Select the type of Aquirer that you want to use for the first target.
  • Enter or select the information required by the aquirer. This usually takes two steps in the wizard.
  • Select or specify information required by the graph.
  • Name the target, and in some cases (new aquirers) specify the Refresh Rate and TimeOut of the Target.
  • Select to add another target, in which case you go back to the top of this list and start again for the second target. The option for up to four targets on a single graph is offered. If you do not require any more targets for the graph then the name of the Graph is required as the final step. The Graph will then be created.

Selecting the Aquirer Type

The option to choose four aquirer types is offered:

  • SNMP
  • PerfMon
  • Script
  • Remote-Script

If you select the Remote-Script then you will need to enter or select the computer that will run the script. If NetProbe-Remote (NetProbe-Remote.pl or NetProbe-Remote-Service) is already setup on the required computer the drop down list will show the computer, allowing you to choose it. If you intend to setup NetProbe-Remote later, then you will have to enter the computer manually.

The option to 'Do a Basic Test on Located scripts' is also offered in the case of the Script Aquirer. The test will often help determine if the script has a chance of working by testing for syntax errors and missing modules.

Figure 8.1. Add Graph Wizard - Select Type

Add Graph Wizard - Select Type

Specifying Info required by the Aquirer

The information required by an aquirer is specific to the type of aquirer.

PerfMon

Settings for the PerfMon takes two steps. The first is to select the host that will be tested. This could be a new host, requiring a new aquirer, or it could be a host that already has a PerfMon aquirer setup. In this second option you are adding a slave target to an existing aquirer. Slave targets cannot have their Refresh Rate or Timeout set to anything other than that selected in the Primary Target of the aquirer. If these values are not suitable then use the 'New Host' option (i.e. you can use the new host option even if there are already aquirers running on the host). From a performance perspective re-using existing aquirers by adding secondary targets is most advantageous.

Figure 8.2. Add Graph Wizard - PrefMon

Add Graph Wizard - PrefMon

The next step (after 'Next' is clicked), will show a list of Performance Objects. It may take a few seconds for this list to be obtained. Selecting the Object will result in the Counter and Instance block being filled in with the relevant info. Select the Counter, and if present, an Instance to complete the requirements for the PerfMon target.

Figure 8.3. Add Graph Wizard - PrefMon Details

Add Graph Wizard - PrefMon Details
SNMP

As with the PerfMon aquirer the SNMP also requires two steps. The first is once again the host. This can be a new host or an existing host. Once again to re-use an existing host means you will be creating a secondary target and your Refresh Rate and Timeout will be dictated by the Primary Target in the aquirer. The 'New Host' option means a new Aquirer will be created. Before you can continue, in the case of a New Host, you must enter the new host's community.

Figure 8.4. Add Graph Wizard - SNMP

Add Graph Wizard - SNMP

Clicking on the 'Next' button will take you to the next step in the setup of the aquirer. This is the selection of a MIB. All MIB's are displayed and you will be required to select the desired one. Only those of types:

Figure 8.5. Add Graph Wizard - SNMP Details

Add Graph Wizard - SNMP Details
  • INTEGER
  • UNSIGNED32
  • COUNTER32
  • COUNTER64
  • GAUG32
can be used.
Script and Script-Remote

The aquirer settings for Script and Script-Remote are almost the same. The only difference is where the script is executed. In the case of Script, it is executed on the computer running Net-Probe. In the case of Script-Remote the script is executed on the host selected on the 'Select Type' page, under the 'Remote Host' option.

