Add note about concurrent writes

Author: pauljewellmsft

articles/storage/blobs/concurrency-manage.md

@@ -7,15 +7,15 @@ author: pauljewellmsft
 
 ms.service: azure-blob-storage
 ms.topic: conceptual
-ms.date: 09/04/2024
+ms.date: 03/25/2025
 ms.author: pauljewell
 ms.devlang: csharp
 ms.custom: devx-track-csharp
 ---
 
 # Manage concurrency in Blob Storage
 
-Modern applications often have multiple users viewing and updating data simultaneously. Application developers need to think carefully about how to provide a predictable experience to their end users, particularly for scenarios where multiple users can update the same data. There are three main data concurrency strategies that developers typically consider:
+Modern applications often have multiple users viewing and updating data simultaneously. Application developers need to think carefully about how to provide a predictable experience to their end users, particularly for scenarios where multiple users can update the same data. The Azure Storage client libraries don't support concurrent writes to the same blob, with the exception of append blobs if the write order doesn't matter. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control. There are three main data concurrency strategies that developers typically consider:
 
 - **Optimistic concurrency**: An application performing an update will, as part of its update, determine whether the data has changed since the application last read that data. For example, if two users viewing a wiki page make an update to that page, then the wiki platform must ensure that the second update doesn't overwrite the first update. It must also ensure that both users understand whether their update was successful. This strategy is most often used in web applications.
 

articles/storage/blobs/storage-blob-upload-go.md

@@ -6,7 +6,7 @@ services: storage
 author: pauljewellmsft
 
 ms.author: pauljewell
-ms.date: 08/05/2024
+ms.date: 03/25/2025
 ms.service: azure-blob-storage
 ms.topic: how-to
 ms.devlang: golang
@@ -40,6 +40,9 @@ To upload a blob, call any of the following methods from the client object:
 
 To perform the upload, the client library might use either [Put Blob](/rest/api/storageservices/put-blob) or a series of [Put Block](/rest/api/storageservices/put-block) calls followed by [`Put Block List`](/rest/api/storageservices/put-block-list). This behavior depends on the overall size of the object and how the data transfer options are set.
 
+> [!NOTE]
+> The Azure Storage client libraries don't support concurrent writes to the same blob. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control to provide a predictable experience. To learn more about concurrency strategies, see [Manage concurrency in Blob Storage](concurrency-manage.md).
+
 ## Upload a block blob from a local file path
 
 The following example uploads a local file to a block blob:

articles/storage/blobs/storage-blob-upload-java.md

@@ -6,7 +6,7 @@ services: storage
 author: pauljewellmsft
 
 ms.author: pauljewell
-ms.date: 08/05/2024
+ms.date: 03/25/2025
 ms.service: azure-blob-storage
 ms.topic: how-to
 ms.devlang: java
@@ -49,6 +49,9 @@ To upload a block blob from a file path, use the following method:
 
 Each of these methods can be called using a [BlobClient](/java/api/com.azure.storage.blob.blobclient) object or a [BlockBlobClient](/java/api/com.azure.storage.blob.specialized.blockblobclient) object.
 
+> [!NOTE]
+> The Azure Storage client libraries don't support concurrent writes to the same blob. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control to provide a predictable experience. To learn more about concurrency strategies, see [Manage concurrency in Blob Storage](concurrency-manage.md).
+
 ## Upload a block blob from a local file path
 
 The following example uploads a file to a block blob using a `BlobClient` object:

articles/storage/blobs/storage-blob-upload-javascript.md

@@ -5,7 +5,7 @@ description: Learn how to upload a blob to your Azure Storage account using the
 services: storage
 author: pauljewellmsft
 ms.author: pauljewell
-ms.date: 10/28/2024
+ms.date: 03/25/2025
 ms.service: azure-blob-storage
 ms.topic: how-to
 ms.devlang: javascript
@@ -36,6 +36,9 @@ You can use any of the following methods to upload data to a block blob:
 
 Each of these methods can be called using a [BlockBlobClient](/javascript/api/@azure/storage-blob/blockblobclient) object.
 
+> [!NOTE]
+> The Azure Storage client libraries don't support concurrent writes to the same blob. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control to provide a predictable experience. To learn more about concurrency strategies, see [Manage concurrency in Blob Storage](concurrency-manage.md).
+
 ## Upload a block blob from a file path
 
 The following example uploads a block blob from a local file path:

articles/storage/blobs/storage-blob-upload-python.md

@@ -6,7 +6,7 @@ services: storage
 author: pauljewellmsft
 
 ms.author: pauljewell
-ms.date: 08/05/2024
+ms.date: 03/25/2025
 ms.service: azure-blob-storage
 ms.topic: how-to
 ms.devlang: python
@@ -47,6 +47,9 @@ To upload a blob using a stream or a binary object, use the following method:
 
 This method creates a new blob from a data source with automatic chunking, meaning that the data source may be split into smaller chunks and uploaded. To perform the upload, the client library may use either [Put Blob](/rest/api/storageservices/put-blob) or a series of [Put Block](/rest/api/storageservices/put-block) calls followed by [Put Block List](/rest/api/storageservices/put-block-list). This behavior depends on the overall size of the object and how the [data transfer options](#specify-data-transfer-options-for-upload) are set.
 
+> [!NOTE]
+> The Azure Storage client libraries don't support concurrent writes to the same blob. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control to provide a predictable experience. To learn more about concurrency strategies, see [Manage concurrency in Blob Storage](concurrency-manage.md).
+
 ## Upload a block blob from a local file path
 
 The following example uploads a file to a block blob using a `BlobClient` object:

articles/storage/blobs/storage-blob-upload.md

@@ -5,7 +5,7 @@ description: Learn how to upload a blob to your Azure Storage account using the
 services: storage
 author: pauljewellmsft
 ms.author: pauljewell
-ms.date: 08/05/2024
+ms.date: 03/25/2025
 ms.service: azure-blob-storage
 ms.topic: how-to
 ms.devlang: csharp
@@ -42,6 +42,9 @@ To open a stream in Blob Storage and write to that stream, use either of the fol
 - [OpenWrite](/dotnet/api/azure.storage.blobs.specialized.blockblobclient.openwrite)
 - [OpenWriteAsync](/dotnet/api/azure.storage.blobs.specialized.blockblobclient.openwriteasync)
 
+> [!NOTE]
+> The Azure Storage client libraries don't support concurrent writes to the same blob. If your app requires multiple processes writing to the same blob, you should implement a strategy for concurrency control to provide a predictable experience. To learn more about concurrency strategies, see [Manage concurrency in Blob Storage](concurrency-manage.md).
+
 ## Upload a block blob from a local file path
 
 The following example uploads a block blob from a local file path: