Update use_cases.md

design/object-reset/use_cases.md

@@ -68,245 +68,3 @@ During the scope of a large ingest effort, a desire arises to normalize pathname
 #### Issue: Purge unwanted files from old object versions
 
 
----
-
-## Implmentation Options
-
-### Scenario
-```yaml
-ark: ark:/111/222
-versions:
-- num: 1
-  files:
-    producer/foo: { size: 10, digest: 'AAA', path: "1/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/cat: { size: 30, digest: 'AAC', path: "1/producer/cat" }
-  size: 60
-- num: 2
-  files:
-    producer/foo: { size: 40, digest: 'FFF', path: "2/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 70
-- num: 3
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "3/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 40
-size: 170
-```
-
-### Option: Mark Current Version as the Reset Version
-
-```yaml
-ark: ark:/111/222
-versions:
-- num: 1
-  files:
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" }
-  size: 20
-- num: 2
-  files:
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 30
-- num: 3
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "3/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 40
-size: 90
-```
-
-#### Process
-- User must fix the current version of the object using existing tools (ingest updates & mrt-delete)
-- New transaction is run to mark the state of the current object as definitive
-  - Is this sent through ingest?
-  - Is this an administrative action sent to inventory?
-- Any files not found in the current version object will be removed from the storage manifest
-- Inventory will remove these files
-- These files will be eligible for deletion from cloud storage
-  - Using the storage scan process?
-  - Using new file delete operations
- 
-#### Pros
-- No files are cloned/copied
-- Version number stays intact
-- Minimizes processing
-
-#### Cons
-- Relies heavily on the existing mrt-delete process to reconcile the current version
-- No mechanism exists to normalize or correct pathnames
-- No evidence is left to indicate that this process took place
-
-
----
-
-### Option: Pull forward desired files using an ingest manifest exported from storage
-
-#### Step 1: Pull Forward
-```yaml
-ark: ark:/111/222
-versions:
-- num: 1
-  files:
-    producer/foo: { size: 10, digest: 'AAA', path: "1/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/cat: { size: 30, digest: 'AAC', path: "1/producer/cat" }
-  size: 60
-- num: 2
-  files:
-    producer/foo: { size: 40, digest: 'FFF', path: "2/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 70
-- num: 3
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "3/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "1/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "2/producer/dog" }
-  size: 40
-- num: 4
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "4/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "4/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "4/producer/dog" }
-  size: 90
-  reload: true
-size: 260
-```
-
-#### Step 2: Purge Old Versions
-```yaml
-ark: ark:/111/222
-versions:
-- num: 4
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "4/producer/foo" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "4/producer/bar" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "4/producer/dog" }
-  size: 90
-  reload: true
-size: 90
-```
-
-#### Process
-- Ingest manifest is generated from Merritt Storage
-- Desired files are selected and renamed as needed
-- Manifest is sent to Ingest as a new request type of `replace`
-- A new version is generated containing a copy of all desired content
-- Storage manifest should reflect that the replacement took place at a specific version
-- Files from prior versions should be treated as if they no longer exist
-- Older version files will be purge-able by inventory
-- Older version files will be purge-able from cloud storage
-- A purge process should exist to purge the older version content
-
-#### Pros
-- Use can review the new state of the object before electing to purge the old versions
-- The storage manifest and the version numbering will convey that this maintenance activity took place
-
-#### Cons
-- Temporary duplication of object content
-- Duplication could persist if the user does not enable / approve the running of the purge process
-- Replication logic will need to change to not assume that versioning starts at 1
-
-
----
-
-### Option: Modify Merritt file paths to use content hash
-
-```yaml
-ark: ark:/111/222
-versions:
-- num: 1
-  files:
-    producer/foo: { size: 10, digest: 'AAA', path: "AAA/10" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "AAB/20" } 
-    producer/cat: { size: 30, digest: 'AAC', path: "AAC/30" }
-  size: 60
-- num: 2
-  files:
-    producer/foo: { size: 40, digest: 'FFF', path: "FFF/40" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "AAB/20" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "AAC/30" }
-  size: 40
-- num: 3
-  files:
-    producer/foo: { size: 40, digest: 'EEE', path: "EEE/40" } 
-    producer/bar: { size: 20, digest: 'AAB', path: "AAB/20" } 
-    producer/dog: { size: 30, digest: 'AAC', path: "AAC/30" }
-  size: 40
-size: 140
-```
-
-#### Process
-- Storage key should be `ark | hash | length` regardless of pathname/version
-- Comment dloy - this only becomes needed if we allow a reset to preserve more than one version - preserving only current not needed
-
-#### Pros
-- Storage optimized solution - duplicate files are only stored once per object
-
-#### Cons
-- Loss of semantically meaningful key names (dloy-serious problem)
-
----
-
-### Option: Reset Version should always become version 1
-
-- _dloy : see below._
-
-#### Process
-
-####  Pros
-
-#### Cons
-
-
----
-
-### Option: Reset object using a new add version
-
-#### Process
-- a version add with reset request is received by ingest
-- storage deletes the content for the specific ark
-- all add version content is treated as new using the original ark
-- inventory receives reset request
-- inventory deletes all existing content on the ark
-- inventory treats the added content as new
-
-####  Pros
-- same key architecture
-- delete and add functions do not change for storage and inventory
-- resulting storage sets all content as 1 so specific match of content to saved keys
-- all changes in new add populate merritt inv without requesting hybrid processing
-- preserving the ark alloww outside references to continue working
-
-#### Cons
-- all content will be written as version 1 so no earlier content is saved - redundant processing
-- recovery of failed process may be issue
-
----
-
-### Option: Reset object using existing current version
-- Note this is similar to _Option: Reset Version should always become version 1_ above
-
-#### Process
-- a reset request is received by ingest - without action
-- storage passed reset
-- storage uses content S3 keys to copy (or leave alone) to a version 1 key. If current file uses previous version 10 then version 10 copied to version 1. Current architecture will not have collisions if only current is preserved
-- storage delete all unused content for specific ark (key version > 1)
-- inventory deletes all existing content on the ark
-- inventory treats the added content as new
-
-####  Pros
-- same key architecture
-- resulting storage sets all content as 1 so specific match of content to saved keys
-- all changes in new add populate merritt inv without requesting hybrid processing
-- preserving the ark alloww outside references to continue working
-
-#### Cons
-- new build copy logic required in storage
-- new delete logic required for this special case
-- Much content will be rewritten except for matching
-- recovery of failed process may be issue