[TC-66] Store CRConfig.json in the database as opposed the file system

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: Traffic Ops
• Assignee: Jeremy Mitchell
• Reporter: Jeremy Mitchell
• Created: 09/Dec/16 17:37
• Updated: 18/Jan/17 18:28
• Resolved: 18/Jan/17 18:28

Description

The desire to have a highly-available traffic ops (HA TO) is complicated by the current method of storing CRConfig.json on the file system at public/CRConfig-Snapshots/:cdn_name/CRConfig.json

With Postgres' support of a json datatype, it has been determined that storing the json for CRConfig.json in the database is the best option so we can support a HA TO.

I plan to create a new table entitled snapshot with 3 columns: cdn, content (type=json) and last_updated. In this table will only be one row per cdn which represents the json of the last snapshot. Going forward we may entertain a more robust solution (i.e. snapshot versioning) but this simple solution helps us get to HA TO quickly.

Things that will change:

• snapshot will write json to snapshot table rather than file system
• snapshot diff will use the json in the snapshot table (if any) as the source of the diff rather than json on file system
• snapshot fetch (/CRConfig-Snapshots/cdn-1/CRConfig.json) will fetch json from db rather than file system.

Issue Links

• links to: GitHub Pull Request #131