Concurrent Sessions Exceeded the Licensed Limit


You receive the following Notice, "Concurrent sessions exceeded the licensed limit."


This notice occurs if the number of active sessions from the PDQ console or Command Line Interface (CLI) to a single instance of the Background Service exceeds the number of licenses that exist for the account. While this notice will mostly be seen while using Central Server, it is not exclusive to it. This may also occur when the console is running in multiple user profiles at the same time (via Terminal Services) or multiple users are connecting to the background service using the CLI.

To resolve this notice, you will need to purchase the correct number of licenses for the number of admins using the software. In the future, concurrent sessions in excess of the licensed amount of administrators will be prevent new sessions.


Our focus has always been to supply remarkably useful tools for system administrators and IT professionals. Providing new features, product updates, and support all at an affordable price point required license compliance so we can continue to improve and expand our products for everyone. With the release of the Central Server feature, it was time to implement modest license compliance checks as part of the program with the use of concurrent sessions.

One of the decisions we made early on was to not charge a per-seat license. We felt the practice was burdensome and went against our philosophy of affordability and ease. Our licensing has always been one license per corporeal being that will access the program. It's simple, it's easy, and it works. has not supported multiple users using the Console at the same time on one machine (such as with Terminal Server). We have also not supported the use of the CLI in environments utilizing a self-service web portal or other method for having end-users access the program.

Central Server overview:

This isn't a component, instead it's a mode of operation. It works in one of three modes. A computer can only be in one mode at a time and all components installed on that computer (Console, CLI, and Background Service) operate in the same mode. The modes are as follows:

  • Local Mode
    This is the only mode available for Free and Pro users. It's the mode the application is in when the Central Server is disabled, though we include it under Central Server because it indicates that Central Server is "OFF". In this mode only the console and CLI on the same computer can attach to the Background Service.
  • Server Mode
    In this mode a computer is acting as a server for other computers, which means that the console and CLI on other computers can access the Background Service on the central server computer. The console and CLI on the central server computer in Server Mode work the same as if the computer is in Local Mode.
  • Client Mode
    In this mode a computer is acting as a client to another computer in Server Mode. The Background Service on the client computer is not running and the console and CLI connect to the Background Service on the computer in Server Mode. A computer can only be connected to one Background Service at a time. This is a computer wide setting so it applies to all of the Consoles and CLI running on the client computer.


Are you removing any features or changing the access to any existing or new features?
We are not. Our licensing has not changed and nothing is being excluded from the product or the usability of the product. The compliance with licensing will not remove any features or your ability to install PDQ consoles where needed.

We have four licenses for PDQ Deploy and two licenses for PDQ Inventory, how many concurrent sessions can we have?
You can have as many concurrent sessions as you have licenses. In this instance, you could have four concurrent sessions to PDQ Deploy, but only two concurrent sessions to PDQ Inventory.

What is considered a "concurrent session"?
A concurrent session is a set of connections to the Background Service from the PDQ console or CLI. Concurrent sessions are only considered within a single Background Service, so PDQ consoles on two computers connected to two different Background Services are two different single sessions. A session can either be from the same computer or from other computers when in Client Mode.

How do multiple sessions from the same user work?
Sessions from one or more PDQ console process running on a single computer within the same Windows user profile are considered a single concurrent session. For example, a user can have two consoles open on the same computer and it will only count as one session. If a single Windows user profile has the PDQ console opened on two computers connecting to the same Background Service then that counts as two sessions. Likewise two user profiles running the PDQ console at the same time on a single computer counts as two sessions.

Connections from CLI are considered the same session if they're using the same Windows account, regardless of the computer. The same user can run the CLI on multiple computers connecting to the same Background Service and only count as one session.

How long does a session remain active?
A concurrent session from the PDQ console will terminate when the last console running within the Windows user session closes. If the closing PDQ console cannot inform the Background Service that it is closing (such as due to a network error or a system crash) then the session will remain open for 30 minutes before closing on its own.

A concurrent session from the CLI will terminate 15 minutes after the last command is run by the user, regardless of which computer the command is run on. Each time the CLI is run again the 15 minutes starts over.

With Central Server, if the PDQ server console is not running, will the PDQ client console(s) be impacted?
Not at all. The PDQ server console is not required to be open and running. As long as the background service on the PDQ server is running with properly working credentials, the PDQ console on the server itself does not need to be running in order for the client console(s) to connect.

With only one license, can I still utilize the Central Server feature?
Yes, as long as both the PDQ console on the server computer and the PDQ console on the client computer are not open and running at the same time. Since we consider an open console as a concurrent session, you cannot actively use the server console and connect from the client console (or CLI) at the same time. Only one connection can be made to the background service at a time.

What if I want to connect to a PDQ central server from my local machine as well as from a machine (laptop) at a remote site?
This would be considered two concurrent sessions. Running PDQ Console on the local machine would be the first session and running the console at the remote site at the same time would be the second session. If the console on the server is running as well, that would create a third session. With only one license, you would need to either run only one PDQ console at a time, or purchase the number of licenses to match the number of sessions you wish to have running.

See Also:

Deploy: Configuring Central Server
Inventory: Configuring Central Server
PDQ Licensing
Incorrect License To Connect To Server

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