The Reality of Failure-Proof Systems in the Cloud

February, 2019

How often does the server/virtualisation stack fail? We take some examples from our own experience and identify 3 things you can do to get you close to 5 nines up-time.
As an OEM software vendor providing technology to integrators and carriers, failsafe systems are our lifeblood.  This gives us some unique insights into how to achieve high uptime in reality. Traditional strategies for High Availability (HA) revolve around redundancy at a process, VM and physical infrastructure level to minimise risk of outage, and minimise recovery time when outage occurs.  But how often does the server/virtualisation stack fail?  Let’s take some examples from our own experience.

Sytel has around 30 rackmount servers in the computer room at our R&D labs. We manage them well and over the last 15 years we have had:

  • one server outage because of a memory chip failure
  • one network switch failure

Downtime virtually zero.  Maybe good management on our part but really an indication of what can be achieved with hardware.

On the software side; yes you can set up services and VMs to fail over to a redundant backup, but unless your contact center software stack does this for you automatically, the management overhead of setup and the likelihood of misconfiguration, virtualisation-based HA is just a fig leaf.

There is another reason why the holy grail of 5 nines uptime can be difficult to achieve with software.  If the software itself is well-proven and reliable, the biggest sources of real-world failure in large-scale contact center systems are:

  • Load-related database errors (both Relational and NoSQL databases)
  • Server OS handling of extreme network load
  • Too much work being done by one application instance

HA solutions per se don’t solve these problems.  But there are three things you can do, in particular, to mitigate the problems that arise here:

  1. Perform application-level caching and support for rollforward recovery on failure for all services that write to the contact center database.
  2. Ensure your platform’s internal signalling protocols (the things that control system state) are hardened to deal with temporary network glitches.
  3. Ensure your system architecture is componentised and able to multiplex everything in order to achieve scale and limit cost of component failure.

If you ensure your platform does these three things (and destruction test to make sure that it does!) then this will get you much closer to 5 nines uptime, rather than just implementing redundant services, virtualisation-based failover and redundant hardware.

It’s not received wisdom, but it’s definitely common sense!

What We Offer

Sytel Limited develops and supplies Softdial Contact Center® (SCC), offering multimedia, multichannel, fully blended cloud contact center solutions, for quick and easy deployment by partners offering CCaaS or enterprise users. All Sytel cloud components are secure, resilient and scale seamlessly from 10 agents to 10,000+, whether local, mobile or remote.

  • Flexible Contact Center Platform

    Softdial Contact Center™ – tightly integrated modules, designed to deliver at scale

  • Blended Media Desktop

    Fully customisable, multi-channel, multi-session workspace

  • Work Anywhere

    Browser-based tools, no software installation required

  • Cloud Or On-Premise, Multi-Tenant

    Scalable, resilient, secure, proven

  • Customise, Localise, White Label

    Design all user interfaces to individual requirements

  • Integration Via APIs

    ‘Swap out’ components and integrate with 3rd party apps

  • World Class Development

    Continuous evolution pushing technical boundaries


Softdial Contact Center™ (SCC) is designed to be flexible, extensible and scalable, integrating with any legacy equipment, and meeting the most complex of requirements.

  • All Media Types

    Voice, chat, email, social, etc – fully integrated and blended

  • Agent Multi-Tasking

    Work with multiple live contact sessions of any media type

  • Dynamic Media Blending

    Automated, ‘best available’ decisions to blend and balance work load across all media types

  • Predictive Dialing

    Best-of-breed performance under compliance

  • Intelligent Routing

    Smart rules and ‘best-available’ decisions to drive great customer service

  • Agent Scripts

    Help agents achieve and maintain excellence

  • Voice and Screen Recording

    See and hear exactly how agents are interacting

  • Analytics and Data Feeds

    Measure and evaluate performance at every level

  • IVR, Bots & Conversational AI

    Design effective automated flows or integrate with 3rd party providers

  • Customer Journey Tracking

    Stored customer contact history, to aid routing and add context to conversations


A complete suite of tools, with unique flexibility to extend and swap out modules to deliver a tailored contact center solution for any environment

  • Softdial One™

    Highly flexible unified web UI for agents, supervisors and administrators

  • Softdial Scripter™

    Create complex process flow scripts for agents, IVR, chatbots and other applications

  • Sytel AI Dialer™

    Best-of-breed predictive dialing under any compliance rules

  • Softdial Pathfinder™

    Precise routing rules for ‘best available’ connection

  • Softdial Media Server™

    Core telephony functions to manage all inbound/ outbound SIP calls

  • Softdial Reporter™ 5

    Fully customisable performance stats, charts and reports, across all channels

  • Softdial Publisher™

    Comprehensive data output to build your own reports

  • Softdial Recording Monitor™

    Audio and screen recording of agent activity to ensure the highest standards

  • Softdial Campaign Manager™

    Comprehensive configuration and control for outbound campaigns

  • Softdial Repository™

    Central storage and configuration of common resources

  • Sytel Global Compliance™

    Flexible ‘no contact’ rules to protect contact center and consumer


Performance and efficiency for a wide range of business applications

  • Customer Service

    Connect quickly to well equipped agents

  • Sales & Telemarketing

    Maximise agent productivity with best-of-breed predictive dialing

  • Healthcare

    Secure, highly-configurable multichannel communications for excellence in patient care

  • Market Research

    Best-of-breed predictive dialing with CATI integration

  • Collections

    Automated inbound/ outbound blending integrated with any debt management app