Experiencing an issue syncing alarms from Spectrum. This appears in the Alarm Console when going to 'Performance->Alarms->Alarm Console'.
When the problem is seen we see the following error that states "An unexpected error has occurred. Please check the logs for any error messages."
This has been seen where the integrated Spectrum Data Source hosts a large number of Global Collections (GC).
We first look for Landscape GCs to build these queries. When the Landscape groups are not found, it defaults to GCs to check. This results in a huge request to OneClick that is rejected if more than 150 comparisons in the REST based OR statement passed to it. This is what triggers the failure when the View is run against a large set of Groups or GCs, such as the default 'All Groups' Group in Performance Management.
Performance Management releases r20.2.1 and earlier
This has been resolved via DE468346 in the r20.2.2 release of the DX NetOps Performance Management tool.
It has also been resolved in the r3.7.15 release.
The Fixed Issues documentation shows the following entry.
If running an impacted release and unable to upgrade, the only workaround possible until upgrade is the use of smaller Groups on these Views to view Alarms.