At Fri, 08 Aug 2008 17:45:00 -0500, Walter Gould <[EMAIL PROTECTED]> wrote:
> > 1. you should specify a larger max-cache-size in named.conf. the > > default size of 9.5.0 (32MB) is normally too conservative for a > > busy server with many clients, reducing cache hit rate and making > > the server busier, and possibly triggering subsequent performance > > troubles as a result. > > 2. #1 may be sufficient for you, but you may also want to raise > > recursive-clients (whose default is 1000) to some reasonable large > > value (e.g., 10000). I suspect the primary reason for the SERVFAIL > > in your case is that the server hits the recursive-clients quota. > > I suspect the server left warning messages like ""no more recursive > > clients: ...". Raising recursive-clients will at least solve this > > issue. > So, why would we have not had these same issues arise six months or a > year ago? Do you think it is related to upgrading to these newer BIND > versions or possibly just a timing coincidence? I expected this question:-) There are several possible explanations: First, if you upgrade from 9.4 or 9.3 or even older version to 9.5.0-P1 or 9.5.0-P2, this may be due to the new default of max-cache-size in 9.5. Second, since the port randomization patch can generally make the server busier (even with a reasonably large max-cache-size), it may take longer time to handle each recursive client, which may then led to hitting the recursive-client quota. But these are just a guess at the moment, and I'm not confident about those theories. Recursive server's behavior is so complicated and varies among users, and something beyond my imagination could easily happen. --- JINMEI, Tatuya Internet Systems Consortium, Inc.
