gocql - one session per keyspace?

[Martin Brzenska]

Hello scylla friends,

i have a GOlang service and a ScyllaDB cluster with several keyspaces.

The service reads and writes to up to 4 keyspaces at a time. When the service boots up, it creates a session instance for each keyspace.

The question is: is it better to have a seperate session instance for each keyspace or should i refactor the code to use one session for all keyspaces?

This Performance Tip says yes

But this article sounds it could be not a good idea ("You might be tempted to open a separate session for each keyspace...").

Thank you

Martin

[Martin Sucha]

Hello Martin,

On Fri, Nov 26, 2021 at 2:55 PM 'Martin Brzenska' via ScyllaDB users <scyllad...@googlegroups.com> wrote:

i have a GOlang service and a ScyllaDB cluster with several keyspaces.

The service reads and writes to up to 4 keyspaces at a time. When the service boots up, it creates a session instance for each keyspace.

The question is: is it better to have a seperate session instance for each keyspace or should i refactor the code to use one session for all keyspaces?

If you have four sessions to the same cluster, you will have 4x the amount of network connections open as each session manages its own connection pools.

In general I'd say it's better to use just one session per cluster unless you need separate sessions for some other reason (like using multiple users).

While there is only one default keyspace per session in gocql, you can specify the keyspace for each query explicitly.

Martin

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