On Mon, Nov 22, 2010 at 2:39 PM, Edward Capriolo wrote:
> @Todd. Good catch about caching HFile blocks.
>
> My point still applies though. Caching HFIle blocks on a single node
> vs individual "dataums" on N nodes may not be more efficient. Thus
> terms like "Slower" and "Less Efficient" could be
Seems accurate to me. One small correction - the daemon in HBase that serves
regions is known as a "region server" rather than a region master. The RS is
the equivalent of the tablet server in Bigtable terminology.
-Todd
On Mon, Nov 22, 2010 at 4:50 PM, David Jeske wrote:
> This is my second at
On Mon, Nov 22, 2010 at 1:58 PM, David Jeske wrote:
> On Mon, Nov 22, 2010 at 11:52 AM, Todd Lipcon wrote:
>
>> Not quite. The replica synchronization code is pretty messy, but basically
>> it will take the longest replica that may have been synced, not a quorum.
>>
>
On Mon, Nov 22, 2010 at 1:26 PM, Edward Capriolo wrote:
> For cassandra all writes must be transmitted to all replicas.
> CASSANDRA-1314 does not change how writes happen. Write operations
> will still effect cache (possibly evicting things if cache is full).
> Reads however will prefer a single n
On Mon, Nov 22, 2010 at 12:03 PM, Edward Capriolo wrote:
> What of reads that are not in the cache?
> Cassandra can use memory mapped io for its data and index files. Hbase
> has a very expensive read path for things that are not in cache. HDFS
> random read performance is historically poor.
>
Ye
On Mon, Nov 22, 2010 at 10:01 AM, David Jeske wrote:
> I havn't used either Cassandra or hbase, so please don't take any part of
> this message as me attempting to state facts about either system. However,
> I'm very familiar with data-storage design details, and I've worked
> extensively optimiz
On Sun, Nov 21, 2010 at 6:25 PM, Jonathan Ellis wrote:
> On Sun, Nov 21, 2010 at 6:16 PM, Todd Lipcon wrote:
> > [only jumping in because info was requested - those who know me know that
> I
> > think Cassandra is a very interesting architecture and a better fit for
> many
On Sun, Nov 21, 2010 at 2:06 PM, Edward Ribeiro wrote:
>
> Also I believe saying HBASE is consistent is not true. This can happen:
>> Write to region server. -> Region Server acknowledges client-> write
>> to WAL -> region server fails = write lost
>>
>> I wonder how facebook will reconcile that.
