Question on how CLIENT_SESSION_KEEP_ALIVE works

[davidhcar]

Issue description

When CLIENT_SESSION_KEEP_ALIVE = true, the connection session kept open until the execution of the query for long running queries, that will run more than 4 hours. Once the query executed and returns result back to .Net process, we close the connection, and that session gets terminated, Is that correct understanding about this flag CLIENT_SESSION_KEEP_ALIVE ?

[colingreen-payroc]

@davidhcar CLIENT_SESSION_KEEP_ALIVE causes a background thread to call a /heartbeat endpoint to keep the session alive on the server. Without that call the sessions can timeout, as by default they have a 4 hour inactivity timeout on the server.

This is not about HTTP connections, but the session state maintained on the Snowflake server side.

The .NET connector nuget has a connection pool that expires the connections after 1 hour of not being used, therefore the four hour session timeout on the server should not be reached in normal circumstances (however, also see #606 which can increase the connection pool timeout to two hours when the clocks go back).

A pooled connection is either used, and the session expiry timer at the server is reset; or it is not used and is removed from the pool after 1 hour.

[sfc-gh-dszmolka]

hi and thank you for raising this question! also apologies for the long period without answer from Snowflake. i see now that colgreen-payroc already kindly answered it, so marking this one as closed. if there's any further concerns, please don't hesitate to comment.

[lnashier]

CLIENT_SESSION_KEEP_ALIVE causes a background thread to call a /heartbeat endpoint to keep the session alive on the server. Without that call the sessions can timeout, as by default they have a 4 hour inactivity timeout on the server.

Does setting CLIENT_SESSION_KEEP_ALIVE to true keep compute resources active and cost money?

[sfc-gh-dszmolka]

as this question seems to be posted randomly in multiple Snowflake driver repositories, and i happened to bump into it on snowflakedb/gosnowflake#1065 first, it was answered first.

It is highly encouraged to use the community forum instead for such discussion, instead of driver repositories.

[lnashier]

Thank you for the response.

Also, my apologies for posting the question here and in other repos instead of community forums as I was not quite sure where to ask. Thanks for sharing the links for future reference.