Re: NGCC 2016

[Jonathan Ellis]

Yes, we'll make the registration deadline April 9 and send out replies
after that.

On Thu, Mar 10, 2016 at 6:43 PM, Dikang Gu  wrote:

> Awesome! Just registered. I did not attend before, shall I expect to get
> response some time later?
>
> Thanks
> DIkang.
>
> On Thu, Mar 10, 2016 at 2:09 PM, Jonathan Ellis  wrote:
>
> > And, it's actually June 9-10.  Correct on the form.  Sorry!
> >
> > On Thu, Mar 10, 2016 at 3:48 PM, Jonathan Ellis 
> wrote:
> >
> > > ... and here's an actual working link: http://goo.gl/forms/Ec6DdNFD6h
> > >
> > > On Thu, Mar 10, 2016 at 3:47 PM, Jonathan Ellis 
> > wrote:
> > >
> > >> Hi all,
> > >>
> > >> This year's Next Generation Cassandra Conference will be June 8-9
> (yes,
> > >> two days!) in Austin, Texas.  The first day will be a single track of
> > >> prepared presentations, similar to previous years'.  The second day
> > will be
> > >> reserved for followup discussions in an "unconference" format.
> > >>
> > >> Details and registration:
> > >>
> >
> https://docs.google.com/forms/d/11CMRuTlUeyPd_X9Oo11X7_xx8RAJEzZ-HOVc5p079c8/edit?usp=forms_home=true
> > >>
> > >> See you there!
> > >>
> > >> --
> > >> Jonathan Ellis
> > >> Project Chair, Apache Cassandra
> > >> co-founder, http://www.datastax.com
> > >> @spyced
> > >>
> > >
> > >
> > >
> > > --
> > > Jonathan Ellis
> > > Project Chair, Apache Cassandra
> > > co-founder, http://www.datastax.com
> > > @spyced
> > >
> >
> >
> >
> > --
> > Jonathan Ellis
> > Project Chair, Apache Cassandra
> > co-founder, http://www.datastax.com
> > @spyced
> >
>
>
>
> --
> Dikang
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder, http://www.datastax.com
@spyced

Re: NGCC 2016

[Jonathan Ellis]

And, it's actually June 9-10.  Correct on the form.  Sorry!

On Thu, Mar 10, 2016 at 3:48 PM, Jonathan Ellis  wrote:

> ... and here's an actual working link: http://goo.gl/forms/Ec6DdNFD6h
>
> On Thu, Mar 10, 2016 at 3:47 PM, Jonathan Ellis  wrote:
>
>> Hi all,
>>
>> This year's Next Generation Cassandra Conference will be June 8-9 (yes,
>> two days!) in Austin, Texas.  The first day will be a single track of
>> prepared presentations, similar to previous years'.  The second day will be
>> reserved for followup discussions in an "unconference" format.
>>
>> Details and registration:
>> https://docs.google.com/forms/d/11CMRuTlUeyPd_X9Oo11X7_xx8RAJEzZ-HOVc5p079c8/edit?usp=forms_home=true
>>
>> See you there!
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder, http://www.datastax.com
>> @spyced
>>
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder, http://www.datastax.com
> @spyced
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder, http://www.datastax.com
@spyced

Re: NGCC 2016

[Jonathan Ellis]

... and here's an actual working link: http://goo.gl/forms/Ec6DdNFD6h

On Thu, Mar 10, 2016 at 3:47 PM, Jonathan Ellis  wrote:

> Hi all,
>
> This year's Next Generation Cassandra Conference will be June 8-9 (yes,
> two days!) in Austin, Texas.  The first day will be a single track of
> prepared presentations, similar to previous years'.  The second day will be
> reserved for followup discussions in an "unconference" format.
>
> Details and registration:
> https://docs.google.com/forms/d/11CMRuTlUeyPd_X9Oo11X7_xx8RAJEzZ-HOVc5p079c8/edit?usp=forms_home=true
>
> See you there!
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder, http://www.datastax.com
> @spyced
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder, http://www.datastax.com
@spyced

NGCC 2016

[Jonathan Ellis]

Hi all,

This year's Next Generation Cassandra Conference will be June 8-9 (yes, two
days!) in Austin, Texas.  The first day will be a single track of prepared
presentations, similar to previous years'.  The second day will be reserved
for followup discussions in an "unconference" format.

Details and registration:
https://docs.google.com/forms/d/11CMRuTlUeyPd_X9Oo11X7_xx8RAJEzZ-HOVc5p079c8/edit?usp=forms_home=true

See you there!

-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder, http://www.datastax.com
@spyced

Re: How to measure the write amplification of C*?

[Benjamin Lerer]

Cassandra should not cause any write amplification. Write amplification
appends only when you updates data on SSDs. Cassandra does not update any
data in place. Data can be rewritten during compaction but it is never
updated.

