External linking Was: Isolation in case of Single Partition Writes and Batching with LWT

[Mark Thomas]

On 12/09/2016 19:22, Jim Ancona wrote:
> Mark,
> 
> Is there some official Apache policy on which sites it's appropriate to
> link to on an Apache mailing list? If so, could you please post a link
> to it so we can all understand the rules. Or is this your personal
> opinion on what you'd like to see here?
> 
> Thanks!

The relevant policy quote from [1] is "... Apache projects are required
to govern themselves independently of undue commercial influence." which
is expanded on in [2].

One of the elements of [2] is that perception is important. If a project
is not independent of commercial influence, or there is a perception
that that is the case, then that is an issue.

In the majority of cases, external links are fine. If the project docs
don't cover something, more depth is required than is available in the
docs, a different perspective on the same topic is better suited to the
problem at hand, etc. are all fine.

It is links that can give the impression that the official Apache
Cassandra docs are hosted by an external entity that are a concern. Such
links increase the risk that the perception is created/re-enforced that
the entity that hosts the external site has some special status within
the project and that falls foul of the 'no undue commercial influence'
requirement.

Mark


[1] http://www.apache.org/foundation/how-it-works.html
[2] http://community.apache.org/projectIndependence.html

Re: External linking Was: Isolation in case of Single Partition Writes and Batching with LWT

[Benedict Elliott Smith]

Again: *dev list*.

"Please Note: These requirements apply to Apache projects: that is, to
*individual
committer and PMC behaviors* and actions within the context of
collaboratively building software products at The Apache Software
Foundation. By definition here, "Apache project" means the collaborative
activity of *building a software release* called an "Apache product" here
at the ASF."

My emphasis.  This document expressly limits its applicability, both in
terms of individuals and activities.  *Neither* of these scopes apply here,
so you have no basis for your actions.

It is, in my view, shameful to try to strong arm a community to your will
without even reading the rules you think you are applying beyond a cursory
glance to check they confirm your prior held beliefs.

Again, and now with *your own* justification, I ask you to stop.





On 13 September 2016 at 11:35, Mark Thomas  wrote:

> On 12/09/2016 19:22, Jim Ancona wrote:
> > Mark,
> >
> > Is there some official Apache policy on which sites it's appropriate to
> > link to on an Apache mailing list? If so, could you please post a link
> > to it so we can all understand the rules. Or is this your personal
> > opinion on what you'd like to see here?
> >
> > Thanks!
>
> The relevant policy quote from [1] is "... Apache projects are required
> to govern themselves independently of undue commercial influence." which
> is expanded on in [2].
>
> One of the elements of [2] is that perception is important. If a project
> is not independent of commercial influence, or there is a perception
> that that is the case, then that is an issue.
>
> In the majority of cases, external links are fine. If the project docs
> don't cover something, more depth is required than is available in the
> docs, a different perspective on the same topic is better suited to the
> problem at hand, etc. are all fine.
>
> It is links that can give the impression that the official Apache
> Cassandra docs are hosted by an external entity that are a concern. Such
> links increase the risk that the perception is created/re-enforced that
> the entity that hosts the external site has some special status within
> the project and that falls foul of the 'no undue commercial influence'
> requirement.
>
> Mark
>
>
> [1] http://www.apache.org/foundation/how-it-works.html
> [2] http://community.apache.org/projectIndependence.html
>
>

Re: Incremental repairs in 3.0

[Jean Carlo]

Hi Paulo!

Sorry there was something I was doing wrong.
Now  I can see that the value of Repaired At changes even if there is no
streaming. I am using cassandra 2.1.14 and the comand was nodetool repair
-inc -par.

Anyway good to know this:

> If you're using subrange repair, please note that this has only partial
support for incremental repair due to CASSANDRA-10422 and should not mark
sstables as repaired, so you could be hitting CASSANDRA-12489.

