Plasma usage across Nodes

From Serialization — Ray v1.10.0 it says:

“”" Ray uses Plasma to efficiently transfer objects across different processes and different nodes. All objects in Plasma object store are immutable and held in shared memory. This is so that they can be accessed efficiently by many workers on the same node. Each node has its own object store. When data is put into the object store, it does not get automatically broadcasted to other nodes. Data remains local to the writer until requested by another task or actor on another node."""

i) If data objects are created on the Controller or a Worker node, how are they transferred to the Plasma object store on each Worker node?

ii) On each node, the data objects in Plasma are immutable. Can the data objects be replaced from the Controller or a Worker node (per i)?

i.) The Ray 1.x Architecture paper discusses object management in more detail. It explains how objects get transferred between nodes.

ii.) I don’t think data objects can get replaced, but new ones can get put into the store.

Ah okay. I need to use the Ray Collective Library. Thanks