Welcome!

Linux Containers Authors: Jnan Dash, Elizabeth White, Pat Romanski, Liz McMillan, Kalyan Ramanathan

Related Topics: Open Source Cloud, Java IoT, Microservices Expo, Linux Containers

Open Source Cloud: Article

Memory Monitoring and Limiting with LXC

Building a Metrics Infrastructure

Original article can be found here: Memory Monitoring with LXC

Memory Monitoring And Limiting With LXC

For a long time we didn't limit the amount of memory that you can use during your build on Codeship. There was the possibility of a bad build eating up all of our memory.

A few weeks ago that bad build happened, using up so much memory that it decreased performance and eventually killed the test server. Even though we measure the memory usage of the whole test server, we didn't have the data to figure out exactly which build caused the trouble.

Combined maximum and minimum memory usage of Amazon EC2 Instances.

Combined maximum and minimum memory usage of Amazon EC2 Instances.

How to avoid builds eating up all of your memory
We couldn't risk that this problem happened again and be a threat to other builds on that test server. We didn't have enough data about the memory limits at this point so we had to take an educated guess. My first assumption was the most conservative one. Each test server has 60G of memory and we run 22 builds on each instance, so each build can get a maximum of 2,5G memory. As LXC manages memory with cgroups, it is simple to set a memory limit for each container.

Setting lxc.cgroup.memory.limit_in_bytes in container config:

lxc.cgroup.memory.limit_in_bytes = 2560M

This worked, the bad build wasn't a threat anymore.

We got a few support request where people were asking about their builds being stuck. While the 2,5G are enough for 95% of the builds, the other 5% were hitting the limit. We needed to increase the memory limit to ensure that all builds are running fine. After 2 incremental steps The Codeship is sailing smooth with a 10GB memory limit for each build.

Codeship - A hosted Continuous Deployment platform for web applications

Monitoring in the Future
We wanted to have more data to improve the memory limit in the future. We started measuring the maximum memory usage for each build. We export it to Librato Metrics and save it as metadata of the build in our database. This allows to inspect the memory usage easily. We plan to show the memory usage to our users in the future.

LXC tracks the memory usage for each container and exposes that and many other values in the cgroup. Right before we shutdown the build, we read the memory usage from the cgroup. You can read the memory usage from the cgroup on the LXC Host.

/sys/fs/cgroup/memory/lxc/name_of_running_container/memory.max_usage_in_bytes

and send the data to Librato Metrics.

Metriks.timer('build.memory_usage) .update(metrics[:max_memory])

Building a Metrics Infrastructure
It is important to back your actions with data. Data is your best argument. In case you don't have any useful data to solve the problem, it is important that you can easily add more metrics to your infrastructure. Sit back with your Coworkers and think about good metricsfor your product. Sometimes it's not easy to spot them on the first glimpse. We often talk about our metrics.

We discuss new metrics but also talk about removing redundant metrics. It is very exciting to talk about data and what your Coworkers conclude from that data. We are able to add new metrics to our infrastructure in minutes. By building this metrics infrastructure you can handle any new challenges by quickly adding mesurements that help you decide on the next steps. This infrastructure can be the difference between life and death of your service, so make sure you have it in place.

Do you monitor? Which tools and services do you use for it? Let us know in the comments!

Further Information on Linux Containers


Download Efficiency in Development Workflows: A free eBook for Software Developers. This book will save you a lot of time and make you and your development team happy.

Go ahead and try Codeship for Continuous Integration and Continuous Deployment! Set up for your GitHub and BitBucket projects only takes 3 minutes. It's free!

More Stories By Manuel Weiss

I am the cofounder of Codeship – a hosted Continuous Integration and Deployment platform for web applications. On the Codeship blog we love to write about Software Testing, Continuos Integration and Deployment. Also check out our weekly screencast series 'Testing Tuesday'!

