Data API (beta) - seems very slow to access data

MongoDB Atlas App Services & Realm Atlas Data API
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I have been testing out mongodb atlas new Data-API.

I have found quite a big hurdle in the way the length of time it takes for a simple document to be returned using /findOne

In comparison , I am using a aws lambda function using the normal node driver to create a database connection to my atlas cluster. Every time the function runs cold the total connection time is about 3 seconds. (warmup, create connection to atlas, query and return the data)
However when the function is warm and the database connection is re-used the round trip time to get data is ranges from 200-800ms (huge difference)

I expected that the data-api would perform much better, but on average it is about 3-4 seconds, and never better on subsequent tries.

Does it mean the using the data api to http://data.mongodb-api.com/xxxx which i believe behind the scenes invokes another cloud function and therefore is always cold and the db connection is always closed?

Using a simple data-set the data-api seems very slow when using the drivers.

Any support on what I may be doing wrong would be appreciated.

1 Like
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Hey Rishi - thanks for your feedback! It would be helpful to understand a little bit more about your scenario. While the API will ineviatably have another hop before reaching the database given it’s going via a HTTPS connection, I’m curious about -

  1. your Atlas tier
  2. Region you’re invoking the request from
  3. Cloud provider and region of your backing cluster.
  4. When you tested this out

3-4s is unexpected and thank you for bringing this to our attention!

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Hello, and thanks for the reply.

  1. My atlas tier is M1 shared HKG region AWS (i seldom get over 20 + connections and using a database that is currently less then 30MB, the http response payload is only 1-2kb, infact i am just returning a small document for testing.

  2. region is Hong Kong AWS. I am also invoking my lamda from Hong Kong, the connecting to lambda is super fast, (as it is with the mongo node driver to my atlas db )

  3. but when i use the data-api i find their is no caching of open db connections on mongo’s side? Does the data-api create a new connection each time? this would certaintely make the request slow. This has not been documented as far as I know, I would like to know how the data -api is working behind he scenes, is a function being called (similar to realm-web?)

  4. Yes HTTPS does carry some overhead, but still, 4 seconds to findOne is slow, my lamda function using node driver is also creating a https connection to Atlas using the connection string is it not?

  5. My last test was lask week, i will try to follow-up with some screenshots with dev tools showing the total time.

  6. Yes 3-4 seconds is perhaps OK on first try, but subsequent tries should be within 200ms, it is for this reason we have refrained form using the DATA-API as it is too slow right now.

My data api is using the global URI as mentioned in my post : http://data.mongodb-api.com/xxxx… I believe this means it would auto select the closest region (out of 4)

I am happy to conduct more testing should you need, or if you have any results on your side I would very much like to see them.

Thanks
Rishi

i would like to know do others also ex

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Hi Rishi -

  • we are selecting the closest region, but the closest one to you is currently located in Sydney, which is why it might be taking longer - we have plans to allow the singapore region in AWS shortly, so that will help a little bit.

  • We do some caching, I’m curious if you’re still running into this today - we had some issues on our end around mid April and I’m wondering if it was related to that

  • Scaling up the cluster might help out a little bit, so will optimizing for the payload size by projecting only what you need in each request. How big is your payload for the find?

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I’ll send a dev tools report in order to provide more context to this issue.

It would be good if there was a deep dive video into the DataAPI and how the backend works with requests/cahching/opening closing of DB connections and how these are re-used. I did watch some live mongodb videos, but they dont discuss this.

My payload is literaly 1 byte, so scaling up should not make a difference at all, infact the free tier should be a perfect use case to measure speed and reliability going forward.

At the current rate of 4 seconds response time, it is way too long even for simple hobby apps.
I am getting better response times using the mongodbDB node driver on a cloud function.
Yes certainly Atlas & Relam need more edge locations for realm-web and the DataAPI.