hanishakoneru opened a new pull request #3034: URL: https://github.com/apache/ozone/pull/3034
## What changes were proposed in this pull request? Negative BlockCount and UsedBytes has been observed in ContainerDB. The BlockCount is incremented only when the Stream is closed and not when the BlockID is added to the DB. If the OutputStream was not closed properly or if, for any reason, the client starts writing to a new pipeline before the full block is written, it could lead to a Block being present in the container but the key_count (BlockCount) not being incremented for it. When a block is deleted from a container, the blockCount is also decremented. But if the blockCount is wrong to start with, it could lead to a negative value. When a block is deleted, usedBytes is decrement in memory first after deleting a chunk. And even if the chunkFile does not exist (already deleted), the usedBytes is decremented. This could lead to usedBytes being decremented multiple times for the same chunk and causing the total usedBytes metadata in the DB to become negative. Once all the chunks in all the blocks in that iteration of BlockDeletingService task are deleted, only then is the usedBytes updated in containerDB by taking the in-memory value. This Jira proposes to first update the DB with correct usedBytes (calculated from the BlockInfo after all chunks are deleted) and then update the in-memory metadata. This is the update sequence logic followed for all other state updates. Also, when a chunk is overwritten, then it is assumed that the size of the chunk remains the same. But it’s possible to overwrite more data into the chunk than originally present. In this case, the used_bytes should be updated with difference in the chunkSizes. (Adding this as a TODO). This PR has the following fixes: 1. Change Container DB KeyCount to BlockCount (to avoid confusion on what the keyCount denotes in ContainerData) 2. Fix BlockCount update logic 3. Fix UsedBytes decrement logic - update container DB first and then in-memory 4. Separate ContainerData metrics like read/write counts and bytes to different class 5. Cleanup and deprecate old Block and Chunk Delete methods 6. Add a test to verify blockCount and usedBytes are updated correctly on write failures ## What is the link to the Apache JIRA https://issues.apache.org/jira/browse/HDDS-5359 ## How was this patch tested? Added a unit test -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
