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mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-22 10:10:06 +00:00

Update Serving stale data

Matthijs Mekking 2021-01-21 15:18:09 +00:00
parent 87299519f8
commit ce79ea342c

@ -57,6 +57,33 @@ All improvements made in 9.16.9 and later will be backported to 9.11-S1.
## A client walks into a bar, and asks the bartender do you have stale data?
| stale-cache-enable | stale-answer-enable | stale-refresh-time | stale-answer-client-timeout |
| ------------------ | ------------------- | ------------------ | --------------------------- |
| no | no | 0 (disabled) | off (disabled) |
| no | no | 0 (disabled) | 0 |
| no | no | 0 (disabled) | value |
| no | no | value | off (disabled) |
| no | no | value | 0 |
| no | no | value | value |
| no | yes | 0 (disabled) | off (disabled) |
| no | yes | 0 (disabled) | 0 |
| no | yes | 0 (disabled) | value |
| no | yes | value | off (disabled) |
| no | yes | value | 0 |
| no | yes | value | value |
| yes | no | 0 (disabled) | off (disabled) |
| yes | no | 0 (disabled) | 0 |
| yes | no | 0 (disabled) | value |
| yes | no | value | off (disabled) |
| yes | no | value | 0 |
| yes | no | value | value |
| yes | yes | 0 (disabled) | off (disabled) |
| yes | yes | 0 (disabled) | 0 |
| yes | yes | 0 (disabled) | value |
| yes | yes | value | off (disabled) |
| yes | yes | value | 0 |
| yes | yes | value | value |
With all these options, we now allow operators to be RFC 8767 compliant. But it is also less predictable when stale data is returned and when an attempt to resolve the query is made.
If `stale-cache-enable` is set to `no`, stale data is not kept in cache and it will not be used in DNS responses. It does not matter what the other options are set to, they are ignored in this case.