Prevent race in SingleDirectoryDbLedgerStorage metrics collection

Open michaeljmarshall opened this issue 1 year ago • 2 comments

Motivation

We swap the writeCache and the writeCacheBeingFlushed on flush. Therefore, it is not safe to call each to get the size/count metrics. Instead, if we expose the underlying accumulators, we can safely get the stats.

Changes

Expose the AtomicLong and the LongAdder objects in the WriteCache for safer metrics reporting.

Apr 22 '24 20:04 michaeljmarshall

How do you guarantee they won't swap during L214-L217? It seems problem is not solved.

Apr 26 '24 06:04 hezhangjian

How do you guarantee they won't swap during L214-L217? It seems problem is not solved.

We're in the constructor. I don't think anything could have access to trigger the swap yet.

Jul 17 '24 18:07 michaeljmarshall