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From kannan chandrasekaran <>
Subject Re: Few questions regarding cassandra deployment on windows
Date Wed, 08 Sep 2010 00:20:05 GMT
Can you please elaborate on why you think Cassandra would not be suitable for 
this ?

Main reasons why we think  cassandra because,
1) We are on focusing on moving to a distributed architecture very soon and 
using cassandra as a backend naturally lends to this.
2) Our schema is relatively simple and we wanted quick read and write access. 
Cassandra response times were faster than Mysql and we expect it to satisfy our 
requirements ( without the need for a cache layer).
3) I believe with 0.7's live schema updates, the need for changing the xml files 
and restarting the service would go away. so I believe usecase2 is only 
difficult in the 0.6 versions... 

I am more interested in knowing if we can start/run/stop  cassandra as a 
embedded service within a jvm


From: Benjamin Black <>
Sent: Tue, September 7, 2010 4:38:41 PM
Subject: Re: Few questions regarding cassandra deployment on windows

This does not sound like a good application for Cassandra at all.  Why
are you using it?

On Tue, Sep 7, 2010 at 3:42 PM, kannan chandrasekaran
<> wrote:
> Hi All,
> We are currently considering Cassandra for our application.
> Platform:
> * a single-node cluster.
> * windows '08
> * 64-bit jvm
> For the sake of brevity let,
> Cassandra service =  a single node cassandra server running as an embedded
> service inside a JVM
> My use cases:
> 1) Start with a schema ( keyspace and set of column families under it) in a
> cassandra service
> 2) Need to be able to replicate the same schema structure (add new
> keyspace/columnfamilies with different names ofcourse).
> 3) Because of some existing limitations in my application, I need to be able
> to write to the keyspace/column-families from a cassandra service and read
> the written changes from a different cassandra service. Both the write and
> the read "cassandra-services" are sharing the same Data directory. I
> understand that the application has to take care of any naming collisions.
> Couple Questions related to the above mentioned usecases:
> 1) I want to spawn a new JVM and launch Cassandra as an embedded service
> programatically instead of using the startup.bat. I would like to know if
> that is possible and any pointers in that direction would be really helpful.
> ( use-case1)
> 2) I understand that there are provisions for live schema changes in 0.7 (
> thank you guys !!!), but since I cant use a beta version in production, I am
> restricted to 0.6 for now. Is it possible to to support use-case 2 in 0.6.5
> ? More specifically, I am planning to make runtime changes to the
> storage.conf xml file followed by a cassandra service restart
> 3) Can I switch the data directory at run-time ?  (use-case 3). In order to
> not disrupt read while the writes are in progress, I am thinking something
> like, copy the existing data-dir into a new location; write to a new data
> directory; once the write is complete; switch pointers and restart the
> cassandra service to read from the new directory to pick up the updated
> changes
> Any help is greatly appreciated.
> Thanks
> Kannan

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