Manage Azure Blob Lifecycle

Question 1

What are some important notes about access tiers in azure storage?

Answer 1

• Can be set on blob during or after upload
• hot and cool can be set at account level, archive has to be set at blob level
• data in archive tier is stored offline
• hot and cool tiers support all redundancy options but archive only supports LRS, GRS and RA-GRS

Question 2

What are blob storage lifecycle mgmt policies? What do they let us do?

Answer 2

• only available on gen v2 SAs
• transition blobs to a cooler tier to optimise performance and cost
• delete blobs at end of lifecycles
• define rules to be run once per day at storage account level
• apply rules to containers or a subset of blobs

Question 3

How can we best design storage options?

Answer 3

• By adjusting storage tiers in respect to age of data we can design the least expensive storage options for your needs
• to achieve the transition, lifecycle mgmt policy rules are available to move aging data to cooler tiers

Question 4

Structurally what makes a lifecycle mgmt policy?

Answer 4

• collection of rules in JSON doc
• at least one rule is required and you can define up to 100
• each rule definition within a policy includes a filter set and an action set
• filter set = limits rule actions to certain set of objects within a container or objects names
• action set = applies the tier or delete actions to the filtered set of objects
• when changing access tier the process cant be cancelled once started

Question 5

What does each rule within a policy have?

Answer 5

• name
• enabled (default is true)
• type
• definition (made up of filter and action set)

Question 6

What are some types of filters?

Answer 6

• blobTypes
• prefixMatch
• blobIndexMatch
• if more than one defined a logical AND runs on filters

Question 7

What are some types of Actions?

Answer 7

• tierToCool
• enableAutoTierToHotFromCool
• tierToArchive
• Delete
• applied to filtered blobs when the run condition is met

Question 8

What does azure do if more than one action is defined on the same blob in a mgmt policy?

Answer 8

• it will apply the least expensive action to the blob
• e.g. delete is cheaper than tierToArchive, tierToArchive is cheaper than tierToCool

Question 9

Wjhat are some examples of run conditions?

Answer 9

• daysAfterModificationsGreaterThan
• daysAfterCreationGreaterThan
• daysAfterLastAccessTimeGreaterThan
• daysAfterLastChangeGreaterThan

Question 10

How can we manage policies using the portal?

Answer 10

• under data mgmt inside storage account resource
• select lifecycle management to change rules
• select list view and then add rule with action and filter sets

Question 11

How can we manage policies using the CLI?

Answer 11

• write policy to a JSON file and call ‘az storage account management-policy create’
• must be read or written in full, no partial updates

Question 12

How can we rehydrate a an archived blob?

Answer 12

• in order to read or modify an archived blob we must rehydrate to online tier (hot or cool)
• We can copy an archived blob to an online tier blob = recommended for most scenarios
• Change a blobs access tier to an online tier = change tier of original blob
• can take several hours either way

Question 13

What are the priorities for blob rehydration?

Answer 13

• priority set using optional x-ms-rehydrate-priority header on a Set Blob Tier or Copy Blob from URL operation
• standard priority = rehydration request is processed in order it was received and might take up to 15 hours
• high = prioritised over standard priority requests and might complete in 1 hour for objects under 10GBt

Question 14

What happens when we copy an archived blob to a new blob in an online tier?

Answer 14

• source blob remains unmodified in archive tier
• must be copied to a new blob with a different name or container
• cant overwrite source blob
• can only copy within same SA
• cant copy an archived blob to a destination blob that is also in archive tier