Welcome!

Recurring Revenue Authors: Liz McMillan, Yeshim Deniz, Carmen Gonzalez, Elizabeth White, Pat Romanski

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
While the focus and objectives of IoT initiatives are many and diverse, they all share a few common attributes, and one of those is the network. Commonly, that network includes the Internet, over which there isn't any real control for performance and availability. Or is there? The current state of the art for Big Data analytics, as applied to network telemetry, offers new opportunities for improving and assuring operational integrity. In his session at @ThingsExpo, Jim Frey, Vice President of S...
"We provide IoT solutions. We provide the most compatible solutions for many applications. Our solutions are industry agnostic and also protocol agnostic," explained Richard Han, Head of Sales and Marketing and Engineering at Systena America, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
DX World EXPO, LLC., a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"We've been engaging with a lot of customers including Panasonic, we've been involved with Cisco and now we're working with the U.S. government - the Department of Homeland Security," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held June 6-8, 2017, at the Javits Center in New York City, NY.
"We are focused on SAP running in the clouds, to make this super easy because we believe in the tremendous value of those powerful worlds - SAP and the cloud," explained Frank Stienhans, CTO of Ocean9, Inc., in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
The financial services market is one of the most data-driven industries in the world, yet it’s bogged down by legacy CPU technologies that simply can’t keep up with the task of querying and visualizing billions of records. In his session at 20th Cloud Expo, Karthik Lalithraj, a Principal Solutions Architect at Kinetica, discussed how the advent of advanced in-database analytics on the GPU makes it possible to run sophisticated data science workloads on the same database that is housing the rich...
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
"The Striim platform is a full end-to-end streaming integration and analytics platform that is middleware that covers a lot of different use cases," explained Steve Wilkes, Founder and CTO at Striim, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that Calligo, an innovative cloud service provider offering mid-sized companies the highest levels of data privacy and security, has been named "Bronze Sponsor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Calligo offers unparalleled application performance guarantees, commercial flexibility and a personalised support service from its globally located cloud plat...
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
SYS-CON Events announced today that Datera, that offers a radically new data management architecture, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera is transforming the traditional datacenter model through modern cloud simplicity. The technology industry is at another major inflection point. The rise of mobile, the Internet of Things, data storage and Big...
"MobiDev is a Ukraine-based software development company. We do mobile development, and we're specialists in that. But we do full stack software development for entrepreneurs, for emerging companies, and for enterprise ventures," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
In his opening keynote at 20th Cloud Expo, Michael Maximilien, Research Scientist, Architect, and Engineer at IBM, discussed the full potential of the cloud and social data requires artificial intelligence. By mixing Cloud Foundry and the rich set of Watson services, IBM's Bluemix is the best cloud operating system for enterprises today, providing rapid development and deployment of applications that can take advantage of the rich catalog of Watson services to help drive insights from the vast t...
SYS-CON Events announced today that EnterpriseTech has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. EnterpriseTech is a professional resource for news and intelligence covering the migration of high-end technologies into the enterprise and business-IT industry, with a special focus on high-tech solutions in new product development, workload management, increased effic...
SYS-CON Events announced today that Massive Networks, that helps your business operate seamlessly with fast, reliable, and secure internet and network solutions, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. As a premier telecommunications provider, Massive Networks is headquartered out of Louisville, Colorado. With years of experience under their belt, their team of...
SYS-CON Events announced today that Cloud Academy named "Bronze Sponsor" of 21st International Cloud Expo which will take place October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara, CA. Cloud Academy is the industry’s most innovative, vendor-neutral cloud technology training platform. Cloud Academy provides continuous learning solutions for individuals and enterprise teams for Amazon Web Services, Microsoft Azure, Google Cloud Platform, and the most popular cloud com...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. 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 ...
SYS-CON Events announced today that CHEETAH Training & Innovation will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CHEETAH Training & Innovation is a cloud consulting and IT training firm specializing in improving clients cloud strategies and infrastructures for medium to large companies.
SYS-CON Events announced today that Datanami has been named “Media Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datanami is a communication channel dedicated to providing insight, analysis and up-to-the-minute information about emerging trends and solutions in Big Data. The publication sheds light on all cutting-edge technologies including networking, storage and applications, and thei...