Dear Cassandra Experts,
Are the number of composite attributes fixed for each column family ?
I have been doing : "create column family MyCF with comparator =
'CompositeType(IntegerType, UTF8Type)'
And this creates a composite { integer:string }
Hector complains when I give a 3rd attribute.
If
Let's say I have rows with composite columns Like
("key1", {('xyz', 'abc'): 'colval1'}, {('xyz', 'def'): 'colval2'})
("key2", {('ble', 'meh'): 'otherval'})
Is it possible to create a composite type index such that I can query on
'xyz'
and get the first two columns?
Thanks
Maxim
I have been playing around with Cassandra for a few months now. Starting to
explore more of the routine maintenance and backup strategies and I have a
general question about nodetool repair. After reading the following page:
http://www.datastax.com/docs/0.8/operations/cluster_management it has
occu
A node will only request data from other nodes on start up if it is
bootstrapping. Bootstrapping happens when there is no system data and the
auto_bootstrap: yaml config is set true, normally nodes only bootstrap once in
their life.
If you bring a node back for whatever reason you will want to
+1 use them if you can.
Also you can reverse the sort order on components in the type, that can make
some common queries faster.
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 21/12/2011, at 9:49 AM, Guy Incognito wrote:
> afaik composi
Hello,
5 nodes running 0.8.7/0.8.9, RF=3, BOP, counter columns inside super
columns. Read queries are multigetslices of super columns inside of which I
read every column for processing (20-30 at most), using Hector with default
settings.
Watching tpstat on the 3 nodes holding the data being most of
Thanks, that worked.
On Tue, Dec 20, 2011 at 4:08 PM, Dave Brosius wrote:
>
> KsDef ksDef = new KsDef();
> Map options = new HashMap();
> options.put("replication_factor", "2");
> ksDef.setStrategy_options(options);
>
>
>
> *- Original Message -*
> *From:* "A J"
> *Sent:* Tue, December 2
The following worked:
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CodingErrorAction;
.
public st
What happens with the data stored for that token range already in the
cluster? will the restarted node actualize it from any of the
replicas?
I readed in the maillist archives that in case of token collision, the
cluster may not work correctly. But if the restarted node takes always
ownership of i
KsDef ksDef = new KsDef();Map>;String, String;String, String
A ByteBuffer is not a byte[] to convert a String to a ByteBuffer do something
likepublic static ByteBuffer toByteBuffer(String value)
throws UnsupportedEncodingException
{
return ByteBuffer.wrap(value.getBytes("UTF-8"));
} see http://wiki.apache.org/cassandra/ThriftExamples --
I am new to java. Can you specify the exact syntax for replication_factor=2 ?
Thanks.
On Tue, Dec 20, 2011 at 1:50 PM, aaron morton wrote:
> It looks like you tried to pass the string "{replication_factor:2}"
>
> You need to pas a Map type , where the the key is the option
> and the value is the
On Tue, Dec 20, 2011 at 2:19 PM, Tyler Hobbs wrote:
> On Tue, Dec 20, 2011 at 1:49 PM, Feng Qu wrote:
>
>> I have two questions for community version of opscenter
>>
>> 1) does it work with multiple cassandra cluster?
>> 2) are agent ports 61620/61621 configurable? these ports are blocked in
>>
The following syntax :
import org.apache.cassandra.thrift.*;
.
.
ColumnOrSuperColumn col = client.get("count_key".getBytes("UTF-8"),
cp, ConsistencyLevel.QUORUM);
is giving the error:
get(java.nio.ByteBuffer,org.apache.cassandra.thrift.ColumnPath,org.apache.cassandra.thrift.ConsistencyLev
afaik composite lets you do sorting in a way that would be
difficult/impossible with string concatenation.
eg with the string ascending, and the integer descending.
if i had composites available (which i don't b/c we are on 0.7), i would
use them over string concatenation. string concatenati
Thank you Aaron! As long as I have plain strings, would you say that I
would do almost as well with catenation?
Of course I realize that mixed types are a very different case where the
composite is very useful.
Thanks
Maxim
On 12/20/2011 2:44 PM, aaron morton wrote:
Component values are co
On Tue, Dec 20, 2011 at 2:24 PM, aaron morton wrote:
> Sorry, got that a little wrong.
>
> At startup the node will use the higher of the current seconds since epoch
> or the stored generation number.
Technically stored generation + 1 so it's always increased on a restart.
-Brandon
Sorry, got that a little wrong.
At startup the node will use the higher of the current seconds since epoch or
the stored generation number.
