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From Sylvain Lebresne <sylv...@datastax.com>
Subject Re: Re: Request Timeout with Composite Columns and CQL3
Date Fri, 29 Jun 2012 07:23:37 GMT
On Thu, Jun 28, 2012 at 6:43 PM, Henning Kropp <Kropp@nurago.com> wrote:
> I would like to use the BulkOutputFormat so. Is it likely to cause the below
> exception? If so, why? Can it be fixed?

It could, and if that only happens when you use it, then there is a
good change this is
where there is a problem. But I'll admit I don't know the BulkOutputFormat well
enough to be definitive. Would you mind opening a ticket on
https://issues.apache.org/jira/browse/CASSANDRA will all those details ?

--
Sylvain

>
> regards
>
> ________________________________
> Am 26.06.2012 17:02 schrieb Sylvain Lebresne <sylvain@datastax.com>:
> On Tue, Jun 26, 2012 at 4:00 PM, Henning Kropp <Kropp@nurago.com> wrote:
>> Thanks for the reply. Should have thought about looking into the log files
>> sooner. An AssertionError happens at execution. I haven't figured out yet
>> why. Any input is very much appreciated:
>>
>> ERROR [ReadStage:1] 2012-06-26 15:49:54,481 AbstractCassandraDaemon.java
>> (line 134) Exception in thread Thread[ReadStage:1,5,main]
>> java.lang.AssertionError: Added column does not sort as the last column
>>        at
>> org.apache.cassandra.db.ArrayBackedSortedColumns.addColumn(ArrayBackedSortedColumns.java:130)
>>        at
>> org.apache.cassandra.db.AbstractColumnContainer.addColumn(AbstractColumnContainer.java:107)
>>        at
>> org.apache.cassandra.db.AbstractColumnContainer.addColumn(AbstractColumnContainer.java:102)
>>        at
>> org.apache.cassandra.db.filter.SliceQueryFilter.collectReducedColumns(SliceQueryFilter.java:141)
>>        at
>> org.apache.cassandra.db.filter.QueryFilter.collateColumns(QueryFilter.java:139)
>>        at
>> org.apache.cassandra.db.CollationController.collectAllData(CollationController.java:283)
>>        at
>> org.apache.cassandra.db.CollationController.getTopLevelColumns(CollationController.java:63)
>>        at
>> org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns(ColumnFamilyStore.java:1321)
>>        at
>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1183)
>>        at
>> org.apache.cassandra.db.ColumnFamilyStore.getColumnFamily(ColumnFamilyStore.java:1118)
>>        at org.apache.cassandra.db.Table.getRow(Table.java:374)
>>        at
>> org.apache.cassandra.db.SliceFromReadCommand.getRow(SliceFromReadCommand.java:69)
>>        at
>> org.apache.cassandra.service.StorageProxy$LocalReadRunnable.runMayThrow(StorageProxy.java:816)
>>        at
>> org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1250)
>>        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)
>
> Obviously that shouldn't happen. You didn't happen to change the
> comparator for the column family or something like that from the
> hector side?
> Are you able to reproduce from a blank DB?
>
> --
> Sylvain
>
>>
>>
>> BTW: I really would love to understand as of why the combined comparator
>> will not allow two ranges be specified for two key parts. Obviously I still
>> lack a profound understanding of cassandras architecture to have a clue.
>> And while client side filtering might seem like a valid option I am still
>> trying to get might head around a cassandra data model that would allow
>> this.
>>
>> best regards
>>
>> ________________________________________
>> Von: Sylvain Lebresne [sylvain@datastax.com]
>> Gesendet: Dienstag, 26. Juni 2012 10:21
>> Bis: user@cassandra.apache.org
>> Betreff: Re: Request Timeout with Composite Columns and CQL3
>>
>> On Mon, Jun 25, 2012 at 11:10 PM, Henning Kropp <Kropp@nurago.com> wrote:
>>> Hi,
>>>
>>> I am running into timeout issues using composite columns in cassandra
>>> 1.1.1
>>> and cql 3.
>>>
>>> My keyspace and table is defined as the following:
>>>
>>> create keyspace bn_logs
>>>     with strategy_options = [{replication_factor:1}]
>>>     and placement_strategy =
>>> 'org.apache.cassandra.locator.SimpleStrategy';
>>>
>>> CREATE TABLE logs (
>>>   id text,
>>>   ref text,
>>>   time bigint,
>>>   datum text,
>>>   PRIMARY KEY(id, ref, time)
>>> );
>>>
>>> I import some data to the table by using a combination of the thrift
>>> interface and the hector Composite.class by using its serialization as
>>> the
>>> column name:
>>>
>>> Column col = new Column(composite.serialize());
>>>
>>> This all seems to work fine until I try to execute the following query
>>> which
>>> leads to a request timeout:
>>>
>>> SELECT datum FROM logs WHERE id='861' and ref = 'raaf' and time > '3000';
>>
>> If it timeouts the likely reason is that this query selects more data
>> than the machine is able to fetch before the timeout. You can either
>> add a limit to the query, or increase the timeout.
>> If that doesn't seem to fix it, it might be worth checking the server
>> log to see if there isn't an error.
>>
>>> I really would like to figure out, why running this query on my laptop
>>> (single node, for development) will not finish. I also would like to know
>>> if
>>> the following query would actually work
>>>
>>> SELECT datum FROM logs WHERE id='861' and ref = 'raaf*' and time >
>>> '3000';
>>
>> It won't. You can perform the following query:
>>
>> SELECT datum FROM logs WHERE id='861' and ref = 'raaf';
>>
>> which will select every datum whose ref starts with 'raaf', but then
>> you cannot restrict
>> the time parameter, so you will get ref where the time is <= 3000. Of
>> course you can
>> always filter client side if that is an option.
>>
>>> or how else there is a way to define a range for the second component of
>>> the
>>> column key?
>>
>> As described above, you can define a range on the second component, but
>> then you
>> won't be able to restrict on the 3rd component.
>>
>>>
>>> Any thoughts?
>>>
>>> Thanks in advance and kind regards
>>> Henning
>>>

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