Preventing an update of a CF row

Hi All, I have a query regarding the insert operation. The insert operation by default inserts an new row or updates an existing row. Is it possible to prevent an update but allow only inserts automatically ( especially when multiple clients are writing to cassandra)? I was wondering if ther

Re: Heap Settings suggestions

Good point.. Thanks to both of you for the replies. Kannan From: Matthew Dennis To: user@cassandra.apache.org Sent: Thu, October 7, 2010 4:59:28 PM Subject: Re: Heap Settings suggestions Keep in mind that .7 and on will have per-CF settings for most things s

Heap Settings suggestions

>From the Cassandra documentation @ riptano I see the following recommendation for Heap size setting MemtableThroughputInMB * 3 * (number of ColumnFamilies) + 1G + (size of internal caches) What if there is more than one keyspace in the system ? Assuming each keyspace has the same number of c

Re: Cassandra Cache Mbean values; bytes or number of elements ? and row count

assandra Cache Mbean values; bytes or number of elements ? elements. it gets the capacity from your configuration setting. cassandra knows how many rows you have, and you told it to cache all of them, so that's what it set capacity to. On Fri, Sep 17, 2010 at 8:58 PM, kannan chandrasekaran

Cassandra Cache Mbean values; bytes or number of elements ?

I am using 0.6.5 and my keycache for the CF is set as "100%" ... What do the values in the Mbean interfaces indicate ? bytes or number of elements ? Specifically, these are the numbers that I observe for one of the column family... capacity = 36826888 (if this is number of elements, how doe

Re: Couple of cache related questions

Thanks a lot Jonathan !!! Kannan From: Jonathan Ellis To: user@cassandra.apache.org Sent: Mon, September 13, 2010 4:47:05 PM Subject: Re: Couple of cache related questions On Sun, Sep 12, 2010 at 6:10 PM, kannan chandrasekaran wrote: >> 1) What dete

Re: Couple of cache related questions

Thanks for the replies Jonathan...Couple more clarifications(in bold) From: Jonathan Ellis To: user@cassandra.apache.org Sent: Sun, September 12, 2010 1:47:09 PM Subject: Re: Couple of cache related questions On Sun, Sep 12, 2010 at 2:56 PM, kannan

Couple of cache related questions

1) What determines the amount of memory used per schema ignoring the general overhead to get cassandra up and running? Is it just the size of the caches for the column Family + the memtable size ? 2) Is the size of the cache configured ( in terms of absolute numbers or percentages), an upper

Re: How to drop a keyspace in 0.6.5?

Thank you for the clarification...very helpful Kannan From: Rob Coli To: user@cassandra.apache.org Sent: Fri, September 10, 2010 12:55:14 PM Subject: Re: How to drop a keyspace in 0.6.5? On 9/10/10 10:10 AM, kannan chandrasekaran wrote: > Thank you for

Re: How to drop a keyspace in 0.6.5?

data files), you drop KS the same way. On Thu, Sep 9, 2010 at 10:31 PM, kannan chandrasekaran wrote: > Hi All, > > I understand that how to drop the column family from the a node using > http://wiki.apache.org/cassandra/FAQ#modify_cf_config . How can I drop an > entire Keyspace ? If I

How to drop a keyspace in 0.6.5?

Hi All, I understand that how to drop the column family from the a node using http://wiki.apache.org/cassandra/FAQ#modify_cf_config . How can I drop an entire Keyspace ? If I drop all the CF's in the Keyspace will the keyspace be automatically dropped ? Thanks Kannan

Re: Few questions regarding cassandra deployment on windows

Thanks for the replies My comments in Bold... Kannan From: Gary Dusbabek To: user@cassandra.apache.org Sent: Thu, September 9, 2010 5:43:31 AM Subject: Re: Few questions regarding cassandra deployment on windows On Tue, Sep 7, 2010 at 17:42, kannan chandrasekaran wrote: > Hi All, >

Re: Few questions regarding cassandra deployment on windows

he did it, so ... From: kannan chandrasekaran Sent: Wednesday, September 08, 2010 1:20 AM To: user@cassandra.apache.org Subject: Re: Few questions regarding cassandra deployment on windows Can you please elaborate on why you think Cassandra would not be suitable for this ? Main reasons wh

Re: Few questions regarding cassandra deployment on windows

: 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

Few questions regarding cassandra deployment on windows

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 sc