CIDuty:QuarantineInstances
When and How to quarantine instances
Choose the worker types you wish to investigate by following the bellow link. https://tools.taskcluster.net/provisioners/releng-hardware/worker-types/
Check which instances have exception(orange) at task state and investigate each of them separately.
Quarantine the ones that have the last 10+ tasks resolved as exception(orange). And accept the default 1000 year quarantine, RelOps can disable the quarantine whenever the instances are fixed.
File a bug in Bugzilla under RelOps similar to this bug example.