From: Evan Hunt Date: Tue, 14 Jan 2014 05:08:20 +0000 (-0800) Subject: [master] improve prefetch doc X-Git-Tag: v9.10.0a2~101 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b751788932cf1a6d98ae83355f38a080125c2f3e;p=thirdparty%2Fbind9.git [master] improve prefetch doc --- diff --git a/CHANGES b/CHANGES index 66cba77f0a3..fcd52335fba 100644 --- a/CHANGES +++ b/CHANGES @@ -1,5 +1,10 @@ -3703. [func] Prefetch about to expire records if they are queried - for, see prefetch option for details. [RT #35041] +3703. [func] To improve recursive resolver performance, cache + records which are still being requested by clients + can now be automatically refreshed from the + authoritative server before they expire, reducing + or eliminating the time window in which no answer + is available in the cache. See the "prefetch" option + for more details. [RT #35041] 3702. [func] 'dnssec-coverage -l' option specifies a length of time to check for coverage; events further into diff --git a/README b/README index b849995612e..72368002f75 100644 --- a/README +++ b/README @@ -1,104 +1,116 @@ BIND 9 - BIND version 9 is a major rewrite of nearly all aspects of the - underlying BIND architecture. Some of the important features of - BIND 9 are: + BIND version 9 is a major rewrite of nearly all aspects of the + underlying BIND architecture. Some of the important features of + BIND 9 are: - - DNS Security - DNSSEC (signed zones) - TSIG (signed DNS requests) + - DNS Security + DNSSEC (signed zones) + TSIG (signed DNS requests) - - IP version 6 - Answers DNS queries on IPv6 sockets - IPv6 resource records (AAAA) - Experimental IPv6 Resolver Library + - IP version 6 + Answers DNS queries on IPv6 sockets + IPv6 resource records (AAAA) + Experimental IPv6 Resolver Library - - DNS Protocol Enhancements - IXFR, DDNS, Notify, EDNS0 - Improved standards conformance + - DNS Protocol Enhancements + IXFR, DDNS, Notify, EDNS0 + Improved standards conformance - - Views - One server process can provide multiple "views" of - the DNS namespace, e.g. an "inside" view to certain - clients, and an "outside" view to others. + - Views + One server process can provide multiple "views" of + the DNS namespace, e.g. an "inside" view to certain + clients, and an "outside" view to others. - - Multiprocessor Support + - Multiprocessor Support - - Improved Portability Architecture + - Improved Portability Architecture - BIND version 9 development has been underwritten by the following - organizations: + BIND version 9 development has been underwritten by the following + organizations: - Sun Microsystems, Inc. - Hewlett Packard - Compaq Computer Corporation - IBM - Process Software Corporation - Silicon Graphics, Inc. - Network Associates, Inc. - U.S. Defense Information Systems Agency - USENIX Association - Stichting NLnet - NLnet Foundation - Nominum, Inc. + Sun Microsystems, Inc. + Hewlett Packard + Compaq Computer Corporation + IBM + Process Software Corporation + Silicon Graphics, Inc. + Network Associates, Inc. + U.S. Defense Information Systems Agency + USENIX Association + Stichting NLnet - NLnet Foundation + Nominum, Inc. - For a summary of functional enhancements in previous - releases, see the HISTORY file. + For a summary of functional enhancements in previous + releases, see the HISTORY file. - For a detailed list of user-visible changes from - previous releases, see the CHANGES file. + For a detailed list of user-visible changes from + previous releases, see the CHANGES file. - For up-to-date release notes and errata, see - http://www.isc.org/software/bind9/releasenotes + For up-to-date release notes and errata, see + http://www.isc.org/software/bind9/releasenotes BIND 9.10.0 - BIND 9.10.0 includes a number of changes from BIND 9.9 and earlier - releases. New features include: - - - DNS Response-rate limiting (DNS RRL) blunts the impact of - reflection and amplification attacks. - - New zone file format "map" is an image of a zone database - that can be loaded directly into memory, allowing much faster - zone loading. - - Substantial improvement in response-policy zone (RPZ) - performance. Up to 32 response-policy zones can be - configured with minimal performance loss. - - New RPZ client-IP triggers and drop policies. - - ACLs can now be specified based on geographic location - using the MaxMind GeoIP databases. - - New XML schema (version 3) for the statistics channel - includes many new statistics and uses a flattened XML tree - for faster parsing. - - A new stylesheet, based on the Google Charts API, displays - XML statistics in charts and graphs on javascript-enabled - browsers. - - The statistics channel can now provide data in JSON - format as well as XML. - - The internal and export versions of the BIND libraries - (libisc, libdns, etc) have been unified so that external - library clients can use the same libraries as BIND itself. - - New 'dnssec-coverage' tool to check DNSSEC key coverage - for a zone and report if a lapse in signing coverage has - been inadvertently scheduled. - - Signing algorithm flexibility and