View source for Exam DP203 Course Tybul 05 Storage Account Access Tiers

05 Storage Account Access Tiers

https://www.youtube.com/watch?v=9m4y1mbJ8y8

Data lake storage pricing. Cost per Mb, and cost per access speed read/writes, and other factors (local vs geo redundancy).

== Access tiers ==
Speed, storage costs, access costs, retention period.

'''Hot''': Fast and cheap to read and write, but expensive to store.

'''Cool''': Cheaper to store, but more expensive to read and write.

'''Cold''': Cheaper still to store, but more expensive again to read and write.

'''Archive''': Very slow access (15 hours), but highest access cost.

Overall the rule is: Hot is expensive store, cheap read/write. Cold is cheap store, expensive read and write.

You set these once you create a container in a storage account, and at the point you upload a file. Note with the sandbox this option does not seem to be available. But in a regular account it is. Note also that it is not necessary to have upgraded the account to Gen2 to get this option.

'''Retention periods''':. If you move a file into the Cool tier, you have to keep it there for a minimum of 30 days. If you move it into another tier before this 30 days is up, you get charged a '''Early Deletion Fee''' corresponding to the number of days short. So for example if you move it after 20 days, you will be charged 10 days Early Deletion Fee. The effect is to charge the user the full 30 days regardless of the number of days it is stored there. Note for the Cold tier it is 90 days, and for the archive tier it is 120 days.

The storage account has a setting for default access tier for new files created.

Note that the access tier is a per-file property. Though the storage account is given a default access tier when you create or modify it.

If you click the Enable Access Tracking checkbox, then in addition to triggering on created and modified dates, it can also trigger on last accessed date (last date it was read).

== Lifecycle Management Policies: ==
These are used to move files from hot to cool to cold to archive according to rules. Find these in the storage account under '''Data Management - Lifecycle Management'''

Set up a rule for example to move a file to cool if its '''modification date''' is > 7 days ago. Or delete it.

You can also tick the "Enable Access Tracking" checkbox (costs a little extra) which then also enables you to process based on file '''last accessed'''.

'''Azure pricing calculator''' - used to calculate estimated costs: https://azure.microsoft.com/en-gb/pricing/calculator/