Service Level Agreements for Carrier-Grade Clouds: beyond best-effort

Service Level Agreements (SLAs) are a the nuts and bolts of a business agreement and next to QoS and Security the final pillar of a Carrier-Grade Cloud offering. SLAs define functional and non-functional conditions under which the service should be delivered. They allow for penalties or compensations to be directly derived.

Ironically these SLAs have historically been best-effort, static (sometimes paper) constructs, taking only the top-level interface into consideration. Service-oriented infrastructures however are built on complex n-tier architectures usually reside (at least in part) under control of external providers.

In practice there is very little the customer can do in order to prove a violation to the provider.

Lack of transparency and SLA monitoring is the biggest hurdle for risk-management departments who need to decide if it’s safe to move a critical part of their business to the cloud, and is amplified even further with Carrier-Grade Cloud platforms.

Best-effort SLAs are a relic from how services and software was sold in the 90ies and has no place in a modern XaaS delivery.

Currently, service providers cannot plan their service landscapes using the SLAs of dependent services. They have no means by which to determine why a certain SLA violation might have occurred, or how to express an associated penalty.

SLA terms are not explicitly related to measurable metrics, nor is their relation to lower-level services clearly defined. As a consequence, service providers cannot determine the necessary (lower-level) monitoring required to ensure top-level SLAs. This missing relationship between top-level SLAs and (lower-level) metrics is a major hurdle to efficient service planning and prediction in service stacks.

The challenge and opportunity for cloud computing businesses is to move beyond best-effort SLAs, and offer services with:

  1. adjustable (machine-readable) SLAs
  2. the ability to negotiate tailor-made agreements in an automated fashion
  3. consistent SLA management across all layers of the technology stack and include the external (Tier-2) stakeholders involved in the delivery
  4. span across all domains, including Security, QoS, Availability
  5. integrate into Billing and Customer-Experience-Management (CEM) and tools for measure Quality-of-Experience (QoE)
  6. transparent monitoring of SLA violations and more intelligent billing
  7. awareness of self-healing, self-organizing & self-configuring systems
  8. integrate into systems which affect the provisioning such as configuration management and Life-Cycle systems

As a pioneer in next generation cloud architecture Valbonne Consulting has the bandwidth, knowledge and right experts to provide these features tailored to your requirements. Call us today to find out how we can  help: +33 (0) 4 92 944 799

Deep Reading:

  1. SLA@SOI EU project includes links Open Source software for SLA automation
  2. Cloud Computing SLAs: http://ec.europa.eu/information_society/newsroom/cf/dae/document.cfm?doc_id=2496
  3. Service Level Agreement Complexity: Processing Concerns for Standalone and Aggregate SLAs: http://arxiv.org/abs/1407.7257
  4. SLA-Enabled Infrastructure Management (with Apache Tashi): http://pd.zhaw.ch/publikation/upload/206042.pdf
  5. PSLA: A PaaS Level SLA Description Language: http://dl.acm.org/citation.cfm?id=2624614