What is the maximum execution time for a Qiskit Runtime job or session?

Job maximum execution time

To ensure fairness, and as a way to help control cost, there is a maximum execution time for each Qiskit Runtime job. If a job exceeds this time limit, it is forcibly cancelled and a RuntimeJobMaxTimeoutError exception is raised.

Note

As of August 7, 2023, the max_execution_time value is based on system execution time, which is the time that the QPU complex (including control software, control electronics, QPU, and so on) is engaged in processing the job, instead of wall clock time.

Simulator jobs continue to use wall clock time.

You can set the maximum execution time (in seconds) on the job options by using one of the following methods:

# Initiate the Options class with parameters
options = Options(max_execution_time=360)

# Create the options object with attributes and values
options = {"max_execution_time": 360}

You can also find the system execution time for previously completed jobs by using:

# Find the system execution time
print(f"Job {job.job_id()} system execution time was {job.metrics()['usage']['seconds']} seconds")

In addition, the system calculates an appropriate job timeout value based on the input circuits and options. This system-calculated timeout is currently capped at 3 hours to ensure fair device usage. If a max_execution_time is also specified for the job, the lesser of the two values is used.

For example, if you specify max_execution_time=5000, but the system determines it should not take more than 5 minutes (300 seconds) to execute the job, then the job will be cancelled after 5 minutes.

Session time limits

When a session is started, it is assigned a maximum session timeout value. After this timeout is reached, the session is terminated, any jobs that are already running continue running, and any queued jobs that remain in the session are put into a failed state. You can set the maximum session timeout value using the max_time parameter:

# Set the session max time
with Session(max_time="1h"):
    ...

If you don’t specify a session max_time, the system defaults are used (see table below).

Additionally, there is an interactive timeout value. If there are no session jobs queued within that window, the session is temporarily deactivated and normal job selection resumes. During job selection, if the job scheduler gets a new job from the session and its maximum timeout value has not been reached, the session is reactivated until its maximum timeout value is reached. The interactive timeout value is based on the plan type:

Note

The timer for the session’s max_time is not paused during any temporary deactivation periods.

	Primitive programs		Private programs
	Premium or Cloud user	Open user	Premium user	Open user
Max time defaults	8h	15m	8h	N/A
Interactive timeout	5m	2s	5m	N/A

Note that a premium user here means an IBM Quantum channel user who has access to backends in instances other than ibm-q/open/main. A Cloud user here means an IBM Qiskit Runtime Cloud Standard plan user.

Note

Session max_time is based on wall clock time.

Other limitations

• Programs cannot exceed 750KB in size.

• Inputs to jobs cannot exceed 64MB in size.

• Open plan users can use up to 10 minutes of system execution time per month (resets at 00:00 UTC on the first of each month). System execution time is the amount of time that the system is dedicated to processing your job. You can track your monthly usage on the Platform dashboard, Jobs, and Account pages.