At 9:48 AM -0700 4/16/02, Mark S. Strom imposed structure on a stream of electrons, yielding: >Recently I updated to SIMS 1.8b8 in order to be able to use multiple >blacklist DNS servers to cut down on the spam. Modeling one poster's >settings I'm using the following dns blacklist: > >sbl.spamhaus.org >spamsites.relays.osirusoft.com >dialups.relays.osirusoft.com >relays.visi.com > >(This is in addition to another 20 or so IP address ranges in the server's >blacklist; these were from known spam relays or dialups used for relays >from a couple of years back that were widely circulated on this list.) > >However, since using the 4 blacklist dns servers I've noticed a substantial >pause on the server (the clock doesn't move) when there is incoming mail, >lasting for about 20 seconds. Is this a normal byproduct of the dns lookups >that are going on? This generally wouldn't be a big deal for the amount of >mail this server processes, but since it does reside on our main web server >(Webstar), it is impacting that.
The DNS queries will cause this. If I recall correctly (always a roulette spin) there really isn't any way to do a DNS query on MacOS without locking the system for as long as the query takes. This is one reason to try to reduce the number of DNSBL's, you use in SIMS. For example, you COULD use the parent relays.osirusoft.com zone instead of the first 3 entries and set up your IP blacklist to only reject the return values that map to spamhaus, spamsites, and dialups. That would ruduce the number of queries you are making with each connection. The other thing to look at is the speed of your nameserver. If you are using a machine on the other side of a slow link of some sort OR a Mac running MacDNS locally to do your resolution, you are imposing a delay. Any mailserver really needs a fast recursing/caching nameserver on the same LAN with it to avoid DNS delays. -- Bill Cole [EMAIL PROTECTED] ############################################################# This message is sent to you because you are subscribed to the mailing list <[EMAIL PROTECTED]>. To unsubscribe, E-mail to: <[EMAIL PROTECTED]> To switch to the DIGEST mode, E-mail to <[EMAIL PROTECTED]> To switch to the INDEX mode, E-mail to <[EMAIL PROTECTED]> Send administrative queries to <[EMAIL PROTECTED]>
