Log cache depends on Loggregator and is expected to offer slightly lower reliability.
This is primarily due to the ephemeral nature of the cache. Loss will occur during a
deployment. Outside of deployments a 99% reliability can be expected.
Cache Duration & Scaling
Log cache is horizontally scalable and we recommend scaling based on the formula below.
We have set a service level objective of 15 minutes with this scaling recommendation.
Log Cache Nodes = Envelopes Per Second / 10,000
Note - this is intentionally designed to match the scaling of the Log Router used in the
Loggregator system for [colocation in cf-deployment][cf-deployment-ops] - that said more
recent testing with this colocation strategy has not met these SLOs. If targeting these
SLOs is critical to your foundation we recommend using a log-cache instance group.
Log Cache API
Documentation about the internals of Log Cache and its API can be found here