N-central Help

Custom service properties

The properties of custom services differ depending on the type of service you are creating. Common properties of all types of custom services include a service name and description.

To create a custom service, click AdministrationService ManagementCustom Services and click Add.

Automation Manager Policy Monitoring Service

The timeout interval is the period that SolarWinds N-central will wait for a response from a service before it causes the service to transition to a different state. The timeout interval for custom services based on Automation Manager Policies is calculated by subtracting two (2) minutes from the scan interval. This value can not be modified.

DETAILS TAB

Select Automation Policy

Select the specific Automation Manager Policy output that the service will monitor.

Service Identifier

Enter a unique identification value to be assigned to the custom service.

SCHEDULE TAB

Interval

Configure the frequency when the service transmits the command string to the TCP port.

THRESHOLDS TAB

String Evaluation

Select the operator used to evaluate the state of the service based on the global output parameters of the associated Automation Manager Policy.

String Value

Enter the character string used for evaluating the state of the service based on the global output parameters of the associated Automation Manager Policy.

If String does not contain {String value} display state as

Select the state that the custom service transitions to if it does not find the string value.

If String does contain {String value} display state as

Select the state that the custom service transitions to if it finds the string value.

Size of Monitored File

Select the threshold ranges for transitioning the state of the custom service based on the size of the monitored file.

External Data Feed Service

An External Data Feed (EDF) service is the best option if you want to monitor a device that does not support WMI or SNMP, and you cannot install an agent on it. EDF is a small Java agent that returns the output of a script or application. SolarWinds N-central displays the output of the script as if it was a conventional service.

Each piece of data that you intend to have the Windows agent or Windows probe report back to SolarWinds N-central is called a metric.

  1. In the Data and Thresholds tab, click Add Metric.
  2. In the Configure Metric dialog box, enter the Metric name.
  3. From the Data Type drop-down menu, select the appropriate value for the data reported by the EDF Agent.
  4. Select the Unit if the metric measured should scale automatically based on the data collected.

    It is critical that you select the appropriate type of data for a metric. If you select an inappropriate metric, SolarWinds N-central will not accept the reported data by the EDF Agent and the service will transition to a Stale state.

  5. Click Save.

Frequently Asked Questions 

Q: Where can I download the EDF Agent and samples of EDF code?

A: You can download the EDF SDK, which contains both the EDF agent and sample EDF code, from the N-able Resource Center.

Q: When would I use a Unit?

A: Units are useful if you are measuring the amount of traffic that is passed through a particular NIC. The amount of traffic is reported in bits, however you can configure your service to report kilobits, megabits, and gigabits as those units are more user-friendly. To do this select Bits from the Unit drop-down list box.

Generic TCP Service

A Generic TCP service is best used when you have an application that is available over a network, for example, a web page or email server, and you want to monitor the application. The Generic TCP service enables you to query the port that the application is running on and determine if the port responds, and if the port sends out the correct response.

SCHEDULE TAB

Interval

Configure the schedule when the service will query the TCP port.

DETAILS TAB

Timeout Value

Enter the Timeout Value in seconds that the Probe waits for a response from the TCP port.

Port Number

Enter the Port Number if it is different than the default provided.

Send Command String

Enter the Send Command String transmitted to the TCP port.

Validating String

Enter the Validating String that the probe receives from the TCP port.

You must use a string, not a regular expression for the Validating String.

THRESHOLDS TAB

DNS Resolution

Configure how the service responds if it can resolve the host name of the device by selecting the states displayed.

Generic Service Availability

Configure how the service responds if the probe receives the Validating Stringby selecting the states displayed.

Round Trip Time (ms)

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the amount of time in milliseconds it takes for the command string transmit to the TCP port, and to receive a response.

Log Scan (Appended) Service

Use a Log Scan (Appended) service when the log file that you want to monitor is updated by new lines at the end of the log file.

If the log file that you want to monitor is completely overwritten whenever the application writes to the log file, use the Log Scan (Batch) service.

SCHEDULE TAB

Interval

Configure the schedule when the service will scan the log.

DETAILS TAB

Log File Name and Path

Enter the Log File Path to define the path and file name for the log file that the service monitors. If the log file is located on the same computer as SolarWinds N-central, click Browse to locate the file.

The path must be local. UNC paths such as \\mydesktop\C$) are not supported.

Rules

Add a regular expression Rule.

THRESHOLDS TAB

Difference in minutes between the last modification date of the file and the local time of the test

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the amount of time between when the log file was last modified and when the service scanned the log.

