Draining a Virtual Site
"Draining" is a special operational mode for virtual sites in Syncplify Server! that is often misunderstood, but is essential for safe maintenance and updates.
What is Draining?
When a virtual site is put into draining mode, it immediately stops accepting new incoming connections. However, all existing (ongoing) client sessions are allowed to continue and finish gracefully, without interruption or forced termination.
Why Use Draining?
Draining is especially useful as a preparatory step before:
- Performing software updates
- Carrying out planned maintenance
- Restarting or stopping a virtual site
By draining a virtual site, you ensure that no new users can connect, while giving current users time to complete their operations. This prevents data loss and avoids abruptly disconnecting active sessions.
How Draining Works
- Activate draining: The virtual site stops accepting new connections, but ongoing sessions remain active.
- Monitor sessions: You can monitor the number of active sessions from the Admin UI (dashboard).
- Complete maintenance: Once all sessions have ended, you can safely stop or update the virtual site. You will then restart it after the maintenance operation is complete.
Can Draining Be Reversed?
Yes. If you change your mind, you can "undrain" a virtual site at any time. This will immediately allow new incoming connections again, without affecting ongoing sessions.
TIP
Use draining mode whenever you need to perform maintenance or updates that require stopping a virtual site, but want to avoid disrupting users who are already connected.