> On June 30, 2014, 3:24 p.m., kturner wrote: > > server/tserver/src/main/java/org/apache/accumulo/tserver/log/TabletServerLogger.java, > > line 262 > > <https://reviews.apache.org/r/22658/diff/2/?file=619604#file619604line262> > > > > Maybe this is a problem in the existing code, but this change may make > > the problem worse. Calling beginUpdatingLogsUsed() updates the tablets in > > memory data structs to indicate the tablet is using the log. If the code > > after this point fails, then all tablets will think the walog is in the > > metadata table even though it is not. > > > > > > Jonathan Park wrote: > I guess you're suggesting that if we failed for whatever reason while > holding the lock, our changes shouldn't be published outside of the lock > (since all readers of the wal in memory structs also lock). > > I think we could either implement some kind of rollback or convince > ourselves that it's harmless (or implement it so that it is harmless). I'll > give this some thought.
Maybe the tablet data structs should be updated in finishUpdatingLogsUsed() after the metadata updates are made successfully. Then have to consider the case where walog ref ends up in metadata table but not in tablet data structs. Seems like this case is easier to prevent and should it occur it seems innocuous. - kturner ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/22658/#review46980 ----------------------------------------------------------- On June 27, 2014, 5:41 p.m., Jonathan Park wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/22658/ > ----------------------------------------------------------- > > (Updated June 27, 2014, 5:41 p.m.) > > > Review request for accumulo. > > > Bugs: ACCUMULO-2889 > https://issues.apache.org/jira/browse/ACCUMULO-2889 > > > Repository: accumulo > > > Description > ------- > > Added additional methods to the Writer class to handle batching. > > Potential risks are that we're now holding onto the locks for a bit longer > than we used to. All tablets present in a batch will have their logLock's > locked until the batch is complete. > > > Diffs > ----- > > core/src/main/java/org/apache/accumulo/core/client/impl/Writer.java d6762e7 > > server/base/src/main/java/org/apache/accumulo/server/util/InternalBatchWriter.java > PRE-CREATION > > server/base/src/main/java/org/apache/accumulo/server/util/MetadataTableUtil.java > 374017d > server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java > 36b2289 > server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java > 57415bd > > server/tserver/src/main/java/org/apache/accumulo/tserver/log/TabletServerLogger.java > d25ee75 > > test/src/test/java/org/apache/accumulo/server/util/InternalBatchWriterIT.java > PRE-CREATION > test/src/test/java/org/apache/accumulo/test/BatchMetadataUpdatesIT.java > PRE-CREATION > > Diff: https://reviews.apache.org/r/22658/diff/ > > > Testing > ------- > > Added a new IT. > > We insert a few entries to tablets and ensure that the relevant entries > appear in the WAL and Metadata Table. > One test case that isn't included yet is verifying that root + metadata table > entries are entered correctly. > > > Thanks, > > Jonathan Park > >
