Log Cache Release is a bosh release for Log Cache. It provides an in memory caching layer as a replacement for cf logs --recent and container metrics retrieval.

Log Cache can be deployed either as a standalone deployment or within Cloud Foundry.

In both cases Log Cache will have to know about Loggregator.

Every bosh deployment requires a cloud config. The Log Cache deployment manifest assumes the CF-Deployment cloud config has been uploaded.

The first step in deploying Log Cache is to create a release. Final releases are preferable, however during the development process dev releases are useful.

The following commands will create a dev release and upload it to an environment named lite.

bosh create-release --force
bosh -e lite upload-release --rebase

Standalone Log Cache only has to know where to find Loggregator. The Loggregator CA is named loggregator_ca. The given variables file should include the deployed Loggregator's CA.

The following command will deploy a standalone Log Cache against a Loggregator that is deployed with a loggregator-vars.yml variables file.

bosh \
    --environment lite \
    --deployment log-cache deploy manifests/log-cache.yml \
    --vars-store vars.yml \
    --vars-file ~/workspace/loggregator-release/vars.yml

Log Cache deployed within Cloud Foundry reads from the Loggregator system and registers with the GoRouter at log-cache.<system-domain> (e.g. for bosh-lite log-cache.bosh-lite.com).

As of cf-deployment version 3.x, Log Cache is included by default in CF.

The following commands will deploy Log Cache in CF.

bosh update-runtime-config \
    ~/workspace/bosh-deployment/runtime-configs/dns.yml
bosh update-cloud-config \
    ~/workspace/cf-deployment/iaas-support/bosh-lite/cloud-config.yml
bosh \
    --environment lite \
    --deployment cf \
    deploy ~/workspace/cf-deployment/cf-deployment.yml \
    --ops-file ~/workspace/cf-deployment/operations/bosh-lite.yml \
    --ops-file ~/workspace/cf-deployment/operations/use-compiled-releases.yml \
    -v system_domain=bosh-lite.com

By Default, Log Cache uses the doppler client included with cf-deployment.

If you would like to use a custom client, it requires the uaa.resource authority:

<custom_client_id>:
    authorities: uaa.resource
    override: true
    authorized-grant-types: client_credentials
    secret: <custom_client_secret>

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.

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.