MongoHealthIndicator not compliant with Mongo stable API with strict setting

[jorgelc]

MongoHealthIndicator uses isMaster command, which is not part of Mongo's stable API https://www.mongodb.com/docs/v5.0/reference/stable-api-changelog/

If the underlying Mongo connection is configured to use the stable API and strict setting, the health indicator yields an error, as Mongo rejects the isMaster command.

Affected versions: Tested with sprinboot 3.3.0, potentially since 3.0.0

To reproduce it, create a blank springboot project including spring-boot-starter-data-mongodb, spring-boot-starter-web and spring-boot-starter-actuator dependencies. Then, set up both Mongo stable API version and strict to true by creating the following bean:

	@Bean
	public MongoClientSettings mongoClientSettings() {
		return MongoClientSettings.builder()
			.applicationName("testApp")
			.serverApi(ServerApi.builder()
				.strict(true)
				.version(ServerApiVersion.V1)
				.build())
			.build();
	}

For reference, such project has been created here https://github.com/jorgelc/mongo-stable-api-springboot-health, with steps about how to reproduced the error and compare the behaviour with when strict is set to false.

[wilkinsona]

Thank you. I've reproduced the problem.

I think we should switch to the hello command. It's supported in MongoDB 5.0 and later and Mongo 4.x reached end of life in February 2024.

[jorgelc]

Thanks @wilkinsona

We implemented that as a temporary workaround locally and it worked for us, but it would be nice to have that supported out of the box.

[jyemin]

Just FYI, the hello command was backported all the way to MongoDB 3.6, so this should be a safe change even for EOL'd MongoDB releases.

[pkunk]

FYI: This is not compatible with Azure Cosmos MongoDB API:
https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/feature-support-60#database-commands

[wilkinsona]

Thanks, @pkunk, but I'm not sure there's much we can do about that. I don't see any mention of isMaster in the list of supported database commands either so it's not clear that this would have worked before. I'd recommend raising this with Microsoft to see if they can improve Cosmos' compliance with the MongoDB API.

In the meantime, anyone who's affected can work around the non-compliance by defining their own bean named mongoHealthIndicator or mongoHealthContributor.

[SimonedeGijt]

We have the same @pkunk . Did you already raise this with Microsoft? Would be great if I can follow the progress on this item :)

[pkunk]

We have the same @pkunk . Did you already raise this with Microsoft?

No. We just use custom mongoHealthIndicator bean.

[SimonedeGijt]

I created a post now, would be great if many people can vote on it 😄 : https://feedback.azure.com/d365community/idea/c7b19748-9276-ef11-a4e6-000d3a059eeb

[gahl-levy]

Hey @pkunk @SimonedeGijt @wilkinsona . I'm Gahl from the Cosmos DB Product Team. The hello command is already supported in Cosmos DB for MongoDB vCore and Cosmos DB for MongoDB RU. We're adding it to our docs now. Sorry for the confusion here and thanks for pointing this out!

[wilkinsona]

Good news! Thanks very much, @gahl-levy.

[ashishrky]

@gahl-levy is there any setting to enable hello command for Cosmos DB for MongoDB RU? I am running Spring Boot v3.3.4 application, and its actuator health endpoint is still failing with the error...

        "mongo": {
            "status": "DOWN",
            "details": {
                "error": "org.springframework.dao.InvalidDataAccessApiUsageException: Command failed with error 115 (CommandNotSupported): 'Command hello not supported.' on server xxxxxxx-centralus.mongo.cosmos.azure.com:10255. The full response is {\"ok\": 0.0, \"errmsg\": \"Command hello not supported.\", \"code\": 115, \"codeName\": \"CommandNotSupported\"}"
            }
        },

My spring boot app is running in App Service, and everything is located in Central US data center.

[miguelrq]

@gahl-levy looks like the way actuator does health checks is with
mongoTemplate.executeCommand"{ hello: 1 }"
which cosmosdb doesn't support

Against a mongo shell
db.runCommand({isMaster:1}) //works
db.runCommand({hello:1}) //doesn't work

[arm749]

@wilkinsona @gahl-levy This issue should not be closed. The actuator health check still fails on a startup of Springboot 3.4.0 while using Azure Cosmos DB Mongo. This is breaking behavior for all Mongo CosmosDB users.

[wilkinsona]

@arm749 Unfortunately, re-opening this issue won't achieve anything as there's no change that can be made in Spring Boot to improve the situation.

We do not want to switch back to { isMaster: 1 } as our health indicator when then be incompatible with Mongo's stable API, undoing the goal of this issue. We also can't affect CosmosDB's support for the stable API.

A workaround has already been suggested above:

In the meantime, anyone who's affected can work around the non-compliance by defining their own bean named mongoHealthIndicator or mongoHealthContributor.

I think this is the best that we can do on the Spring Boot side until Microsoft have a chance to clarify their support for Mongo's stable API.

[arm749]

@wilkinsona Thanks. Is Microsoft aware of this? By the looks of above, it doesn't seem like they have any action items on this.

[wilkinsona]

They should be given the existence of https://feedback.azure.com/d365community/idea/c7b19748-9276-ef11-a4e6-000d3a059eeb and @gahl-levy's involvement in this issue.

[kubav182]

@gahl-levy is there any chance cosmos db will support db.runCommand({hello:1}) soon?

[dafnenavita]

Hi @gahl-levy @thekid - is there a fix expected soon for this ? I see some developments but I’m still facing the same issue for any springboot version 3.2.7 and above

[gahl-levy]

So sorry folks, these reply notifications were getting filtered. I'm following up on this now and will have an update soon.

[gahl-levy]

Hey Folks- Unfortunately, only db.hello was working in Azure Cosmos DB for MongoDB RU, but that was not enough for the health check. Confirmed that the fix to fully support "hello" is being deployed to production in Azure Cosmos DB for MongoDB RU. We are expecting it'll be out there for everyone in roughly two months or sooner. Thanks again for your patience.

Just FYI: "hello" is already fully supported in Azure Cosmos DB for MongoDB vCore in case you need something sooner. Thanks!

[SimonedeGijt]

Thank you so much @gahl-levy !