virajjasani commented on a change in pull request #3407: URL: https://github.com/apache/hbase/pull/3407#discussion_r687501045
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/LruAdaptiveBlockCache.java ########## @@ -646,14 +639,16 @@ private long updateSizeMetrics(LruCachedBlock cb, boolean evict) { @Override public Cacheable getBlock(BlockCacheKey cacheKey, boolean caching, boolean repeat, boolean updateCacheMetrics) { - LruCachedBlock cb = map.computeIfPresent(cacheKey, (key, val) -> { - // It will be referenced by RPC path, so increase here. NOTICE: Must do the retain inside - // this block. because if retain outside the map#computeIfPresent, the evictBlock may remove - // the block and release, then we're retaining a block with refCnt=0 which is disallowed. - // see HBASE-22422. - val.getBuffer().retain(); - return val; - }); + LruCachedBlock cb = map.get(cacheKey); + if (cb != null) { + try { + cb.getBuffer().retain(); Review comment: > A cached buffer item detached from the cache still needs to have its #release called w/ refcount at zero so the backing memory gets readded to the pool. Yeah I think this makes sense. Let me get back to this in case I find some better and obvious way to improve perf and get some YCSB results. -- 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: issues-unsubscr...@hbase.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org