Benjamin

On Thu, Mar 10, 2016 at 12:42 PM, Alain RODRIGUEZ 
wrote:

> Hi Dikang,
>
> I am not sure about what you call "amplification", but as sizes highly
> depends on the structure I think I would probably give it a try using CCM (
> https://github.com/pcmanus/ccm) or some test cluster with 'production
> like'
> setting and schema. You can write a row, flush it and see how big is the
> data cluster-wide / per node.
>
> Hope this will be of some help.
>
> C*heers,
> ---
> Alain Rodriguez - al...@thelastpickle.com
> France
>
> The Last Pickle - Apache Cassandra Consulting
> http://www.thelastpickle.com
>
> 2016-03-10 7:18 GMT+01:00 Dikang Gu :
>
> > Hello there,
> >
> > I'm wondering is there a good way to measure the write amplification of
> > Cassandra?
> >
> > I'm thinking it could be calculated by (size of mutations written to the
> > node)/(number of bytes written to the disk).
> >
> > Do we already have the metrics of "size of mutations written to the
> node"?
> > I did not find it in jmx metrics.
> >
> > Thanks
> >
> > --
> > Dikang
> >
> >
>

Re: How to measure the write amplification of C*?

[Alain RODRIGUEZ]

Hi Dikang,

I am not sure about what you call "amplification", but as sizes highly
depends on the structure I think I would probably give it a try using CCM (
https://github.com/pcmanus/ccm) or some test cluster with 'production like'
setting and schema. You can write a row, flush it and see how big is the
data cluster-wide / per node.

Hope this will be of some help.

C*heers,
---
Alain Rodriguez - al...@thelastpickle.com
France

The Last Pickle - Apache Cassandra Consulting
http://www.thelastpickle.com

2016-03-10 7:18 GMT+01:00 Dikang Gu :

> Hello there,
>
> I'm wondering is there a good way to measure the write amplification of
> Cassandra?
>
> I'm thinking it could be calculated by (size of mutations written to the
> node)/(number of bytes written to the disk).
>
> Do we already have the metrics of "size of mutations written to the node"?
> I did not find it in jmx metrics.
>
> Thanks
>
> --
> Dikang
>
>

Re: Cassandra-stress output

[Jean Carlo]

However can it be nice to have the posibility to configurate that with
cassandra options, or when using a file yaml to insert data on any table.


Saludos

Jean Carlo

"The best way to predict the future is to invent it" Alan Kay

On Thu, Mar 10, 2016 at 10:48 AM, Jean Carlo 
wrote:

> Thank you very much S. Alborghetti I will consider that suggestion.
>
>
> Saludos
>
> Jean Carlo
>
> "The best way to predict the future is to invent it" Alan Kay
>
> On Thu, Mar 10, 2016 at 5:47 AM, Stefania Alborghetti <
> stefania.alborghe...@datastax.com> wrote:
>
>> On Tue, Mar 8, 2016 at 8:39 PM, Jean Carlo 
>> wrote:
>>
>> > Hi guys,
>> >
>> > I use cassandra stress to populate the next table
>> >
>> > CREATE TABLE cf1 (
>> > kvalue text,
>> > ktype text,
>> > prov text,
>> > dname text,
>> > dattrib blob,
>> > dvalue text,
>> > PRIMARY KEY (kvalue, ktype, prov, dname)
>> >   ) WITH bloom_filter_fp_chance = 0.01
>> >  AND caching = '{"keys":"ALL", "rows_per_partition":"60"}'
>> > AND comment = ''
>> > AND compaction = {'class':
>> > 'org.apache.cassandra.db.compaction.LeveledCompactionStrategy'}
>> > AND compression = {'sstable_compression':
>> > 'org.apache.cassandra.io.compress.SnappyCompressor'}
>> > AND dclocal_read_repair_chance = 0.02
>> > AND default_time_to_live = 0
>> > AND gc_grace_seconds = 864000
>> > AND max_index_interval = 2048
>> > AND memtable_flush_period_in_ms = 0
>> > AND min_index_interval = 128
>> > AND read_repair_chance = 0.01
>> > AND speculative_retry = '99.0PERCENTILE';
>> >
>> > And cassandra stress create the next string to the field kvalue of type
>> > text:
>> >
>> > "P*d,xY\x03m\x1b\x10\x0b$\x04pt-G\x08\n`7\x1fs\x15kH\x02i1\x16jf%YM"
>> >
>> > what bothers me is that kvalue has control characters like \x03. do you
>> > guys know any way to avoid creating this kind of characters while using
>> > cassandra-stress?
>> >
>> >
>> >
>> > Thank you very much
>> >
>> > Jean Carlo
>> >
>> > "The best way to predict the future is to invent it" Alan Kay
>> >
>>
>>
>> There is no way to avoid the control characters (<32 and ==127), other
>> than
>> modifying the source code, which is located in
>> tools/stress/src/org/apache/cassandra/stress/generate/values/Strings.java.
>>
>> Changing this line:
>>
>> chars[i++] = (char) (((v & 127) + 32) & 127);
>>
>> with this:
>>
>> chars[i++] = (char) (((v & 127) % 95) + 32);
>>
>> should work but I could not avoid the expensive modulo operation. You can
>> rebuild cassandra-stress with ant stress-build.
>>
>> I wonder if the original intention was to avoid control characters
>> however,
>> given the +32 in the original line. For this reason I've copied this
>> message to the dev mailing list.
>>
>>
>> --
>>
>>
>> [image: datastax_logo.png] 
>>
>> Stefania Alborghetti
>>
>> Apache Cassandra Software Engineer
>>
>> |+852 6114 9265| stefania.alborghe...@datastax.com
>>
>
>