On 6/23/21 9:02 AM, Garbacik, Joe wrote: > I noticed that my squid server queries every second for the same > destination (because we have a clients requiring access to this > destination). My squid server does not have the negative_dns_ttl nor > the positive_dns_ttl values set so I would expect that they are using > the defaults. The destination has a 5 second TTL in DNS. My question > is this, why does it still query so often if it should at least have > the answer for five seconds? I can think of two general reasons: * The cached address is purged by other, newer addresses. See ipcache_size and other ipcache_* directives in squid.conf.documented. * Squid DNS TTL handling bugs. For example, Squid v4 does not have the following v5 fix AFAICT: > Also fixed two DNS TTL bugs. Squid now uses minimum TTL among all used > DNS records[2]. Old ipcacheParse() was trying to do the same but: > * could overwrite a zero TTL with a positive value > * took into account TTLs from unused record types (e.g., CNAME). > [2] Subject to *_dns_ttl limits in squid.conf, as before. Cache.log analysis with debug options set to "ALL,9" (or possibly just "ALL,1 14,9") can determine the exact cause. Alex. _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
