Welcome!

Recurring Revenue Authors: Antonella Corno, PagerDuty Blog, Dana Gardner, XebiaLabs Blog, AppNeta Blog

Related Topics: Recurring Revenue, Industrial IoT, Linux Containers, @CloudExpo, Apache, @DevOpsSummit

Recurring Revenue: Blog Feed Post

Surviving a Datacenter Outage By @PagerDuty | @DevOpsSummit [#DevOps]

Unlike some companies that are using Cassandra to support their big data efforts, our data set is relatively small

Surviving a Datacenter Outage

By Amanda Folson

PagerDuty was built around one simple idea: waking up the right people when things break. When an event is triggered, PagerDuty makes magic to notify the right person or team that something is wrong.

However, ensuring that the message makes it out of our pipeline to you isn’t so simple. Because we’re providing notifications when your systems are down, there’s a pretty big constraint on us to be up. If you can’t trust us, who can you trust?

We rely on a few distributed technologies in our alerting pipeline because they offer us the redundancy we need to ensure alerts make it to users. We’ve spent a lot of time architecting our infrastructure to be as fault-tolerant as possible in order to provide durable and consistent read/write operations in our critical alerting pipeline.

pd-overview

This pipeline starts with an event endpoint — either HTTP or email. From there, each event from a customer’s monitoring tool goes through a pipeline of separate services (such as incident management and notification management services) and ultimately ends up at the messaging service that actually reaches out to people. Many of these services are built on Scala and supported by Cassandra on the back end for data storage. We also make use of other technologies such as Zookeeper for coordination. This pipeline must always be up and healthy so we can ensure notifications are reaching people.

Cassandra at PagerDuty

We’ve had Cassandra in production for about two and a half years. Unlike some companies that are using Cassandra to support their “big data” efforts, our data set is relatively small — in the order of 10s of GB at any given moment. Since we’re using it to usher events through our pipeline, once the event reaches the end the data about it can be purged from the pipeline. We aim to keep our dataset as slim as possible.

pdeventtimeline

Cluster Configuration

We typically create clusters of 5 Cassandra nodes, with a replication factor of 5. These nodes are split across three datacenters; two nodes in one, two nodes in another, and one node in yet another facility. We make use of Cassandra’s quorum consistency level in order to provide us with the durability we need in the pipeline. This means that every write must be written to a majority of the cluster i.e. at least 3 of the 5 nodes.

cassandracluster

This pattern isn’t without its flaws. Every operation is across the WAN and takes an inter-DC latency hit. In some ways, this runs counter to typical recommendations for database clusters. However, since this latency hit is not exposed to humans, we’re willing to live with this tradeoff given the benefits: events aren’t lost, messages aren’t repeated, and we get durability and availability in the event that we lose an entire datacenter. With this 3 of 5 pattern, everything is written to at least two datacenters.

How do we know this works?

We intentionally introduce failures into our infrastructure to make sure that everything continues to run smoothly in the event of an outage. This includes thoroughly testing Cassandra nodes in degraded and non-functional states. For more about this, see our Failure Friday post.

At PagerDuty, we like to solve interesting technical problems. If you’re interested in making our cluster more robust, we’re currently hiring for positions in San Francisco and Toronto.

The post Surviving a Datacenter Outage appeared first on PagerDuty.

Read the original blog entry...

More Stories By PagerDuty Blog

PagerDuty’s operations performance platform helps companies increase reliability. By connecting people, systems and data in a single view, PagerDuty delivers visibility and actionable intelligence across global operations for effective incident resolution management. PagerDuty has over 100 platform partners, and is trusted by Fortune 500 companies and startups alike, including Microsoft, National Instruments, Electronic Arts, Adobe, Rackspace, Etsy, Square and Github.

@ThingsExpo Stories
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
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.
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...
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.
What sort of WebRTC based applications can we expect to see over the next year and beyond? One way to predict development trends is to see what sorts of applications startups are building. In his session at @ThingsExpo, Arin Sime, founder of WebRTC.ventures, will discuss the current and likely future trends in WebRTC application development based on real requests for custom applications from real customers, as well as other public sources of information,
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
TechTarget storage websites are the best online information resource for news, tips and expert advice for the storage, backup and disaster recovery markets. By creating abundant, high-quality editorial content across more than 140 highly targeted technology-specific websites, TechTarget attracts and nurtures communities of technology buyers researching their companies' information technology needs. By understanding these buyers' content consumption behaviors, TechTarget creates the purchase inte...
With the introduction of IoT and Smart Living in every aspect of our lives, one question has become relevant: What are the security implications? To answer this, first we have to look and explore the security models of the technologies that IoT is founded upon. In his session at @ThingsExpo, Nevi Kaja, a Research Engineer at Ford Motor Company, will discuss some of the security challenges of the IoT infrastructure and relate how these aspects impact Smart Living. The material will be delivered i...
In his session at @ThingsExpo, Eric Lachapelle, CEO of the Professional Evaluation and Certification Board (PECB), will provide an overview of various initiatives to certifiy the security of connected devices and future trends in ensuring public trust of IoT. Eric Lachapelle is the Chief Executive Officer of the Professional Evaluation and Certification Board (PECB), an international certification body. His role is to help companies and individuals to achieve professional, accredited and worldw...
Your homes and cars can be automated and self-serviced. Why can't your storage? From simply asking questions to analyze and troubleshoot your infrastructure, to provisioning storage with snapshots, recovery and replication, your wildest sci-fi dream has come true. In his session at @DevOpsSummit at 20th Cloud Expo, Dan Florea, Director of Product Management at Tintri, will provide a ChatOps demo where you can talk to your storage and manage it from anywhere, through Slack and similar services ...
My team embarked on building a data lake for our sales and marketing data to better understand customer journeys. This required building a hybrid data pipeline to connect our cloud CRM with the new Hadoop Data Lake. One challenge is that IT was not in a position to provide support until we proved value and marketing did not have the experience, so we embarked on the journey ourselves within the product marketing team for our line of business within Progress. In his session at @BigDataExpo, Sum...
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
SYS-CON Events announced today that Linux Academy, the foremost online Linux and cloud training platform and community, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Linux Academy was founded on the belief that providing high-quality, in-depth training should be available at an affordable price. Industry leaders in quality training, provided services, and student certification passes, its goal is to c...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
Now that the world has connected “things,” we need to build these devices as truly intelligent in order to create instantaneous and precise results. This means you have to do as much of the processing at the point of entry as you can: at the edge. The killer use cases for IoT are becoming manifest through AI engines on edge devices. An autonomous car has this dual edge/cloud analytics model, producing precise, real-time results. In his session at @ThingsExpo, John Crupi, Vice President and Eng...