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Azure Cosmos DB Throttling Issues RRS feed

  • Question

  • Our Avg Throughput is 100 RUs/s and we have assigned 10,000 RUs /s for a database having two collection one for sensor data and one for gps data, both are sharing same through put. Inflow rates are 20 doc/second with size 1 kb, and we do not have any query, using cosmos db trigger for real time updates. 

    • We have set 'Time to Live' off, if we make it on, will it help us?  Our Data Size is as of now is 21.2 GB and Index Size - 1.22 GB
    • We want to change GPS data collection from provisional to reserve, how to do it ?
    • We have leases collection in same database, sharing same throughput, if we make it reserve, will it stop throttling?

    Kindly help

    Wednesday, May 22, 2019 5:40 PM

Answers

All replies

  • Hi Param,


    1. Time to Live will not effect the throttling as deleting items based on TTL is free. There is no additional cost (that is, no additional RUs are consumed) when item is deleted as a result of TTL expiration.


    2/3. As such making the throughput reserved for a collection would not solve the throttling issue. If you want to reserve throughput for a particular collection. You need to have enough throughput provisioned for each collection so that it meets your requirement.


    Also, With Azure Cosmos DB, you pay for the throughput you provision and the storage you consume on an hourly basis.


    When you’re exceeding your RU quota, Cosmos DB doesn’t reject your additional requests by just screaming ERROR! Not only does it explicitly flag these throttled requests with the HTTP status code 429, but the response also provides a very useful header: x-ms-retry-after-ms. As its name implies, this header tells you how much time you should wait before re-trying.


    Although this hint has its own limits (it may not be very reliable if multiple clients overload your RU quota at the same time), it’s still a very useful information to have in order to define the cool-off period one should wait and avoid a retry policy that would be too aggressive (making things even worse!).

    You can refer this blog to help you further understand how throttling works in Cosmos db.

    Hope this helps.

    Thursday, May 23, 2019 7:01 AM
    Moderator
  • I have followed this link https://docs.microsoft.com/en-us/azure/cosmos-db/performance-tips#indexing-policy religiously point by point, it has resolved my problem.  

    Thanks&Regards 

    Wednesday, July 31, 2019 4:24 AM