Setting up TTL on CosmosDB for Mongo

Hi @Mahesh Kurva ,

Thank you for your guidance.

We tried these steps before via MongoDB Compass, but it did not seem to work. I reset everything and tried again. The index now seems to be properly flagged as TTL and after a couple of tests with the TTL property on a few documents, they seem to be removed properly. All seems to work.

Before accepting you answer though, just a couple of small clarifications.

1. On step 5, you said I should ensure that documents have the _ts field populated. However, that field is nto visible to me in any way. How can I confirm that in the future, if I ever need to?
2. The Settings section of my collection still shows the message from my screenshot - that I need to create a TTL index. Now that I have the index though, how do I get to the screens that allow to change the default expiration time, etc.? Similar to the video on page https://zcusa.951200.xyz/en-us/azure/cosmos-db/mongodb/indexing, timestamp 1:54?

Hi @Daniel Ivanov,

Thanks for getting back to me.

How can I confirm that in the future, if I ever need to?

• To confirm that the _ts field is populated, you can run a query in the MongoDB shell or Compass to retrieve documents and include the _ts field in the projection.

db.collection.find({}, { _ts: 1 })

For more information, please refer the document: https://www.mongodb.com/docs/manual/reference/method/db.collection.find/

Changing the Default Expiration Time:

To change the default expiration time for your TTL index, you can use the collMod command in the MongoDB shell.

db.runCommand({
  collMod: "yourCollectionName",
  index: {
    keyPattern: { "_ts": 1 },
    expireAfterSeconds: newExpirationTimeInSeconds
  }
})

For more information, please refer the document: https://www.mongodb.com/docs/manual/core/index-ttl/

I hope this information helps. Please do let us know if you have any further queries.