Creating and Managing Alerts¶
Use options accessed through the Manage Alerts tab to create, copy, or modify an alert. To open the Manage Alerts tab, select Manage Alerts… from the PEM client’s Management menu.
Use the Quick Links toolbar to open dialogs and tabs that you can use to manage alerts and alerting behavior:
- Select Copy Alerts to open the Copy Alert Configuration dialog and copy an alert definition.
- Select Alert Templates to open the Alert Template tab, and create or modify an alert template.
- Select Email Groups to open the Email Groups tab, and manage or create an email group.
- Select Server Configuration to open the server configuration dialog and review or modify server configuration settings.
- Select Help to open the PEM online help.
The Alerts table displays the alerts that are defined for the item currently highlighted in the PEM client tree control. You can use the Alerts table to modify an existing alert, or to create a new alert.
Creating a New Alert¶
To open the alert definition dialog and create a new alert, click the Add icon (+) in the upper-right corner of the table.
Use the fields on the General tab to provide information about the alert:
- Enter the name of the alert in the Name field.
- Use the drop-down listbox in the Template field to select a template for the alert. An alert template is a function that uses one (or more) metrics or parameters to generate a value to which PEM compares user-specified alert boundaries. If the value returned by the template function evaluates to a value that is within the boundary of a user-defined alert (as specified by the Operator and Threshold values fields), PEM raises an alert, adds a notice to the Alerts overview display, and performs any actions specified on the template.
- Use the Enable? switch to specify if the alert is enabled (Yes) or disabled (No).
- Use the controls in the Interval box to specify how often the alert should confirm if the alert conditions are satisfied. Use the Minutes selector to specify an interval value. Use the Default switch to set or reset the Minutes value to the default (recommended) value for the selected template.
- Use controls in the History retention box to specify the number of days that PEM will store data collected by the alert. Use the Days selector to specify the number of days that the data will be stored. Use the Default switch to set or reset the Days value to the default value (30 days).
- Use controls in the Threshold values box to define the triggering criteria for the alert. When the value specified in the Threshold Values fields evaluates to greater-than or less-than the system value (as specified with the Operator), PEM will raise a Low, Medium or High level alert:
- Use the Operator drop-down listbox to select the operator that PEM will use when evaluating the current system values.
- Select a greater-than sign (>) to indicate that the alert should be triggered when the system values are greater than the values entered in the Threshold values fields.
- Select a less-than sign (<) to indicate that the alert should be triggered when the system values are less than the values entered in the Threshold values fields.
- Use the threshold fields to specify the values that PEM will compare to the system values to determine if an alert should be raised. Please note that you must specify values for all three thresholds (Low, Medium, and High):
- Enter a value that will trigger a low-severity alert in the Low field.
- Enter a value that will trigger a medium-severity alert in the Medium field.
- Enter a value that will trigger a high-severity alert in the High field.
The Parameter Options table contains a list of parameters that are required by the selected template; the table displays both pre-defined parameters, and parameters for which you must specify a value. Please note that you must specify a value for any parameter that displays a prompt in the Value column.
Use the Notification tab to specify how PEM will behave if an alert is raised.
PEM can send a notification or execute a script if an alert is triggered, or if an alert is cleared.
Use the fields in the Email notification box to specify the email group that will receive an email notification if the alert is triggered at the specified level. Use the *Email Groups* tab to create an email group that contains the address of the user or users that will be notified when an alert is triggered. To access the Email Groups tab, click the Email Groups icon located in the Quick Links menu of the Manage Alerts tab.
To instruct PEM to send an email when a specific alert level is reached, set the slider next to an alert level to Yes, and use the drop-down listbox to select the pre-defined user or group that will be notified.
Please note that you must configure the PEM Server to use an SMTP server to deliver email before PEM can send email notifications.
Use the Trap notification options to configure trap notifications for this alert:
- Set the Send trap slider to Yes to send SNMP trap notifications when the state of this alert changes.
- Set the SNMP Ver slider to v1 or v2 to identify the SNMP version.
- Use the Low alert, Med alert and High alert sliders to select the level(s) of alert that will trigger the trap. For example, if you set the slider next to High alert to Yes, PEM will send a notification when an alert with a high severity level is triggered.
Please note that you must configure the PEM Server to send notifications to an SNMP trap/notification receiver before notifications can be sent.
Use the field in the Nagios notification box to instruct the PEM server to notify Nagios network-alerting software when the alert is triggered or cleared. For detailed information about configuring and using Nagios with PEM, please see Using PEM with Nagios.
- Set the Submit passive service check result to Nagios switch to Yes to instruct the PEM server to notify Nagios when the alert is triggered or cleared.
