Expired secondary zone retry-interval?

[Oskar]

Hi!

I just experienced an outage where a zone is defined via catalogzone
and the following is set:
SOA Refresh 900
SOA Retry 300
SOA Expiry 3600 (i'm aware it's very short)

Primary was intermittently unreachable and had wrong config for about 1.5h.

According to logs the Secondary was retrying transfer every 7-8minutes
as expected until the zone expired, after it expired it seems like it
tried a couple times more then stopped trying for many hours.

The only related config parameters i find are min-retry-time (default
5min) and max-retry-time (default 2 weeks) but there seems to be no
mention if this is also related to the unreachability-cache for a
certain master, or if this cache-time is even configurable.

Now i wonder: Did it actually stop trying for many hours or was it
retrying silently behind the scenes?
If it did stop trying for many hours, how / where is this behavior
defined (so i can learn to understand it) and can i cap it to retry
failed zonetransfers at max X minute intervals if master is
unreachable?

18:20:27 named: zone xx.yy/IN: expired
18:20:27 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
18:21:25 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
18:23:03 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
18:27:20 named: zone xx.yy/IN: refresh: retry limit for master
aa.bb.cc.dd#53 exceeded (source 0.0.0.0#0)
18:34:53 named: zone xx.yy/IN: refresh: retry limit for master
aa.bb.cc.dd#53 exceeded (source 0.0.0.0#0)
18:48:01 named: zone xx.yy/IN: refresh: retry limit for master
aa.bb.cc.dd#53 exceeded (source 0.0.0.0#0)
18:50:19 named: zone xx.yy/IN: notify from aa.bb.cc.dd#54418: no serial
18:50:20 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
19:33:00 named: zone xx.yy/IN: notify from aa.bb.cc.dd#58236: no serial
19:33:00 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
19:59:42 named: zone xx.yy/IN: notify from aa.bb.cc.dd#50608: no serial
19:59:42 named: zone xx.yy/IN: refresh: skipping zone transfer as
master aa.bb.cc.dd#53 (source 0.0.0.0#0) is unreachable (cached)
23:39:42 named: zone xx.yy/IN: sending notifies (serial 42)

/Oskar