To enable Azure repositories, you have first to set your azure storage settings in elasticsearch.yml file:

cloud:
    azure:
        storage:
            my_account:
                account: your_azure_storage_account
                key: your_azure_storage_key

Note that you can also define more than one account:

cloud:
    azure:
        storage:
            my_account1:
                account: your_azure_storage_account1
                key: your_azure_storage_key1
                default: true
            my_account2:
                account: your_azure_storage_account2
                key: your_azure_storage_key2

my_account1 is the default account which will be used by a repository unless you set an explicit one.

You can set the client side timeout to use when making any single request. It can be defined globally, per account or both. It’s not set by default which means that elasticsearch is using the default value set by the azure client (known as 5 minutes).

max_retries can help to control the exponential backoff policy. It will fix the number of retries in case of failures before considering the snapshot is failing. Defaults to 3 retries. The initial backoff period is defined by Azure SDK as 30s. Which means 30s of wait time before retrying after a first timeout or failure. The maximum backoff period is defined by Azure SDK as 90s.

cloud:
    azure:
        storage:
            timeout: 10s
            my_account1:
                account: your_azure_storage_account1
                key: your_azure_storage_key1
                default: true
                max_retries: 7
            my_account2:
                account: your_azure_storage_account2
                key: your_azure_storage_key2
                timeout: 30s

In this example, timeout will be 10s per try for my_account1 with 7 retries before failing and 30s per try for my_account2 with 3 retries.

# The simpliest one
PUT _snapshot/my_backup1
{
    "type": "azure"
}

# With some settings
PUT _snapshot/my_backup2
{
    "type": "azure",
    "settings": {
        "container": "backup-container",
        "base_path": "backups",
        "chunk_size": "32m",
        "compress": true
    }
}


# With two accounts defined in elasticsearch.yml (my_account1 and my_account2)
PUT _snapshot/my_backup3
{
    "type": "azure",
    "settings": {
        "account": "my_account1"
    }
}
PUT _snapshot/my_backup4
{
    "type": "azure",
    "settings": {
        "account": "my_account2",
        "location_mode": "primary_only"
    }
}

client.admin().cluster().preparePutRepository("my_backup_java1")
    .setType("azure").setSettings(Settings.builder()
        .put(Storage.CONTAINER, "backup-container")
        .put(Storage.CHUNK_SIZE, new ByteSizeValue(32, ByteSizeUnit.MB))
    ).get();