Complete Outages and Degraded Service
A complete service outage is the nightmare all system administrators fear. In a complete service outage, a service is 100% unavailable to its users. These outages are all too often the cause of 3:00 a.m. pages on a Saturday.
Not all outages are as catastrophic as those just described. Sometimes problems just cause a service to become degraded. Much as a power brownout causes lights to dim but not fail, users can still use a degraded service; it just doesn't perform as well as it normally would.
A POP3 mail service example can help illustrate degraded service outages. Users of these servers are used to clicking on a “Retrieve Mail” button on their clients and receiving their new mail within seconds. However, ...
Get Unix® System Management Primer Plus now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
