|By Automic Blog||
|September 29, 2016 07:00 PM EDT||
Art of Rollback III: Rollback Strategies Through the Ages
By Pierre-Boris Bonafous
We learned that a good rollback mechanism cannot be designed without having an intimate knowledge of the application architecture, the nature of your components and their dependencies. Now that we know what we have to restore and in which order, the question is how?
There are always different possible strategies available to restore your services. The only criteria for deciding which one to choose is speed. For this reason, the rollback must be automated and the best rollback features available must be leveraged for each of your application components and technologies. The automation tool will be in charge of the orchestration of the different technologies involved in the rollback process.
How Much Money Should You Spend on Rollback?
Always go for the fastest process you can afford. No company can afford data loss, data corruption and service interruption. Never cut cost on this part. Trying to reuse old backup systems or mutualized backup, for example, is not advisable, as investing in new technologies can give you more reactivity with an immediate ROI.
The budget of rollback implementation should be calculated at the beginning of your project, according to the cost of an error for the business and not by looking at best solution price or providers' bundles available on the market.
The acceptable cost of an error should not be estimated by Ops or Devs but by the business itself, as it can be a mix of unexpected factors. Some are part of the company plan and should not be shared internally. For example, it can be related to the company share price, risk assessment, compliance and compensation, SLA and penalties, customer retention, sales objectives, transactions per days and so on...
Time is money, so the equation is really easy to solve for Ops: the maximum recovery time objective (RTO) of an application depends on the maximum acceptable loss for the business. Your company may already have defined this metric in the disaster recovery plan.
Unfortunately, like most other technical services, the rollback system is too often taken in account at the end of a project. This is a big mistake as the cost of implementing the rollback can be huge, sometimes higher than essential features like automated deployment or monitoring. The rollback cost does not only include the cost of the implementation and the possible additional tools but also the cost of maintenance and regular testing of the rollback system.
Automic is helping his customers to create value with automation. Automated deployments and automated rollbacks must be considered together as a whole when you want to cover the Release Automation activities.
Let's take a look at the most popular rollback strategies implemented today for static components. There are two different ways to manage immutable components: restore and switch.
Restore Rollback: This is the traditional way to roll back, from a time when applications were installed on premise, on physical boxes, and when the materials and software were expensive. Thanks to virtualization, containers and automated provisioning, the restore approach has enjoyed a renaissance. The original intent was to simply to reinstall the previous version of the application(s). That can be done by overriding files, uninstalling/reinstalling binaries or going back to a restoration point.
Today it's more about redelivering the previous complete application stack, pre-configured: the OS, the middleware and the application layer itself. Virtualization has paved the way with templates and Gold VMs. But container technologies like Docker do even better, as you can instantiate a container from an image in a couple of seconds. You have to re-instantiate a container from the previous images instead of delivering old binaries
Automic Release Automation enables you to define rollback at the workflow or job/task level. When the default rollback is activated, you can assign backup and rollback tasks. The backup task will be executed before the main action, while the rollback task will be executed in case of failure.
However, not every application today is a good candidate for containerization. If this is the case, you can go for the switch strategy, to achieve the same outstanding performance but for old systems.
Switch Rollback: Switch rollback maintains two releases of your application in parallel but makes only one accessible to your users while the other remains offline. When you want to deploy a new application release, you install the new release on the offline system. Once the new version is ready you just have to put the old version offline and new version online. If you want to rollback your application, you just switch back.
The switch can be really transparent when the application is a bunch of files in a flat directory. All you have to do is to switch two repositories with the old and the new release content. Sometimes it can be trickier if you rely on an application server or a cluster.
Blue-green deployment is a typical example of switch rollback. The blue environment is offline and the green is online. An environment can be a cluster or collection of machines. The switch (or change of color) can be done quickly by reassigning the IP addresses between the blue and the green machines in the DNS, in the load balancer or at the proxy level. Another advantage of blue-green deployment is that the rollback does not need a specific procedure because it the same procedure used for the initial rollout.
How much does this cost? Well, you must maintain a duplicated platform. That can be quite expensive if your platform is a cluster or a server farm. However, virtualization and automated provisioning can help you to limit the cost of administration, licenses and maintenance of the blue platform if you build and destroy the environments on the fly.
As you may be aware, immutable components are not an issue anymore. The problem we must solve today is rolling back dynamic components. Data is now stored on various formats: files, relational databases, NoSQL databases and so on... each technology with its own properties for recovery management.
In this scenario it's difficult to rollback without downtime or data loss if you do not have specific features embedded in the application itself. Some examples of possible function could be a data resilience system, a database virtualization layer, a data cache mechanism or treating your database structure as code.
Let's take an even more simple use case: a database upgrade with zero downtime. Not all databases can support that feature. There is no set plan to follow so you must exploit the best technologies available on the market like checkpoints or point-in-time recovery for databases and snapshots for virtual machines when your software architecture does not support rollback natively.
In fact, the only way to achieve zero downtime and to keep control of your data during deployments and rollbacks is to design backward and forward compatibility in the application itself. But this is another story...
Rolling forward; Why is it better than rollback? Because rolling forward is the best way of accepting that we, Dev and Ops, are intimately involved in time-flow, no matter what Albert Einstein or Brian Green told us! Stay tuned.
Adobe is changing the world though digital experiences. Adobe helps customers develop and deliver high-impact experiences that differentiate brands, build loyalty, and drive revenue across every screen, including smartphones, computers, tablets and TVs. Adobe content solutions are used daily by millions of companies worldwide-from publishers and broadcasters, to enterprises, marketing agencies and household-name brands. Building on its established design leadership, Adobe enables customers not o...