Use the fields in the Script execution box to (optionally) define a script that will be executed if an alert is triggered, and to specify details about the script execution.
- Set the Execute script slider to Yes to instruct PEM to execute the provided script if an alert is triggered.
- Set the Execute on alert cleared slider to Yes to instruct PEM to execute the provided script when the situation that triggered the alert has been resolved.
- Use the radio buttons next to Execute script on to indicate that the script should execute on the PEM Server or the Monitored Server.
- Provide the script that PEM should execute in the Code field. You can provide a batch/shell script, or SQL code. Within the script, you can use placeholders for the following:
- %AlertName% - this placeholder will be replaced with the name of the triggered alert.
- %ObjectName% - this placeholder will be replaced with the name of the server or agent on which the alert was triggered.
- %ThresholdValue% - this placeholder will be replaced with the threshold value reached by the metric when the alert triggered.
- %CurrentValue% - this placeholder will be replaced with the current value of the metric that triggered the alert.
- %CurrentState% - this placeholder will be replaced with the current state of the alert.
- %OldState% - this placeholder will be replaced with the previous state of the alert.
- %AlertRaisedTime% - this placeholder will be replaced with the time that the alert was raised, or the most recent time that the alert state was changed.
When you have defined the alert attributes, click the edit icon to close the alert definition editor, and then the save icon (in the upper-right corner of the Alerts table). To discard your changes, click the refresh icon; a popup will ask you to confirm that you wish to discard the changes.
Modifying an Existing Alert¶
Use the Alerts table to manage an existing alert or create a new alert. Highlight an object in the PEM client tree control to view the alerts that monitor that object.
You can modify some properties of an existing alert in the Alerts table:
- The Name column displays the name of the alert; to change the alert name, simply replace the name in the table, and click the save icon.
- The Auto created? column indicates if the alert definition was automatically created; Yes indicates that the alert was created by PEM, and No indicates that the alert was manually created.
- The Template column displays the name of the alert template that specifies properties used by the alert. You can use the drop-down listbox to change the alert template associated with an alert.
- Use the Enable? switch to specify if an alert is enabled (Yes) or disabled (No).
- Use the Interval column to specify how often PEM should check to see if the alert conditions are satisfied. Set the Default switch to No and specify an alternate value (in Minutes), or return the Default switch to Yes to reset the value to its default setting. By default, PEM will check the status of each alert once every minute.
- Use the History retention field to specify the number of days that PEM will store data collected by the alert. Set the Default switch to No and specify an alternate value (in Days), or return the Default switch to Yes to reset the value to its default setting. By default, PEM will recommend storing historical data for 30 days.
Click the Edit icon to the left of an alert name to open the Alert details editor and access the complete alert definition. After modifying an alert in the editor, click the Save button to make your changes persistent.
Deleting an Alert¶
To mark an alert for deletion, highlight the alert name in the Alerts table and click the delete icon to the left of the name; the alert will remain in the list, but in red strike-through font.
The delete icon acts as a toggle; you can undo the deletion by clicking the delete icon a second time; when you click the Save icon, the alert definition will be permanently deleted.
The screen shown below defines an alert (named System Usage High) that monitors the committed transactions on the system:
To re-create this example, highlight the name of a PEM Agent in the tree-control, and select Manage Alerts… from the PEM client Management menu. When the Manage Alerts tab opens, click the add icon (+) in the upper-right hand corner of the Alerts table to open the alert editor.
Fields on the General tab instruct PEM to use the Disk busy percentage template to create the alert. The PEM server will check the free memory available once every minute, and:
- Trigger a low-severity alert if the free memory available drops below 20%
- Trigger a medium-severity alert if the free memory available drops below 10%
- Trigger a high-severity alert if the free memory available drops below 5%
Fields on the Notifications tab instruct PEM to:
- Send an email notification to the administrator email group.
- Submit a passive service check result to Nagios.
- Execute the script shown in the Code field when the alert is triggered.
- To invoke a script on a Linux system, you must modify the entry for batch_script_user parameter of agent.cfg file and specify the user that should be used to run the script. You can either specify a non-root user or root for this parameter. If you do not specify a user, or the specified user does not exist, then the script will not be executed. Restart the agent after modifying the file. If pemagent is being run by a non-root user then the value of batch_script_user will be ignored and the script will be executed by the same non-root user that is being used for running the pemagent.
- To invoke a script on a Windows system, set the registry entry for AllowBatchJobSteps to true and restart the PEM agent. PEM registry entries are located in HKEY_LOCAL_MACHINE\Software\Wow6432Node\EnterpriseDB\PEM\agent.
Click the edit icon to close the editor and add the example to the Alert List; click the save icon before closing the Manage Alerts tab to save your work.