This is a continuation of an article that describes operational considerations for hosting solutions on Azure public cloud.

 

1.       Blob rehydration to the archive tier can be for either hot or cool tier. There are two options for rehydrating a blob that is stored in the archive tier. A) One can copy an archived blob to an online tier using the reference of the blob or its URL. B) Or one can change the blob access tier to an online tier. It can rehydrate the archived blob to hot or cool by changing its tier. Rehydrating might take several hours but several of them can be done concurrently. Rehydration priority might also be set.

2.       Virtual Network peering allows us to connect virtual networks in the same region or across regions as in the case of Global VNet Peering through the Azure Backbone network. When the peering is setup, traffic to the remote virtual network, traffic forwarded from the remote virtual network, virtual network gateway or Route server and traffic to the virtual network can be allowed by default.

3.       Transaction processing in Azure is not on by default. A transactions locks and logs records so that others cannot use it, but it can be bound to partitions, enabled as distributed transactions and with two phase commit protocol. Transaction processing requires two communication steps for a resource manager and a response from the transaction coordinator which are costly for a datacenter in Azure. It does not scale as the number resource to calls expands as 2 resources – 4 network calls, 4 resources – 16 calls, 100 resource – 400 calls. Besides, the datacenter contains thousands of machines, failures are expected, and the system must deal with network partitions. Waiting for response from all resource managers has costly communication overhead.

4.       Diagnostic settings to send platform logs and metrics to different destinations can be authored. Logs include Azure Activity logs and resource logs. Platform metrics are collected by default and stored in the Azure monitor metrics database. Each Azure resource requires its own diagnostic settings, and a single setting can define no more than one of each of the destinations. The available categories will vary for different resource types. The destinations for the logs could include the Log Analytics workspace, Event Hubs and Azure Storage. Metrics are sent automatically to the Azure Monitor Metrics. Optionally, settings can be used to send metrics to Azure monitor logs for analysis with other monitoring data using restricted queries. Multi-dimensional metrics (MDM) are not supported. They must be flattened

5.       Legacy authentication to Azure AD can be blocked with conditional access which gives users’ easy access to the cloud apps. Azure Active Directory supports a broad variety of authentication protocols including legacy authentication but those protocols such as POP, SMTP, IMAP and MAPI cannot enforce MFA and create a vulnerability to the overall service. A conditional access policy blocks legacy authentication. The Azure portal shows Azure Active Directory Sign-ins where the client app column indicates those that use legacy authentication.  Policies can then be set to block those applications directly or indirectly.