# Ensure only 1 actor runs on a node at a time

**URL:** <https://discuss.ray.io/t/ensure-only-1-actor-runs-on-a-node-at-a-time/7142>\
**Category:** Ray Clusters\
**Created:** [August 10, 2022, 4:47am UTC](https://discuss.ray.io/t/ensure-only-1-actor-runs-on-a-node-at-a-time/7142 "2022-08-10T04:47:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![WBerq](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/wberq/32/2994_2.png) [@WBerq](https://discuss.ray.io/u/WBerq)\
**Post date:** [August 10, 2022, 4:47am UTC](https://discuss.ray.io/t/ensure-only-1-actor-runs-on-a-node-at-a-time/7142/1 "2022-08-10T04:47:35Z")

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**How severe does this issue affect your experience of using Ray?**

- Medium: It contributes to significant difficulty to complete my task, but I can work around it.

Hello everyone!

I have a requirement where I need to send an actor to every node, but it can only be 1 actor at a time. This is because the actor will be completing a task that will use up all of the memory of the node it is on. Only when I get the results from the task that the actor completes can I then send a new actor to that node.

I am not sure how I can go about doing this. Does anyone have any suggestions?

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**Author:** ![ckw017](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/ckw017/32/1683_2.png) [@ckw017](https://discuss.ray.io/u/ckw017)\
**Post date:** [August 10, 2022, 6:07pm UTC](https://discuss.ray.io/t/ensure-only-1-actor-runs-on-a-node-at-a-time/7142/2 "2022-08-10T18:07:05Z")

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There’s an example here of adding resource constraints on actors which might fit your usecase: [Memory Management — Ray 1.13.0](https://docs.ray.io/en/latest/ray-core/objects/memory-management.html#memory-aware-scheduling)

In this case, you’d want to set the memory to be the amount of memory on each of your nodes.