Data ejection not works even ejection policy set to Eject data when RAM is full for ephemeral bucket

I am using the
Couchbase server Community Edition 7.0.2, I have created buckets(type Ephemeral, ejection policy : Eject data when RAM is full, Metadata Purge Interval:1) however when bucket memory full then it should eject the older document instantly and add new one but it is not happening for me

It looks due high value of Metadata Purge Interval, if I reduced to 0.0007 then it’s working fine. If I am not using the cross-data center replication(XDCR) and not using the query or index service then any other impact of it, if I keep Metadata Purge Interval value 0.0007

This isn’t my area of expertise, but I’ll give it a go…

Can you point me to the documentation for that just to make sure we’re on the same page? Thanks.

it should eject the older document instantly and add new one but it is not happening for me

How are you determining that is not happening?

It looks due high value of Metadata Purge Interval

While a “Metadata Purge” would give more space, I’m not sure that it should affect ejection. (note to self : 0.0007 is roughly one minute).

Thanks for reply

Can you point me to the documentation for that just to make sure we’re on the same page? Thanks.

Please find the document and check for Ephemeral buckets

How are you determining that is not happening?

In my scenario assigned memory to bucket(ehpemeral) got full and when meta purge interval is low(0.0007) then it remove the deleted item’s keys and metadata so bucket is able to reclaim the memory

While a “Metadata Purge” would give more space, I’m not sure that it should affect ejection

No it would not provide the more space however at time of ejection it remove item’s data only but not remove key and metadata of the item and that would remove at metadata purge interval time

Also refer the below link for more details

In my scenario assigned memory to bucket(ehpemeral) got full and when meta purge interval is low(0.0007) then it remove the deleted item’s keys and metadata so bucket is able to reclaim the memory

That shows that the smaller Metadata purge interval purges Metadata of deleted documents resulting in more space.

correct so just want to confirm that if any other impacts if reduced the meta purge interval for ephemeral buckets.

as can see some Cautions below here Auto-Compaction | Couchbase Docs

If the metadata purge interval is set too low, it can also cause severe issues with transactions, especially for ephemeral buckets.

here bit confused what kind of transactions would be impacted

These transactions - Using Couchbase Transactions | Couchbase Docs

That is quite different from your original post.

Data ejection not works even ejection policy set to Eject data when RAM is full for ephemeral bucket