Busk: Created page with "Loki’s Azure “blobs” are really just the compressed chunks of log entries that the Ingester flushes to your `/chunks//…` path. The size o..."

2025-07-07T16:09:22Z

Created page with "Loki’s Azure “blobs” are really just the compressed **chunks** of log entries that the Ingester flushes to your `<container>/chunks/<tenant-ID>/…` path. The **size** o..."

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Loki’s Azure “blobs” are really just the compressed **chunks** of log entries that the Ingester flushes to your `<container>/chunks/<tenant-ID>/…` path. The **size** of each blob is controlled by Loki itself, not by Azure:

* **`chunk_target_size`** (default \~1 MiB) tells Loki roughly how big to let a chunk grow before flushing.
* **`max_chunk_age`** (default 1 h) forces a flush once a chunk has been open for that long, even if it hasn’t hit `chunk_target_size`.
* **`chunk_idle_period`** (default 1 h) flushes any stream that hasn’t received new entries in that window.
You tune these under your Ingester config (`ingester.chunk_target_size`, `ingester.max_chunk_age`, etc.) in `loki.yaml` or via Helm values ([medium.com][1]).

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### What Azure does under the covers

When Loki hands off a chunk file to Azure, it uses the **Block Blob** API. Azure will automatically break any upload into blocks (up to 50 000 blocks per blob) and stitch them together:

* The **max block size** and **max blob size** are governed by the Storage service version—e.g. service 2019-12-12+ supports up to 4000 MiB per block and \~190 TiB per blob ([learn.microsoft.com][2]).
* Loki’s client-side buffer controls (e.g. `azure.upload_buffer_size`, default 256 KiB) simply govern how much of the chunk is read/streamed per block upload; they do **not** change the logical size of your chunk blob ([techdocs.akamai.com][3]).

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### Bottom line

* **To change blob sizes**, adjust Loki’s chunk‐flush settings (`chunk_target_size`, `max_chunk_age`, etc.).
* **You cannot** alter Azure’s internal block-splitting behavior via Loki—it’s handled by the Azure SDK/service.
* The only other knobs are the SDK buffer sizes (`upload_buffer_size`, `download_buffer_size`), which affect upload/download performance but **not** the chunk‐blob’s overall size.

[1]: https://medium.com/django-unleashed/get-visibility-into-your-docker-container-logs-with-grafana-loki-of-a-django-application-9584bddfe540 "Get Visibility into Your Docker Container Logs with Grafana Loki of a Django Application. | Jan, 2023 | Medium | Django Unleashed"
[2]: https://learn.microsoft.com/en-us/rest/api/storageservices/understanding-block-blobs--append-blobs--and-page-blobs?utm_source=chatgpt.com "Understanding block blobs, append blobs, and page blobs"
[3]: https://techdocs.akamai.com/cloud-computing/docs/using-grafana-loki-with-object-storage?utm_source=chatgpt.com "Use Grafana Loki with Object Storage - Akamai TechDocs"

Loki chunks size - Revision history

Busk: Created page with "Loki’s Azure “blobs” are really just the compressed **chunks** of log entries that the Ingester flushes to your `/chunks//…` path. The **size** o..."

Busk: Created page with "Loki’s Azure “blobs” are really just the compressed chunks of log entries that the Ingester flushes to your `/chunks//…` path. The size o..."