Background data clearing

[rkistner]

The issue

The main replication loop periodically checks whether there are new replication jobs that should be started, old ones to be stopped, or data to be cleared.

The issue is that the data clearing was a "blocking" operation, and would prevent the loop from running again until it completed. In most cases it's fine - the actual replication jobs would already be running, and continue fine in the background.

However, there is an edge case: If a replication job was not immediately due to a competing sync rules lock, but the clearing was started, then the replication job would not be retried until the clearing has completed. This could result in significant replication lag building up.

The fix

This removes the blocking behavior of the clearing jobs, resolving the issue.

[changeset-bot]

🦋 Changeset detected

Latest commit: 3e7c1fc

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@powersync/service-core	Patch
@powersync/service-image	Patch
@powersync/service-core-tests	Patch
@powersync/service-module-core	Patch
@powersync/service-module-mongodb-storage	Patch
@powersync/service-module-mongodb	Patch
@powersync/service-module-mysql	Patch
@powersync/service-module-postgres-storage	Patch
@powersync/service-module-postgres	Patch
test-client	Patch
@powersync/service-schema	Patch

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[Copilot]

Pull Request Overview

This PR refactors the replication clearing process to remove blocking behavior that was causing replication lag.

• Introduces a new asynchronous clearingJobs map for tracking non-blocking data clearing tasks.
• Modifies the main replication loop to schedule clearing jobs asynchronously.
• Updates termination logic with additional logging and comments explaining the process.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/service-core/src/replication/AbstractReplicator.ts	Refactors sync rule clearing to run asynchronously and removes blocking behavior.
.changeset/orange-comics-buy.md	Documents the patch for non-blocking sync rule clearing.