[rrdtool-maint] Bug#890286: rrdcached: "gmetad RRD_update [...] rrdcached: Permission denied" if limited socket specified first

[Jean-Michel Vourgère]

Hi Chad

Thank you for your detailed report.

Before I dig more into it, can you double check there is no other instance of 
rrdcached running, and using the same socket location?

I think rrdcached was disabled by default on jessie, and was enabled by 
default on stretch. And since you are using the default rrdcached socket 
location /var/run/rrdcached.sock there might be a conflict there.