The first thing I noticed is your script uses python threading library, which
is hampered by the Global Interpreter Lock
http://docs.python.org/2/library/threading.html
You don't really have multiple threads running in parallel, try using the
multiprocessor library.
Cheers
-
On Tue, 2013-02-05 at 21:38 +1300, aaron morton wrote:
The first thing I noticed is your script uses python threading library, which
is hampered by the Global Interpreter Lock
http://docs.python.org/2/library/threading.html
You don't really have multiple threads running in parallel, try
Made a d-test for easier reproduction and created
https://issues.apache.org/jira/browse/CASSANDRA-5223
On 1 February 2013 15:14, Alexei Bakanov russ...@gmail.com wrote:
Hi again,
Once started playing with CCM it's hard to stop, such a great tool.
My issue with secondary indexes is following:
The Datastax docs repeatedly say (e.g.
http://www.datastax.com/docs/1.2/install/install_jre) that Java 7 is not
recommended, but they don't say why. It would be helpful to know this. Does
anyone know?
The same documentation is referenced from the Cassandra wiki, for example,
There have been tons of threads/convos on this.
In the early days of Java 7 it was pretty unstable and there was pretty much no
convincing reason to use Java 7 over Java 6.
Now that Java 7 has stabilized and Java 6 is EOL it's a reasonable decision to
use Java 7 and we do it in production with
Our in-memory version has a slight different we just found out about that we
want to fix in the case where we are using UTF8 sorting and our column name
Is String.long.String. With our in-memory, two different longs are sometimes
generating the same string causing a clash and overwriting a
The comparator should be defined in the UTF8Type class.
On Tue, Feb 5, 2013 at 10:46 AM, Hiller, Dean dean.hil...@nrel.gov wrote:
Our in-memory version has a slight different we just found out about that we
want to fix in the case where we are using UTF8 sorting and our column name
Is
As I understand the num_tokens setting, it makes Cassandra do the following
pseudocode when a new node is added:
for 1...num_tokens do
my_token = rand(0, 2^128-1)
next_token = min(tokens in cluster where token my_token)
my_range = (my_token, next_token - 1)
done
Now the new node owns
Thanks, I misread the code Šgot it now.
Thanks,
Dean
On 2/5/13 9:22 AM, Edward Capriolo edlinuxg...@gmail.com wrote:
The comparator should be defined in the UTF8Type class.
On Tue, Feb 5, 2013 at 10:46 AM, Hiller, Dean dean.hil...@nrel.gov
wrote:
Our in-memory version has a slight different
The simple thing to do would be use the multiprocessing package and eliminate
all shared state.
On a multicore box python threads can run on different cores and battle over
obtaining the GIL.
Cheers
-
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
Thanks, I will use the multiprocessing package, since I need to scale it to
multiple nodes.
I will also try to optimize the function calls and use global variables.
Thank you very much for your help.
On Tue, Feb 5, 2013 at 9:12 AM, aaron morton aa...@thelastpickle.comwrote:
The simple thing
Hi,
I am trying to read fields using pycassa api. But seems like I am missing
something and not getting expected results.
pool = pycassa.ConnectionPool('usertable', server_list=['1.1.1.1'])
cf = pycassa.ColumnFamily(pool, 'data')
cf.get('7573657232323132333035343936323937363138343433')
Hey Guys,
Are there any specific operational considerations one should make when using
counter columns families? How are counter column families stored on disk? How
do they effect compaction?
-- Drew
Without stating the obvious, if you are interested in scale, then why
pick python?. I did want to point out that YCSB is not even the gold
standard for benchmarks using cassandra's stress you can get more ops
per sec then YCSB.
On Tue, Feb 5, 2013 at 1:13 PM, Pradeep Kumar Mantha
I answered this here:
https://groups.google.com/forum/?fromgroups=#!topic/pycassa-discuss/9-GzSPEJqPU
You may want to check your subscription to the pycassa mailing list; it
seems like you're not getting my responses for some reason.
On Tue, Feb 5, 2013 at 12:20 PM, Pradeep Kumar Mantha
So I have three nodes in a ring in one data center. My configuration has
num_tokens: 256 set and initial_token commented out. When I look at the ring,
it shows me all of the token ranges of course, and basically identical data for
each range on each node. Here is the Cliff's Notes version of
Hi Tyler,
Thanks, I didn't get your response regarding this post on pycassa group. I
will check my subscription.
thanks
pradeep
On Tue, Feb 5, 2013 at 11:23 AM, Tyler Hobbs ty...@datastax.com wrote:
I answered this here:
I tried to run with tracing, but it says 'Scanned 0 rows and matched 0'.
