PlanetScale

Overview

The PlanetScale connector reads changes from Vitess through the VStream API, the same feed PlanetScale uses for its own replication. Workflows react to writes on every shard without polling, and every event shows up in the trace of the run it started.

Teams use it to sync new accounts into Intercom, to load order events into BigQuery for reporting and to refund a Stripe charge when a cancellation row is written.

Supported databases

• PlanetScale Vitess databases, MySQL 8.0 compatible

• Sharded and unsharded keyspaces, read from every shard

• Production and development branches, production recommended

How VStream works

Tessel opens a VStream for each shard in the keyspaces you choose and tracks a VGTID position for each one. Events are checked against the schema and delivered in commit order per shard. If Tessel pauses, it resumes from the stored position.

host: aws.connect.psdb.cloud
database: shop
branch: main
username: tessel_readonly
tables: [orders, customers]
start_position: current

host: aws.connect.psdb.cloud
database: shop
branch: main
username: tessel_readonly
tables: [orders, customers]
start_position: current

host: aws.connect.psdb.cloud
database: shop
branch: main
username: tessel_readonly
tables: [orders, customers]
start_position: current

Schema changes

PlanetScale ships schema changes through deploy requests. When a deploy request merges, Tessel reads the new schema before the next event, so added columns show up in typed events right away. Dropped columns are flagged in the trace of the first run that misses them.

Permissions needed

Create a dedicated password for the branch Tessel reads. A read-only password is enough for change events and read queries. Writer access and a service token are only required for the write and branch actions.

• A password with the readonly role for events and reads

• A password with the readwriter role only if workflows write back

• A service token with create_branch only for the branch action