Cluster Sharding
in Effect
Warehouse
a concurrency example
User 1
User 2
System 1
Stock A
System 2
Stock A
Create Order
Create Order
- Read the stock
- Verify the stock
- Write the transaction
- Read the stock
- Verify the stock
- Write the transaction
Global Lock
- Acquire some kind of global lock between services/servers
- Perform the write
- Release the lock
Single Writer
-
Redirect the write request to a single entity that will handle request
Warehouse
a concurrency example
User 1
User 2
System 1
redirect
System 2
redirect
Create Order
Create Order
- Read the stock
- Verify the stock
- Write the transaction
System 3
Stock A
What is Shardcake?
-
Single writer: Ensures each entity is running only in one place
- Location transparency: Communicate with entities with just their ID, without knowing their location
Inspired by the original scala library
by devsisters
Keywords
- Entity: defines a behaviour
- Pod: Hosts many entities
- Shard: A grouping of instances of entities
- Assignments: A correlation between Pod and Shard
- Shard Manager: Single instance that supervises and performs assignments
How it works?
