Intermittent/failed search errors - API, Dublin

Incident Report for Traveltek

Postmortem

Impact
On 16 January 2026, customers experienced intermittent and occasionally failed search responses on the Searches API. The issue was first identified at 13:05 GMT and occurred in short bursts through the afternoon, with the service stabilising after fixes were applied.

Cause & Resolution
A sustained increase in traffic caused our task processing system to reach a threshold where an existing configuration issue affected how search-related processes were queued and handled. In simple terms, this system acts like a dispatch office, receiving tasks and handing them to available workers. Under higher load, the dispatch rules were not balancing work as effectively as expected, which led to intermittent search failures.

We investigated from 13:05 GMT, applied fixes to restore search results, and continued monitoring. A fix was deployed at 15:50 GMT to reconfigure how tasks were delegated, which improved stability. We observed a brief recurrence shortly afterwards, carried out additional tuning, and continued monitoring until the platform returned to normal operation.

Prevention Measures
To reduce the risk of a repeat:

We have improved the task delegation configuration so the task processing system behaves predictably during higher traffic volumes.

  • We have added more targeted monitoring and alerting for the task processing system, so we are notified earlier if queueing or worker behaviour begins to degrade.
  • We will continue to review capacity and operational thresholds to ensure the platform remains stable during traffic surges.
Posted Jan 19, 2026 - 12:14 GMT

Resolved

A fix was deployed at 15:50. We will monitor this closely, and a report will be attached to this incident after further investigation.
Posted Jan 16, 2026 - 16:50 GMT

Update

We identified a recurrence at 15:55 and are actively monitoring the situation.
Posted Jan 16, 2026 - 16:16 GMT

Monitoring

Root cause analysis is ongoing, and we are monitoring the recovery.
Posted Jan 16, 2026 - 14:33 GMT

Update

We are analysing the root cause. Searches have recovered and are returning results.
Posted Jan 16, 2026 - 14:16 GMT

Investigating

We are currently investigating this issue.
Posted Jan 16, 2026 - 13:05 GMT
This incident affected: iSell London (Searches) and iSell Dublin (Searches).