Retrieve All keys from KeyValue Map and store to Cache

[#1]

Hi,

I have a KeyValueMap created at Environment Level. I would like to create a sharedFlow that reads the KeyValueMap and populates it into a Cache so all the api proxies will read from the Cache and not the KVM.

Is there any proposed policy to Retrieve all the key/value pairs from the KVM in a single go

Thanks in advance

[DChiesa]

You might THINK you want to do that, but you probably don't.

The KeyValueMapOperations policy with Action:GET will populate a cache, so that subsequent reads will read from cache until the expiry. So you shouldn't need to do the work you are describing, to optimize performance.

You *could* use a sharedflow to just read the KVM, which will implicitly populate the cache. But there is no policy to "retrieve all the values".

If it is super important to pre-populate the Cache with values, then you could populate a single KVM entry with a JSON payload, then shred the JSON payload and populate individual cache entries for each of the JSON properties.... You could do that in a loop using the nodejs target and the apigee-access module.

But honestly this seems like a lot of work for very little advantage. The initial KVM read will take single-digit milliseconds, let's guess around 5ms. Subsequent KVM reads will take much less than 1ms. In either case you're not gaining a lot, by introducing this additional complexity.

[#3]

Thanks for coming back...I was actually referring to another communitu post with respect to Caching of KVM community link

But your proposal is different from what it said...Has anything changed?

[DChiesa]

I don't know if anything has changed, but my proposal is the right one!

[#5]

Hi @Deepa , Thanks for bringing it up.

I see that @Ozan Seymen wrote that article in May but looks like some enhancements were made in June as per http://docs.apigee.com/release-notes/content/160615-ui-apigee-edge-public-cloud-release-notes#Expiry...

With the enhanced policy you can cache keys in-memory and you don't need to define explicit cache. Whenever you want to update the cache, you can PUT "PUT operation writes keys/values to the specified KVM. If the PUT writes to a key that already exists in cache, that cache is immediately refreshed and now holds the new value for the number of seconds specified in the policy's <ExpiryTimeInSecs> element." which is what Ozan explained but with explicit cache.

Hi @Ozan Seymen, any comments?

[ozanseymen]

Thanks for the heads-up Maruti

[ozanseymen]

Hi @Deepa

The community post for caching KVM values has been written when there were no built-in method for caching values. I have updated the community post but also noted some caveats and differences between the in-built implementation and the pattern explained in the post. Please consider the differences before going forward with any of those patterns as in-built method may not be the right way for you (yet).

[#8]

@Ozan Seymen Thanks for the clarification. This helps and avoids confusion.