Update azure.md for storage initializer environment variables (#541)

* Update azure.md

Signed-off-by: Agoston Horvath <[email protected]>

* Update azure.md

Fix example

Signed-off-by: Agoston Horvath <[email protected]>

* Added AWS S3 doc

Signed-off-by: Horvath Agoston <[email protected]>

---------

Signed-off-by: Agoston Horvath <[email protected]>
Signed-off-by: Horvath Agoston <[email protected]>

Author: agoston

docs/model-serving/storage/providers/azure.md

@@ -97,6 +97,25 @@ Apply the `sklearn-azure.yaml`.
 kubectl apply -f sklearn-azure.yaml
 ```
 
+### Configuring blob download
+
+There are a number of environment variables that allow to configure azure blob download parallelization:
+
+```yaml
+kind: ClusterStorageContainer
+spec:
+  container:
+    env:
+    - name: AZURE_MAX_FILE_CONCURRENCY
+      value: 4
+    - name: AZURE_MAX_CHUNK_CONCURRENCY
+      value: 4
+```
+(only relevant entries shown)
+
+The above example shows the default values. Together they control how many files are downloaded in parallel, and the download parallelism of each file.
+Note that each download has a buffer of 8MiB.
+
 ## Run a prediction
 
 Now, the ingress can be accessed at `${INGRESS_HOST}:${INGRESS_PORT}` or follow [this instruction](../../../getting-started/predictive-first-isvc.md#4-determine-the-ingress-ip-and-ports)

docs/model-serving/storage/providers/s3/s3.md

@@ -106,6 +106,24 @@ Apply the YAML file:
 kubectl apply -f mnist-s3.yaml
 ```
 
+### Configuring object download
+
+There are a number of environment variables that allow to configure S3 object download parallelization:
+
+```yaml
+kind: ClusterStorageContainer
+spec:
+  container:
+    env:
+    - name: S3_MAX_FILE_CONCURRENCY
+      value: 4
+```
+(only relevant entries shown)
+
+The above example shows the default value. It controls how many files are downloaded in parallel from S3.
+Note that each parallel download forks python and creates a new boto3 client.
+
+
 ## Run a prediction
 
 Now, the ingress can be accessed at `${INGRESS_HOST}:${INGRESS_PORT}` or follow [this instruction](../../../../getting-started/predictive-first-isvc.md#4-determine-the-ingress-ip-and-ports)