Your first choice in setting up these aquirers is, if you wish to make use of an existing aquirer or you want to create a new aquirer. As with all other types, using an existing aquirer (Use Existing Script) means you cannot specify the Refresh Rate and the Timeout. This option does however have performance advantages. Select a New Script means a new aquirer will be created and you will be required to specify the Refresh Rate and Timeout. If a new script is chosen then you can simply click on the check box of one of the Located Scripts, or you can browse for a script anywhere on your file system. The located scripts are in the Net-Probe installed directory under 'ScriptsTargets' directory. Under this directory a number of other directories are shown, each the name of a Script Engine. All located scripts are placed within these directories. The Wizard uses the name of the Parent Directory to determine which script language to use. If you browse and select a script you will be required to select a script engine located or enter the name of a new script engine (you will only be permitted to enter the name of the engine if the script is of type Script-Remote).

The Located Scripts will offer some additional information about the script. If the 'Perform Basic Test on Script' was previously selected, then some of the scripts may have a red background and will not offer a checkbox. These script have failed the basic test. The last column in the list will offer some information as to why the test failed. The test is recommended in the case of Script Aquirers. Scripts may be marked red for other reasons, i.e. if the script is only suitable for an alarm.

Figure 8.6. Add Graph Wizard - Script

Add Graph Wizard - Script

Clicking on the Next option takes you to the Script Arguments section of the wizard. Here you are required to enter information that will be fed into the script. You will also be required to select the Return Arg. This is, which of the return values would be used to create your graph. You will also be asked to select or enter the host which will be passed to the script.

Figure 8.7. Add Graph Wizard - Script Details

Add Graph Wizard - Script Details

If one of the 'Located Scripts' was selected then the wizard will make things a lot easier for you. Possible return arguments will be named and limited to what is applicable. Only required In Args will be enabled for entry. They will also be labeled with a decriptive name indicating what is required. This makes it very easy for anyone to make use of the pre-written scripts even if they know nothing about scripting.

Specifying Graph Related Info

Once the aquirer settings have been completed, Next will take you to the Graph Settings portion of the Wizard. Settings here are explained in more detail further down, but a brief run down will be given here. The most complicated is the Data Type. A detailed explanation is provided later, but for now you will most lightly want to select Gauge unless you have selected a Counter type using the SNMP MIB browser, or the Script Back Arg was called a counter. The Counter option measures the change in the returned value over time, where as the gauge only takes the value that is measured at that point in time.

The Graph Mark type can be a line or a bar. The line option draws a graph with a line joining each measured value. The Bar option also draws a line but fills in the area below the line as well. Take care not to use more then one Bar target on a graph. The Mark Color specifies the color of the graphed target. The Max Value is used by the Graph Indicator to indicate the Y scale of the graph. Once again, more info offered on this later.

The other options are provided in an 'Advanced' section. This is the Offset and the Multiplier. These values can be used to adjust the value drawn. This does not change the value recorded, only the value shown.

Figure 8.8. Add Graph Wizard - Graph Info

Add Graph Wizard - Graph Info

Also See: the section called “Graph Type (Counter/Gauge)”, the section called “Scales ('Max Value' and 'Graph Axis Scales')”

Naming the Target, Refresh Rate and Timeout

Next will take you to the page requesting the Name of the Target. Under some conditions the wizard would have tried to guess a suitable name, but you may wish to change it. The Refresh Rate and Timeout of the Target is also required. The Refresh Rate is the interval between each time the aquirer is run. The Timeout is the how long the aquirer will wait for a value to be obtained. PerfMon does not require Timeout.

Figure 8.9. Add Graph Wizard - Target Info

Add Graph Wizard - Target Info

Adding another target or Finishing off by naming the Graph

Next will take you to, potentially, the last step in the wizard. If you want to draw more than one target on a graph then you can select the option 'Add another Target to the Graph'. This will take you back to the first step in the wizard, but this time you will be adding the second target. Up to four targets can be added to one graph. If you do not wish to add another target then select the option 'No More Targets to Add' and enter the name of the Graph. At this point there will be a 'Finish' button. Clicking on this will close the wizard and take you back to the Workspace with the new graph added.

Figure 8.10. Add Graph Wizard - Finish

Add Graph Wizard - Finish

Copyright (c) Warren Flemmer 2006www.net-probe.com