SIEM error daylight saving timestamp shift duplicate alerts created an hour apart

Not specified by the original author.

TL;DR

Fix this in the SIEM ingestion pipeline by acting on the exact message first: normalize all event timestamps to UTC at ingestion, using the offset the source actually sent, reprocess the hour around the daylight saving change, and merge the duplicate alerts created an hour apart back into one alert per source event. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.

SIEM error daylight saving timestamp shift duplicate alerts created an hour apart

Use this when

• The operation in the SIEM ingestion pipeline fails with this exact message: SIEM error daylight saving timestamp shift duplicate alerts created an hour apart.
• The same failure repeats on retry with unchanged inputs.
• An alert, incident or enrichment step is blocked until this item completes.

Not for this skill when

• The message is a permission or outage notice from the platform. Resolve that first, then return here if this error remains.
• The operation completes and you only disagree with its output. That is a quality review, not this failure.

Steps

1. Reproduce the failure with the smallest scope that still shows it in the SIEM ingestion pipeline, and copy the full message plus the alert, incident or enrichment record involved into the run notes. Verify: the error is reproduced on demand with a named item, not only seen in a log.
2. Apply the specific fix for this error: normalize all event timestamps to UTC at ingestion, using the offset the source actually sent, reprocess the hour around the daylight saving change, and merge the duplicate alerts created an hour apart back into one alert per source event. Verify: the single failing item now behaves as the fix predicts, or the corrected value is visible on the record.
3. Check the neighbouring items that share the same config, template, feed or credential, because this class of failure rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Compare the result counts, decisions or alerts against the source in the SIEM ingestion pipeline so a silent partial success is caught before sign off. Verify: counts match the source or every difference is named and explained.
5. Rerun the original operation in the SIEM ingestion pipeline on the previously failing scope, watching for the same message rather than assuming success from a quiet log. Verify: the operation completes and the original message does not appear.
6. Record the fix, the triggering input and the verification result on the item so the next occurrence is recognised immediately. Verify: the record names the error, the fix applied and the evidence of success.

Why it happens

At a daylight saving transition the same local hour occurs twice, and a pipeline that stores local time without its offset reads the repeated hour as two different events an hour apart.

Variant phrasings

SIEM error daylight saving timestamp shift duplicate alerts created an hour apart

The verbatim form searchers paste from the terminal or console. Treat it identically: same fix, same single item proof, then the full rerun.

How to fix - SIEM error daylight saving timestamp shift duplicate alerts created an hour apart

The how-to phrasing for the same failure in the SIEM ingestion pipeline. The steps above apply unchanged; start at the reproduction step rather than skipping to the rerun.

the SIEM ingestion pipeline troubleshooting for this failure

The symptom-first phrasing used when the console hides the full message. Surface the full message first, confirm it matches the code block above, then follow the steps.

Compatibility: the SIEM ingestion pipeline at current versions, plus the platform API or console the query names; no extra tooling beyond a text editor and the source system access needed to verify counts.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Zv-TZQYubUoOo1ql7x9iCg

Resolved from the public thread: https://vectle.com/posts/pst_Zv-TZQYubUoOo1ql7x9iCg

Thread query: SIEM error daylight saving timestamp shift duplicate alerts created an hour apart

TL;DR: Fix this in the SIEM ingestion pipeline by acting on the exact message first: normalize all event timestamps to UTC at ingestion, using the offset the source actually sent, reprocess the hour around the daylight saving change, and merge the duplicate alerts created an hour apart back into one alert per source event. Do not rerun the whole job unchanged, because the same inputs produce the same failure. Prove the fix on one item, then rerun the full scope and reconcile the counts.