The IaaS market has expanded beyond Amazon Web Services, with competitors including Rackspace, GoGrid, and emerging platforms vying for enterprise workloads. Evaluating IaaS providers requires looking beyond headline pricing to assess reliability, support, networking capabilities, and ecosystem maturity.
Key Evaluation Criteria
Service Level Agreements define the provider's commitment to availability, typically expressed as a monthly uptime percentage. Look beyond the headline SLA number to understand how uptime is measured, what constitutes a qualifying outage, and what remedies (usually service credits) are available when the SLA is breached. A 99.95% SLA allows approximately 22 minutes of downtime per month.
Evaluate the provider's networking architecture, including available bandwidth, inter-region connectivity, and support for private networking between instances. Data transfer pricing can significantly impact total cost, particularly for applications that serve large amounts of content. Some providers charge asymmetrically for ingress and egress, making cost estimation complex.
Consider portability and lock-in risks. Proprietary APIs and services create dependency on a single provider. Favor providers that support standard formats and protocols, and architect your application to abstract provider-specific services behind interfaces that allow substitution. The ability to migrate between providers gives you negotiating leverage and protects against provider failures or pricing changes.