Thx Paulo :)


Saludos

Jean Carlo

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

On Mon, Sep 12, 2016 at 2:06 PM, Paulo Motta 
wrote:

> > I truncate a table lcs, Then I inserted one line and I used nodetool
> flush to have all the sstables. Using a RF 3 I ran a repair -inc directly
> and I observed that the value of Reaired At was equal 0.
>
> Were you able to troubleshoot this? The value of repairedAt should be
> mutated even when there is not streaming, otherwise there might be
> something going on. What version are you using and what command did you use
> to trigger incremental repair?
>
> If you're using subrange repair, please note that this has only partial
> support for incremental repair due to CASSANDRA-10422 and should not mark
> sstables as repaired, so you could be hitting CASSANDRA-12489.
>
> 2016-09-07 8:15 GMT-03:00 Jean Carlo :
>
>> Well I did an small test on my cluster and I didn't get the results I was
>> expecting.
>>
>> I truncate a table lcs, Then I inserted one line and I used nodetool
>> flush to have all the sstables. Using a RF 3 I ran a repair -inc directly
>> and I observed that the value of Reaired At was equal 0.
>>
>> So I start to think that if there is no changes ( diff on the merkles
>> trees) the repair will not pass to the streaming phase, and it is there
>> where the sstables are marked as repaired.
>>
>> I did another test to confirm my assomptions and I saw the sstables
>> marked as repaired. ("repaired at" value isn't 0). Well just those sstables
>> not sync.
>>
>> So my quesion is, if we migrate to repair inc in prod and we dont use the
>> migration procedure, for tables that some sstables are never mutated, they
>> will keep in a not repaired state ?
>>
>> Probably there is something I am not able to see
>>
>>
>>
>>
>>
>> Saludos
>>
>> Jean Carlo
>>
>> "The best way to predict the future is to invent it" Alan Kay
>>
>> On Tue, Sep 6, 2016 at 8:19 PM, Bryan Cheng 
>> wrote:
>>
>>> HI Jean,
>>>
>>> This blog post is a pretty good resource: http://www.datastax.
>>> com/dev/blog/anticompaction-in-cassandra-2-1
>>>
>>> I believe in 2.1.x you don't need to do the manual migration procedure,
>>> but if you run regular repairs and the data set under LCS is fairly large
>>> (what this means will probably depend on your data model and
>>> hardware/cluster makeup) you can take advantage of a full repair to make
>>> anticompaction a bit easier. What we observed was the anticompaction
>>> procedure taking longer than a standard full repair and with a higher load
>>> on the cluster while running.
>>>
>>> On Tue, Sep 6, 2016 at 2:00 AM, Jean Carlo 
>>> wrote:
>>>
 Hi @Bryan

 When you said "sizable amount of data" you meant a huge amount of data
 right? Our big table is in LCS and if we use the migration process we will
 need to run a repair seq over this table for a long time.

 We are planning to go to repairs inc using the version 2.1.14


 Saludos

 Jean Carlo

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

 On Tue, Jun 21, 2016 at 4:34 PM, Vlad  wrote:

> Thanks for answer!
>
> >It may still be a good idea to manually migrate if you have a
> sizable amount of data
> No, it would be brand new ;-) 3.0 cluster
>
>
>
> On Tuesday, June 21, 2016 1:21 AM, Bryan Cheng 
> wrote:
>
>
> Sorry, meant to say "therefore manual migration procedure should be
> UNnecessary"
>
> On Mon, Jun 20, 2016 at 3:21 PM, Bryan Cheng 
> wrote:
>
> I don't use 3.x so hopefully someone with operational experience can
> chime in, however my understanding is: 1) Incremental repairs should be 
> the
> default in the 3.x release branch and 2) sstable repairedAt is now 
> properly
> set in all sstables as of 2.2.x for standard repairs and therefore manual
> migration procedure should be necessary. It may still be a good idea to
> manually migrate if you have a sizable amount of data and are using LCS as
> anticompaction is rather painful.
>
> On Sun, Jun 19, 2016 at 6:37 AM, Vlad  wrote:
>
> Hi,
>
> assuming I have new, empty Cassandra cluster, how should I start using
> incremental repairs? Is incremental repair is default now (as I don't see
> *-inc* option in nodetool) and nothing is needed to use it, or should
> we perform migration procedure
> 

How to query '%' character using LIKE operator in Cassandra 3.7?

