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https://issues.apache.org/jira/browse/CASSANDRA-11443?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15222759#comment-15222759
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Erick Ramirez commented on CASSANDRA-11443:
-------------------------------------------
I am just a little overloaded at the moment but I will write up a test for
this. I believe it's a simple case of:
- create a table with a clustering column
- insert data and flush to disk
- alter the table to change the clustering order
- insert data and flush to disk
- force compaction
> Prevent (or warn) changing clustering order with ALTER TABLE when data
> already exists
> -------------------------------------------------------------------------------------
>
> Key: CASSANDRA-11443
> URL: https://issues.apache.org/jira/browse/CASSANDRA-11443
> Project: Cassandra
> Issue Type: Improvement
> Components: Compaction, CQL
> Reporter: Erick Ramirez
> Fix For: 2.1.x, 2.2.x, 3.0.x
>
>
> Inexperienced DBAs get caught out on certain schema changes thinking that
> Cassandra will automatically retrofit/convert the existing data on disk.
> We should prevent users from changing the clustering order on existing tables
> or they will run into compaction/read issues such as (example from Cassandra
> 2.0.14):
> {noformat}
> ERROR [CompactionExecutor:6488] 2015-07-14 19:33:14,247 CassandraDaemon.java
> (line 258) Exception in thread Thread[CompactionExecutor:6488,1,main]
> java.lang.AssertionError: Added column does not sort as the last column
> at
> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:116)
>
> at org.apache.cassandra.db.ColumnFamily.addColumn(ColumnFamily.java:121)
> at org.apache.cassandra.db.ColumnFamily.addAtom(ColumnFamily.java:155)
> at
> org.apache.cassandra.io.sstable.SSTableIdentityIterator.getColumnFamilyWithColumns(SSTableIdentityIterator.java:186)
>
> at
> org.apache.cassandra.db.compaction.PrecompactedRow.merge(PrecompactedRow.java:98)
>
> at
> org.apache.cassandra.db.compaction.PrecompactedRow.<init>(PrecompactedRow.java:85)
>
> at
> org.apache.cassandra.db.compaction.CompactionController.getCompactedRow(CompactionController.java:196)
>
> at
> org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:74)
>
> at
> org.apache.cassandra.db.compaction.CompactionIterable$Reducer.getReduced(CompactionIterable.java:55)
>
> at
> org.apache.cassandra.utils.MergeIterator$ManyToOne.consume(MergeIterator.java:115)
>
> at
> org.apache.cassandra.utils.MergeIterator$ManyToOne.computeNext(MergeIterator.java:98)
>
> at
> com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
>
> at
> com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
> at
> org.apache.cassandra.db.compaction.CompactionTask.runMayThrow(CompactionTask.java:164)
>
> at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
> at
> org.apache.cassandra.db.compaction.CompactionTask.executeInternal(CompactionTask.java:60)
>
> at
> org.apache.cassandra.db.compaction.AbstractCompactionTask.execute(AbstractCompactionTask.java:59)
>
> at
> org.apache.cassandra.db.compaction.CompactionManager$BackgroundCompactionTask.run(CompactionManager.java:198)
>
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
>
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>
> at java.lang.Thread.run(Thread.java:745)
> {noformat}
> At the very least, we should report a warning advising users about possible
> problems when changing the clustering order if the table is not empty.
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