[bind10-dev] document zonemgr configurations

[Jerry.zzchen]

On Fri, Dec 9, 2011 at 3:09 AM, Jeremy C. Reed <jreed at isc.org> wrote:
> Please help provide some succinct explanations for the the zonemgr
> configurations. Any clarifications would be appreciated.
>       reload_jitter
>       This value is a real number. The default is 0.75.
>
> * What is this reload_jitter? Why is the default 0.75? I attempted to
> read the code several times. Why is it called "reload"?  Why doesn't it
> have a maximum? Can it be disabled?
The initial goal of reload_jitter is to avoid many zones need to do
refresh at the same time on zonemgr startup.
For more information, please refer to http://bind10.isc.org/ticket/387.

>       max_transfer_timeout defines the maximum amount of time in
> seconds for a transfer.  The default is 14400 (4 hours).
>
> * Why "transfer"? Isn't this a timeout for doing the refresh (SOA
> lookup)? I set to zero and still worked -- according to code the timeout
> is set to the current time; it did cause 83 ZONEMGR_REFRESH_ZONE lines
> to be logged (for a single refresh) but it appeared to work (it got my
> updated zone). Why four hour default?
The max_transfer_timeout is a timeout for waiting for response from
Xfrin module.
Since Xfrin may retry many times for zone transfer(by using
exponential backoff), Zonemgr shouldn't send zone refresh requests too
often.

Thanks.

-- 
Jerry