feat: Add support for storing chunk deletion markers in object storage instead of local disk #19689
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💻 Deploy preview available (feat: Add support for storing chunk deletion markers in object storage instead of local disk): |
paul1r
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Nov 4, 2025
pkg/compactor/config.go
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| HorizontalScalingModeDisabled, HorizontalScalingModeMain, HorizontalScalingModeWorker)) | ||
| cfg.WorkerConfig.RegisterFlagsWithPrefix("compactor.worker.", f) | ||
| cfg.JobsConfig.RegisterFlagsWithPrefix("compactor.jobs.", f) | ||
| f.StringVar(&cfg.DeletionMarkerObjectStorePrefix, "compactor.deletion-marker-object-store-prefix", "", "Object storage path prefix for storing deletion markers. Leave empty to store deletion markers on local disk.") |
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nit: add rule about trailing slash in this
JStickler
reviewed
Nov 4, 2025
docs/sources/shared/configuration.md
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| [max_retries: <int> | default = 3] | ||
| # Object storage path prefix for storing deletion markers. Leave empty to store | ||
| # deletion markers on local disk. |
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Question re: "local disk" does this require a persistent volume to be configured? Or does this mean storage will be on file system?
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Compactor should have a persistent volume attached to it. It already uses the local disk for storing deletion markers. This feature enables operators to use object storage for storing the deletion markers.
However, it does not allow us to run the compactor without a disk because the disk is also needed for other operations.
paul1r
approved these changes
Nov 10, 2025
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What this PR does / why we need it:
When retention support was initially introduced to Loki, we stored chunk deletion markers on local disk without any support for storing them on object storage instead. Chunk deletion markers are created for chunks which are supposed to be deleted due to running out of retention or a deletion request. At a large scale, if a large number of chunks are selected in a short span due to a significant change in retention period or a delete request touching too much data, there would be a significant surge in the disk space usage by deletion marker files, which can cause the compactor to run out of disk space.
With this PR, I am adding support for configuring the compactor to store chunk deletion markers in the object storage under a prefix. If the prefix is empty (default), the compactor will, as usual, continue to store the deletion markers on the local disk.
When the compactor is configured to store chunk deletion markers in object storage, the chunk markers are stored in a period-specific object store according to the schema configuration.
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