High CPU usage after upgrading to Azure Cosmos DB Java SDK 4.76.0

[koufa13]

Describe the bug
After upgrading to Azure Cosmos DB Java 4.76.0 (com.azure:azure-cosmos:4.76.0) we saw tremendous increase of CPU usage of our services running on Azure Container Apps. Downgrading again to 4.75.0 fixed the issue immediately.

Unfortunately I cannot provide more details at the moment. I checked the changelogs of v4.76.0 and there some improvements of some features which may affect CPU but I could not pinpoint any specific change.

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @kushagraThapar @pjohari-ms @TheovanKraay.

[FabianMeiswinkel]

@koufa13 thanks for reporting this - I would be very interested in getting as much context as possible to see whether we can come-up with an in-house repro. Are you using direct mode or gateway mode? Can you share the name of your account (or if not here, can you explain a bit of what operations your app typically uses)

[koufa13]

@FabianMeiswinkel We don't have dedicated gateway enabled for our Azure CosmosDB. Our most common operations using the Reactor Async CosmosDB Client are similar to the below:

• Paginated queries using the byPage like:

SELECT * FROM container c 
WHERE ARRAY_CONTAINS(@filters, c.field)
AND ARRAY_CONTAINS(@filterIds, c.id)
AND c.type = @filterType

• Find all queries like:

SELECT * FROM container c
WHERE c.id2 = @id2
AND (c.id1 != @id1 OR c.version != @currentVersion)
AND c.env = @env

• Delete multiple items after first finding the items based on a find query
• Save multiple items in an async loop like:

items.map { item -> async { cosmosDbClient.save(item) } }
    .awaitAll()