@ThingsExpo Stories
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2017 New York The 7th Internet of @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, New York. Chris Matthieu is the co-founder and CTO of Octoblu, a revolutionary real-time IoT platform recently acquired by Citrix. Octoblu connects things, systems, people and clouds to a global mesh network allowing users to automate and control design flo...
In addition to all the benefits, IoT is also bringing new kind of customer experience challenges - cars that unlock themselves, thermostats turning houses into saunas and baby video monitors broadcasting over the internet. This list can only increase because while IoT services should be intuitive and simple to use, the delivery ecosystem is a myriad of potential problems as IoT explodes complexity. So finding a performance issue is like finding the proverbial needle in the haystack.
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at 20th Cloud Expo, Ed Featherston, director/senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
According to Forrester Research, every business will become either a digital predator or digital prey by 2020. To avoid demise, organizations must rapidly create new sources of value in their end-to-end customer experiences. True digital predators also must break down information and process silos and extend digital transformation initiatives to empower employees with the digital resources needed to win, serve, and retain customers.
The WebRTC Summit New York, to be held June 6-8, 2017, at the Javits Center in New York City, NY, announces that its Call for Papers is now open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 20th International Cloud Expo and @ThingsExpo. WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web co...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
The Internet of Things (IoT) promises to simplify and streamline our lives by automating routine tasks that distract us from our goals. This promise is based on the ubiquitous deployment of smart, connected devices that link everything from industrial control systems to automobiles to refrigerators. Unfortunately, comparatively few of the devices currently deployed have been developed with an eye toward security, and as the DDoS attacks of late October 2016 have demonstrated, this oversight can ...
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
"Once customers get a year into their IoT deployments, they start to realize that they may have been shortsighted in the ways they built out their deployment and the key thing I see a lot of people looking at is - how can I take equipment data, pull it back in an IoT solution and show it in a dashboard," stated Dave McCarthy, Director of Products at Bsquare Corporation, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Unsecured IoT devices were used to launch crippling DDOS attacks in October 2016, targeting services such as Twitter, Spotify, and GitHub. Subsequent testimony to Congress about potential attacks on office buildings, schools, and hospitals raised the possibility for the IoT to harm and even kill people. What should be done? Does the government need to intervene? This panel at @ThingExpo New York brings together leading IoT and security experts to discuss this very serious topic.
We are always online. We access our data, our finances, work, and various services on the Internet. But we live in a congested world of information in which the roads were built two decades ago. The quest for better, faster Internet routing has been around for a decade, but nobody solved this problem. We’ve seen band-aid approaches like CDNs that attack a niche's slice of static content part of the Internet, but that’s it. It does not address the dynamic services-based Internet of today. It does...
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, discussed the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
As data explodes in quantity, importance and from new sources, the need for managing and protecting data residing across physical, virtual, and cloud environments grow with it. Managing data includes protecting it, indexing and classifying it for true, long-term management, compliance and E-Discovery. Commvault can ensure this with a single pane of glass solution – whether in a private cloud, a Service Provider delivered public cloud or a hybrid cloud environment – across the heterogeneous enter...
An IoT product’s log files speak volumes about what’s happening with your products in the field, pinpointing current and potential issues, and enabling you to predict failures and save millions of dollars in inventory. But until recently, no one knew how to listen. In his session at @ThingsExpo, Dan Gettens, Chief Research Officer at OnProcess, discussed recent research by Massachusetts Institute of Technology and OnProcess Technology, where MIT created a new, breakthrough analytics model for ...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, discussed why and how ReadyTalk diverted from healthy revenue and mor...
SYS-CON Events has announced today that Roger Strukhoff has been named conference chair of Cloud Expo and @ThingsExpo 2017 New York. The 20th Cloud Expo and 7th @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, NY. "The Internet of Things brings trillions of dollars of opportunity to developers and enterprise IT, no matter how you measure it," stated Roger Strukhoff. "More importantly, it leverages the power of devices and the Internet to enable us all to im...
Information technology is an industry that has always experienced change, and the dramatic change sweeping across the industry today could not be truthfully described as the first time we've seen such widespread change impacting customer investments. However, the rate of the change, and the potential outcomes from today's digital transformation has the distinct potential to separate the industry into two camps: Organizations that see the change coming, embrace it, and successful leverage it; and...
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.