Reliability is a property or level that system is generally functioning properly.

As an example an LDAP Server Implementation may answer to a "ping" but not be able to make a Success for a Bind Request.

Reliability implies there is a some level of Fault tolerance

Reliability for Data At Rest is often referred to a Durability

Health-check and Load Balancing#

Instances continuously start, restart and stop because of failures, deployments or autoscaling. These operations makes an instance temporarily or permanently unavailable. For Load Balancing a Health-check should mark the instance as unavailable and Load Balancing should skip unhealthy instances from the routing as they cannot serve requests.

More Information#

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