Does couchbase eventing service stores events indefinitely?

[blackpanther]

I was following following link to learn about eventing service in couchbase server: Data Enrichment | Couchbase Docs

I have a couple of queries:

1. In case #2 article asks us to undeploy the function created for case #1. why? is it because that function will also be triggered, and try to upsert same doc?
2. In both the cases, article made some changes in db, then created/deployed the functions. Does it mean that couchbase stores all the mutation history somewhere, and as and when I create some eligible function, it gets automatically applied to all the existing mutations? I read in the docs, that couchbase doesn’t store these mutations indefinitely, but didn’t got much detail - like for how long, etc…
3. If I had a scenario like this where I would like to run a certain function on all existing mutation ever occured in some collection, can I rely on couchbase to be storing all these mutations? Or should I look for some other solutioning?

[mreiche]

I’m not an the eventing expert, but I did look at the examples.

@blackpanther

1. In case #2 article asks us to undeploy the function created for case #1. why? is it because that function will also be triggered, and try to upsert same doc?

Looking at the instructions - there are two independent cases. And undeploying the function for case #1 would be to keep them independent. You could try not undeploying the first one and see if both are triggered.

@blackpanther

2. In both the cases, article made some changes in db, then created/deployed the functions. Does it mean that couchbase stores all the mutation history somewhere, and as and when I create some eligible function, it gets automatically applied to all the existing mutations?

Isn’t that what step 8 in case #1 demonstrates? (I believe there is a typo in the description of the result where it says ‘without’ instead of ‘with’ while the data definitely shows it is ‘with’ the two new properties).

@blackpanther

3. If I had a scenario like this where I would like to run a certain function on all existing mutation ever occured in some collection, can I rely on couchbase to be storing all these mutations? Or should I look for some other solutioning?

It seems that it would not be necessary to store the “mutations” to create/modify a document BEFORE the function is deployed as the existing document is sufficient to record that it was created.