Vitess v2.0.0-rc.1

Changes since v2.0.0-beta.2

This is the first release candidate for v2.0.0. We are now freezing the release-2.0 branch for anything except bug fixes.

Client API

• Allow specifying a connection-wide default keyspace for VTGateV3 queries.
  (#1725,
  #1727,
  #1738)
  • Similar to the concept of a default database for a MySQL client connection.

SQL Support

• Preserve case of column names in query result field info.
• Preserve trailing comments in queries rewritten by VTGateV3.
• Support string-based hash vindexes
  • Previously, the value to hash had to be numeric or binary.

Management

• Hide VtTablet* and VtGate* commands behind a flag in vtctl/vtctld
  (#1700).
  • These commands are mostly meant for development, and should usually not be
    allowed in production.
  • Launch vtctld with the -enable_queries flag to allow these commands.
• Restart replication automatically
  if a tablet is restarted (e.g. as part of a Vitess upgrade).
• Optionally allow the use of insecure caller ID.
• It's no longer required to set a "sharding column name" when using VTGateV3.
  • i.e. no more vtctl SetKeyspaceShardingInfo when using VTGateV3.

Schema and VSchema

• VSchema config format changed
  • Some fields have been renamed for consistency.
• VSchema updates are now denormalized into per-cell records.
  (#1750)
  • No longer need to restart VTGate to pick up VSchema for new/removed
    keyspaces.
  • VSchema is still available if global topology goes down.
  • It's now possible to atomically move tables between keyspaces, for example
    when doing a vertical split.
  • NOTE: Even if you don't use VSchema, it's now required to run
    RebuildVSchemaGraph
    to initialize these records for a new keyspace.
• Schema changes are tested as a group, rather than individually.
  (#1749)
  • This allows batches of schema changes that depend on one another (#1731).

Interoperability

• Support MySQL 5.7
• Orchestrator Integration
  • Along with some patches contributed to Orchestrator, these new Vitess
    features allow the two systems to work together automatically.
    We'll be updating the documentation soon to show how to use it.

Code Cleanup

• Remove deprecated "serving graph" system, which had already been replaced by
  streaming health checks.
  • #1679,
    #1683,
    #1685,
    #1698,
    #1699,
    #1706
• Remove deprecated rowcache
  • This will be replaced by a caching scheme that makes sense for both VTGateV2
    and VTGateV3.
• Remove deprecated -target_tablet_type flag
  • Use -init_tablet_type instead.