Episode Details

LLDB Threading support now ready, Multiple IPSec VPN tunnels with FreeBSD, Netflix Optimized FreeBSD's Network Stack More Than Doubled AMD EPYC Performance, happy eyeballs with unwind(8), AWS got FreeBSD ARM 12, OpenSSH U2F/FIDO support, and more.

Headlines

LLDB Threading support now ready for mainline

Upstream describes LLDB as a next generation, high-performance debugger. It is built on top of LLVM/Clang toolchain, and features great integration with it. At the moment, it primarily supports debugging C, C++ and ObjC code, and there is interest in extending it to more languages.

In February, I have started working on LLDB, as contracted by the NetBSD Foundation. So far I've been working on reenabling continuous integration, squashing bugs, improving NetBSD core file support, extending NetBSD's ptrace interface to cover more register types and fix compat32 issues and fixing watchpoint support. Then, I've started working on improving thread support which is taking longer than expected. You can read more about that in my September 2019 report.

So far the number of issues uncovered while enabling proper threading support has stopped me from merging the work-in-progress patches. However, I've finally reached the point where I believe that the current work can be merged and the remaining problems can be resolved afterwards. More on that and other LLVM-related events happening during the last month in this report.

Multiple IPSec VPN tunnels with FreeBSD

The FreeBSD handbook describes an IPSec VPN tunnel between 2 FreeBSD hosts (see https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/ipsec.html)

But it is also possible to have multiple, 2 or more, IPSec VPN tunnels created and running on a FreeBSD host. How to implement and configure this is described below.

The requirements is to have 3 locations (A, B and C) connected with IPSec VPN tunnels using FreeBSD (11.3-RELEASE).

Each location has 1 IPSec VPN host running FreeBSD (VPN host A, B and C).

VPN host A has 2 IPSec VPN tunnels: 1 to location B (VPN host B) and 1 to location C (VPN host C).

News Roundup

Netflix Optimized FreeBSD's Network Stack More Than Doubled AMD EPYC Performance

Drew Gallatin of Netflix presented at the recent EuroBSDcon 2019 conference in Norway on the company's network stack optimizations to FreeBSD. Netflix was working on being able to deliver 200Gb/s network performance for video streaming out of Intel Xeon and AMD EPYC servers, to which they are now at 190Gb/s+ and in the process that doubled the potential of EPYC Naples/Rome servers and also very hefty upgrades too for Intel.

Netflix has long been known to be using FreeBSD in their data centers particularly where network performance is concerned. But in wanting to deliver 200Gb/s throughput from individual servers led them to making NUMA optimizations to the FreeBSD network stack. Allocating NUMA local memory for kernel TLS crypto buffers and for backing files sent via sentfile were among their optimizations. Changes to network connection handling and dealing with incoming connections to Nginx were also made.

For those just wanting the end result, Netflix's NUMA optimizations to FreeBSD resulted in their Intel Xeon servers going from 105Gb/s to 191Gb/s while the NUMA fabric utilization dropped from 40% to 13%.

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