[HDDS-8421] Reduce DN IO times when writeChunk (FilePerBlockStrategy)

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Implemented
• Fix Version/s: 1.4.0
• Component/s: Ozone Datanode
• Labels: pull-request-available
• Assignee: ChenXi
• Reporter: ChenXi
• Created: 14/Apr/23 17:37
• Updated: 22/Apr/23 06:49
• Resolved: 22/Apr/23 06:49

Description

In the FilePerBlockStrategy#writeChunk will generate twice IO process.

• The first is to check whether the write operation is an overwrite, will check whether the chunk file is exist (ChunkUtils#verifyChunkFileExists).
• The second is write Chunk, will open file and write file.

Those two IO operation can merge to once. just need to check whether is overwrite after open file and before write Chunk

Issue Links

• links to: GitHub Pull Request #4570