The compactor component of Thanos applies the compaction procedure of the Prometheus 2.0 storage engine to block data stored in object storage. It is generally not semantically concurrency safe and must be deployed as a singleton against a bucket.
$ thanos compact --gcs.bucket example-bucket --data-dir /tmp/thanos-compact
The compactor needs local disk space to store intermediate data for its processing. Generally, about 100GB are recommended for it to keep working as the compacted time ranges grow over time. On-disk data is safe to delete between restarts and should be the first attempt to get crash-looping compactors unstuck.
usage: thanos compact [<flags>] continuously compacts blocks in an object store bucket Flags: -h, --help Show context-sensitive help (also try --help-long and --help-man). --version Show application version. --log.level=info Log filtering level. --gcloudtrace.project=GCLOUDTRACE.PROJECT GCP project to send Google Cloud Trace tracings to. If empty, tracing will be disabled. --gcloudtrace.sample-factor=1 How often we send traces (1/<sample-factor>). If 0 no trace will be sent periodically, unless forced by baggage item. See `pkg/tracing/tracing.go` for details. --http-address="0.0.0.0:10902" Listen host:port for HTTP endpoints. --data-dir="./data" Data directory in which to cache blocks and process compactions. --gcs.bucket=<bucket> Google Cloud Storage bucket name for stored blocks. --s3.bucket=<bucket> S3-Compatible API bucket name for stored blocks. --s3.endpoint=<api-url> S3-Compatible API endpoint for stored blocks. --s3.access-key=<key> Access key for an S3-Compatible API. --s3.insecure Whether to use an insecure connection with an S3-Compatible API. --s3.signature-version2 Whether to use S3 Signature Version 2; otherwise Signature Version 4 will be used. --s3.encrypt-sse Whether to use Server Side Encryption --sync-delay=30m Minimum age of fresh (non-compacted) blocks before they are being processed. --retention.resolution-raw=0d How long to retain raw samples in bucket. 0d - disables this retention --retention.resolution-5m=0d How long to retain samples of resolution 1 (5 minutes) in bucket. 0d - disables this retention --retention.resolution-1h=0d How long to retain samples of resolution 2 (1 hour) in bucket. 0d - disables this retention -w, --wait Do not exit after all compactions have been processed and wait for new work.