File Size

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the size in bytes of the log file.

Line Count of Log File

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the number of lines contained within the log file.

Log Scan (Batch) Service

Use the Log Analysis (Batch) service when the log file that you want to monitor is completely overwritten whenever the application writes to the log file. If the log file that you want to monitor is updated by new lines appended to the end of the log file, use the Log Analysis (Appended) service.

Log Analysis (Batch) services can recognize wildcard characters for the name of the monitored log file. If the file name is modified, use a * symbol to instruct the Windows agent to look for the most recent log file that meets the search criteria.

If the log file is C:\test20091010.log and the only thing that remains constant in the filename is the word "test" and the suffix .log, type C:\test*.log in the Log File Name and Path.

SCHEDULE TAB

Interval

Configure the schedule when the service will scan the log.

DETAILS TAB

Log File Name and Path

Enter the Log File Path to define the path and file name for the monitored log file. If the log file is located on the same computer as SolarWinds N-central, click Browse to identify the file.

The path must be local. UNC paths such as \\mydesktop\C$) are not supported.

Rules

Add a regular expression Rule.

THRESHOLDS TAB

Difference in minutes between the last modification date of the file and the local time of the test

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the amount of time between when the log file was last modified and when the service scanned the log.

File Size

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the size (in bytes) of the log file.

Line Count of Log File

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the number of lines contained within the log file.

Last Parsed Dates in Time Zone

Select the range for the service to report a Normal state.

SNMP Service

SNMP is a communications protocol supported by many devices including printers, firewalls, switches, and routers, which includes Windows and Linux devices. Use an SNMP custom service to obtain information from those types of devices.

SolarWinds N-central services use Reverse Polish Notation (RPN) for all calculation formulae.

SCHEDULE TAB

Interval

Configure the schedule when the service will query the target device using SNMP.

QUERIES TAB

Queries

Create an SNMP query.

For each query, you can uniquely identify and display each instance with the SNMP index or the text description, for example, CPU-O or Process - store.exe. This only applies if you want to have multiple instances of the service on a device.

DATA AND THRESHOLDS TAB
Metrics

Each piece of data that you intend to have the Windows agent or Windows probe report back to SolarWinds N-central is called a metric. You an configure a maximum of thirty metrics for each custom SNMP service.

  1. Enter the Metric Name.
  2. Select one of the following:
    • Variable to Use - Select if the service will not perform any calculations on the data gathered through SNMP. This option requires selecting the appropriate variable.
    • Calculation to Use - Enter the appropriate algebraic calculation if the service will perform calculations on the data gathered through SNMP.
  3. From the Data Type drop-down menu, select the appropriate value for the data reported by SNMP.

    If you select an inappropriate value for the Data Type, SolarWinds N-central will not accept the data reported by the Agent or Probe and the service will transition to a Stale state.

  4. Select the appropriate Unit if the metric being measured should scale automatically based on the data collected.
  5. Click Save.

To configure thresholds:

  1. Select Use Mapping to map specific values or ranges of values to Normal, Warning, or Failed.
  2. When you enable Use Mapping with a numeric Type of Data, you can specify numeric ranges. Enable Use Mapping with a string Type of Data to map number values string values.
  3. Specify the appropriate thresholds for your service. If you do not want to set thresholds for this metric, clear the Configure Thresholds check box. For example, if it is a string value.
Frequently Asked Questions 

Q: What is an SNMP Index?

A: Everything in SNMP has a unique numeric identifier called an SNMP index. For example, if you have two NIC cards on a device, one NIC may have an SNMP index of .1 while the other may have an SNMP index of .2. When you make an SNMP query to find out information about the NIC, such as the NIC speed, you must specify the OID to query and the SNMP index to use.

SolarWinds N-central enables you to configure up to 15 SNMP queries within one service. If you have six different metrics that you want to but from two different SNMP indices, you can have two separate SNMP queries in the service: one for the first SNMP index, and one for the second SNMP index.

Q: What mathematical operators does the SDK accept?

A: SolarWinds N-central accepts the following mathematical operators:

  • / Divide
  • * Multiply
  • + Add
  • - Subtract

Note that variables in the SDK start with a $ symbol (for example, $Var1, $Var2)

Example calculations:

  • $Var1 + $Var2
  • ($Var1 + $Var2) / 100

To perform a delta calculation, for example, collect two data samples and then return the difference, replace the $ in front of the variable with a carat ^. For example, enter ^Var1 in the Calculation to Use field.

Q: When would I use a Unit?

