[HADOOP-14520] WASB: Block compaction for Azure Block Blobs

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.4
• Fix Version/s: 2.9.0, 3.0.0-beta1
• Component/s: fs/azure
• Release Note: Block Compaction for Azure Block Blobs. When the number of blocks in a block blob is above 32000, the process of compaction replaces a sequence of small blocks with with one big block.
• Assignee: Georgi Chalakov
• Reporter: Georgi Chalakov
• Created: 11/Jun/17 04:14
• Updated: 26/Sep/17 10:55
• Resolved: 11/Sep/17 13:18

Description

Block Compaction for WASB allows uploading new blocks for every hflush/hsync call. When the number of blocks is above 32000, next hflush/hsync triggers the block compaction process. Block compaction replaces a sequence of blocks with one block. From all the sequences with total length less than 4M, compaction chooses the longest one. It is a greedy algorithm that preserve all potential candidates for the next round. Block Compaction for WASB increases data durability and allows using block blobs instead of page blobs. By default, block compaction is disabled. Similar to the configuration for page blobs, the client needs to specify HDFS folders where block compaction over block blobs is enabled.

Results for HADOOP_14520_07.patch
tested endpoint: fs.azure.account.key.hdfs4.blob.core.windows.net
Tests run: 777, Failures: 0, Errors: 0, Skipped: 155

Issue Links

• is depended upon by: HADOOP-14552 Über-jira: WASB client phase II: performance and testing
• relates to: HADOOP-14610 Block compaction for WASB (Block Blobs Instead of Page Blobs)