I found existing issue on this bug
https://issues.apache.org/jira/browse/CASSANDRA-4973
I made a d-test for reproducing it and attached to the ticket.
Alexei
On 2 February 2013 23:00, aaron morton aa...@thelastpickle.com
Are there any specific operational considerations one should make when using
counter columns families?
Performance, as they incur a read and a write.
There were some issues with overcounts in log replay (see the changes.txt).
How are counter column families stored on disk?
Same as
Use nodetool status with vnodes
http://www.datastax.com/dev/blog/upgrading-an-existing-cluster-to-vnodes
The different load can be caused by rack affinity, are all the nodes in the
same rack ? Another simple check is have you created some very big rows?
Cheers
-
Aaron Morton
With N nodes, the ring is divided into N*num_tokens. Correct?
There is always num_tokens tokens in the ring.
Each node has (num_tokens / N) * RF ranges on it.
so the ranges of keys are not uniform, although with enough nodes in the
cluster there probably won't be any really large ranges.
On Tue, Feb 5, 2013 at 12:42 PM, aaron morton aa...@thelastpickle.comwrote:
With N nodes, the ring is divided into N*num_tokens. Correct?
There is always num_tokens tokens in the ring.
Each node has (num_tokens / N) * RF ranges on it.
That means every node should have the same num_token
Also, what is particular reason to use Oracle JDK over Open JDK? Sorry, I
could not find this information online.
Thanks,
Ilya
From: Michael Kjellman [mailto:mkjell...@barracuda.com]
Sent: Tuesday, February 05, 2013 7:29 AM
To: user@cassandra.apache.org
Subject: Re: Why do Datastax docs
Thanks Aaron, so will there only be one value for each counter column per
sstable just like regular columns? For some reason I was under the impression
that Cassandra keeps a log of all the increments not the actual value.
On Feb 5, 2013, at 12:36 PM, aaron morton aa...@thelastpickle.com
There is always num_tokens tokens in the ring.
I got this wrong.
Each node *does* have num_tokens tokens.
With N nodes, the ring is divided into N*num_tokens. Correct?
Yes
In other words it is cluster wide parameter. Correct?
Yes.
Cheers
-
Aaron Morton
Freelance
On Tue, Feb 5, 2013 at 4:19 PM, aaron morton aa...@thelastpickle.com wrote:
There is always num_tokens tokens in the ring.
I got this wrong.
Each node *does* have num_tokens tokens.
With N nodes, the ring is divided into N*num_tokens. Correct?
Yes
In other words it is cluster wide
Oracle now owns the sun hotspot team, which is inarguably the highest powered
java vm team in the world. Its still really the epicenter of all java vm
development.
Sent from my Verizon Wireless BlackBerry
-Original Message-
From: Ilya Grebnov i...@metricshub.com
Date: Tue, 5 Feb 2013
Hi,
We found this issue is specific to 1.0.1 through 1.0.8, which was fixed
at 1.0.9.
https://issues.apache.org/jira/browse/CASSANDRA-4023
So by upgrading, we will see a reasonable performnace no matter how
large row we have!
Thanks,
Takenori
(2013/02/05 2:29), aaron morton wrote:
Yes,
Hi - We are designing a Cassandra based storage for the following use cases-
*Store SMS messages
*Store MMS messages
*Store Chat history
What would be the ideal was to design the data model for this kind of
application ? I am thinking on these lines ..
Row-Key :
Hello,
Composite keys are always good and model looks clean to me. Run pilot with
around 10 GB or more data and compare it with RDBMS and make changes
accordingly.
Thanks and Regards
Rishabh Agrawal
From: Kanwar Sangha [mailto:kan...@mavenir.com]
Sent: Wednesday, February 06, 2013 7:10 AM
Avoid super columns. If you need Sorted, wide rows then go for Composite
columns.
-Vivek
On Wed, Feb 6, 2013 at 7:09 AM, Kanwar Sangha kan...@mavenir.com wrote:
Hi – We are designing a Cassandra based storage for the following use
cases-
** **
**·**Store SMS messages
Hi!
I have couple of questions regarding your model:
1. What Cassandra version are you using? I am still working with 1.0 and
this seems to make sense, but 1.2 gives you much more power I think.
2. Maybe I don't understand your model, but I think you need
DynamicComposite columns, as user
I would prefer Oracle to own an Azul's Zing JVM over any other (GC) to provide
it for free for anyone :)
Best regards / Pagarbiai
Viktor Jevdokimov
Senior Developer
Email: viktor.jevdoki...@adform.commailto:viktor.jevdoki...@adform.com
Phone: +370 5 212 3063, Fax +370 5 261 0453
J. Jasinskio
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