So if you restart the old node it should always take ownership of it's token.
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
ht
On Tue, Dec 20, 2011 at 1:49 PM, Feng Qu wrote:
> I have two questions for community version of opscenter
>
> 1) does it work with multiple cassandra cluster?
> 2) are agent ports 61620/61621 configurable? these ports are blocked in
> our env.
>
> Thanks in advance
>
> Feng Qu
>
They are configu
I wasn't aware of CompositeColumns, thanks for the tip. However I think
it still doesn't allow me to do the query I need - basically I need to
do a timestamp range query, limiting only to certain file names at
each timestamp. With BOP and a separate row for each timestamp,
prefixed by a random UUID
I have two questions for community version of opscenter
1) does it work with multiple cassandra cluster?
2) are agent ports 61620/61621 configurable? these ports are blocked in our
env.
Thanks in advance
Feng Qu
Component values are compared in a type aware fashion, an Integer is an
Integer. Not a 10 character zero padded string.
You can also slice on the components. Just like with string concat, but nicer.
. e.g. If you app is storing comments for a thing, and the column names have
the form or yo
> - What happens in Cassandra with a failed node that has been
> decommissioned if it returns to the cluster with old data and its old
> token?
If it starts normally it *may* take ownership of the token away from the
previous node. The Gossip Generation is compared and the server with the higher
If you get the sizing wrong there area couple of emergency pressure valves in
the config…
https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L113
Watch for log messages with "Cassandra is now reducing cache sizes to free up
memory." in them.
Cheers
-
Aaron Mort
Bryce,
Have you considered using CompositeColumns and a standard CF? Row key
is the UUID column name is (timestamp : dir_entry) you can then slice all
columns with a particular time stamp.
Even if you have a random key, I would use the RP unless you have an
extreme use case.
Yes you can do a rolling restart. For more info on the counters architecture
see the presentation here
http://www.datastax.com/events/cassandrasf2011/presentations
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 20/12/2011, at 10:10 PM, Al
It looks like you tried to pass the string "{replication_factor:2}"
You need to pas a Map type , where the the key is the option
and the value is the option value.
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 20/12/2011, at 12:02 PM,
With regards to static, what are major benefits as it compares with
string catenation (with some convenient separator inserted)?
Thanks
Maxim
On 12/20/2011 1:39 PM, Richard Low wrote:
On Tue, Dec 20, 2011 at 5:28 PM, Ertio Lew wrote:
With regard to the composite columns stuff in Cassandra,
On Tue, Dec 20, 2011 at 5:28 PM, Ertio Lew wrote:
> With regard to the composite columns stuff in Cassandra, I have the
> following doubts :
>
> 1. What is the storage overhead of the composite type column names/values,
The values are the same. For each dimension, there is 3 bytes overhead.
> 2
With regard to the composite columns stuff in Cassandra, I have the
following doubts :
1. What is the storage overhead of the composite type column names/values,
and
2. what exactly is the difference between the DynamicComposite and Static
Composite ?
Hello,
I have several questions about decommissioned nodes that I would like
to clarify:
- What happens in Cassandra with a failed node that has been
decommissioned if it returns to the cluster with old data and its old
token?
- Will it actualize the data using ReadRepair or the bootstrapping pro
> It is not telling you to multiply your key size by 10-12, it is telling you to
> multiply the output of the nodetool cfstats reported "key cache size" by
> 10-12.
The "key cache size" reported is actually the number of keys in the key cache.
So,
it is the same thing as suggesting each key ta
I think it comes down to how much you benefit from row range scans, and
how confident you are that going forward all data will continue to use
random row keys.
I'm considering using BOP as a way of working around the non indexes
super column limitation. In my current schema, row keys are random
UU
Generally, RandomPartitioner is the recommended one.
If you already provide randomized keys it doesn't make much of a
difference, the nodes should be balanced with any partitioner.
However, unless you have UUID in all keys of all column families
(highly unlikely) ByteOrderedPartitioner and
OrderPre
Any way I was able to delete the keyspace using python pycassa
Thanks
Michael
From: aaron morton [mailto:aa...@thelastpickle.com]
Sent: Monday, December 19, 2011 9:39 PM
To: user@cassandra.apache.org
Subject: Re: Drop schema Called "Index"
Which keyspace are you trying to delete ?
By the way, I wonder if a rolling restart is still possible when I am using
counters ? Don't we lose the SPOF too, considering that counters are wrong
every time we retry to write them with the client ?
2011/12/16 Alain RODRIGUEZ
> Can we have a hope that counters will be replayed as safely as
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