Re: Getting HexToBytes Error while reading from Cassandra

2012-02-18 Thread David Allsopp
Is this maybe related to CASSANDRA-2851 (make hexToBytes refuse invalid input?). hexToBytes() will throw exceptions if the input has an odd number of characters, or contains on-hex characters (or is null). On 16 February 2012 18:00, PJunk wrote: > > Hello, > > We are trying to read data from

Re: Cassandra x MySQL Sharded - Insert Comparison

2012-01-22 Thread David Allsopp
When I did some performance testing on Cassandra 0.7.6, I was getting 10,000 - 20,000 inserts per second on a *single *Cassandra node, on real hardware (a consumer desktop PC with 4 GB RAM). Cassandra has got substantially faster since then. I was inserting 1KB columns each on a new row, if I remem

Re: Storing (python) objects

2011-09-23 Thread David Allsopp
We have done exactly as you describe (nested dicts etc) - works fine as long as you are happy to read the whole lump of data, i.e. don't need to read at a finer granularity. This approach can also save a lot of storage space as you don't have the overhead of many small columns. Some folks also wri

Re: Queue suggestion in Cassandra

2011-09-19 Thread David Allsopp
I have had similar experiences. On the advice of the Cassandra team, I now maintain the queue itself in-memory, but persist the data items in Cassandra (one per row). When re-starting the system I pull data from Cassandra to re-construct the ordered queue in-memory. In some cases I write columns to

Re: NotFoundException thrown for get(), but not get_slice() with a column_names predicate

2011-07-28 Thread David Allsopp
On 28 July 2011 16:23, Sylvain Lebresne wrote: > To be honest, collecting the names that were missing in the first name > query and doing a new name query for those (if there is any) is so simple > that I think it is a bit dishonest to say that "it pushes work to the > clients". > > It seems simp

Re: NotFoundException thrown for get(), but not get_slice() with a column_names predicate

2011-07-28 Thread David Allsopp
ppens to exist between > start and end." It's valid for the answer to be "nothing." > > On Thu, Jul 28, 2011 at 6:55 AM, David Allsopp > wrote: > > If I try to retrieve a column that is not present, using get(), then I'll > > get a NotFoundExceptio

NotFoundException thrown for get(), but not get_slice() with a column_names predicate

2011-07-28 Thread David Allsopp
If I try to retrieve a column that is not present, using get(), then I'll get a NotFoundException. If (for efficiency's sake) I try to retrieve several named columns using get_slice, with a column_names predicate (i.e. a list of columns) then I won't get the exception if one of those columns is mi