Software Update: PowerDNS Recursor 4.1.11

PowerDNS is a dns server with a database as backend, which makes it easy to manage a large number of dns entries. The developers have previously decided to release the two parts that make up PowerDNS, a recursor and an authoritative name server, to allow for a faster and more targeted release of a new version, the developers said.

When you perform a dns lookup, a recursor initially starts asking the lookup query to a dns root server. This can then redirect to other servers, from where it can redirect to other servers and so on, until finally a server is reached that knows the answer or knows that the look-up is not possible. The latter can be the case if the name does not exist or the servers do not respond. The process of going through different authoritative servers is called recursion. The developers have released PowerDNS Recursor 4.1.11. The changes in this release are as follows:

Version 4.1.11

Since Specter/Meltdown, system calls have become more expensive. This made exporting a very high number of protobuf messages costly, which is addressed in this release by reducing the number of sycalls per message.

Improvements

• Add an option to export only responses over protobuf to the Lua protobufServer() directive.
• Reduce system call usage in prototype logging. (See #7428.)

Version 4.1.10

This release fixes a bug when trying to build PowerDNS Recursor with protobuf support disabled, thus this release is only relevant to people building PowerDNS Recursor from source and not if you’re installing it as a package from our repositories.

Bug Fixes

• PowerDNS Recursor release 4.1.9 introduced a call to the Lua ipfilter() hook that required access to the DNS header, but the corresponding variable was only declared when protobuf support had been enabled.