---
sourceDocument: Australia IT Operations Management
sourceDocumentLink: https://www.servicenow.com/docs/r/it-operations-management
Release :
- australia
ft:locale :
- en-US
ft:publication_title :
- Australia IT Operations Management
ft:clusterId :
- itom
bundleId :
- itom
workflow :
- Technology
---
# Logs for horizontal discovery
# Logs for horizontal discovery {#ariaid-title1}
* Release version: Australia
*
* Updated March 12, 2026
*
*  2 minutes to read
The system collects logs to reflect the activity that takes place during a horizontal
discovery based on both patterns and probes. Use the logs to fine-tune or troubleshoot the
discovery process.
For horizontal discovery the system generates logs of the following types:
Probe-based
: The logs for probe-based horizontal discovery cover classification failures, CMDB updates, and authentication failures. A
Discovery Log record is created for each action associated with a discovery status.
Note:
The Discovery log also displays errors that occur during identification by taking log entries from the Identification Engine log. See [Examine run logs](https://www.servicenow.com/docs/access?context=identification-simulation&version=australia&pubname=australia-servicenow-platform§ion=examine-identification-engine-logs&ft:locale=en-US) for more information about the identification engine and possible errors.
Pattern-based
: The logs for pattern-based horizontal discovery include the information about
discoveries that were performed with patterns. A horizontal discovery log record is
created for an entire horizontal discovery run, which includes the results of all the
operations specified in the pattern.
## Review the logs for horizontal discovery {#ariaid-title2}
Access the logs to understand the discovery process and fine-tune the discovery
process.
### Before you begin
Role required: discovery_admin
### Procedure
1. Navigate to AllDiscoveryStatus.
2. Open a [Discovery Status](https://www.servicenow.com/docs/dFvQyz6xpvKLV0WZztk0hQ "The Discovery status provides a summary of a Discovery launched from a schedule. You can also cancel a Discovery that is in progress from the status form.") record.
The Discovery Log related list displays the logs for probe-based discovery. See [Discovery log details](https://www.servicenow.com/docs/E6xtO~ipUs7zraVfcExa0g "Discovery logs contain information on the horizontal discovery process based on probes and patterns.").
3. **Optional:** Find out the information related to the relevant log entry:
* Select the link in the CI column to open the record for that CI.
* Select the link in the Created column to view the log record.
* Select the IP address link in the Device column to view the log records for a particular device.
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4. To view logs for pattern-based discovery, select the Here link for a log entry that has HorizontalDiscoveryProbe in the ECC queue input.
The Horizontal Discovery Log window opens showing the list of pattern-based
log entries. For information on logged discovery phases, see [Discovery log details](https://www.servicenow.com/docs/E6xtO~ipUs7zraVfcExa0g "Discovery logs contain information on the horizontal discovery process based on probes and patterns.").
Figure 1. Horizontal Discovery log
5. Select an item in the left-hand column to see more information about it in the right-hand column.
6. **Optional:** To debug the pattern, select the name of the Identification Section, and then select the Debug button.
7. To return to the log record, select Close.
### What to do next
* To fine-tune or troubleshoot the pattern-based discovery, retrieve the payload as described in [KB0998923: Retrieve Payload
Feature](https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0998923).
* [Validate commands used in pattern-based discovery](https://www.servicenow.com/docs/RYAtRQESXvnxcBJ6If2EJQ "Validate pattern commands to verify that the MID Server can successfully run them. Typically, commands might fail if you haven't configured the credentials necessary to run these commands on your ServiceNow instance. Another common reason of command failure is that the IP addresses used for discovery aren’t reachable."), if there is one of the following errors:
* Authentication issue
* Authorization/Permission issue
* No Valid credentials present
* IP not reachable from mid
* Command with wrong syntax
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* If there is an error in payload processing, select the IRE Error Documentation button to learn about the Identification and Reconciliation Engine (IRE) error that occurred and how to resolve it.
{#t-OpenDiscoLog__ul_asy_vj5_dsb}
**Related topics**
* [Identification and Reconciliation engine (IRE)](https://www.servicenow.com/docs/access?context=ire&version=australia&pubname=australia-servicenow-platform&ft:locale=en-US)
* [KB0854603: Pattern Debugger Session Timed Out](https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0854603)
## Change retention time for probe-based discovery logs {#ariaid-title3}
You can configure the amount of time that Discovery retains log
entries for the probe-based horizontal discovery.
### Before you begin
Role required: admin
### About this task
By default, the probe-based discovery log retains information for 30 days, or 2,592,000 seconds.
### Procedure
1. Open the Auto Flushes table by typing sys_auto_flush.list in the navigation filter.
2. Open the discovery_status record.
3. Change the value in the Age in seconds field.
4. For the change to take effect immediately, run the Table Cleaner Job in the Schedule \[sys_trigger\] table.
5. Click Update.
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