have you put your commit log on a disk by itself? not a logical
partition shared by oracle or cassandra "data". this will make a
difference, as you don't want the cassandra commit logs competing with
other OS and oracle I/O. look in storage-conf.xml and see if you can
move this.
also check "MemtableThroughputInMB". if you are doing a _lot_ of writes
you probably want to jack this up a bunch to get through the migration,
then put it back down for normal operation. the default out of the box
is too low i believe.
On 05/10/2010 02:05 AM, David Boxenhorn wrote:
I read something like 80,000 rows from Oracle and write them to
Cassandra in chunks of 1000 rows - so I'm supposedly working to
Cassandra's strength and Oracle's weakness.
Reading 1000 rows from Oracle is "instantaneous", writing them takes
maybe 30 seconds. Not too much data per row, maybe 1K.
On Mon, May 10, 2010 at 11:48 AM, Ran Tavory <ran...@gmail.com
<mailto:ran...@gmail.com>> wrote:
Hector uses tsocket. not sure what you mean by "buffered" - is
that framed? Hector by default does not use framed.
The code is here if you'd like to have a look
http://github.com/rantav/hector/blob/master/src/main/java/me/prettyprint/cassandra/service/CassandraClientFactory.java#L77
However, I find it hard to believe that the actual connection is
the slowing factor.
Roughly speaking, cassandra is fast on writes and slow on reads.
Exact numbers are per-scenario so it's hard to say, but if you
only write and objects are small then from my experience you
should expect a few k writes per second on a single host. How much
do you see?
There are many configuration factors and they all depend on
expected usage and available h/w.
On Mon, May 10, 2010 at 11:27 AM, vd <vineetdan...@gmail.com
<mailto:vineetdan...@gmail.com>> wrote:
What is the complete code string you are using to connect with
cassandra from Java code
On Mon, May 10, 2010 at 1:49 PM, David Boxenhorn
<da...@lookin2.com <mailto:da...@lookin2.com>> wrote:
I don't know what "TSocket or the buffered one" means.
Maybe I should know?
I'm using Hector. Does that explain anything?
On Mon, May 10, 2010 at 11:15 AM, vd
<vineetdan...@gmail.com <mailto:vineetdan...@gmail.com>>
wrote:
Hi
what is it that you are using to connect with
cassnadra TSocket or the buffered one ?
____________________________________
_______________________________________
On Mon, May 10, 2010 at 1:29 PM, David Boxenhorn
<da...@lookin2.com <mailto:da...@lookin2.com>> wrote:
I'm running Java on the client, jdbc queries on
Oracle, Hector on Cassandra.
The Cassandra and Oracle database designs are
radically different, as you might guess.
I have no doubt that Cassandra can be tuned, in a
multiple-server cluster, to have superior
throughput (that's why I'm doing it!). But for
now, it's really frustrating my development effort
that Cassandra is so slow. Can't I get it up to
twice as slow as Oracle in my configuration?
On Mon, May 10, 2010 at 10:47 AM, vd
<vineetdan...@gmail.com
<mailto:vineetdan...@gmail.com>> wrote:
Hi David
If I may ask...how do you plan to import data
from oracle to cassandra ?
As answer AFAIK cassandra's true ability comes
into play when running on more than one
machine...and please share how you are making
comparisons like on writes or reads from
cassandra.
_______________________________________
_______________________________________
On Mon, May 10, 2010 at 1:04 PM, David
Boxenhorn <da...@lookin2.com
<mailto:da...@lookin2.com>> wrote:
I'm running Oracle and Cassandra on my
machine, trying to import my data to
Cassandra from Oracle.
In my configuration Oracle is about ten
times faster than Cassandra. Cassandra has
out-of-the-box tuning.
I am new to Cassandra. How do I begin
trying to tune it?
Thanks.
