In one of our Class 1 application, plancache filled up nearly 100GB within 15 minutes on MA and at the same time occupying full /var/lib/memsql which was sized at 128GB. This resulted in a highly critical cluster outage.
I spoke to our SingleStore TAM. We would need a feature where we limit the plancache based on space occupied than based on the days to retain. Right now, only option is disk_plancache_expiration_minutes . We would need something like disk_plancache_retention_max_size.
I landed up in a bridge call on a weekend and a problem ticket has been assigned to me.