Sep. 30, 2016 07:30 AM EDT
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, will discuss why and how ReadyTalk diverted from healthy revenue an...
Sep. 30, 2016 07:15 AM EDT Reads: 2,239
Cognitive Computing is becoming the foundation for a new generation of solutions that have the potential to transform business. Unlike traditional approaches to building solutions, a cognitive computing approach allows the data to help determine the way applications are designed. This contrasts with conventional software development that begins with defining logic based on the current way a business operates. In her session at 18th Cloud Expo, Judith S. Hurwitz, President and CEO of Hurwitz & ...
Sep. 30, 2016 07:15 AM EDT Reads: 3,266
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform and how we integrate our thinking to solve complicated problems. In his session at 19th Cloud Expo, Craig Sproule, CEO of Metavine, will demonstrate how to move beyond today's coding paradigm ...
Sep. 30, 2016 07:00 AM EDT Reads: 3,464
Digitization is driving a fundamental change in society that is transforming the way businesses work with their customers, their supply chains and their people. Digital transformation leverages DevOps best practices, such as Agile Parallel Development, Continuous Delivery and Agile Operations to capitalize on opportunities and create competitive differentiation in the application economy. However, information security has been notably absent from the DevOps movement. Speed doesn’t have to negat...
Sep. 30, 2016 07:00 AM EDT Reads: 2,334
Leading cloud-centric IT organizations are establishing core capabilities to improve productivity, control costs and provide a highly responsive end-user experience. Key steps along this journey include creating an end-user cloud services catalog, automating workflows and provisioning, and implementing IT showback and chargeback. In his session at 19th Cloud Expo, Mark Jamensky, executive vice president of Products at Embotics, will walk attendees through an in-depth case study of enterprise I...
Sep. 30, 2016 07:00 AM EDT Reads: 1,506
Without a clear strategy for cost control and an architecture designed with cloud services in mind, costs and operational performance can quickly get out of control. To avoid multiple architectural redesigns requires extensive thought and planning. Boundary (now part of BMC) launched a new public-facing multi-tenant high resolution monitoring service on Amazon AWS two years ago, facing challenges and learning best practices in the early days of the new service. In his session at 19th Cloud Exp...
Sep. 30, 2016 06:15 AM EDT Reads: 1,128
The Transparent Cloud-computing Consortium (abbreviation: T-Cloud Consortium) will conduct research activities into changes in the computing model as a result of collaboration between "device" and "cloud" and the creation of new value and markets through organic data processing High speed and high quality networks, and dramatic improvements in computer processing capabilities, have greatly changed the nature of applications and made the storing and processing of data on the network commonplace.
Sep. 30, 2016 06:00 AM EDT Reads: 1,260
Your business relies on your applications and your employees to stay in business. Whether you develop apps or manage business critical apps that help fuel your business, what happens when users experience sluggish performance? You and all technical teams across the organization – application, network, operations, among others, as well as, those outside the organization, like ISPs and third-party providers – are called in to solve the problem.
Sep. 30, 2016 06:00 AM EDT Reads: 2,736
Digital transformation is too big and important for our future success to not understand the rules that apply to it. The first three rules for winning in this age of hyper-digital transformation are: Advantages in speed, analytics and operational tempos must be captured by implementing an optimized information logistics system (OILS) Real-time operational tempos (IT, people and business processes) must be achieved Businesses that can "analyze data and act and with speed" will dominate those t...
Sep. 30, 2016 05:30 AM EDT Reads: 1,281
While DevOps promises a better and tighter integration among an organization’s development and operation teams and transforms an application life cycle into a continual deployment, Chef and Azure together provides a speedy, cost-effective and highly scalable vehicle for realizing the business values of this transformation. In his session at @DevOpsSummit at 19th Cloud Expo, Yung Chou, a Technology Evangelist at Microsoft, will present a unique opportunity to witness how Chef and Azure work tog...
Sep. 30, 2016 05:15 AM EDT Reads: 1,847
Almost two-thirds of companies either have or soon will have IoT as the backbone of their business in 2016. However, IoT is far more complex than most firms expected. How can you not get trapped in the pitfalls? In his session at @ThingsExpo, Tony Shan, a renowned visionary and thought leader, will introduce a holistic method of IoTification, which is the process of IoTifying the existing technology and business models to adopt and leverage IoT. He will drill down to the components in this fra...
Sep. 30, 2016 05:00 AM EDT Reads: 1,884
As ridesharing competitors and enhanced services increase, notable changes are occurring in the transportation model. Despite the cost-effective means and flexibility of ridesharing, both drivers and users will need to be aware of the connected environment and how it will impact the ridesharing experience. In his session at @ThingsExpo, Timothy Evavold, Executive Director Automotive at Covisint, will discuss key challenges and solutions to powering a ride sharing and/or multimodal model in the a...
Sep. 30, 2016 04:45 AM EDT Reads: 673
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo Silicon Valley Call for Papers is now open.
Sep. 30, 2016 04:45 AM EDT Reads: 4,719
I'm a lonely sensor. I spend all day telling the world how I'm feeling, but none of the other sensors seem to care. I want to be connected. I want to build relationships with other sensors to be more useful for my human. I want my human to understand that when my friends next door are too hot for a while, I'll soon be flaming. And when all my friends go outside without me, I may be left behind. Don't just log my data; use the relationship graph. In his session at @ThingsExpo, Ryan Boyd, Engi...
Sep. 30, 2016 04:45 AM EDT Reads: 1,411