First thing to do would be to update to 0.7.5. The assertionError you're running into is a assertion where we check if a skipBytes did skip all the bytes we had ask him to. As it turns out, the spec for skipBytes authorize it to not skip all the bytes asked even with no good reason. I'm pretty sure on a linux box skipBytes on a file will always read the number of asked bytes unless it reaches EOF, but I see you're running windows, so who knows what can happen.
Anyway, long story short, it's a "bug" in 0.7.4 that has been fixed in 0.7.5. If you still run into this in 0.7.5 at least we'll know it's something else (and we will have a more helpful error message). -- Sylvain On Tue, May 17, 2011 at 12:41 PM, Desimpel, Ignace <ignace.desim...@nuance.com> wrote: > I use a custom comparator class. So I think there is a high chance that I do > something wrong there. I was thinking that the stack trace could give a clue > and help me on the way, maybe because some already got the same error. > > > > Anyway, here is some more information you requested. > > > > Yaml definition : > > name: ForwardStringValues > > column_type: Super > > compare_with: > be.landc.services.search.server.db.cassandra.node.ForwardCFStringValues > > compare_subcolumns_with: BytesType > > keys_cached: 100000 > > rows_cached: 0 > > comment: Stores the values of functions returning string > > memtable_throughput_in_mb: 64 > > memtable_operations_in_millions: 15 > > min_compaction_threshold: 2 > > max_compaction_threshold: 5 > > > > Column Family: ForwardStringValues > > SSTable count: 8 > > Space used (live): 131311776690 > > Space used (total): 131311776690 > > Memtable Columns Count: 0 > > Memtable Data Size: 0 > > Memtable Switch Count: 0 > > Read Count: 1 > > Read Latency: 404.890 ms. > > Write Count: 0 > > Write Latency: NaN ms. > > Pending Tasks: 0 > > Key cache capacity: 100000 > > Key cache size: 8 > > Key cache hit rate: 1.0 > > Row cache: disabled > > Compacted row minimum size: 150 > > Compacted row maximum size: 7152383774 > > Compacted row mean size: 3064535 > > > > No secondary indexes. > > Total database disk size 823 Gb > > disk_access_mode: auto on 64 bit windows os > > partitioner: org.apache.cassandra.dht.ByteOrderedPartitioner > > Data was stored over a period of 5 days. > > Cassandra 0.7.4 was running as an embedded server. > > Batch insert, using the StorageProxy.mutate. > > No errors were logged during the batch insert period. > > The row key is a string representation of a positive integer value. > > The same row key is used during many different mutate calls, but all super > column names are different for each call. > > The column name of the super class stored is composed of the 32 bytes and > the bytes of 2 integer (positive and negative) values and the bytes (UTF8) > of the string value :[32 bytes][4 int bytes][4 int bytes][string bytes] > > The custom comparator class ...ForwardCFStringValues sorts the names by > first sorting the string , then the 32 bytes, and then the two integer > values > > For each column name two subcolumns are inserted with fixed name and some > small binary value (about 40 bytes) > > > > The query : > > Get_slice using thrift. > > Params : > > Row key : the string representation of the positive integer String ‘1788’ > thus hex values 31 37 38 38 > > ColumnParent : the column family ForwardStringValues > > SlicePredicate : SlicePredicate(slice_range:SliceRange(start:00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 FF FF FF FF FF FF FF FF 55 52 49 4E 41 52 59 20 54 52 41 43 54 20 > 49 4E 46 45 43 54 49 4F 4E, finish:7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F > 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F 7F FF FF FF 7F FF FF FF > 7F 55 52 49 4E 41 52 59 20 54 52 41 43 54 20 49 4E 46 45 43 54 49 4F 4E, > reversed:false, count:10000)) > > > > This SlicePredicate is supposed to fetch all the columns with the string ‘55 > 52 49 4E 41 52 59 20 54 52 41 43 54 20 49 4E 46 45 43 54 49 4F 4E’ > regardless of the other bytes in the column name. So the start and finish > have the same string bytes. The rest of the bytes for the start values are > set to the lowest possible value (32 zero bytes and the bytes FFFFFFFF > representing the integer value -1) , the finish is set the highest possible > value (32 bytes with value 7F, …) > > > > I tested the same code but with a small data set and all seemed to be OK. > Even on the same database I get back results without exception if I use > different String values. I’m almost sure that there should be columns with > that string. If the string is not present I don’t get the error. > > > > > > > > > > From: Aaron Morton [mailto:aa...@thelastpickle.com] > Sent: Monday, May 16, 2011 11:33 PM > To: user@cassandra.apache.org > Subject: Re: AssertionError > > > > The code is trying to follow the column index for a row in an sstable, but > it cannot skip as many bytes as it would like to to get to the column. > Helpfully the help says running out of bytes is only one of the reasons why > this could happen:) > > > > Can you provide some more information about the query and the data, and also > the upgrade history for your cluster. > > > > Thanks > > Aaron > > On 17/05/2011, at 3:07 AM, "Desimpel, Ignace" <ignace.desim...@nuance.com> > wrote: > > Environment : java 64 bit server, java client, thrift get_slice method, > Cassandra 0.7.4, single node > > Depending on the data I pass for a query on a CF I get the following listed > below. Any suggestions what could be wrong based on the stack trace? > > > > java.lang.AssertionError > > at > org.apache.cassandra.db.columniterator.IndexedSliceReader$IndexedBlockFetcher.getNextBlock(IndexedSliceReader.java:176) > > at > org.apache.cassandra.db.columniterator.IndexedSliceReader.computeNext(IndexedSliceReader.java:120) > > at > org.apache.cassandra.db.columniterator.IndexedSliceReader.computeNext(IndexedSliceReader.java:48) > > at > com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:136) > > at > com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:131) > > at > org.apache.cassandra.db.columniterator.SSTableSliceIterator.hasNext(SSTableSliceIterator.java:108) > > at > org.apache.commons.collections.iterators.CollatingIterator.set(CollatingIterator.java:282) > > at > org.apache.commons.collections.iterators.CollatingIterator.least(CollatingIterator.java:325) > > at > org.apache.commons.collections.iterators.CollatingIterator.next(CollatingIterator.java:229) > > at > org.apache.cassandra.utils.ReducingIterator.computeNext(ReducingIterator.java:68) > > at > com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:136) > > at > com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:131) > > at > org.apache.cassandra.db.filter.SliceQueryFilter.collectReducedColumns(SliceQueryFilter.java:116) > > at > org.apache.cassandra.db.filter.QueryFilter.collectCollatedColumns(QueryFilter.java:130) > > at > org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1368) > > at > org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1245) > > at > org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1173) > > at org.apache.cassandra.db.Table.getRow(Table.java:333) > > at > org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:63) > > at > org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:453) > > at > org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:30) > > at > java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) > > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) > > at java.lang.Thread.run(Thread.java:662) > > > > Ignace Desimpel
