incubator-cassandra-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From William Katsak <wkat...@cs.rutgers.edu>
Subject Re: Write Timestamps
Date Thu, 25 Oct 2012 15:43:31 GMT
I was using Thrift...I discovered it while debugging a replica placement 
scheme. I originally thought that my code was at fault, but then tried 
it with the regular NetworkTopologyStrategy and saw the same thing.

However, I have now tried with 1.1.6 and everything seems to work fine 
now. There must have been some bug that managed to make into the 1.1.5 
release.

Thanks,
Bill


On 10/24/2012 10:13 PM, Jeremiah Jordan wrote:
> How are you doing the write?  CQL or Thrift?  In thrift, the client specifies the timestamp,
and you should always be seeing that as the timestamp.  In CQL, the CQL layer on the server
adds the timestamp.  I am less familiar with the CQL code, maybe something screwy is going
on there.  1.1.6 is out, do you see the same behavior there?
>
> -Jeremiah
>
> On Oct 24, 2012, at 3:57 PM, William Katsak<wkatsak@cs.rutgers.edu>  wrote:
>
>> Here is what I am seeing on each replica node. This is after a write with consistencylevel=ALL.
>>
>> DEBUG [MutationStage:48] 2012-10-24 16:56:01,050 RowMutationVerbHandler.java (line
56) RowMutation(keyspace='normal', key='746573746b65793337', modifications=[ColumnFamily(data
[636f6c:false:3@1351112161048000,])]) applied.  Sending response to 770151@/172.16.18.112
>>
>> DEBUG [MutationStage:59] 2012-10-24 16:56:02,889 RowMutationVerbHandler.java (line
56) RowMutation(keyspace='normal', key='746573746b65793337', modifications=[ColumnFamily(data
[636f6c:false:3@1351112162785000,])]) applied.  Sending response to 770152@/172.16.18.112
>>
>> DEBUG [MutationStage:46] 2012-10-24 16:55:59,129 RowMutationVerbHandler.java (line
56) RowMutation(keyspace='normal', key='746573746b65793337', modifications=[ColumnFamily(data
[636f6c:false:3@1351112159127000,])]) applied.  Sending response to 770153@/172.16.18.112
>>
>> Now, if I do a read of this data, I will always see a digest failure the first time.
>>
>> Thanks,
>> Bill
>>
>>
>> On 10/24/2012 04:09 PM, Jonathan Ellis wrote:
>>> Timestamps are part of the ColumnFamily objects and their Columns,
>>> contained in the RowMutation.
>>>
>>> On Wed, Oct 24, 2012 at 2:57 PM, William Katsak<wkatsak@cs.rutgers.edu>
  wrote:
>>>> Hello,
>>>>
>>>> I sent this message a few days ago, but it seems to have gotten lost (I
>>>> don't see it on the archive), so I am trying again.
>>>>
>>>> -----
>>>>
>>>> I am using Cassandra for some academic-type work that involves some hacking
>>>> of replica placement, etc. and I am observing a strange behavior (well,
>>>> strange to me).
>>>>
>>>> Using the stock 1.1.5 snapshot, when you do a write (even with
>>>> consistencylevel = ALL), it seems that all nodes will get the data with a
>>>> slightly different timestamp, and any read (even at ALL) with always have
a
>>>> digest failure on the first read (and subsequent reads until read repair
>>>> catches up).
>>>>
>>>> It would make sense to me that timestamps should be distributed with the
>>>> RowMutation, not set on each node independently.
>>>>
>>>> Is this the intended behavior? Is there a design reason for this that I
>>>> should be aware of?
>>>>
>>>> Thanks,
>>>> Bill Katsak
>>>

Mime
View raw message