# Horizontal Scaling or Upgrade issue - Weaviate cluster

**URL:** <https://forum.weaviate.io/t/horizontal-scaling-or-upgrade-issue-weaviate-cluster/2081>\
**Category:** Support\
**Created:** [April 22, 2024, 3:32am UTC](https://forum.weaviate.io/t/horizontal-scaling-or-upgrade-issue-weaviate-cluster/2081 "2024-04-22T03:32:17Z")\
**Posts on this page:** 1\
**Showing post:** 16

<div class="post-metadata">

**Author:** ![andrii](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/andrii/32/2235_2.png) [@andrii](https://forum.weaviate.io/u/andrii)\
**Post date:** [September 5, 2024, 5:27pm UTC](https://forum.weaviate.io/t/horizontal-scaling-or-upgrade-issue-weaviate-cluster/2081/16 "2024-09-05T17:27:41Z")

</div>

There is now what looks like a different issue, caused by the same process of replacing one pod out of the cluster.  
Still same setup: 3 replicas, collection has a replication factor of 3 and async replication enabled. When pod weaviate-1 got replaced, it now has this message in logs:

```auto
{"action":"async_replication","build_git_commit":"9a4ea6d","build_go_version":"go1.21.13","build_image_tag":"1.26.3","build_wv_version":"1.26.3","class_name":"AndriiTest","hashbeat_iteration":51,"level":"warning","msg":"hashbeat iteration failed: collecting differences: \"10.0.198.209:7001\": status code: 401, error: ","shard_name":"554JMVbS6e2m","time":"2024-09-05T17:25:51Z"}

```

When I try to call `v1/cluster/statistics` endpoint I am getting this error back:

```auto
{
    "error": [
        {
            "message": "node: weaviate-1: unexpected status code 401 ()"
        }
    ]
}

```

Restarting the ReplicaSet helps, but it seems to not be able to recover on its own

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_[View the full topic](https://forum.weaviate.io/t/horizontal-scaling-or-upgrade-issue-weaviate-cluster/2081)._