Hello,
The main differences between using patterns for horizontal discovery and using only probes for horizontal discovery are outlined in this table:
| Topic | Horizontal discovery with probes | Horizontal discovery with patterns |
|---|---|---|
| Discovery phases | Probes run during all four discovery phases. | Patterns run only during the identification and exploration phases. Discovery still uses the Shazzam probe and port probes to kick off discovery. |
| Finding new CIs |
Discovery offers several out-of-box probes and sensors. However, if you want to find new CIs or change the data that Discovery populates in the CMDB, you must create news probes and sensors or customize the existing ones. To do this, you need knowledge of Java and JavaScript, and you need to understand how probes work together with other probes and with sensors. |
Discovery is offering more patterns in every major release and on the ServiceNow App Store. If you want to create a new pattern or customize an existing one, you can use the pattern designer, which is a user-friendly interface that helps you construct steps and enter values. |
| Feature support | Supports all standard network, and CI discovery. Certain applications are not supported without the use of patterns. See Detailed information on products discovered by ITOM Visibility for a full list. | In addition to supporting all standard discovery, patterns support:
|
| The ECC queue and troubleshooting |
Discovery creates Multiple ECC Queue records depending on how many probes are launched. To troubleshoot any issues with horizontal discovery, you must analyze several ECC queue records to see the data that Discovery retrieved. |
Discovery creates only one additional ECC queue record for the pattern. To troubleshoot any issues with horizontal discovery during identification and exploration, you only have to analyze one ECC queue record for the pattern. |
| Performance | Depending on what type of target CI you are trying to identify and explore, Discovery might trigger multiple probes during the identification phase, and then trigger additional probes during the discovery phase. It is possible that horizontal discovery with probes can take longer because of the extra overhead in triggering and processing many probes. | Discovery triggers one pattern during the identification an exploration phases. All operations that Discovery needs to run are in the pattern and Discovery can execute them in order until the pattern is finished. Therefore, pattern discovery can lead to faster performance. |
The official documentation for the above table:-
Also why pattern is used mostly because Horizontal Discovery patterns have become the standard for discovering Configuration Items (CIs). Patterns provide a simpler and more intuitive way to debug and troubleshoot discovery compared with legacy probes and sensors.
Please mark my answer as correct based on Impact.
