MultiplexedSession

Class used to manage connections to Spanner using multiplexed session.

You don't need to use this class directly, connections will be handled for you.

Constructor

new MultiplexedSession()

Extends

EventEmitter

Methods

(async) _acquire() → {Promise.<(Session|null)>}

Acquires a session asynchronously, and prepares the transaction for the session.

Once a session is successfully acquired, it returns the session object (which may be null if unsuccessful).

Returns:

Type	Description
Promise.<(Session\|null)>	A Promise that resolves with the acquired session (or `null` if no session is available after retries).

_maintain() → {void}

Maintains the multiplexed session by periodically refreshing it.

This method sets up a periodic refresh interval for maintaining the session. The interval duration is determined by the @param refreshRate option, which is provided in days. The default value is 7 days.

Returns:

Type	Description
void	This method does not return any value.

Throws:

If the multiplexed session creation fails in _createSession, the error is caught and ignored. This is because the currently active multiplexed session has a 30-day expiry, providing the maintainer with four opportunities (one every 7 days) to refresh the active session.
Type Error

createSession()

Creates a new multiplexed session and manages its maintenance.

This method initiates the session creation process by calling the _createSession method, which returns a Promise.

getSession(callback) → {void}

Retrieves a session asynchronously and invokes a callback with the session details.

Parameters:

Name	Type	Description
`callback`	GetSessionCallback	The callback to be invoked once the session is acquired or an error occurs.

Returns:

Type	Description
void	This method does not return any value, as it operates asynchronously and relies on the callback.