Limitations when running concurrent scripts

Learn the existing limitations when running concurrent IBM RPA bots on a computer.

  • The computer must have available system general resources
    The amount of system resources a bot consumes varies according to what the bot does. The average resource a Bot Runtime instance consumes is 40MB of random-access memory (RAM). See Concurrent running scripts to learn about the Bot Runtime sandbox.

  • You need to consider the application the bots automate
    Even though the Bot Runtime instance doesn't consume too many resources, the application a bot automates also consumes system resources. For example, running multiple bots that open browser tabs might consume all resources available.

  • The application can limit concurrent running instances
    Some applications like SAP limit the number of concurrently running instances of the same application.

  • Simulating human can affect concurrent bots
    If your automation process depends on visual elements on the screen or simulating human input on an application, you might need to use commands to manage critical regions. See Commands to limit access to critical regions for a list of commands.

  • Shared resources can limit concurrency
    You need to manage critical regions when running concurrent scripts to prevent runtime exceptions. See Commands to limit access to critical regions for a list of commands to manage shared resources. See Concurrent running scripts to learn about critical regions.

  • Computer's capacity limits concurrency
    By default the computer's capacity is 1. You need to change this value to more than one if you want to run bots concurrently; each bot running requires one Bot Runtime license.
    For more information about how to change the default value, see Modifying computer's capacity.

  • Running scripts on the same user session
    IBM RPA scripts can run on the same user session. In this scenario, scripts share resources, imposing to you the challenge of controlling access to critical regions, which can limit concurrency. Some software also limit the number of active sessions per user session. Web automation usually works best in concurrent scenarios.

  • Running scripts on different user sessions
    Although you can run IBM RPA scripts on different user sessions, this scenario limits the actions scripts can do. If your scripts need to interact with components drawn on-screen, which require an active console session, you can't use different user sessions because the operating system supports only one active console session at a time. It's possible that web automation using a headless browser could work.
    You can only run bots on different user sessions if you schedule them with different credentials to unlock the machine or by launching them on a server that accepts multiple user sessions. Keep in mind that triggering the script through the API or orchestrating scripts use the credentials set on the Computer configuration on IBM RPA Control Center.