AWS CloudWatch Logs Archive (not S3), how to use it

I am reading AWS CloudWatch Logs documentation here. They says

Archive log data – You can use CloudWatch Logs to store your log data in highly durable storage. The CloudWatch Logs agent makes it easy to quickly send both rotated and non-rotated log data off of a host and into the log service. You can then access the raw log data when you need it.

And in the pricing page, they have

Store (Archival) $0.03 per GB

And in the Pricing Calculator, they mention

Log Storage/Archival (Standard and Vended Logs)
Log volume archived is estimated to be 15% of Log volume ingested (due to compression). Storage/Archival costs are estimated assuming customer choses a retention period of one (1) month. Default retention setting is ‘never expire’.


I am trying to understand the behavior of this archive feature to decide if I need to move my log data to S3. but I cannot find any further details. I have tried exploring every button and link in CloudWatch Logs pages but cannot find a way to archive the data, I can only delete them or edit their retention rules.

So how does it work? The remark in the Pricing Calculator says it is estimated to be 15% of ingested volume, does this mean it always archive 15% of the log automatically? And why do they have to assume in the calculation taht the retention period is set to 1 month, does the archive feature behave differently otherwise?

>Solution :

The Archive log data feature refers to storing log data in CloudWatch Logs. You do not need to do anything additional to ‘archive’. It is the regular storage you can see on console.

Considering only storage pricing, storing logs in S3 is cheaper. It varies depending on region but in average on S3 Standard is about $0.025 per GB vs $0.03 per GB on CloudWatch Logs Storage. And if you move the objects to other storage classes it becomes cheaper.


Log volume archived is estimated to be 15% of Log volume ingested (due
to compression)

It refers to if 100GB of data are ingested on CloudWatch Logs, it reflects as only 15GB (15%) on Storage due to the special compressed format in which they stored this logs.

Leave a Reply