I recommend starting with
http://www.rackspacecloud.com/blog/2010/05/12/cassandra-by-example/,
then reading the other Recommended articles at
http://wiki.apache.org/cassandra/ArticlesAndPresentations
On Fri, Aug 27, 2010 at 3:07 AM, Sean Bowman <pico...@gmail.com> wrote:
> Do I not want to get the key to be the UUID, so I can slice based on
> timestamp? If so, the only thing the insert statement takes is a String for
> a key. Why would I place the UUID into a column value? Doesn't it belong as
> the key if I want to be able to slice and sort on it?
>
> I guess I'm just completely confused about how Cassandra works. All I'm
> trying to do is record a history of what' going on in my app, and be able to
> pull it out in the order that it happens, similar to the comments example in
> the WTF? article. Am I going about this the wrong way?
>
> On Aug 27, 2010, at 1:51 AM, Benjamin Black wrote:
>
>> You are using the wrong part of the example. That code sample just
>> produces the string representation. Scroll down in that FAQ entry to
>> the sample labeled:
>>
>> "When you want to actually place the UUID into the Column then you'll
>> want to convert it like this. This method is often used in conjuntion
>> with the getTimeUUID() mentioned above."
>>
>>
>> b
>>
>> On Fri, Aug 27, 2010 at 12:28 AM, Sean Bowman <pico...@gmail.com> wrote:
>>> I'm at my wits end with Cassandra; is 0.6.4 just broken? I've created a
>>> very simple keyspace:
>>>
>>> <Keyspace Name="MyApp">
>>> <ColumnFamily Name="History" CompareWith="TimeUUIDType"/>
>>>
>>> Using the Thrift sample code for 0.6 on the wiki, and the FAQ about
>>> TimeUUID's and Java, I tried to generate a GUID using this method:
>>>
>>> String key = new com.eaio.uuid.UUID().toString()
>>>
>>> Since all the Thrift get and insert statements use Strings for the keys.
>>> But when I send one of these GUID's, I get:
>>>
>>> Exception in thread "main" InvalidRequestException(why:UUIDs must be
>>> exactly 16 bytes)
>>> at
>>> org.apache.cassandra.thrift.Cassandra$insert_result.read(Cassandra.java:12295)
>>> at
>>> org.apache.cassandra.thrift.Cassandra$Client.recv_insert(Cassandra.java:675)
>>> at
>>> org.apache.cassandra.thrift.Cassandra$Client.insert(Cassandra.java:648)
>>>
>>> I even tried something like:
>>>
>>> client.insert(keyspace, new String(asByteArray(getTimeUUID()), path,
>>> "Some value".getBytes("UTF-8"), timestamp, ConsistencyLevel.ONE);
>>>
>>> Can anyone point me in the direction of how I send a time-based UUID to
>>> Cassandra 0.6.4 through the Java Thrift client? Or am I missing the point
>>> of all of this somehow?
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
