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CHECK BLOB CHECKSUM

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The CHECK BLOB CHECKSUM command checks for and displays columnstore blob file corruptions. Applies to the blobs in local disk and local blob cache.

Syntax

CHECK BLOB CHECKSUM [ON <database_name>][WITH REPAIR[FORCE]];

Arguments

  • ON <database_name>: restricts the check and repair to the blob files of the specified database. If omitted then all databases on all nodes are checked.

  • When High Availability (HA) is enabled, the WITH REPAIR option will repair the corruption by replacing the corrupt blob with a valid copy (HA replica) from another partition. When HA is not enabled, the corruption cannot be repaired.

  • The WITH REPAIR FORCE option deletes the metadata for the corrupt blob. While this will allow the table to be queried, it will also result in data loss.

Remarks

  • This command requires the SUPER privilege.

  • WITH REPAIR takes a cluster level lock in the exclusive mode and will queue behind other cluster operations, so it should be planned for a maintenance window. CHECK BLOB CHECKSUM without WITH REPAIR is read-only and does not take that lock.

  • WITH REPAIR FORCE also deletes the blob when a copy exists on another node but that copy is itself invalid. Confirm from the Repair operations column of a CHECK BLOB CHECKSUM run that a valid copy exists before using FORCE.

  • When you see error 2517, ER_CORRUPT_BLOB means a columnstore blob file failed to decode on the reporting node. This normally indicates a problem with the storage on that host rather than an engine defect, and the host's kernel logs should be checked alongside running this command.

Example

This is a simple use showing how the output of CHECK BLOB CHECKSUM displays corruption in columnstore blob files.

CHECK BLOB CHECKSUM;
+---------+-----------+-------+----------+-------+---------------------+----------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------+
| node_id | Host      | Port  | Database | Table | Filename            | Reason                                                                                 | Repair operations                                                                                             |
+---------+-----------+-------+----------+-------+---------------------+----------------------------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------------+
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_29  | File has incorrect checksum. Actual checksum 0x29072b55, expected checksum 0xe6ac67b6. | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_58  | Missing file                                                                           | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_88  | File has incorrect size. Actual size 49, expected size 44                              | Remove file (a copy of the file is avaliable on 127.0.0.1:10000, but its not valid.  Hit error 1017)          |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_112 | File has incorrect size. Actual size 51, expected size 46                              | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_118 | File has incorrect size. Actual size 49, expected size 44                              | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_191 | Missing file                                                                           | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_203 | File has incorrect checksum. Actual checksum 0xf6aac90f, expected checksum 0x390185ec. | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_208 | Missing file                                                                           | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_214 | File has incorrect checksum. Actual checksum 0x205df634, expected checksum 0xdb081c6a. | copy blob file from replica on '127.0.0.1':10000                                                              |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_232 | File has incorrect checksum. Actual checksum 0x460d1e1a, expected checksum 0xbbab2e04. | Remove file (a copy of the file is avaliable on 127.0.0.1:10000, but its not valid.  Hit error 1017)          |
| 2       | 127.0.0.1 | 10001 | db3      | rtab  | blobs/22/0/0/10_238 | File has incorrect checksum. Actual checksum 0x31705cf0, expected checksum 0xca25b6ae. | copy blob file from replica on '127.0.0.1':10000                                                              |

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Verification instructions

Note: You must install cosign to verify the authenticity of the SingleStore file.

Use the following steps to verify the authenticity of singlestoredb-server, singlestoredb-toolbox, singlestoredb-studio, and singlestore-client SingleStore files that have been downloaded.

You may perform the following steps on any computer that can run cosign, such as the main deployment host of the cluster.

  1. (Optional) Run the following command to view the associated signature files.

    curl undefined

  2. Download the signature file from the SingleStore release server.

    • Option 1: Click the Download Signature button next to the SingleStore file.

    • Option 2: Copy and paste the following URL into the address bar of your browser and save the signature file.

    • Option 3: Run the following command to download the signature file.

      curl -O undefined

  3. After the signature file has been downloaded, run the following command to verify the authenticity of the SingleStore file.

    echo -n undefined |
        cosign verify-blob --certificate-oidc-issuer https://oidc.eks.us-east-1.amazonaws.com/id/CCDCDBA1379A5596AB5B2E46DCA385BC \
          --certificate-identity https://kubernetes.io/namespaces/freya-production/serviceaccounts/job-worker \
          --bundle undefined \
          --new-bundle-format -
    Verified OK

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