A: Units are useful if you are measuring the amount of traffic that passes through a particular NIC. The amount of traffic reported is in bits, however you would like your service to report kilobits, megabits, and gigabits in the SolarWinds N-central UI because those units are more user-friendly. For this situation, you would choose Bits from the Units drop-down menu.

Syslog Service

Many networking devices such as switches, routers, or firewalls will send a syslog message when they detect that an event has occurred. Custom Syslog services are used to monitor these types of events.

SCHEDULE TAB

Interval

Configure the schedule for when the service will scan the syslog.

DETAILS TAB

Rules

Add a regular expression Rule.

THRESHOLDS TAB

Number of Lines Processed

Select the ranges for transitioning the service to a Normal, Warning, or Failed state based on the number of lines processed in the syslog file.

Frequently Asked Questions 

Q: How do I add a new regular expression?

A: To add a new regular expression, click Add String to Match up to a maximum of six regular expressions.

Q: How does the Windows probe receive syslog messages?

A: When you add an syslog message-based service to a device, the Windows probe begins monitoring port 514. Any syslog messages that the probe receives are then logged and the Windows probe then scans the syslog for any regular expressions that you have specified in your custom service.

The log file is: C:\Program Files\N-able Technologies\Windows Probe\syslog\log\syslog.log.

Q: How does the Windows Probe know when a new syslog message has been received from a specific device?

A: When the Windows Probe receives a new syslog message, it records that message in the syslog.log file. This entry is preceded by a date/time stamp as well as the IP address of the device that sent the syslog message.

For example, 07/07/2009 12:42 192.168.1.1 <syslog message text>.

By tracking the IP address of the device that sent the syslog message, the Windows Probe can recognize if the syslog message has originated from a device that it has been configured to be monitored by SolarWinds N-central.

WMI Service

Use a Windows Management Instrumentation (WMI) custom service to collect either performance information or asset information from Windows devices using the WMI protocol.

Previously in the SDK, variable names were configured in the format of a combination of the WMI Property and WMI class. For example, if the WMI Class was Class and the WMI Property was Property, the variable name would be $Property.Class which would be a unique name. If a new WMI Query was added and the same WMI Class and WMI Property were used, the SDK would configure the new variable with an incremental number such as $Property.Class.1 to ensure that the variable name was unique.

Adding an incremental number to the end of a variable name was not considered an optimal method to ensure that variable names are unique and so when the SDK was incorporated into , this model was changed.

Now with the creation of custom services, variable names are formatted as a combination of the WMI Namespace, WMI Class and WMI Property with the addition of validation to ensure the uniqueness of any variable names. With this new method in place, an example of this new configuration would be $Property.Class.root\cimv2\Ncentral.

SCHEDULE TAB

Interval

Configure the schedule when the service will scan the target devices.

QUERIES TAB

Queries

  1. Click Add.
  2. Enter the WMI Namespace.
  3. In the Variables in SELECT Statement table, click + to add variables to the query statement.
  4. Edit the variables in the table by double-clicking the WMI Property.
  5. Enter the FROM WMI Class.
  6. From Calculate As, select the format for the data that the query will report from.
  7. After WHERE, click + to add constraints for the query.
  8. In the Constraints in WHERE Clause table, double-click the elements to edit the constraints.
  9. Click Save.

To reorder the queries, click the up or down arrow to the left of each query.

DATA AND THRESHOLDS TAB
Metrics

Configure a maximum of 30 metrics for each custom WMI service.

  1. Enter the Metric Name.
  2. Select one of the following:
    • Variable to Use - Select if the service will not perform any calculations on the data gathered through WMI. This option requires selecting the appropriate variable.
    • Calculation to Use - Enter the appropriate algebraic calculation if the service will perform calculations on the data gathered through WMI.
  3. From the Data Type drop-down menu, select the appropriate value for the data reported by WMI.

    If you select an inappropriate value for the Data Type, SolarWinds N-central will not accept the data reported by the Agent or Probe and the service will transition to a Stale state.

  4. Select the appropriate Unit if the metric being measured should scale automatically based on the data collected.
  5. Click Save.

To configure thresholds

  1. Select Use Mapping to map specific values or ranges of values to Normal, Warning, or Failed.
  2. When you enable Use Mapping with a numeric Type of Data, you can specify numeric ranges (for example, 1,3,5, or 1,3-20,21,25,30-35).
  3. Specify the appropriate thresholds for your service. If you do not want to set thresholds for this metric (for example, if it is a string value), clear the Configure Thresholds check box.