Highlights
Failure is an expected state in production systems, and no predictable failure of either software or hardware components should result in a negative experience for users. The exact failure mode may vary, but certain remediation steps must be taken after detection. A common example is when an error occurs on a server, rendering it unfit for production workloads, and requiring action to recover.
It can be tempting to rely on the expertise of world-class engineers to remediate these faults, but this would be manual, repetitive, unlikely to produce enduring value, and not scaling.
The commonality of lower-priority failures makes it obvious when the response required, as defined in runbooks, is “toilsome”. To reduce this toil, we had previously implemented a plethora of solutions to automate runbook actions such as manually-invoked shell scripts, cron jobs, and ad-hoc software services. These had grown organically over time and provided solutions on a case-by-case basis, which led to duplication of work, tight coupling, and lack of context awareness across the solutions.
A good solution would not allow only the SRE team to auto-remediate, it would empower the entire company. The key to adding self-healing capability was a generic interface for all teams to self-service and quickly remediate failures at various levels: machine, service, network, or dependencies.
Temporal is a durable execution platform which is useful to gracefully manage infrastructure failures such as network outages and transient failures in external service endpoints. This capability meant we only needed to build a way to schedule “workflow” tasks and have Temporal provide reliability guarantees.
After a workflow is validated in the staging environment, we can then do a full release to production. It seems obvious, but catching simple configuration errors before releasing has saved us many hours in development/change-related-task time.
Building a system that is maintained by several SRE teams has allowed us to iterate faster, and rapidly tackle long-standing problems. We have set ambitious goals regarding toil elimination and are on course to achieve them, which will allow us to scale faster by eliminating the human bottleneck.