Re: Cassandra compression not working?

2012-09-25 Thread aaron morton
Nothing jumps out. Are you able to reproduce the fault on a test  node ?

There were some schema change problems in the early 1.1X releases. Did you 
enable compression via a schema change ?

Cheers

-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 25/09/2012, at 9:14 AM, Mike mthero...@yahoo.com wrote:

 I forgot to mention we are running Cassandra 1.1.2.
 
 Thanks,
 -Mike
 
 On Sep 24, 2012, at 5:00 PM, Michael Theroux mthero...@yahoo.com wrote:
 
 Hello,
 
 We are running into an unusual situation that I'm wondering if anyone has 
 any insight on.  We've been running a Cassandra cluster for some time, with 
 compression enabled on one column family in which text documents are stored. 
  We enabled compression on the column family, utilizing the SnappyCompressor 
 and a 64k chunk length.
 
 It was recently discovered that Cassandra was reporting a compression ratio 
 of 0.  I took a snapshot of the data and started a cassandra node in 
 isolation to investigate.
 
 Running nodetool scrub, or nodetool upgradesstables had little impact on the 
 amount of data that was being stored.
 
 I then disabled compression and ran nodetool upgradesstables on the column 
 family.  Again, not impact on the data size stored.
 
 I then reenabled compression and ran nodetool upgradesstables on the column 
 family.  This resulting in a 60% reduction in the data size stored, and 
 Cassandra reporting a compression ration of about .38.
 
 Any idea what is going on here?  Obviously I can go through this process in 
 production to enable compression, however, any idea what is currently 
 happening and why new data does not appear to be compressed?
 
 Any insights are appreciated,
 Thanks,
 -Mike



Cassandra compression not working?

2012-09-24 Thread Michael Theroux
Hello,

We are running into an unusual situation that I'm wondering if anyone has any 
insight on.  We've been running a Cassandra cluster for some time, with 
compression enabled on one column family in which text documents are stored.  
We enabled compression on the column family, utilizing the SnappyCompressor and 
a 64k chunk length.

It was recently discovered that Cassandra was reporting a compression ratio of 
0.  I took a snapshot of the data and started a cassandra node in isolation to 
investigate.

Running nodetool scrub, or nodetool upgradesstables had little impact on the 
amount of data that was being stored.

I then disabled compression and ran nodetool upgradesstables on the column 
family.  Again, not impact on the data size stored.

I then reenabled compression and ran nodetool upgradesstables on the column 
family.  This resulting in a 60% reduction in the data size stored, and 
Cassandra reporting a compression ration of about .38.

Any idea what is going on here?  Obviously I can go through this process in 
production to enable compression, however, any idea what is currently happening 
and why new data does not appear to be compressed?

Any insights are appreciated,
Thanks,
-Mike

Re: Cassandra compression not working?

2012-09-24 Thread Mike
I forgot to mention we are running Cassandra 1.1.2.

Thanks,
-Mike

On Sep 24, 2012, at 5:00 PM, Michael Theroux mthero...@yahoo.com wrote:

 Hello,
 
 We are running into an unusual situation that I'm wondering if anyone has any 
 insight on.  We've been running a Cassandra cluster for some time, with 
 compression enabled on one column family in which text documents are stored.  
 We enabled compression on the column family, utilizing the SnappyCompressor 
 and a 64k chunk length.
 
 It was recently discovered that Cassandra was reporting a compression ratio 
 of 0.  I took a snapshot of the data and started a cassandra node in 
 isolation to investigate.
 
 Running nodetool scrub, or nodetool upgradesstables had little impact on the 
 amount of data that was being stored.
 
 I then disabled compression and ran nodetool upgradesstables on the column 
 family.  Again, not impact on the data size stored.
 
 I then reenabled compression and ran nodetool upgradesstables on the column 
 family.  This resulting in a 60% reduction in the data size stored, and 
 Cassandra reporting a compression ration of about .38.
 
 Any idea what is going on here?  Obviously I can go through this process in 
 production to enable compression, however, any idea what is currently 
 happening and why new data does not appear to be compressed?
 
 Any insights are appreciated,
 Thanks,
 -Mike


Re: Cassandra compression not working?

2012-09-24 Thread Fred Groen
You are going to need a fully optimized flux-capacitor for that.

On Tue, Sep 25, 2012 at 5:00 AM, Michael Theroux mthero...@yahoo.comwrote:

 Hello,

 We are running into an unusual situation that I'm wondering if anyone has
 any insight on.  We've been running a Cassandra cluster for some time, with
 compression enabled on one column family in which text documents are
 stored.  We enabled compression on the column family, utilizing the
 SnappyCompressor and a 64k chunk length.

 It was recently discovered that Cassandra was reporting a compression
 ratio of 0.  I took a snapshot of the data and started a cassandra node in
 isolation to investigate.

 Running nodetool scrub, or nodetool upgradesstables had little impact on
 the amount of data that was being stored.

 I then disabled compression and ran nodetool upgradesstables on the column
 family.  Again, not impact on the data size stored.

 I then reenabled compression and ran nodetool upgradesstables on the
 column family.  This resulting in a 60% reduction in the data size stored,
 and Cassandra reporting a compression ration of about .38.

 Any idea what is going on here?  Obviously I can go through this process
 in production to enable compression, however, any idea what is currently
 happening and why new data does not appear to be compressed?

 Any insights are appreciated,
 Thanks,
 -Mike