PCA Storage & Retention Flashcards
6 cards from real PCA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 PCA Storage & Retention flashcards as text
What is the default local storage retention period for Prometheus time-series data?
Answer: 15 days
By default, Prometheus retains local data for 15 days before it is deleted.
Which Prometheus storage format organizes data into time-based directories called blocks?
Answer: TSDB (Time Series Database)
Prometheus uses its own TSDB which stores data in immutable time-based blocks on disk.
Which flag sets the maximum amount of disk space Prometheus can use for local storage?
Answer: --storage.tsdb.retention.size
The --storage.tsdb.retention.size flag caps how much disk Prometheus uses, deleting old blocks when the limit is reached.
What is the Write-Ahead Log (WAL) in Prometheus TSDB used for?
Answer: Durably recording incoming samples before they are compacted into blocks
The WAL ensures that data received by Prometheus is not lost if the process crashes before samples are flushed to a block.
How long does Prometheus keep data in memory before writing it to a disk block by default?
Answer: 2 hours
Prometheus accumulates data in a head block in memory for approximately 2 hours before compacting it to disk.
What does Prometheus do when its local disk retention limit is reached?
Answer: Deletes the oldest TSDB blocks first
When the retention limit is hit, Prometheus removes the oldest data blocks to free disk space.