nanog mailing list archives
Re: Content Delivery Networks
From: Bjørn Mork <bjorn () mork no>
Date: Tue, 14 Aug 2007 11:24:19 +0200
"Chris L. Morrow" <christopher.morrow () verizonbusiness com> writes:
that sets a lower-bar on TTL in the nscd cache - (from the manpage for nscd.con) positive-time-to-live cachename value Sets the time-to-live for positive entries (successful queries) in the specified cache. value is in integer seconds. Larger values increase cache hit rates and reduce mean response times, but increase problems with cache coherence. Note that sites that push (update) NIS maps nightly can set the value to be the equivalent of 12 hours or more with very good perfor- mance implications. This is still a client issue as, hopefully, the cache-resolvers don't funnel their business through nscd save when applications on them need lookups... (things like ping/telnet/traceroute/blah)
nscd may represent a problem if the application in question is a http-proxy without it's own resolver. There's also a number of more-or-less broken http-proxies doing their own resolver caching regardless of actual TTL. Such applications represent a problem wrt any DNS-based load balancing, including CDNs, since they can serve a large number of end-users, redirecting them to the "wrong" address long after the TTL should have expired. Bjørn
Current thread:
- RE: Content Delivery Networks, (continued)
- RE: Content Delivery Networks andrew2 (Aug 10)
- Re: Content Delivery Networks John Levine (Aug 10)
- Re: Content Delivery Networks Patrick W. Gilmore (Aug 10)
- Re: Content Delivery Networks Crist Clark (Aug 10)
- Message not available
- Re: Content Delivery Networks Rodney Joffe (Aug 10)
- Re: Content Delivery Networks Chris L. Morrow (Aug 10)
- Message not available
- Re: Content Delivery Networks Chris L. Morrow (Aug 11)
- Re: Content Delivery Networks Florian Weimer (Aug 13)
- Re: Content Delivery Networks Rodney Joffe (Aug 13)
- Re: Content Delivery Networks Chris L. Morrow (Aug 13)
- Re: Content Delivery Networks Bjørn Mork (Aug 14)
- Re: Content Delivery Networks Chris L. Morrow (Aug 14)
- Re: Content Delivery Networks Warren Kumari (Aug 10)
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E Daniel Roesen (Aug 03)
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E Giuliano (UOL) (Aug 03)
- Re: Cisco CRS-1 vs Juniper 1600 vs Huawei NE5000E JP Velders (Aug 11)