# Ray cluster uses only Head node

**URL:** <https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616>\
**Category:** Ray Clusters\
**Created:** [June 23, 2021, 6:21pm UTC](https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616 "2021-06-23T18:21:16Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kpavel](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/kpavel/32/1170_2.png) [@kpavel](https://discuss.ray.io/u/kpavel)\
**Post date:** [June 23, 2021, 6:21pm UTC](https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616/1 "2021-06-23T18:21:16Z")

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![image](https://us1.discourse-cdn.com/flex020/uploads/ray/original/2X/1/1594b0e63ab21ff7d13bb068b21e003213925120.png)

Hello, my cluster spawned successfully, but for some reason when running tasks it is utilizing head node only.

Didn’t notice any relevant errors in logs.

Head node been spawned with:  
_ulimit -n 65536; ray start --head --port=6379 --object-manager-port=8076 --autoscaling-config=~/ray\_bootstrap\_config.yaml --dashboard-host=$RAY\_HEAD\_IP_  
And workers with:  
_ulimit -n 65536; ray start --address=$RAY\_HEAD\_IP:6379 --object-manager-port=8076_

Please point me what do I miss. Thanks.

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**Author:** ![architkulkarni](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/architkulkarni/32/10_2.png) [@architkulkarni](https://discuss.ray.io/u/architkulkarni)\
**Post date:** [June 25, 2021, 6:22pm UTC](https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616/2 "2021-06-25T18:22:19Z")

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Hi @kpavel, can you provide some more details about what tasks you’re running? If you’re running more than 2 tasks in parallel, i would expect the tasks beyond the 2nd task to be scheduled on the other two nodes. For example,

```auto
import ray
import time
ray.init(address="auto")
@ray.remote
def f(i):
    time.sleep(30)
    return i
futures = [f.remote(i) for i in range(6)]
print(ray.get(futures))

```

If you run this on the head node, do you see the tasks show up in the dashboard?

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<div class="post-metadata">

**Author:** ![kpavel](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/kpavel/32/1170_2.png) [@kpavel](https://discuss.ray.io/u/kpavel)\
**Post date:** [June 27, 2021, 1:26pm UTC](https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616/3 "2021-06-27T13:26:49Z")

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Hello @architkulkarni. Thanks, we can close the issue.  
It appears that when you use ray.init() without **address=“auto”** it schedules tasks to head node only.  
Didn’t see it documented anywhere.

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<div class="post-metadata">

**Author:** ![architkulkarni](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/architkulkarni/32/10_2.png) [@architkulkarni](https://discuss.ray.io/u/architkulkarni)\
**Post date:** [June 28, 2021, 5:44pm UTC](https://discuss.ray.io/t/ray-cluster-uses-only-head-node/2616/4 "2021-06-28T17:44:16Z")

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Ah yeah, that’s correct: [Starting Ray — Ray v2.0.0.dev0](https://docs.ray.io/en/master/starting-ray.html). We definitely want to make our documentation crystal-clear, so any edits or suggestions would be very welcome!