# Injection parameter to simulate access to website

**URL:** <https://community.gatling.io/t/injection-parameter-to-simulate-access-to-website/5776>\
**Category:** Gatling (Open-Source)\
**Created:** [August 25, 2020, 10:27am UTC](https://community.gatling.io/t/injection-parameter-to-simulate-access-to-website/5776 "2020-08-25T10:27:30Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Antharis](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@Antharis](https://community.gatling.io/u/Antharis)\
**Post date:** [August 25, 2020, 10:27am UTC](https://community.gatling.io/t/injection-parameter-to-simulate-access-to-website/5776/1 "2020-08-25T10:27:30Z")

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Hi,

I have discover Gatling last week. I misunderstand Simulation Model and parameter Injection.

I tested many arguments from simulation setup documentation.

I want to simulate 10 000 users (during few minutes to allow time for scalling) coming to my public website (on Google Cloud Platform).

Its not 10000 active users.

Open or close model is the most suitable for my requirements ?

- Closed systems, where you control the concurrent number of users
- Open systems, where you control the arrival rate of users

I do not control the concurrent number of users nor the arrival rate of users.

Regards,  
Antharis

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**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\
**Post date:** [August 25, 2020, 9:40pm UTC](https://community.gatling.io/t/injection-parameter-to-simulate-access-to-website/5776/2 "2020-08-25T21:40:22Z")

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If your application has a mechanism to push concurrent users excess into a queue (such as what you can see in gaming or ticketing, eg “The system is at full capacity, please wait N minutes”), it’s a closed system. Hint: it’s most likely hasn’t.  
Otherwise it’s an open one.

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**Author:** ![Antharis](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@Antharis](https://community.gatling.io/u/Antharis)\
**Post date:** [August 26, 2020, 2:10pm UTC](https://community.gatling.io/t/injection-parameter-to-simulate-access-to-website/5776/3 "2020-08-26T14:10:41Z")

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Hi Stéphane,

Thanks for the tip !

I will test rampUsers and rampUsersPerSec. I don’t know which is most suitable for my requirement.

Regards,  
Antharis