KV Graveler: Staging Area compaction

[N-o-Z]

Graveler KV implementation introduces branch staging area composed of staging token and a list of sealed tokens. Potentially the sealed tokens list can become quite large and affect performance of reading from staging area. To prevent performance degradation, we suggest performing compaction as a background operation.

Mechanism

• Define threshold for branch sealed tokens list size
• Compaction mechanism to either triggered as a post operation explicitly in the background or as a background service
• The compaction mechanism will take the branch staging area and build it on a single token which will replace the current staging area
• Compaction of branch staging area will be an atomic operation, that will either succeed completely or fail without repercussions
• The operation can be retried at any given time