Session Tracking FAQ
Answers to the generally asked questions related to RudderStack’s session tracking feature.
Do the RudderStack server-side SDKs support the automatic session tracking feature?
No, the server-side SDKs do not support automatic session tracking. However, you can create your own session start and end events as backend events using the SDKs.
How does RudderStack determine the
RudderStack passes the event’s
timestamp (in milliseconds) as the
Does RudderStack attach any user information to the
RudderStack does not attach any user information to the
sessionId. This is so that a user cannot be traced back or identified only with the
Are session IDs unique across users?
sessionId is not guaranteed to be unique across users. RudderStack calculates the current
timestamp (in milliseconds) and sets it as the
sessionId. It is helpful to measure session-related properties like number of sessions for a given user, session length, etc.
How do I correctly count the number of sessions for a given user?
To correctly count the number of sessions, you can pair
sessionId with the user’s
What happens if automatic session tracking is enabled but I call the
If you call the
startSession() API while automatic session tracking is enabled, RudderStack ends the existing session and starts a new session. Also, it disables automatic session tracking.
What happens to the existing session if I call the
If you call the
reset()API, RudderStack ends the existing session and generates a new one.
Which events and APIs does RudderStack support for session tracking?
RudderStack currently supports session tracking only for the following events:
Is automatic session tracking permanently disabled if I trigger manual session tracking?
If you manually trigger a session using the
startSession() API, RudderStack will disable automatic session tracking only till the app is closed.
What happens if I manually trigger a new session during an active session?
RudderStack will end the active session and generate a new session.
What happens if I set
timeout to 0 or less than 10 ms?
If you set the session’s
timeout to 0, RudderStack disables automatic session tracking. This is because upon setting the
timeout to 0, RudderStack creates a new session for each event. As such, enabling automatic session tracking serves no purpose.
If your session
timeout is less than 10 ms, RudderStack gives a caution but proceeds with the session tracking.
RudderStack persists the following session tracking-related information in local storage/cookie in a new field called
|String||Uniquely identifies a session.|
|Session expiration time||Number||Time when the session expires. RudderStack calculates it as the last event’s |
|Manual session tracking status||Boolean||-|
|Automatic session tracking status||Boolean||-|
|Session started||Boolean||A flag that identifies the first event of the session.|
What happens I close a website tab and reopen it after some time?
If the time between closing the tab and reopening it is less than the session timeout (default is 30 minutes), then RudderStack continues the same session. Otherwise, it starts a new session.
Does the existing session end if an
identify call is made with a different
If you identify a user with a new
userId in an existing session, RudderStack triggers a
reset() call. This ends the existing session and generates a new one.
This is applicable for both automatic and manual session tracking.
What is the scope of persistence in case of automatic session tracking?
When an application is closed completely and launched from scratch, RudderStack checks if the inactivity timeout of the previous automatically tracked session has elapsed. If yes, RudderStack creates a new session, otherwise it continues the previous session.
What is the scope of persistence in case of manual session tracking?
The scope of manual session tracking depends on whether the automatic session tracking feature is enabled.
- If automatic session tracking is enabled: On the next app launch (from scratch), RudderStack clears the manual session even if
endSession() is not called and generates a new automatic session.
- If automatic session tracking is disabled: On the next app launch, the manual session will still be active and cleared only when the user ends the session using
Where does RudderStack store the
sessionId, last event time, and automatic session tracking status?
RudderStack stores the
sessionId, the last event timestamp (used to determine session expiration), and the status of automatic session tracking in the following locations:
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