The architecture of the infrastructure-as-code (IaC) tooling you use will determine the level to which your IaC definitions are exposed to bit rot.
This is a maxim I have arrived at after working with multiple IaC tool sets, both professionally and personally, over the last few years. In this blog post, I will explain how I arrived at this maxim by describing three architectural patterns for IaC tools, each with differing levels of risk for bit rot.
This blog reports and summarizes the contents of a Cloudflare research paper which appeared at the ACM Internet Measurement Conference, that measures and prototypes connection coalescing with ORIGIN Frames.
Some readers might be surprised to hear that a single visit to a web page can cause a browser to make tens, sometimes even hundreds, of web connections. Take this very blog as an example. If it is your first visit to the Cloudflare blog, or it has been a while since your last visit, your browser will make multiple connections to render the page. The browser will make DNS queries to find IP addresses corresponding to blog.cloudflare.com and then subsequent requests to retrieve any necessary subresources on the web page needed to successfully render the complete page. How many? Looking below, at the time of writing, there are 32 different hostnames used to load the Cloudflare Blog. That means 32 DNS queries and at least 32 TCP (or QUIC) connections, unless the client is able to reuse (or coalesce) some of those connections.
Each new web connection not only introduces additional load on a server's processing capabilities – potentially leading to scalability challenges during peak usage hours Continue reading
The first set of BGP labs covered the basics; the next four will help you master simple routing policy tools (BGP weights, AS-path filters, prefix filters) using real-life examples:
The labs are best used with netlab (it supports BGP on almost 20 different devices), but you could use any system you like (including GNS3 and CML/VIRL). For more details, read the Installation and Setup documentation.
The first set of BGP labs covered the basics, the next four will help you master simple routing policy tools (BGP weights, AS-path filters, prefix filters) using real-life examples:
The labs are best used with netlab (it supports BGP on almost 20 different devices), but you could use any system you like (including GNS3 and CML/VIRL). If you’re stubborn enough it’s possible to make them work with the physical gear, but don’t ask me for help. For more details, read the Installation and Setup documentation.
Valley-free routing is a concept that may not be well known but that is relevant to datacenter design. In this post, we’ll valley-free routing based on a leaf and spine topology.
There are many posts about leaf and spine topology and the benefits. To summarize, some of the most prominent advantages are:
Now, what does this have to do with valley-free routing? To understand what valley-free routing is, first let’s take a look at the expected traffic flow in a leaf and spine topology:
For traffic between Leaf1 and Leaf4, the two expected paths are:
This means that there is only one intermediate hop between Leaf1 and Leaf4. Let’s confirm with a traceroute:
Leaf1# traceroute 203.0.113.4 traceroute to 203.0.113.4 (203.0.113.4), 30 hops max, 48 byte packets 1 Spine2 (192.0.2.2) 1.831 ms 1.234 ms 1.12 ms 2 Leaf4 (203. Continue reading
Any network device, be it a transit router or a host, usually has multiple IP addresses assigned to its interfaces. One of the first things we learn as network engineers is how to determine which IP address is used for the locally-sourced traffic. However, the default scenario can be changed in a couple of different ways and this post is a brief documentation of the available options.
Whenever a local application decides to connect to a remote network endpoint, it creates a network socket, providing a minimal amount of details required to build and send a network packet. Most often, this information includes a destination IP and port number as you can see from the following abbreviated output:
$ strace -e trace=network curl http://example.com
socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 6
setsockopt(6, SOL_TCP, TCP_NODELAY, [1], 4) = 0
setsockopt(6, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0
setsockopt(6, SOL_TCP, TCP_KEEPIDLE, [60], 4) = 0
setsockopt(6, SOL_TCP, TCP_KEEPINTVL, [60], 4) = 0
connect(6, {sa_family=AF_INET, sin_port=htons(80), sin_addr=inet_addr("93.184.216.34")}, 16)
While this output does not show the DNS resolution part (due to getaddrinfo() not being a syscall), we can see that the only user-specific input information provided by an application ( Continue reading
If you look back at it now, especially with the advent of massively parallel computing on GPUs, maybe the techies at Tera Computing and then Cray had the right idea with their “ThreadStorm” massively threaded processors and high bandwidth interconnects. …
The post What Would You Do With A 16.8 Million Core Graph Processing Beast? first appeared on The Next Platform.
What Would You Do With A 16.8 Million Core Graph Processing Beast? was written by Timothy Prickett Morgan at The Next Platform.
Year after year network engineering media, vendors, and influencers talk about the importance of network automation—and yet according to surveys, most network operators still have not automated their network operations. In this episode of the Hedge, part 1 of 2, Chris Grundemann and Scott Robohn join the Hedge to give their ideas on why network automation isn’t happening, and how we can resolve the many blockers to automation.
Welcome to the Calico monthly roundup: August edition! From open source news to live events, we have exciting updates to share—let’s get into it!
*NEW* The State of Calico Open Source: Usage & Adoption Report 2023 Get insights into Calico’s adoption across container and Kubernetes environments, in terms of platforms, data planes, and policies. |
Customer case study: HanseMerkur Using Calico, HanseMerkur was able to reduce infrastructure overhead and achieve organizational compliance. Read our new case study to find out how. |
In today's sponsored Heavy Networking we explore new features in Cisco Thousand Eyes, an operational tool based on visibility and observability of public and private network. Thousand Eyes has continued to grow into complex operational areas such AWS Network Path, Webex performance, and integrations with Meraki to help you identify and fix network and application performance problems.
The post Heavy Networking 697: Getting Operational Visibility Into The Networks That Matter (Sponsored) appeared first on Packet Pushers.
In a world where Nvidia is allocating proportional shares of its GPU hotcakes to all of the OEMs and ODMs, companies like Dell, Hewlett Packard, Lenovo, and Supermicro get their shares and then they turn around and try to sell systems using them at the highest possible price. …
The post Dell Making The Most Of Its GPU Allocations, Like Everyone Else first appeared on The Next Platform.
Dell Making The Most Of Its GPU Allocations, Like Everyone Else was written by Timothy Prickett Morgan at The Next Platform.
I was watching a Youtube video this week that had a great quote. The creator was talking about sanding a woodworking project and said something about how much it needed to be sanded.
Whenever you think you’re done, that’s when you’ve just started.
That statement really resonated with me. I’ve found that it’s far too easy to think you’re finished with something right about the time you really need to hunker down and put in extra effort. In running they call it “hitting the wall” and it usually marks the point when your body is out of energy. There’s often another wall you hit mentally before you get there, though, and that’s the one that needs to be overcome with some tenacity.
If your brain is like mine you don’t like belaboring something. The mind craves completion and resolution. Once you’ve solved a problem it’s done and finished. No need to continue on with it once you’ve reached a point where it’s good enough. Time to move on to something else that’s new and exciting and a source of dopamine.
However, that feeling of being done with something early on is often a false sense of completion. Continue reading