Running a Test
From the web interface
Open a project, go to Run Test, choose where to run, and press Run.
There is no separate deploy step. Atlas reserves the machines, powers on any that are switched off, copies the files, and starts JMeter.
Choosing where it runs
| Servers | Pick individual load generators by name. Switched-off machines can still be selected — they are powered on for you. |
| Cluster | Run on a cluster and say how many units you want. Units are created for the test and destroyed afterwards. |
The number of machines multiplies your load: a plan with 100 threads run on 5 generators applies 500 concurrent users to your system.
Thread counts are per machine
Atlas does not divide your thread count across machines — each one runs the plan as written. Five generators running a 100-thread plan is 500 users, not 100.
From the CLI
atlas run -p SHOP --jmx checkout.jmx --servers 5 --wait--servers 5 | use any 5 available load generators |
--server gen-01 --server gen-02 | pick specific ones by name |
--cluster my-cluster --units 10 | run on 10 units in a cluster |
--jmx <filename> | which uploaded plan to run (needed only if the project holds more than one) |
--args "<jmeter args>" | extra JMeter arguments |
--no-split | send whole data files to every machine |
--wait | follow the run and print the report when it finishes |
--timeout 30m | how long --wait waits before giving up (default 2h) |
While it runs
The Run Test tab becomes a live view showing each stage — powering on, deploying, running — with a Stop button.
Watch in the sidebar shows live per-machine statistics while a test is in progress, which is the quickest way to confirm every generator is actually producing load.
From the CLI:
atlas status SHOP-20260818-194201If a machine is busy
A load generator can only run one test at a time. If you ask for machines that are already in use, your run is queued and starts when they free up. You don't need to retry.
Stopping a test
Press Stop, or:
atlas stop SHOP-20260818-194201Atlas asks JMeter to shut down cleanly so the final results are recorded, and only reports the machine as stopped once the process has actually ended.
TIP
If a machine can't be reached when you stop a test, Atlas tells you rather than pretending it worked, and the run stays open. Retry once the machine is reachable — this prevents a test carrying on unnoticed in the background.
When a test ends
A test ends by itself when the plan says so — a thread group's duration or loop count running out. When it does, the machines are released and any that Atlas powered on are switched off.