petersomogyi commented on code in PR #8128:
URL: https://github.com/apache/hbase/pull/8128#discussion_r3161345788
##########
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/DataTieringManager.java:
##########
@@ -347,4 +387,29 @@ private static boolean
isDataTieringFeatureEnabled(Configuration conf) {
public static void resetForTestingOnly() {
instance = null;
}
+
+ public Map<String, Pair<List<String>, Long>> getRegionColdDataSize() {
+ return regionColdDataSize;
+ }
+
+ /**
+ * Updates regionColdData size for the region containing the passed
compactedFiles.
+ */
+ public void updateRegionColdDataSize(String encodedRegionName,
+ Collection<HStoreFile> compactedFiles, Collection<HStoreFile> newFiles) {
+ regionColdDataSize.computeIfPresent(encodedRegionName, (k, v) -> {
+ for (HStoreFile file : compactedFiles) {
+ if (v.getFirst().contains(file.getPath().getName())) {
+ v.getFirst().remove(file.getPath().getName());
+ v.setSecond(v.getSecond() -
Bytes.toLong(file.getMetadataValue(FILE_SIZE)));
+ }
+ }
+ for (HStoreFile file : newFiles) {
+ // call isHotData to account for the new file size in
regionColdDataSize, if the new file is
+ // considered cold data as per data-tiering logic.
+ isHotData(file.getFileInfo().getHFileInfo(),
file.getFileInfo().getConf());
Review Comment:
I checked this part with Claude and it gave this answer:
> No — this is a single-thread deadlock. That's what makes it especially
insidious.
>
> One thread does this:
>
> 1. Enters computeIfPresent(regionName, lambda) — acquires the internal
bin lock
> 2. Inside the lambda, calls isHotData(...)
> 3. isHotData calls compute(regionName, lambda2) — tries to acquire the
same bin lock
> 4. The lock is non-reentrant, so the same thread blocks waiting on itself
>
> It's not a classic two-thread deadlock — it's a single thread trying to
re-acquire a lock it already holds, on a lock that doesn't support reentrancy.
The thread hangs forever.
>
> This will happen every time a compaction produces a new cold file in a
region that already has cold data tracked. That's a normal steady-state
scenario, not a rare race condition.
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