Internet Systems Consortium is pleased to announce the release of Kea 1.7.6.
Kea releases are divided into two branch sequences: 1) A current stable branch (currently 1.6.x) which receives only important bug fixes and is otherwise feature-stable, and 2) An experimental development branch (currently 1.7.x) where new features are added and made available for testing during development, before eventually being included in the next stable release branch. Kea 1.7.6 is the latest release in the experimental development branch. This is the first release to contain the results of our work to support multi-threading in Kea and we are eager for feedback on this new feature. Operators wishing to provide feedback have several options for supplying it: 1) if you have discovered a bug you may open an issue in our public issue tracker at https://gitlab.isc.org. 2) you may participate in discussion on kea-users, an open community list operated by ISC. visit https://lists.isc.org if you want to subscribe. 3) customers who have an ISC support subscription may open a ticket in their support queue. Michael McNally ISC Support ----------------------- # Kea 1.7.6, March 25th 2020, Release Notes Welcome to Kea 1.7.6, a monthly development release of Kea. This is the first public release that offers multi-threading support. As with any other development release, use this with caution. Development releases are not recommended for production use. Changes introduced in this version: 1. **Multi-threading**. After more than half a year of development, the code is now ready for broader testing. We have implemented the `-N` command line switch that lets you specify number of threads. The special value of 0 (`-N0`) means Kea should autodetect CPU capabilities and pick the number for you. Our early tests show a substantial increase in performance even in the worst cases. We are interested in your feedback, so please share your observations. Keep in mind that this feature is experimental; we strongly discourage its use in production networks. There are some [known problems](https://gitlab.isc.org/isc-projects/kea/-/wikis/known-issues-li st). In particular, HA in its current form is not compatible with multi-threading yet. We hope to address this incompatibility in the coming weeks. A number of issues were addressed related to MT: #893, #1016, #1136, #1148. When running in multi-threaded mode, each client packet is processed by an individual thread. For logging clarity, you may wish to add the thread-id to the log statements. This can be done by adding "%t" to the logging pattern. Please see [Logging pattern](https://kea.readthedocs.io/en/latest/arm/logging.html#the-patter n-string-option) for more information. 2. **Performance improvements**. Two performance improvements made it into this release. One flips the order in which Kea does the lease and host reservations lookups; now the check for a lease for an address is done first. This should improve performance in case of high pool utilization (#1124). Another performance fix is related to client classes defined in host reservations: the classes now can influence lease allocation. #1139 3. **Resend DDNS updates**. Two new commands - `lease4-resend-ddns` and `lease6-resend-ddns` - have been implemented. Using those, Kea can now repeat a DNS update for existing leases. This may prove useful if your DNS zone file has been corrupted, if Kea timed out while your DNS server was unreachable, if your TSIG keys were misconfigured, or in a variety of other failure scenarios. #1106 4. **RADIUS hook update**. We fixed a reported issue in RADIUS accounting. Kea now sends delegated-ipv6-prefix if that attribute is available in FreeRADIUS-client. If not, the older behavior, using the framed-ipv6-prefix attribute, is used. Please make sure you upgrade your FreeRADIUS-client library as well if you intend to use this feature. #1140 5. **Leasequery design**. Work has started on leasequery support. As usual for larger features, the first step is to come up with a design that explains what code changes are necessary, how we are going to organize the extra processing, data storage details, etc. This first step is now [in review](https://gitlab.isc.org/isc-projects/kea/-/wikis/designs/Basic-Lea seQuery-Design). Please share your feedback if you're interested in LQ. #994 6. **Performance testing improvements**. As part of ongoing performance testing and preparation for multi-threading, we extended our performance testing tool. Perfdhcp is now able to simulate traffic coming in from multiple subnets (#931) and can report the results in a format that is easier to parse (comma- or space-separated values). #1046 7. **Documentation update**. Several aspects of the Kea ARM have been updated. We now have a separate file with a list of [supported