I use aws cloudwatch to collect aws ecs farget task's logs.
The config is in the following pic:
And I get the following logs, it is wired. Some lines with datetime is combined in one log. I think every log starts with datetime should be seen as one single log.
The %L option of awslogs-datetime-format has incorrect documentation. I had the same problem and then looked at the driver source code and %L matches .\d{3} Here`s a source link. This means it requires a leading . at the start of the pattern. You may change the format like this and it will work.
awslogs-datetime-format: '%Y-%m-%d %H:%M:%S%L'