T11568 appears to describe an environmental issue related to extremely poor query performance, possibly because of write synchronization in a master/master cluster.

Broadly, we could make an attempt to benchmark the host, either during setup or in a dedicated way in Config. We're unlikely to get a very precise value, but if we're within an order of magnitude that would let us raise "your host/config is completely potato and nothing is going to work" warnings. In particular, it might be useful to benchmark:

• CPU (detect raspberry pi emulated on an amiga)
• Database I/O (detect global cluster configured with write synchronization)
• Disk I/O (detect NFS on the moon)
• (With T11553) HTTP round-trip time?