Hi, Metadata is working slowly for past two days. Is there any maintenance work going?
Many thanks for your post.
If you are referring to the http://search.crossref.org/ tool then it was suffering a little over the last couple of days from some users trying to use it as an API rather than a simple search tool.
You can see details of that issue here: Crossref Status - Errors with search.crossref.org
You can also check on that status page or subscribe for updates on any incidents with our tools and services.
I hope this helps and if you have any further question or queries on this then please do not hesitate to contact us again.