OSes](https://gitlab.isc.org/isc-projects/kea/-/blob/master/platforms.rst ) (#1055), documentation for BOOTP has been improved (#1107), and the ARM now has a section about easier native (RPM, deb, and APK) package installation from [cloudsmith.io](cloudsmith.io/~isc/repos/). #1138 8. **Notable bug fixes**. The shutdown command now can optionally take an exit-value parameter that Kea will report as status code. This is used internally when shutting down after failed DB reconnection attempts, but can be used when doing planned shutdowns (#1115). The lease file now properly handles situations where there is a comma in the filename and other fields. In particular, the lease file is now able to store multiple entries in the user context, which uses JSON syntax that separates entries with commas. #608 ## Changes to Release Model The Kea project has been in development for several years now, and it has a significant production deployment base with users who are looking for stability, rather than a constant stream of new "bleeding-edge" features. At the same time, we want to continue developing the software and add some new powerful, but difficult-to-implement, features. As a result, we decided to change the release cycle. Starting from 1.6.0, there are two series of releases: stable and development. Stable releases are what you would expect: stable, released infrequently, without new features or significant changes, very well-tested. These can be identified by the middle version number being even. The current stable release is 1.6.2. If we discover important bugs that require fixing, we may release 1.6.3, but that will be determined on a case-by-case basis. The next major stable version will be 1.8.0, followed by 2.0.0 in the future. Our team continues development of new features. In particular, we're tackling the difficult problem of being able to use all available CPU cores simultaneously. The multi-threading implementation is a complex task and it is unknown how long it will take before the solution is stable and ready for a production environment. At the same time, we continue to receive a stream of requests for small features and bug fixes. We don't want to force users to wait half a year or more for the fixes and features that are already done. Therefore, we have started issuing development releases on a monthly basis. Those are slightly less well-tested and may have features that are not complete. For example, it is possible that one of the next releases will provide a configuration knob to specify the number of threads in multi-threading, but the actual code that spawns those threads will not yet have been added. The development releases can be easily identified by the middle version number being odd: for example, 1.7.5 is a development release. In March 2020 we are releasing 1.7.6, the next development version. Once 1.8.0 is out, we will continue our development work with 1.9.0, then 1.9.1, and so on. Our goal is to make the development release available on the last Wednesday of each month. There may be exceptions (such as during holidays), but that's the general plan. We encourage users to test the development releases and report back their findings. For more details on the plan, see ISC's Software Support Policy at https://kb.isc.org/docs/aa-00896. ## Kea overview Kea is a DHCP implementation developed by Internet Systems Consortium, Inc. that features fully functional DHCPv4 and DHCPv6 servers, a dynamic DNS update daemon, a Control Agent (CA) that provides a REST API to control the DHCP and DNS update servers, an example shell client to connect to the CA, a daemon that is able to retrieve YANG configuration and updates from Sysrepo, and a DHCP performance-measurement tool. Both DHCP servers fully support server discovery, address assignment, renewal, rebinding, release, decline, information request, DNS updates, client classification, and host reservations. The DHCPv6 server also supports prefix delegation. Lease information is stored in a CSV file by default; it can optionally be stored in a MySQL, PostgreSQL, or Cassandra database instead. Host reservations can be stored in a configuration file, or in a MySQL, PostgreSQL, or Cassandra database. They can also be retrieved from a RADIUS server, although this functionality is somewhat limited. Kea DHCPv4 and DHCPv6 daemons provide support for YANG models, which are stored in a Sysrepo datastore and can be configured via the NETCONF protocol. This text references issue numbers. For more details, visit the Kea GitLab page at https://gitlab.isc.org/isc-projects/kea/issues. ## License This version of Kea is released under the Mozilla Public License, version 2.0. https://www.mozilla.org/en-US/MPL/2.0 The premium and subscriber-only hook libraries are provided in source code form, under the terms of an End User License Agreement (you will