What continuous operation means.
WHAT UPTIME MEASURES
The proportion of time a service is available.
HOW IT IS EXPRESSED
As a percentage, usually with several nines.
WHAT THOSE TRANSLATE TO
Each additional nine reduces permitted downtime by roughly a factor of ten.
The difference between figures that sound similar is substantial.
WHAT TO DO WITH ANY FIGURE
Translate it into permitted downtime per month, and judge whether that is acceptable.
WHAT UPTIME COMMITMENTS USUALLY COVER
The facility's power and cooling, or the provider's platform.
WHAT THEY USUALLY DO NOT COVER
Your own equipment Your own software Scheduled maintenance Your connection to the facility
WHAT THE REMEDY USUALLY IS
Service credits, not compensation for your losses.
WHY THAT MATTERS
A credit does not cover a day of lost trading.
WHAT ACTUALLY PROTECTS YOU
Your own arrangements: backups, redundancy where warranted, and a plan.
WHAT TO ASK
The facility's actual outage history, not only its commitment.
