With this count query by bin:
filter @message like / error /
| stats count() as exceptionCount by bin(30m)
I get a discontinuous graph, which is hard to grasp:
Is is possible for AWS Cloudwatch Log Insights to consider the empty bin as zero count to get a continuous graph?
Found your question looking for my own answer to this.
The best that I came up with is to calculate a 'presence' field and then use sum to get 0's in the time bins.
I used strcontains, which returns a 1 when matched or 0 when not. https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CWL_QuerySyntax.html#CWL_QuerySyntax-operations-functions
Mine looks like this:
fields @timestamp, @message
| fields strcontains(@message, 'Exit status 1') as is_exit_message
| stats sum(is_exit_message) as is_exit_message_count by bin(15m) as time_of_crash
| sort time_of_crash desc
So, yours would be:
fields strcontains(@message, 'error') as is_error
| stats sum(is_error) as exceptionCount by bin(30m)
Use strcontains + sum or parse + count.
The point is not using filter. You should query all of logs.