How Block Scanners Work?
- Periodic Scanning: Block scanners run periodically to check the integrity of data blocks stored on DataNodes. The frequency of these scans can be configured based on the system’s requirements.
- Checksum Verification: During the scan, the block scanner verifies the checksum of each block. A checksum is a value calculated from the data in the block, and it serves as a fingerprint for that data. If the checksum of a block matches the expected value, the block is considered intact.
- Detection of Corruption: If the checksum does not match, the block scanner flags the block as corrupted. This discrepancy indicates that the data in the block has been altered or damaged.
What happens when Block Scanner Detects a Corrupted Data Block?
Data integrity is a critical aspect of computer systems, ensuring that information remains accurate, steady, and reliable during its lifecycle. One of the critical components in maintaining this integrity is the block scanner. When a block scanner detects a corrupted data block, several processes and mechanisms come into play to handle the situation effectively.
This article delves into the intricacies of what happens when a block scanner detects a corrupted data block, particularly in the context of Hadoop Distributed File System (HDFS).
Table of Content
- What happens when Block Scanner Detects a Corrupted Data Block?
- Understanding Block Scanners
- How Block Scanners Work?
- What Happens When Corruption is Detected?
- 1. Immediate Actions
- 2. Recovery Process
- 3. Long-Term Strategies
- Importance of Block Scanners
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