Support for keyspace notifications

[vazois]

Feature request type

enhancement

Is your feature request related to a problem? Please describe

Keyspace notifications allow clients to subscribe to Pub/Sub channels in order to receive events affecting the Garnet data set in some way.

Describe the solution you'd like

We already have PubSub support, but it is only for user defined channels.
It will be nice to support keyspace notification as described here.

Describe alternatives you've considered

N/A

Additional context

No response

[MichaCo]

Is this documented that this is not supported? Luckily I found this issue after wondering why my code isn't doing anything ;)

+1

[joshua-siw]

Hi, I am currently trying to implement this.
When sending keyspace notifications, a database ID should be provided. However, since Garnet only supports one database at the moment, would it be okay if I hardcode the value 0 for the DB ID?

I looked into how the SELECT command is implemented, hoping to find a variable that might be used in the future if multiple databases are supported, but couldnt find one.

[robd003]

Is it possible to send the original key & value in the notification?

I'd really like to use Garnet as a write back cache where I get a high number of modifications, then 60 seconds after there are no updates I'd like to expire the key and write the details to a database.