Thanos is an open-source project that provides highly available Prometheus setup with long-term storage capabilities. It is designed to aggregate data from multiple Prometheus instances and store it in a highly available manner. Thanos consists of several components, including the Store Gateway, which plays a crucial role in reading data from object storage and serving it to query components.
One common issue encountered in Thanos is the error message: store: failed to load block
. This error indicates that the Store Gateway is unable to load a specific block of data. This can lead to incomplete data being served to queries, affecting the reliability of your monitoring setup.
The error store: failed to load block
typically arises when the Store Gateway encounters corrupted block files. Blocks in Thanos are immutable chunks of data stored in object storage, and any corruption can prevent them from being read correctly. This issue can be due to various reasons, such as incomplete uploads, storage backend issues, or file system errors.
To resolve the store: failed to load block
error, follow these steps:
First, check the integrity of the block files. You can use tools like Prometheus or Thanos tools to verify block consistency. Run the following command to check for corrupted blocks:
thanos tools bucket verify --objstore.config-file=
If corruption is detected, restore the affected blocks from backups. Ensure that your backup strategy is robust to prevent data loss. Use the following command to restore a block:
aws s3 cp s3://your-backup-bucket/ s3://your-thanos-bucket/ --recursive
If backups are not available, consider re-uploading the blocks from the source Prometheus instance. Ensure that the upload process completes without interruptions. Use the following command to re-upload:
thanos sidecar upload --objstore.config-file=
To minimize the risk of block corruption in the future, consider implementing the following practices:
For more detailed information on Thanos and its components, visit the official Thanos documentation.
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)