Hello! We have a problem with Bind [2] during incoming IXFR. When there is a huge IXFR (ie 1,8GB tranferred in 15minutes [1]), the response time heavily increases. Using dsc's newest "Reponse Time Indexer" we clearly see that Bind answers slow:
Response Time normal during Window operation IXFR ------------------------------------------------ 1-10us 2 10-100us 16033 100-1000us 37768 1-10ms 180 21 10-100ms 43 179 100-1000ms 748 1-10s 2224 timeout 124 6930 ------------------------------------------------ Sum 54150 10102 (The drop in total happens as the resolvers switch to other authoritative nameservers) The VM has 4 vCPUs which are all at 100% (99% user-space load)during the incoming IXFR. The memory consumption doubled during the IXFR but there is enough RAM in the server (no swapping) So I have 2 theories: a) While "patching" the in-memory zone the "IXFR-worker" somehow locks the zone so that the "request-handler" has to wait and becomes slow. b) The "IXFR-worker" eats all CPU so that there is no more CPU left for the "request-handler". So, what do Bind developers mean about my theories? Are there any ideas to improve response time during IXFR? Ie. throttling CPU of the "IXFR handler"? Were there related changed in 9.12 or 9.14? Thanks Klaus [1] Transfer completed: 27733 messages, 12689911 records, 1789M bytes, 847.424 secs (2111887 bytes/sec) [2] Seen on Ubuntu 14.04/16.04/18.04 aka Bind 9.9.5/9.10.3/9.11.3 _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users