[FLINK-20107] Issues with setting InputChannel.statePersister

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.12.0
• Fix Version/s: 1.12.0
• Component/s: Runtime / Checkpointing, Runtime / Network
• Labels: pull-request-available
• Assignee: Roman Khachatryan
• Reporter: Roman Khachatryan
• Created: 12/Nov/20 11:27
• Updated: 22/Jun/21 13:55
• Resolved: 18/Nov/20 07:27

Description

ChannelStatePersister is a non-final field in InputChannel.

The need for injection is caused by different places, where network- and state- related objects are created (task executor vs stream task).

It is set on remote and local channels upon requesting partitions, after converting unknown or recovered channel.

 Issues

1. Not set on RemoteInputChannel when converting from UnknownChannel
2. No visibility guarantee: written by task thread without any (explicit) synchronization, read by network thread (checkForBarrier)

I see that "final" channels (both remote and local) are created only when the writer is known (partitions requested).

So we can just make it final in "final" channels and pass from recovered/unknown. For that,

• need to add to UnknownChannel
• no need to make it volatile/guarded because in "non-final" channels it's accessed only by the task thread; and in "final" channels it will be final

Issue Links

• links to: GitHub Pull Request #14051