Downtime or maintenance duration in ACS

Hi @dharsanprakash 

Great question — here's a detailed explanation regarding downtime/maintenance in Adobe Campaign Standard (ACS) and how it affects transactional events.

🔧 Maintenance & Downtime Duration in ACS
Adobe Campaign Standard is a cloud-based SaaS platform, and as such, all maintenance operations are managed by Adobe. Typically:Planned maintenance windows are brief and occur outside of peak usage hours.

Notifications are sent in advance through the Adobe System Status page or the Admin Console, depending on your configuration.

Unplanned outages are rare but monitored actively by Adobe's reliability team.

You can subscribe to updates here: https://status.adobe.com

🚨 Impact on Transactional Events During Downtime
If a transactional event is triggered from an external source during a downtime window, the following behaviors apply:

The event call (API request) will typically fail with an HTTP 5xx error (e.g., 503 Service Unavailable).

ACS does not queue or retry transactional events internally. If the request fails, the responsibility to retry or handle the failure lies with the calling system.

For mission-critical messages, it’s recommended to implement retry logic with exponential backoff in your integration layer.

Adobe recommends using monitoring and alerting on your API gateway or integration platform to detect delivery issues proactively.

✅ Recommendation
To mitigate the risk of lost events during maintenance, consider:

Implementing resilient integration patterns (e.g., retry on failure, dead-letter queues).

Monitoring the Adobe Status page regularly or subscribing to status alerts.

For enterprise-critical events, ensure fallback messaging strategies or alternate delivery paths are in place.
Best Regards, 

@dharsanprakash Have a look at this documentation to see when the maintenance is happening for ACS.

https://experienceleague.adobe.com/en/docs/campaign-standard/using/administrating/application-settings/updates-and-maintenance-operations

Regarding any transaction event coming from an external system has to look at the API response code and retrigger the event again.