You are using replication factor of one and the Lustre clustered
filesystem over the network. Not good practice.
Try RF=3 and local disks. Lustre duplicates much of the functionality
of Cassandra, there is no point using both. Make your Lustre server
nodes into Cassandra nodes instead.
Adrian
On
The Cassandra team is pleased to announce the release of Apache Cassandra
version 0.7.10.
Cassandra is a highly scalable second-generation distributed database,
bringing together Dynamo's fully distributed design and Bigtable's
ColumnFamily-based data model. You can read more here:
http://cassan
Thanks, good point, splitting wide rows via sharding is a good
optimization for the get_count approach.
On Mon, Oct 31, 2011 at 10:58 AM, Zach Richardson
wrote:
> Ed,
>
> I could be completely wrong about this working--I haven't specifically
> looked at how the counts are executed, but I think th
Ed,
I could be completely wrong about this working--I haven't specifically
looked at how the counts are executed, but I think this makes sense.
You could potentially shard across several rows, based on a hash of
the username combined with the time period as the row key. Run a
count across each r
Hello,
One good way to manage such things is to give your columns a name that will
allow you to make some slices query...
Your column name could be something like:
image-png-other_identifier1
image-gif-other_identifier2
In your slice query, you could do a search for "image-png-A" to "image-png
I'm looking at the scenario of how to keep track of the number of
unique visitors within a given time period. Inserting user ids into a
wide row would allow me to have a list of every user within the time
period that the row represented. My experience in the past was that
using get_count on a row
Thanks so much SebWajam for this great piece of work!
Is there a way to set a data type for displaying the column names/ values
of a CF ? It seems that your project always uses String Serializer for
any piece of data however most of the times in real world cases this is not
true so can we anyhow
On Mon, Oct 31, 2011 at 2:58 PM, Sylvain Lebresne wrote:
> On Mon, Oct 31, 2011 at 1:10 PM, Mick Semb Wever wrote:
>> On Mon, 2011-10-31 at 13:05 +0100, Mick Semb Wever wrote:
>>> Given a 60G sstable, even with 64kb chunk_length, to read just that one
>>> sstable requires close to 8G free heap me
On Mon, Oct 31, 2011 at 1:10 PM, Mick Semb Wever wrote:
> On Mon, 2011-10-31 at 13:05 +0100, Mick Semb Wever wrote:
>> Given a 60G sstable, even with 64kb chunk_length, to read just that one
>> sstable requires close to 8G free heap memory...
>
> Arg, that calculation was a little off...
> (a lon
Cleanup would have the same effect I think, in exchange for a minor
amount of extra CPU used.
On Mon, Oct 31, 2011 at 4:08 AM, Sylvain Lebresne wrote:
> On Mon, Oct 31, 2011 at 9:07 AM, Mick Semb Wever wrote:
>> On Mon, 2011-10-31 at 08:00 +0100, Mick Semb Wever wrote:
>>> After an upgrade to ca
Should the different datatype col values or names be first read as byte
buffer & then converted to appropriate type using Hector's provided
serializers api like the way shown below ?
ByteBuffer bb;
..
String s= StringSerializer.get().fromByteBuffer(bb);
Or are there any better ways ?
On Mon, 2011-10-31 at 13:05 +0100, Mick Semb Wever wrote:
> Given a 60G sstable, even with 64kb chunk_length, to read just that one
> sstable requires close to 8G free heap memory...
Arg, that calculation was a little off...
(a long isn't exactly 8K...)
But you get my concern...
~mck
--
"Whe
On Mon, 2011-10-31 at 09:07 +0100, Mick Semb Wever wrote:
> The read pattern of these rows is always in bulk so the chunk_length
> could have been much higher so to reduce memory usage (my largest
> sstable is 61G).
Isn't CompressionMetadata.readChunkOffsets(..) rather dangerous here?
Given a 60
On Mon, Oct 31, 2011 at 11:41 AM, Mick Semb Wever wrote:
> On Mon, 2011-10-31 at 10:08 +0100, Sylvain Lebresne wrote:
>> you can
>> trigger a "user defined compaction" through JMX on each of the sstable
>> you want to rebuild.
>
> May i ask how?
> Everything i see from NodeProbe to StorageProxy is
On Mon, Oct 31, 2011 at 11:35 AM, Mick Semb Wever wrote:
> On Mon, 2011-10-31 at 10:08 +0100, Sylvain Lebresne wrote:
>> >> I set chunk_length_kb to 16 as my rows are very skinny (typically 100b)
>> >
>> >
>> > I see now this was a bad choice.
>> > The read pattern of these rows is always in bulk
The Cassandra team is pleased to announce the release of Apache Cassandra
version 1.0.1.
Cassandra is a highly scalable second-generation distributed database,
bringing together Dynamo's fully distributed design and Bigtable's
ColumnFamily-based data model. You can read more here:
http://cassand
On Mon, 2011-10-31 at 10:08 +0100, Sylvain Lebresne wrote:
> you can
> trigger a "user defined compaction" through JMX on each of the sstable
> you want to rebuild.
May i ask how?
Everything i see from NodeProbe to StorageProxy is ks and cf based.
~mck
--
“Anyone who lives within their means s
On Mon, 2011-10-31 at 10:08 +0100, Sylvain Lebresne wrote:
> >> I set chunk_length_kb to 16 as my rows are very skinny (typically 100b)
> >
> >
> > I see now this was a bad choice.
> > The read pattern of these rows is always in bulk so the chunk_length
> > could have been much higher so to reduce
On Mon, Oct 31, 2011 at 9:07 AM, Mick Semb Wever wrote:
> On Mon, 2011-10-31 at 08:00 +0100, Mick Semb Wever wrote:
>> After an upgrade to cassandra-1.0 any get_range_slices gives me:
>>
>> java.lang.OutOfMemoryError: Java heap space
>> at
>> org.apache.cassandra.io.compress.CompressionMeta
On Mon, 2011-10-31 at 08:00 +0100, Mick Semb Wever wrote:
> After an upgrade to cassandra-1.0 any get_range_slices gives me:
>
> java.lang.OutOfMemoryError: Java heap space
> at
> org.apache.cassandra.io.compress.CompressionMetadata.readChunkOffsets(CompressionMetadata.java:93)
> at
After an upgrade to cassandra-1.0 any get_range_slices gives me:
java.lang.OutOfMemoryError: Java heap space
at
org.apache.cassandra.io.compress.CompressionMetadata.readChunkOffsets(CompressionMetadata.java:93)
at
org.apache.cassandra.io.compress.CompressionMetadata.(CompressionM
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