ECS Container logs cannot be displayed if the log group is in a different region

Hello.

Probably, but I think that in order to check the logs from the ECS console, they need to be output to the CloudWatch Logs log group in the same region.
We have confirmed that you can view log groups if you create them in the same region as your ECS cluster.
Therefore, I think that the UI side is probably set so that it cannot be obtained unless it is in the same region.

If you look at Google Chrome's developer tools, you can see that the following URL is being accessed.
In my environment, I have an ECS cluster in the Tokyo region, so I can see that I am accessing "ap-northeast-1".

https://logs.ap-northeast-1.amazonaws.com/

Hi,

What you are trying to achieve is not possible due to Region Isolation:

All Regions currently have three or more Availability Zones. Regions themselves are isolated 
and independent from other Regions with a few exceptions noted later in this document 
(refer to Global single-Region operations). This separation between Regions limits service failures, 
when they occur, to a single Region. Other Regions’ normal operations are unaffected in this case. 
Additionally, the resources and data that you create in one Region do not exist in any other Region 
unless you explicitly use a replication or copy feature offered by an AWS service or replicate the resource yourself.

See https://docs.aws.amazon.com/whitepapers/latest/aws-fault-isolation-boundaries/regions.html

The idea is that each region must be able to operate without any dependence on any other region. Additionally, it has compliance requirements: lots of customers wants to be sure that 100% of their data (even logs) in contained in one single region and cannot be spread all around.

To match your needs, you may want to use the cross-region (and cross-account) CloudWatch console: https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html

Best,

Didier