03Prometheus memory jumped 400% overnight. Find the cause and stop it recurring.▼hard★ EssentialNewDatadogUberGrafana Labs2 repliesunlockedThe observability failure that scales with your success. Cardinality is the cost driver in every metrics system, and the fix has to be structural or it comes back next quarter.Open full answer →
10How does Prometheus actually store time series? Walk me through the WAL, blocks, compaction and retention.▼hardNewDatadogCloudflareGitLabunlockedMost candidates recite the pull model and stop. The interviewer asking this wants the storage engine story, because that is where Prometheus hurts in production: crash recovery, cold queries, disk death.Open full answer →
