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new 090b67e5b4a0 CAMEL-19254: Document blob ConditionNotMet error during
concurrent modification (#23803)
090b67e5b4a0 is described below
commit 090b67e5b4a0274455b7c496100befaafc281f24
Author: Claus Ibsen <[email protected]>
AuthorDate: Sat Jun 6 07:21:55 2026 +0200
CAMEL-19254: Document blob ConditionNotMet error during concurrent
modification (#23803)
Signed-off-by: Claus Ibsen <[email protected]>
Co-authored-by: Claude <[email protected]>
---
.../src/main/docs/azure-storage-blob-component.adoc | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git
a/components/camel-azure/camel-azure-storage-blob/src/main/docs/azure-storage-blob-component.adoc
b/components/camel-azure/camel-azure-storage-blob/src/main/docs/azure-storage-blob-component.adoc
index 1f7621f0f247..fcdc6e93dda8 100644
---
a/components/camel-azure/camel-azure-storage-blob/src/main/docs/azure-storage-blob-component.adoc
+++
b/components/camel-azure/camel-azure-storage-blob/src/main/docs/azure-storage-blob-component.adoc
@@ -892,6 +892,22 @@ from("direct:rehydrate")
.to("mock:result");
--------------------------------------------------------------------------------
+=== Blob modification during download (ConditionNotMet)
+
+When downloading a blob via streaming (the `getBlob` operation or the consumer
without `fileDir`), the Azure SDK reads the blob in chunks.
+On the first chunk it captures the blob's ETag and uses it as an `if-match`
condition on subsequent chunk requests.
+If the blob is modified by another process between chunks (which changes its
ETag), Azure returns HTTP 412 `ConditionNotMet`.
+
+This is by design in the Azure SDK — it ensures read consistency so that you
do not receive half of one version concatenated with half of another.
+The error is more likely with larger blobs and slower network connections
(e.g., in real Azure environments versus local emulators).
+
+Workarounds:
+
+* Use the `fileDir` option so the consumer downloads the blob atomically to a
file via `downloadBlobToFile` instead of streaming.
+* Use blob snapshots — read from an immutable snapshot ID via the `snapshotId`
option or the `CamelAzureStorageBlobSnapshotId` header, which cannot be
modified.
+* Use blob versioning — read from a specific version via the `versionId`
option or the `CamelAzureStorageBlobVersionId` header.
+* Avoid modifying blobs while they are being consumed.
+
=== SAS Token generation example
SAS Blob Container tokens can be generated programmatically or via Azure UI.
To generate the token with java code, the following can be done:
