[PHOENIX-3534] Support multi region SYSTEM.CATALOG table

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.15.0, 5.1.0
• Assignee: Thomas D'Silva
• Reporter: James R. Taylor
• Created: 15/Dec/16 01:20
• Updated: 17/Aug/22 11:42
• Resolved: 11/Dec/18 22:58

Description

Currently Phoenix requires that the SYSTEM.CATALOG table is single region based on the server-side row locks being held for operations that impact a table and all of it's views. For example, adding/removing a column from a base table pushes this change to all views.

As an alternative to making the SYSTEM.CATALOG transactional (PHOENIX-2431), when a new table is created we can do a lazy cleanup of any rows that may be left over from a failed DDL call (kudos to lhofhansl for coming up with this idea). To implement this efficiently, we'd need to also do PHOENIX-2051 so that we can efficiently find derived views.

The implementation would rely on an optimistic concurrency model based on checking our sequence numbers for each table/view before/after updating. Each table/view row would be individually locked for their change (metadata for a view or table cannot span regions due to our split policy), with the sequence number being incremented under lock and then returned to the client.

Issue Links

• causes: PHOENIX-6773 PhoenixDatabaseMetadata.getColumns() always returns null COLUMN_DEF
• duplicates: PHOENIX-4587 Store child links in separate table from system catalog
• links to: GitHub Pull Request #248
• links to: GitHub Pull Request #303

Sub-Tasks

• Changing a base table property value should be reflected in child views (if the property wasn't changed): Closed
• Cleanup metadata of child views for a base table that has been dropped: Closed
• Add client and server side config property to enable rollback of splittable System Catalog if required: Closed
• Create client side config to stop sending parent metadata while creating child views: Resolved
• Remove code in MetadataEndpointImpl.createTable that removes parent table column metadata: Resolved
• Update encoded col qualifiers on the base table correctly: Closed
• Write cells using checkAndMutate to prevent conflicting changes: Closed
• Send parent->child link mutations to SYSTEM.CHILD_LINK table in MetdataClient.createTableInternal: Closed
• Continue to write base table column metadata when creating a view in order to support rollback: Closed
• Don't acquire a mutex while dropping a table and while creating a view: Closed
• Add tests for salted tables to AlterMultiTenantTableWithViewsIT: Resolved
• Move parent column combining logic of view and view indexes from server to client: Closed
• Move parent index inheriting logic of views to server: Resolved
• Move MetaDataEndpointImplTest to integration test: Closed
• Modify MetdataEndpointImpl.processRemoteRegionMutations to run as login user: Resolved
• Perform splittable SYSCAT actions on the client only: Closed
• While adding a view column make a single RPC to update the encoded column qualifier counter and remove the table from the cache of the physical table: Open
• Move check to client side to see if there are any child views that need to be dropped while receating a table/view: Open
• When dropping a view, use the PTable for generating delete mutations for links rather than scanning SYSTEM.CATALOG: Open
• When dropping a view, send delete mutations for parent->child links from client to server rather than doing server-server RPCs: Open
• Create a column attribute IS_EXCLUDED to denote a dropped derived column and remove LinkType.EXCLUDED_COLUMN: Resolved
• Move the check for existence of child views and task addition to drop those child views to the client side when dropping a table/view: Open