other improvements - for the "rndc" control channel. - - 'named-checkzone' and 'named-compilezone' can now read - journal files, allowing them to process dynamic zones. - - Multiple DLZ databases can now be configured. Individual - zones can be configured to be served from a specific DLZ - database. DLZ databases now serve zones of type "master" - and "redirect". - - "rndc zonestatus" reports information about a specified zone. - - "named" now listens on IPv6 as well as IPv4 interfaces - by default. + BIND 9.10.0 includes a number of changes from BIND 9.9 and earlier + releases. New features include: + + - DNS Response-rate limiting (DNS RRL) blunts the impact of + reflection and amplification attacks. + - New zone file format "map" is an image of a zone database + that can be loaded directly into memory, allowing much faster + zone loading. + - Substantial improvement in response-policy zone (RPZ) + performance. Up to 32 response-policy zones can be + configured with minimal performance loss. + - To improve recursive resolver performance, cache records + which are still being requested by clients can now be + automatically refreshed from the authoritative server + before they expire, reducing or eliminating the time + window in which no answer is available in the cache. + - New RPZ client-IP triggers and drop policies. + - ACLs can now be specified based on geographic location + using the MaxMind GeoIP databases. + - New XML schema (version 3) for the statistics channel + includes many new statistics and uses a flattened XML tree + for faster parsing. + - A new stylesheet, based on the Google Charts API, displays + XML statistics in charts and graphs on javascript-enabled + browsers. + - The statistics channel can now provide data in JSON + format as well as XML. + - The internal and export versions of the BIND libraries + (libisc, libdns, etc) have been unified so that external + library clients can use the same libraries as BIND itself. + - New 'dnssec-coverage' tool to check DNSSEC key coverage + for a zone and report if a lapse in signing coverage has + been inadvertently scheduled. + - Signing algorithm flexibility and other improvements + for the "rndc" control channel. + - 'named-checkzone' and 'named-compilezone' can now read + journal files, allowing them to process dynamic zones. + - Multiple DLZ databases can now be configured. Individual + zones can be configured to be served from a specific DLZ + database. DLZ databases now serve zones of type "master" + and "redirect". + - "rndc zonestatus" reports information about a specified zone. + - "named" now listens on IPv6 as well as IPv4 interfaces + by default. - "named" now preserves the capitalization of names when - responding to queries. - - New 'named-rrchecker' tool to verify the syntactic - correctness of individual resource records. - - When re-signing a zone, the new "dnssec-signzone -Q" option - drops signatures from keys that are still published but are - no longer active. + responding to queries. + - new "dnssec-importkey" command allows the use of offline + DNSSEC keys with automatic DNSKEY management. + - New 'named-rrchecker' tool to verify the syntactic + correctness of individual resource records. + - When re-signing a zone, the new "dnssec-signzone -Q" option + drops signatures from keys that are still published but are + no longer active. + - "named-checkconf -px" will print the contents of configuration + files with the shared secrets obscured, making it easier to + share configuration (e.g. when submitting a bug report) + without revealing private information. + BIND 9.9.0 diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml index b1dd4169e5a..158e4f7109d 100644 --- a/doc/arm/Bv9ARM-book.xml +++ b/doc/arm/Bv9ARM-book.xml @@ -8737,17 +8737,36 @@ avoid-v6-udp-ports { 40000; range 50000 60000; }; - - prefetch - + + prefetch + - Specifies the trigger ttl value (range [1..10]) - at which prefetch of the current query will be - made and optionally the minimum ttl value that will be - accepted for the records to be candidates for - prefetching. The defaults are 2 and 9 respectively. - Setting a trigger ttl value of 0 will disable - prefetching. A minimum delta of 6 is enforced. + When a query is received for cached data which + is to expire shortly, named can + refresh the data from the authoritative server + immediately, ensuring that the cache always has an + answer available. + + + The specifies the the + "trigger" TTL value at which prefetch of the current + query will take place: when a cache record with a + lower TTL value is encountered during query processing, + it will be refreshed. Valid trigger TTL values are 1 to + 10 seconds. Setting a trigger TTL to zero disables + prefetch. + + An optional second argument can be used + to set the smallest original + TTL value that will be accepted for a record to be + eligible for prefetching. The difference between + the trigger TTL and the eligibility TTL must be + at least 6 seconds. + + + The default trigger and eligibility TTLs are + 2 and 9, + respectively.