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:[email protected]]
Sent: Monday, May 16, 2011 11:33 PM
To: [email protected]
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" <[email protected]>
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