get the source code that you can modify freely, but you are not permitted to redistribute it). ## Download Pre-built ISC packages for current versions of the most popular Linux operating systems are available at: https://cloudsmith.io/~isc/repos/ The Kea source and PGP signature for this release may be downloaded from: https://www.isc.org/download The signature was generated with the ISC code signing key which is available at: https://www.isc.org/pgpkey ISC provides detailed documentation, including installation instructions and usage tutorials, in the Kea Administrator Reference Manual. Documentation is included with the installation, at https://kea.readthedocs.io/en/latest/, or via https://kb.isc.org/docs/kea-administrator-reference-manual in HTML, plain text, or PDF formats. ISC maintains a public open source code tree, a wiki, an issue tracking system, milestone planning, and a roadmap at https://gitlab.isc.org//isc-projects/kea. Limitations and known issues with this release can be found at https://gitlab.isc.org/isc-projects/kea/wikis/known-issues-list. We ask users of this software to please let us know how it worked for you and what operating system you tested on. Feel free to share your feedback on the Kea Users mailing list (https://lists.isc.org/mailman/listinfo/kea-users). Also we would like to hear whether the documentation is adequate and accurate. Please open tickets in the Kea GitLab project for bugs, documentation omissions and errors, and enhancement requests. We want to hear from you even if everything worked. ## Support Professional support for Kea is available from ISC. We encourage all professional users to consider this option; Kea development and maintenance are funded with support subscriptions. For more information on ISC's Kea and DHCP software support see https://www.isc.org/support/. Free best-effort support is provided by our user community via a mailing list. Information on all public email lists is available at https://www.isc.org/community/mailing-list. If you have any comments or questions about working with Kea, please share them to the Kea Users List (https://lists.isc.org/mailman/listinfo/kea-users). Bugs and feature requests may be submitted via GitLab at https://gitlab.isc.org/isc-projects/kea/issues. ## Changes The following summarizes changes and important upgrade notes since the previous release (1.7.5). ``` 1735. [func] wlodek Added clean output mode to perfdhcp with configurable separator for periodic reports. (Gutlab #1046) 1734. [doc] vicky A list of supported OSes is now described in a separate platforms.rst file. (Gitlab #1055) 1733. [func] tmark Added lease4-resend-ddns and lease6-resend-ddns commands to the Lease Commands hook library. These commands may be used to instruct kea-dhcp4 or kea-dhcp6 to resend a request to update a lease's DNS entries to kea-dhcp-ddns. (Gitlab #1106) 1732. [func] marcin Client classes specified within host reservations can be used to influence subnet selection within a shared network and pool selection within a subnet. (Gitlab #1139) 1731. [func] razvan The NameChangeSender class is thread safe, making DNS updates compatible with multi-threading packet processing. (Gitlab #1148) 1730. [func] razvan Added -N command line switch that enables experimental multi-threading support. Number of threads can be specified (e.g. -N8) or Kea can be told to autodetect number of CPU threads (-N0). This feature is experimental. It hasn't been tested extensively and is known to cause problems with DDNS and HA. Do not use in production! (Gitlab #893) 1729. [func] razvan The RAII MultiThreadingCriticalSection class is now able to automatically stop and start the packet thread pool in order to perform server configuration and avoid race conditions in non thread safe code. (Gitlab #1016) 1728. [bug] tmark Memfile now supports commas in the hostname and user-context columns. Commas in either column now escaped as "," when written out, and unescaped when read back in. (Gitlab #608) 1727. [bug] tmark When shutting down due to lost backend database connetivity, kea-dhcp4 and kea-dhcp6 processes will exit with a non-zero value. This was temporarily altered by #1108. In addition, the "shutdown" command now supports an "exit-value" argument. (Gitlab #1115) 1726. [func] razvan Handling SKIP and DROP state in hooks so that the same operation is not performed multiple times. Some hooks will throw exceptions if the pktX_receive or pktX_send is handled by other hooks, in such case, the configuration order of the hooks must be changed. (Gitlab #1088) ``` Thank you again to everyone who assisted us in making this release possible. We look forward to receiving your feedback. _______________________________________________ Kea-announce mailing list Keaemail@example.com https://lists.isc.org/mailman/listinfo/kea-announce