General – Behavior Of QoS Queues On Cisco IOS
I have been running some QoS tests lately and wanted to share some of my results. Some of this behavior is described in various documentation guides but it’s not really clearly described in one place. I’ll describe what I have found so far in this post.
QoS is only active during congestion. This is well known but it’s not as well known how congestion is detected. the TX ring is used to hold packets before they get transmitted out on an interface. This is a hardware FIFO queue and when the queue gets filled, the interface is congested. When buying a subrate circuit from a SP, something must be added to achieve the backpressure so that the TX ring is considered full. This is done by applying a parent shaper and a child policy with the actual queue configuration.
The LLQ is used for high priority traffic. When the interface is not congested, the LLQ can use all available bandwidth unless an explicit policer is configured under the LLQ.
A normal queue can use more bandwidth than it is guaranteed when there is no congestion.
When a normal queue wants to use more bandwidth than its guaranteed, it can if Continue reading
Scale Testing Docker Swarm to 30,000 Containers
1,000 nodes, 30,000 containers, 1 Swarm manager Swarm is the easiest way to run Docker app in production. It lets you take an an app that you’ve built in development and deploy it across a cluster of servers. Recently we … ContinuedDocker Security Gets a Hardware Assist
DockerCon EU kicks off with a few practical new features.
Docker Content Trust Gets Hardware Signing
Three months ago we launched Docker Content Trust, integrating the guarantees from The Update Framework (TUF) into Docker using Notary, an open source tool that provides trust over any content. Today we’re incredibly excited to announce the support of hardware … ContinuedGetting Started with Docker Toolbox and Compose
Today at DockerCon EU 2015, I ran through a demo of running and developing an app from a fresh computer using Docker Toolbox and Compose. This was to show how easy it is for new developers to get started when … ContinuedHow to get rid of VNC and use telnet access for your Linux image?
We are, network engineers, have many *nix tools at our disposal: exaBGP, nmap, tcpdump, to name a few. And with UNetlab its very easy to run a linux system inside a topology (not to mention that you could use cloud pnet interface to bridge unetlab topology with the real world). By default UNetLab’s linux template optsWelcome!
This is Under Construction Personal blog, travel stories, opinions and more craptology![[ Summary content only, you can read everything now, just visit the site for full story ]]
Rancher Gets Hyperconverged with Its Docker Platform
Nexenta and Redapt are helping Rancher flesh out Linux-container infrastructure.
How Facebook’s Safety Check Works
I noticed on Facebook during this horrible tragedy in Paris that there was some worry because not everyone had checked in using Safety Check. So I thought people might want to know a little more about how Safety Check works.
If a friend or family member hasn't checked-in yet it doesn't mean anything bad has happened to them. Please keep that in mind. Safety Check is a good system, but not a perfect system, so keep your hopes up.
This is a really short version, there's a longer article if you are interested.
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How it works:
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If you are in an area impacted by a disaster Facebook will send you a push notification asking if you are OK.
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Tapping the “I’m Safe” button marks that your are safe.
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All your friends are notified that you are safe.
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Friends can also see a list of all the people impacted by the disaster and how they are doing.
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How do you build the pool of people impacted by a disaster in a certain area? Building a geoindex is the obvious solution, but it has weaknesses.
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People are constantly moving so the index will be stale.
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A geoindex of 1.5 billion Continue reading
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k8s + opencontrail on AWS
For anyone interested in running a testbed with Kubernetes and OpenContrail on AWS i managed to boil down the install steps to the minimum:
- Use AWS IAM to create a user and download a file “credentials.csv”
- Checkout the scripts via `git clone https://github.com/pedro-r-marques/examples.git`
- Change to the “ec2-k8s-cluster” directory (e.g. /Users/roque/src/examples/ec2-k8s-cluster)
- Edit “credentials.sh” with the location of you csv file and user name and then “eval” this script.
- Run ./setup.sh
The setup script will:
- Create 5 VMs in a VPC on AWS;
- Run the ansible provisioning script that installs the cluster;
- Run a minimal sanity check on the cluster;
- Launch an example;
- Fetch the status page of the example app in order to check whether it is running successfully.
Please let me know if you run into any glitch… the “setup.sh” script can be rerun multiple times (the ansible provisioning is designed to be idempotent).
Next, I need to wrap this up with a Jenkins CI pipeline. And build permutations for:
- kubernetes vs openshift;
- single vs multiple network interfaces;
- direct internet access vs http-proxy;
- software gateway or a vSRX (for hybrid cloud interconnect);
The fun never stops !
SDxCentral Weekly News Roundup — November 13, 2015
Azure is letting users kick the tires on virtual machine scale sets while A10 debuts a new security offering.
Docker Online Meetups #28 and #29: Production-Ready Docker Swarm and Docker Networking is Now GA
This week, we hosted two Docker Online Meetups. The first on Wednesday featured Alexander Beslic presenting on production-ready Swarm. For the second one on Thursday, Madhu Venugopal discussed the recently-GA Docker Networking. Below are the recorded videos and slides from … ContinuedA Handy GUI Tool for Working with APIs
In this post I’m going to share with you an OS X graphical application I found that makes it easier to work with RESTful APIs. The topic of RESTful APIs has come up here before (see this post on using cURL to interact with RESTful APIs), and RESTful APIs have been a key part of a number of other posts (like my recent post on using jq to work with JSON). Unlike these previous posts—which were kind of geeky and focused on the command line—this time around I’m going to show you an application called Paw, which provides a graphic interface for working with APIs.
Before I start talking about Paw, allow me to first explain why I’m talking about working with APIs using this application. I firmly believe that the future of “infrastructure engineers”—that is, folks who today are focused on managing servers, hypervisors, VM, storage, networks, and firewalls—lies in becoming the “full-stack engineer,” someone who has knowledge and skills across multiple areas, including automation/orchestration. In order to gain those skills in automation/orchestration, it’s pretty likely that you’re going to end up having to work with APIs. Hence, why I’m talking about this stuff, and why Continue reading