I’ve been waiting for >12 hours since uploading files for processing by UCHIME, but they have been stuck in the same status since yesterday. Some files are in gray and some in yellow (job currently running), but none are completed. Is this normal? I was under the impression that UCHIME is not very computationally heavy.
Yes, that sounds like normal processing. When jobs queue (gray), that means they are waiting for appropriate resources (cluster nodes) to free up. The time spent executing (yellow) is the complete runtime (dispatching, processing, then results written back to Galaxy). The job details view ( per dataset) will report exactly how long the processing itself took to run, and some servers will report even more information like estimated costs, etc.