100% CPU / wedge with 9.8.3-P4 & RPZ?

[Phil Mayers]

All,

In the last 12 hours, we've had repeated instances of named getting 
wedged. The symptoms are:

  * named consuming nearly 100% CPU, all in user-time
  * lots of queries apparently not processed, and based on query 
logging, a sharp drop in the rate of queries that are
  * a very sharp drop (almost a complete halt, in fact) in the rate of 
RPZ "hits" in the logs at the exact time this happens
  * no other interesting logs, as far as I can see

Re-starting the named process clears it.

I can't see anything in the release notes for 9.8.4/9.8.5 - any ideas?

This is with the Spamhaus DBL, in case it matters.

Cheers,
Phil