> unless data was stored in incorrect order and I don't know if that is > possible through the API.. >
That's exactly what happens and that's why I say it's a bug. > > ii. I am also seeing some sporadic cases where a single column cas() > update is hitting this same issue (the bug you mentioned) as multiple > columns, do you see any reason for that happening? > That would be slightly weirder, but frankly that's almost surely due to https://issues.apache.org/jira/browse/CASSANDRA-5786 too. -- Sylvain > Thank you, > Soumava > > > On Mon, Jul 22, 2013 at 12:11 AM, Sylvain Lebresne > <sylv...@datastax.com>wrote: > >> This is a bug really: >> https://issues.apache.org/jira/browse/CASSANDRA-5786. >> >> This should get fixed in the next beta of 2.0, but if you really want to >> test CAS updates in the meantime, you'll have to provide the columns in >> (column family comparator) sorted order to the thrift cas() method. >> >> -- >> Sylvain >> >> >> On Sun, Jul 21, 2013 at 1:22 PM, Soumava Ghosh <soum...@cs.utexas.edu>wrote: >> >>> Hi, >>> >>> I'm taking a look at the Check and Set functionalities provided by the >>> cas() API provided by cassandra 2.0 (the code available on git). I'm >>> running a few tests on a small sized cluster (replication factor 3, >>> consistency level quorum) with a few clients. I've observed a lot of cases >>> seem to hit the TimedOutException while paxos is in progress. On inspection >>> of the server side logs the following stack was seen: >>> >>> ERROR [Thread-582] 2013-07-21 01:17:46,169 CassandraDaemon.java (line >>> 196) Exception in thread Thread[Thread-582,5,main] >>> java.lang.AssertionError: Added column does not sort as the last column >>> at >>> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:115) >>> at >>> org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:117) >>> at >>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:119) >>> at >>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:96) >>> at >>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:91) >>> at >>> org.apache.cassandra.service.paxos.Commit$CommitSerializer.deserialize(Commit.java:139) >>> at >>> org.apache.cassandra.service.paxos.Commit$CommitSerializer.deserialize(Commit.java:128) >>> at org.apache.cassandra.net.MessageIn.read(MessageIn.java:99) >>> at >>> org.apache.cassandra.net.IncomingTcpConnection.receiveMessage(IncomingTcpConnection.java:175) >>> at >>> org.apache.cassandra.net.IncomingTcpConnection.handleModernVersion(IncomingTcpConnection.java:135) >>> at >>> org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:82) >>> >>> I was updating multiple columns using the same cas() call, and looking >>> at the assert (code below) I added code to sort them before sending. >>> However, now I'm seeing the same issue *even with single column* cas() >>> calls. >>> >>> int c = >>> internalComparator().compare(columns.get(getColumnCount() - 1).name(), >>> column.name()); >>> // note that we want an assertion here (see addColumn javadoc), >>> but we also want that if >>> // assertion are disabled, addColumn works correctly with >>> unsorted input >>> assert c <= 0 : "Added column does not sort as the " + (reversed >>> ? "first" : "last") + " column"; >>> >>> I have also seen this error occur in the getRow() path, as below: >>> >>> java.lang.AssertionError: Added column does not sort as the last column >>> at >>> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:115) >>> at >>> org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:117) >>> at >>> org.apache.cassandra.db.ColumnFamily.addAtom(ColumnFamily.java:151) >>> at >>> org.apache.cassandra.db.CollationController.collectTimeOrderedData(CollationController.java:95) >>> at >>> org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:57) >>> at >>> org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1452) >>> at >>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1281) >>> at >>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1195) >>> at org.apache.cassandra.db.Table.getRow(Table.java:331) >>> at >>> org.apache.cassandra.db.SliceByNamesReadCommand.getRow(SliceByNamesReadCommand.java:55) >>> at >>> org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:1288) >>> at >>> org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1813) >>> at >>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) >>> at >>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) >>> at java.lang.Thread.run(Thread.java:722) >>> >>> Could someone provide me a little more clarity about what the context of >>> the error is and what the client needs to do to fix it? I understand that >>> running with assertions disabled would do away with this error, but i'd >>> like to know if there is a proper way to fix this. Moreover, what could >>> possibly be going wrong in the get path that is hitting this issue? >>> >>> Some guidance, on the fact that whether it is expected that the client >>> sort the columns before calling the API with multiple columns, would be >>> really appreciated. >>> >>> Thanks, >>> Soumava >>> >> >> >
