Welcome!

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'!

Latest Stories
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm. In his Day 3 Keynote at 20th Cloud Expo, Chris Brown, a Solutions Marketing Manager at Nutanix, will explore t...
NHK, Japan Broadcasting, will feature the upcoming @ThingsExpo Silicon Valley in a special 'Internet of Things' and smart technology documentary that will be filmed on the expo floor between November 3 to 5, 2015, in Santa Clara. NHK is the sole public TV network in Japan equivalent to the BBC in the UK and the largest in Asia with many award-winning science and technology programs. Japanese TV is producing a documentary about IoT and Smart technology and will be covering @ThingsExpo Silicon Val...
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...
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor – all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
Join IBM November 2 at 19th Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how to go beyond multi-speed it to bring agility to traditional enterprise applications. Technology innovation is the driving force behind modern business and enterprises must respond by increasing the speed and efficiency of software delivery. The challenge is that existing enterprise applications are expensive to develop and difficult to modernize. This often results in what Gartner calls ...
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 ...
The age of Digital Disruption is evolving into the next era – Digital Cohesion, an age in which applications securely self-assemble and deliver predictive services that continuously adapt to user behavior. Information from devices, sensors and applications around us will drive services seamlessly across mobile and fixed devices/infrastructure. This evolution is happening now in software defined services and secure networking. Four key drivers – Performance, Economics, Interoperability and Trust ...
SYS-CON Events announced today that CollabNet, a global leader in enterprise software development, release automation and DevOps solutions, will be a Bronze Sponsor of SYS-CON's 20th International Cloud Expo®, taking place from June 6-8, 2017, at the Javits Center in New York City, NY. CollabNet offers a broad range of solutions with the mission of helping modern organizations deliver quality software at speed. The company’s latest innovation, the DevOps Lifecycle Manager (DLM), supports Value S...
“DevOps is really about the business. The business is under pressure today, competitively in the marketplace to respond to the expectations of the customer. The business is driving IT and the problem is that IT isn't responding fast enough," explained Mark Levy, Senior Product Marketing Manager at Serena Software, in this SYS-CON.tv interview at DevOps Summit, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
All organizations that did not originate this moment have a pre-existing culture as well as legacy technology and processes that can be more or less amenable to DevOps implementation. That organizational culture is influenced by the personalities and management styles of Executive Management, the wider culture in which the organization is situated, and the personalities of key team members at all levels of the organization. This culture and entrenched interests usually throw a wrench in the work...
With billions of sensors deployed worldwide, the amount of machine-generated data will soon exceed what our networks can handle. But consumers and businesses will expect seamless experiences and real-time responsiveness. What does this mean for IoT devices and the infrastructure that supports them? More of the data will need to be handled at - or closer to - the devices themselves.
Building a cross-cloud operational model can be a daunting task. Per-cloud silos are not the answer, but neither is a fully generic abstraction plane that strips out capabilities unique to a particular provider. In his session at 20th Cloud Expo, Chris Wolf, VP & Chief Technology Officer, Global Field & Industry at VMware, will discuss how successful organizations approach cloud operations and management, with insights into where operations should be centralized and when it’s best to decentraliz...
Translating agile methodology into real-world best practices within the modern software factory has driven widespread DevOps adoption, yet much work remains to expand workflows and tooling across the enterprise. As models evolve from pockets of experimentation into wholescale organizational reinvention, practitioners find themselves challenged to incorporate the culture and architecture necessary to support DevOps at scale. In his session at @DevOpsSummit at 20th Cloud Expo, Anand Akela, Senior...
Web Real-Time Communication APIs have quickly revolutionized what browsers are capable of. In addition to video and audio streams, we can now bi-directionally send arbitrary data over WebRTC's PeerConnection Data Channels. With the advent of Progressive Web Apps and new hardware APIs such as WebBluetooh and WebUSB, we can finally enable users to stitch together the Internet of Things directly from their browsers while communicating privately and securely in a decentralized way.
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).