What will be the latency for the zk based atomic increase?
On Tue, Apr 6, 2010 at 8:22 PM, Chris Goffinet goffi...@digg.com wrote:
http://issues.apache.org/jira/browse/CASSANDRA-704
http://issues.apache.org/jira/browse/CASSANDRA-721
We have our own internal codebase of Cassandra at Digg. But
You would have a Column Family, not a column for that; let's call it
the Users CF. You'd use username as the row key and have a column
called 'password'. For your example query, you'd retrieve row key
'usr2', column 'password'. The general pattern is that you create CFs
to act as indices for
Benjamin I quite agree to you, but what in case of duplicate usernames,
suppose if I am not using unique names as in email id's . If we have
duplicacy in usernames we cannot use it for key, so what should be the
solution. I think keeping incremental numeric id as key and keeping the name
and value
Hi
I've been thinking of using cassandra for our existing application, which
has a very complex RDBMS schema as of now, and we need to make a lot of
queries using joins and where.
Whereas we can eliminate joins by using duplicate entries, its still hard to
query cassandra. I have thought of a way
Dop
You can help us all by sharing your experiences here, so that new users dont
face the same problem :
A group to bring all HA force together (help the effort)
http://www.facebook.com/groups/edit.php?edit_membersgid=116428271708033#!/group.php?gid=116428271708033
On Sat, Apr 10, 2010 at 8:19
Sorry, I don't understand your example.
On Sun, Apr 11, 2010 at 12:54 AM, Lucifer Dignified
vineetdan...@gmail.com wrote:
Benjamin I quite agree to you, but what in case of duplicate usernames,
suppose if I am not using unique names as in email id's . If we have
duplicacy in usernames we
Hi Benjamin
I'll try to make it more clear to you.
We have a user table with fields 'id', 'username', and 'password'. Now if
use the ideal way to store key/value, like :
username : vineetdaniel
timestamp
password : password
timestamp
second user :
username: seconduser
timestamp
On 11 April 2010 07:59, Lucifer Dignified vineetdan...@gmail.com wrote:
For a very simple query wherin we need to check username and password I
think keeping incremental numeric id as key and keeping the name and value
same in the column family should work.
It is highly unlikely that your
Can we not implement counts by just storing all the deltas in a row, and
then summing them all up to acheive a count.
If a row ends up with too many deltas, a reader could just summarise the
deltas occasionally into a single value (in a way which avoids race
conditions, of course).
So you'd map
It was just an example to showcase how i want to implement it, and I have
even added that this entierly depends upon what you want and what the
scenario is, i'm thinking of using this for articles that we are storing,
and the number is big. thinking of making each values as column name itself.
How to handle same usernames. Otherwise seems fine to me.
On Sun, Apr 11, 2010 at 6:17 PM, Dop Sun su...@dopsun.com wrote:
Hi,
As far as I can see it, the Cassandra API currently supports criterias on:
Token – Key – Super Column Name (if applicable) - Column Names
I guess Token is
Ah, I see what you are doing. No, that won't work. The mistake you
are making is in thinking a CF is a table and that Cassandra is
storing columns. A CF is a namespace and Cassandra stores key/value
pairs, where the keys are the row keys and the values are maps:
'usr1': {'password':'foo',
A system that permits multiple people to have the same username has a
serious problem.
On Sun, Apr 11, 2010 at 6:12 AM, vineet daniel vineetdan...@gmail.com wrote:
How to handle same usernames. Otherwise seems fine to me.
On Sun, Apr 11, 2010 at 6:17 PM, Dop Sun su...@dopsun.com wrote:
Hi,
its not a problem its a scenario, which we need to handle. And all I am
trying to do is to achieve what is not there with API i.e a workaroud.
On Sun, Apr 11, 2010 at 11:06 PM, Benjamin Black b...@b3k.us wrote:
A system that permits multiple people to have the same username has a
serious
Benjamin is pointing out that you must be using the word username to
mean something different than he is using it.
BY DEFINITION usernames are unique in the most common use of the word.
So what do you really mean if not username?
On Sun, Apr 11, 2010 at 11:12 AM, vineet daniel
Well my initial idea is to use value as column name, keeping key as an
incremental integer. The discussion after each mail has drifted from this
point which I had made. Will put it again.
we want to store user information. We keep 1,2,3,4.so on as keys. AND
values as column names i.e rather
Why do you want to directly read column names as values, and what will
you put in the column values?
On Sun, Apr 11, 2010 at 11:37 AM, vineet daniel vineetdan...@gmail.com wrote:
Well my initial idea is to use value as column name, keeping key as an
incremental integer. The discussion after
I assume that using the key i can get the all the columns like an array. Now
i'd be using php to extract arraykey=value in that array, just want to
avoid that i.e i can directly print the column names. If you guys think its
not a good idea I can drop it, anyways m new to it and a lot of things
Just to be clear: do you understand we are saying you need to use
multiple CFs to achieve the goal, not a single one?
The Users CF would be indexed on a unique integer as you are saying
you intend. There is no point in having values as column names here,
other than making things incredibly
I am dropping the idea, dont want to irritate you guys more. I've got your
points.
On Mon, Apr 12, 2010 at 12:41 AM, Benjamin Black b...@b3k.us wrote:
Just to be clear: do you understand we are saying you need to use
multiple CFs to achieve the goal, not a single one?
The Users CF would be
On Sun, Apr 11, 2010 at 12:10 PM, vineet daniel vineetdan...@gmail.com wrote:
I assume that using the key i can get the all the columns like an array. Now
i'd be using php to extract arraykey=value in that array, just want to
avoid that i.e i can directly print the column names.
It doesn't
On Sun, Apr 11, 2010 at 3:30 AM, Mark Robson mar...@gmail.com wrote:
Can we not implement counts by just storing all the deltas in a row, and
then summing them all up to acheive a count.
If a row ends up with too many deltas, a reader could just summarise the
deltas occasionally into a single
Hello,
I would like to know if the following is indeed possible with Cassandra,
from my understanding of key column slices it is but I am just beggining
to get my head around Cassandra...
I have data that is two dimensional, time varying (think of a grid). At each
cell of this grid,I store a
I don't know whether I'm wrong or not (I'm also new to Cassandra). But looks
like we only can query a single Super Column at a single query since these
values are specified in the ColumnParent parameter. Which means that you
only can query a single week or month (as your super column).
From:
I have spent the last few days playing with Cassandra and I have attempted to
create a simple Java-Thrift-Cassandra Discussion Group Server (because the
world needs another one) to teach myself the data model and try everything out.
With all the great blog posts on cassandra out there, I am
On Fri, 2010-04-09 at 11:28 -0500, Jonathan Ellis wrote:
The jit on debian may take longer to warm up by default.
Also, the Debian package will pull in OpenJDK by default, but there is
nothing to stop you from using the Sun JVM (which I assume is what's in
use on the other machines). It is even
On Sat, 2010-04-10 at 10:49 +1200, Todd Nine wrote:
I want the data that is written from the different partitioned
processing nodes (our c# app servers) to be available in both data
centres. I'm assuming I would need an equal number of nodes at each
data centre, then use the RackAwareStrategy
http://wiki.apache.org/cassandra/FAQ#range_ghosts
On Sun, Apr 11, 2010 at 5:12 PM, Kevin Wiggen kwig...@xythos.com wrote:
I have spent the last few days playing with Cassandra and I have attempted
to create a simple Java-Thrift-Cassandra Discussion Group Server
(because the world needs
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