How to compare the performance of mongoDb with CosmosDb on Azure cloud?

1
votes

I have a mongoDb instance provisioned on Azure cloud used as IAAS. There is a load balancer behind which there is a shard cluser, each shard has 2 replicas. Each replica is a VM. So I can go inside that VM and check the storage space, RAM etc and check on the hardware details for that VM.

Now, I have cosmosDb provisioned as well which is actually a managed service and I have no control over what it uses behind the hoods. For example, I would not know how much RAM, what storage space etc is used.

So if I have to compare the performance of mongoDb and cosmosDb on azure cloud, I am not sure how to compare apples to apples if I don't have the exact information about the underlying hardware.

Can someone suggest a way I can compare the performance of the two ?

1
mongodbazure-cosmosdb
Why would you attempt to compare hardware characteristics for IaaS vs a fully managed PaaS service? Compare read/write performance for known access patterns and be done with it – Jesse Carter
mongodb instance on azure cloud running inside a 1 core 1 gb ram VM and cosmosdb with much better hardware resources. Do you think it is ok to compare read/write performance in both under such circumstaces? – Hary
You'll need to benchmark, but you're comparing apples to oranges. Hardware spec is irrelevant, as Cosmos DB lets you tune your database on an RU/second (and RU burst/minute) model, per collection. There's no direct comparison to a given MongoDB configuration (which will be impacted by indexing scheme, cpu, ram, network, disk speed, sharding, etc). Unfortunately no way for anyone to answer this except you, via testing with your specific data model and typical read/write operations. – David Makogon
thanks. wondering why was this question down voted if the comparison isn't possible ? I was just looking for the answer like David said that there is no direct comparison possible because of the reasons he gave. – Hary

1 Answers

0
votes

Why not compare on price?

Take the direct Azure charges for your IAAS mongodb and allocate the same budget to purchase an allowance of CosmosDb request units. This would represent a very basic comparison.

Next fine tune your comparison to genuinely reflect some advantages of PaaS CosmosDb.

  • Assume you could dial down allocated RU by 30% for 10 hours per day.

  • Enable the new add-on provisioning for request units per minute. 20% cost savings have been cited by Microsoft when this feature is enabled.

  • Finally, add 10% of the salary of a Database Administrator to your total IAAS cost.