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Archiving Logs in Sematext

You can configure each Logs App to compress and store all logs it receives to an S3-compatible object store. This includes:

How to Configure Log Archiving

In Sematext, go to Logs view and choose Archive Logs in the App context menu (three-dots icon) of the App whose logs you want to ship to an S3-compatible object store:

For Amazon S3, all you have to provide are credentials and a bucket name:

For any other S3-compatible object store you'll also have to provide a service endpoint. Cloud object store providers, like DigitalOcean Spaces or IBM Cloud Object Storage usually refer to it as a Public Service Endpoint in bucket configuration. For Minio users this would be your Minio public URL.

Paste Access key ID and Secret access key in the corresponding fields.

Enter Bucket name (just the simple name, not fully qualified ARN) and choose Compression (read on for more details about compression) and confirm with Verify and save.

At this point, your Logs App is going to check whether the information is valid using the AWS S3 API.

After the check is done you'll see a feedback message confirming information validity or an error message.

How to Obtain Credentials from AWS

For our Logs App AWS S3 Settings, besides S3 bucket name, you'll need Access Key ID and Secret Access Key.

Log in to your AWS account, go to IAM > Users and open (or create) a user that you want to use for S3 uploads:

Click on Create Access Key:

Note down Access Key ID and Secret Access Key (you can Download Credentials to a safe place if you like, but it's not necessary).

Credentials Required When Using the AWS S3 Bucket Access Policy

In order to verify access to your S3 bucket, the Logs App will first use the credentials to log in and, if successful, proceed to create a dummy file inside the bucket.

If the file creation was successful Logs App will attempt to delete it.

For these reasons, the following credentials must be given to the bucket when saving AWS S3 settings:

  • s3:GetObject
  • s3:PutObject
  • s3:DeleteObject

After the verification is done you can remove the s3:DeleteObject permission from the bucket policy.

NOTE: if deletion of the dummy object fails the Logs App will ignore it and conclude that it can start shipping logs.

Compression of Archived Logs

You have the option of choosing between two modern, lossless compression codecs from the LZ77 family, with excellent speed/compression ratio, LZ4 and LZF.

If you choose No compression option, logs will be stored in raw, uncompressed format, as JSON files.

Decompressing Archived Logs

You can decompress logs by installing these command line programs (then useman lz4orman lzf for further instructions):


sudo apt-get install liblz4-tool
sudo apt-get install libcompress-lzf-java (landed in Ubuntu 15.04)


brew install lz4
brew install liblzf

Folder Structure Used for Logs Archived in S3

Inside a bucket that you specify in settings, the following folder hierarchy is created:


Where [app-token-start] is the first sequence of your Logs App's token.

For example, an App whose token begins with f333a7d7 will have a folder with the following path on May 01, 2021 at 11:20PM UTC:


warning Note:

Before May 01, 2017 the folder hierarchy was more flat:


For example: 856f4f9c3c084da08ec7ea9ad5d4cadf/logsene_2016-07-20/18