html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/5883#issuecomment-949875448,https://api.github.com/repos/pydata/xarray/issues/5883,949875448,IC_kwDOAMm_X844nfL4,4666753,2021-10-22T18:37:06Z,2021-10-22T18:37:06Z,CONTRIBUTOR,"I see the issue now. Closing the issue, but in case anyone else is figuring this out:

- I initially had this problem with coordinate ""a"" (index over dimension). In retrospect, since it was a dimension index, it was not chunked. So parallel writes are not safe (since they are not to independent chunks).
- At some point, while constructing my MCVE, I swapped the chunking of ""x"". Right now, it is not chunked on a, but rather on b. So, parallel writes are not safe (since they are not to independent chunks).
- If I write `chunks=(1, None)` for the dummy value for `x`, the example no longer has errors.

In summary, main takeaways are:
- check that your chunking aligns with your parallel writes using regions.
- dimension coordinates cannot be chunked in zarr (to my knowledge, at least), and so, they do not support parallel writes. Write these either before or after the parallel writes.

Sorry for opening this issue that wasn't a real issue!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1033142897