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https://issues.apache.org/jira/browse/HBASE-26999?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17532206#comment-17532206
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Duo Zhang commented on HBASE-26999:
-----------------------------------
I need to say the problem is on step 6, not the order.
When we fail to write the compaction marker, it usually means we have already
dead, then there is no way to still allow the RS to delete any HFiles on HDFS.
We need to review the logic of aborting again, if under this case we will still
delete files on HDFS, then this is a very serious bug...
> HStore should try write WAL compaction marker before replacing compacted
> files in StoreEngine
> ---------------------------------------------------------------------------------------------
>
> Key: HBASE-26999
> URL: https://issues.apache.org/jira/browse/HBASE-26999
> Project: HBase
> Issue Type: Sub-task
> Reporter: Wellington Chevreuil
> Assignee: Wellington Chevreuil
> Priority: Major
>
> On HBASE-26064, it seems we altered the order we update different places with
> the results of a compaction:
> {noformat}
> @@ -1510,14 +1149,13 @@ public class HStore implements Store, HeapSize,
> StoreConfigInformation,
> List<Path> newFiles) throws IOException {
> // Do the steps necessary to complete the compaction.
> setStoragePolicyFromFileName(newFiles);
> - List<HStoreFile> sfs = commitStoreFiles(newFiles, true);
> + List<HStoreFile> sfs = storeEngine.commitStoreFiles(newFiles, true);
> if (this.getCoprocessorHost() != null) {
> for (HStoreFile sf : sfs) {
> getCoprocessorHost().postCompact(this, sf, cr.getTracker(), cr,
> user);
> }
> }
> - writeCompactionWalRecord(filesToCompact, sfs);
> - replaceStoreFiles(filesToCompact, sfs);
> + replaceStoreFiles(filesToCompact, sfs, true);
> ...
> @@ -1581,25 +1219,24 @@ public class HStore implements Store, HeapSize,
> StoreConfigInformation,
> this.region.getRegionInfo(), compactionDescriptor,
> this.region.getMVCC());
> }
>
> - void replaceStoreFiles(Collection<HStoreFile> compactedFiles,
> Collection<HStoreFile> result)
> - throws IOException {
> - this.lock.writeLock().lock();
> - try {
> -
> this.storeEngine.getStoreFileManager().addCompactionResults(compactedFiles,
> result);
> - synchronized (filesCompacting) {
> - filesCompacting.removeAll(compactedFiles);
> - }
> -
> - // These may be null when the RS is shutting down. The space quota
> Chores will fix the Region
> - // sizes later so it's not super-critical if we miss these.
> - RegionServerServices rsServices = region.getRegionServerServices();
> - if (rsServices != null &&
> rsServices.getRegionServerSpaceQuotaManager() != null) {
> - updateSpaceQuotaAfterFileReplacement(
> -
> rsServices.getRegionServerSpaceQuotaManager().getRegionSizeStore(),
> getRegionInfo(),
> - compactedFiles, result);
> - }
> - } finally {
> - this.lock.writeLock().unlock();
> + @RestrictedApi(explanation = "Should only be called in TestHStore", link =
> "",
> + allowedOnPath = ".*/(HStore|TestHStore).java")
> + void replaceStoreFiles(Collection<HStoreFile> compactedFiles,
> Collection<HStoreFile> result,
> + boolean writeCompactionMarker) throws IOException {
> + storeEngine.replaceStoreFiles(compactedFiles, result);
> + if (writeCompactionMarker) {
> + writeCompactionWalRecord(compactedFiles, result);
> + }
> + synchronized (filesCompacting) {
> + filesCompacting.removeAll(compactedFiles);
> + }
> + // These may be null when the RS is shutting down. The space quota
> Chores will fix the Region
> + // sizes later so it's not super-critical if we miss these.
> + RegionServerServices rsServices = region.getRegionServerServices();
> + if (rsServices != null && rsServices.getRegionServerSpaceQuotaManager()
> != null) {
> + updateSpaceQuotaAfterFileReplacement(
> + rsServices.getRegionServerSpaceQuotaManager().getRegionSizeStore(),
> getRegionInfo(),
> + compactedFiles, result); {noformat}
> While running some large scale load test, we run into File SFT metafiles
> inconsistency that we believe could have been avoided if the original order
> was in place. Here the scenario we had:
> 1) Region R with one CF f was open on RS1. At this time, the given store had
> some files, let's say these were file1, file2 and file3;
> 2) Compaction started on RS1;
> 3) RS1 entered a long GC pause, lost ZK lock. Compaction is still running,
> though.
> 4) RS2 opens R. The related File SFT instance for this store then creates a
> new meta file with file1, file2 and file3.
> 5) Compaction on RS1 successfully completes the
> *storeEngine.replaceStoreFiles* call. This updates the in memory cache of
> valid files (StoreFileManager) and the SFT metafile for the store engine on
> RS1 with the compaction resulting file, say file4, removing file1, file2 and
> file3. Note that the SFT meta file used by RS1 here is different (older) than
> the one used by RS2.
> 6) Compaction on RS1 tries to update WAL marker, but fails to do so, as the
> WAL already got closed when the RS1 ZK lock expired. This triggers a store
> close in RS1. As part of the store close process, it removes all files it
> sees as completed compacted, in this case, file1, file2 and file3.
> 7) RS2 still references file1, file2 and file3. It then gets
> FileNotFoundException when trying to open any of these files.
> This situation would had been avoided if the original order of a) write WAL
> marker, then b) replace store files was kept.
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