Understanding Endpoint Deduplication and Why a Device May Be Overwritten or Removed

Overview of Endpoint Deduplication

In any system that tracks multiple devices, duplicate entries can create confusion and errors. Endpoint deduplication is a process that helps maintain clean records by identifying and managing duplicate device entries in the system. When two devices appear to have the same identity, deduplication helps prevent duplicate listings by combining them into a single entry.

While this is beneficial in most cases, there are rare situations where one device may unintentionally overwrite or replace another due to specific deduplication rules.

Why One Device Might Overwrite Another in Combine

In the Combine, deduplication primarily relies on device information like the serial number and hostname. Here’s how the system handles deduplication and why a device might be overwritten:

1. Serial Number Matching:

   • Typically, Combine uses a device’s serial number as the primary identifier to prevent duplicates. If two devices share the same serial number, Combine will recognize them as the same device and merge their records.
   • Since serial numbers are unique, they’re the preferred method for deduplication and rarely lead to errors.

2. Hostname Matching as a Secondary Identifier:

   • If a device does not have a serial number, Combine will attempt to deduplicate using the hostname (the name assigned to a device).
   • In rare cases, if two devices share the same hostname and neither has a serial number, Combine will treat these devices as potential duplicates and may combine or remove one of the entries.

How Hostname-Based Deduplication Can Cause Overwriting or Removal

Hostname-based deduplication is typically a fallback for when serial numbers are missing. However, because hostnames are not unique across devices, using them as an identifier can lead to unintended overwriting in these cases:

• Shared Hostnames: If two devices without serial numbers share the same hostname, Combine will generate an endpoint ID based on the hostname alone. The system may interpret this as a duplicate entry and remove one of the devices.
• Endpoint ID Creation: Combine generates a unique endpoint ID based on the available identifiers (hostname and serial number). When only the hostname is present and it’s a duplicate, the system might deduplicate by treating one device as a duplicate and removing it.

Preventing Device Overwriting and Removal

While these situations are rare, understanding the deduplication logic can help you prevent unintended overwriting. Here are a few best practices:

1. Ensure Serial Numbers Are Available:
   Whenever possible, ensure that devices are registered with a serial number, as this significantly reduces the risk of unintended deduplication.

2. Unique Hostnames:
   Assign unique hostnames to devices to avoid conflicts, especially if they lack serial numbers. This will help the system distinguish between devices and prevent accidental merges.

3. Regularly Monitor Device Records:
   Periodically review device records to confirm that entries are correctly combined and that no devices have been mistakenly removed.

Summary

Endpoint deduplication in Combine is a helpful tool for managing device records, but rare cases may result in one device overwriting or removing another, especially when serial numbers are missing and devices share the same hostname. By following best practices to provide unique identifiers, you can help prevent accidental deduplication and maintain accurate device records.