Increase Unbound Host Cache
Versions 2.* have a drop-down option under DNS Resolver -> Advanced:
"Number of Hosts to cache"
The maximum number of hosts presented is 50,000. This value is updated in /var/unbound/unbound.conf:
Several of our servers appear to be exceeding this:
The server referenced above is an R320 with a 10gig NIC. It frequently passes over 1Gb of traffic with several thousand clients.
Additionally, several tuning guides recommend increasing this value to 100,000. Here is one of them:
Rather than hacking something outside of the webGUI I feel it'd be of value to add 100,000 as an option in the drop-down.
Updated by Phillip Davis over 5 years ago
The code here (and in other places around the system) has lots of repeated stuff (e.g. that array of known values appears the same 3 times), which is a recipe for maintenance errors. One day (not for this feature) all that should be cleaned up, defining constant objects somewhere central that can be referenced by anything that needs them (display code, validation code, implementation code...).