Reading or writing to a database not configured in WAL mode will perform excessive I/O and reduce the health of storage devices. This is known to cause excessive I/O for your users.

[amruth-movano]

Describe the bug

We are getting high disk usage

Steps To Reproduce

Configure amplify
Launch app
Use app

Expected behavior

It should not give a warning for high disk usage.

Amplify Framework Version

2.39.0

Amplify Categories

DataStore

Dependency manager

Swift PM

Swift version

5.9.2

CLI version

12.11.1

Xcode version

15.2

Relevant log output

-

Is this a regression?

Yes

Regression additional context

Platforms

iOS

OS Version

iOS 18.0

Device

iPhone 12

Specific to simulators

No response

Additional context

No response

[5d]

Hi @amruth-movano,

We use the SQLite.swift library to handle SQLite queries. From what I understand, WAL mode is not enabled by default in SQLite.swift. It uses a single connection to perform serialized database operations. The warning you're seeing usually arises when there are multiple connections accessing the same database.

Could you share more details on how to reproduce the issue? How are you testing the app? Did you restart the DataStore? Also, how many models are defined in your schema?

[amruth-movano]

@5d
We are using 14 models.
On launch, we do amplify.start synchronization and getting this error

[5d]

Hi @amruth-movano ,

Thanks for the quick response. Is this during the initial sync (e.g., when the app is opened for the first time) of the datastore? What is the estimated data volume?

[amruth-movano]

@5d yes its begin to happen on app launch and memory increasing in MBs. cpu usage also increasing to 100-200 %

[amruth-movano]

@5d is there any update on this?

[thisisabhash]

Hello, Would you be able to post more context about the issue?

• How many models and number of records per model are being synced when you call Amplify.Datastore.start() ?
• Have you considered selective sync for your use case? https://docs.amplify.aws/gen1/swift/build-a-backend/more-features/datastore/sync-to-cloud/#selectively-syncing-a-subset-of-your-data
• Would you be able to share a sample schema and code snippets, which can help us reproduce the issue locally?