[Mikhail Krupitskiy]

Hi Cassandra guys,

I use Cassandra 3.7 and wondering how to use ‘%’ as a simple char in a search 
pattern.
Here is my test script:

DROP keyspace if exists kmv;
CREATE keyspace if not exists kmv WITH REPLICATION = { 'class' : 
'SimpleStrategy', 'replication_factor':'1'} ;
USE kmv;
CREATE TABLE if not exists kmv (id int, c1 text, c2 text, PRIMARY KEY(id, c1));
CREATE CUSTOM INDEX ON kmv.kmv  ( c2 ) USING 
'org.apache.cassandra.index.sasi.SASIIndex' WITH OPTIONS = {
'analyzed' : 'true',
'analyzer_class' : 
'org.apache.cassandra.index.sasi.analyzer.NonTokenizingAnalyzer',
'case_sensitive' : 'false', 
'mode' : 'CONTAINS'
};

INSERT into kmv (id, c1, c2) values (1, 'f22', 'qwe%asd');
INSERT into kmv (id, c1, c2) values (2, 'f22', '%asd');
INSERT into kmv (id, c1, c2) values (3, 'f22', 'asd%');
INSERT into kmv (id, c1, c2) values (4, 'f22', 'asd%1');
INSERT into kmv (id, c1, c2) values (5, 'f22', 'qweasd');

SELECT c2 from kmv.kmv where c2 like ‘_pattern_';

_pattern_ '%%%' finds all columns that contain %.
How to find columns that start form ‘%’ or ‘%a’?
How to find columns that end with ‘%’?
What about more complex patterns: '%qwe%a%sd%’? How to differentiate ‘%’ char 
form % as a command symbol? (Also there is a related issue CASSANDRA-12573).


Thanks,
Mikhail

Re: How to query '%' character using LIKE operator in Cassandra 3.7?

[DuyHai Doan]

Use % to escape %

cqlsh:test> select * from escape;

 id | val
+---
  1 | %escapeme
  2 | escape%me


Contains search

cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';

 id | val
+---
  1 | %escapeme

(1 rows)


Prefix search

cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';

 id | val
+---
  2 | escape%me

On Tue, Sep 13, 2016 at 5:06 PM, Mikhail Krupitskiy <
mikhail.krupits...@jetbrains.com> wrote:

> Hi Cassandra guys,
>
> I use Cassandra 3.7 and wondering how to use ‘%’ as a simple char in a
> search pattern.
> Here is my test script:
>
> DROP keyspace if exists kmv;
> CREATE keyspace if not exists kmv WITH REPLICATION = { 'class' :
> 'SimpleStrategy', 'replication_factor':'1'} ;
> USE kmv;
> CREATE TABLE if not exists kmv (id int, c1 text, c2 text, PRIMARY KEY(id,
> c1));
> CREATE CUSTOM INDEX ON kmv.kmv  ( c2 ) USING 
> 'org.apache.cassandra.index.sasi.SASIIndex'
> WITH OPTIONS = {
> 'analyzed' : 'true',
> 'analyzer_class' : 'org.apache.cassandra.index.sasi.analyzer.
> NonTokenizingAnalyzer',
> 'case_sensitive' : 'false',
> 'mode' : 'CONTAINS'
> };
>
> INSERT into kmv (id, c1, c2) values (1, 'f22', 'qwe%asd');
> INSERT into kmv (id, c1, c2) values (2, 'f22', '%asd');
> INSERT into kmv (id, c1, c2) values (3, 'f22', 'asd%');
> INSERT into kmv (id, c1, c2) values (4, 'f22', 'asd%1');
> INSERT into kmv (id, c1, c2) values (5, 'f22', 'qweasd');
>
> SELECT c2 from kmv.kmv where c2 like ‘_pattern_';
>
> _pattern_ '%%%' finds all columns that contain %.
> How to find columns that start form ‘%’ or ‘%a’?
> How to find columns that end with ‘%’?
> What about more complex patterns: '%qwe%a%sd%’? How to differentiate ‘%’
> char form % as a command symbol? (Also there is a related issue
> CASSANDRA-12573).
>
>
> Thanks,
> Mikhail

Re: How to query '%' character using LIKE operator in Cassandra 3.7?

[Mikhail Krupitskiy]

Thanks for the reply.
Could you please provide what index definition did you use?
With the index from my script I get the following results:

cqlsh:test> select * from escape;

 id | val
+---
  1 | %escapeme
  2 | escape%me
  3 | escape%esc

Contains search

cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';

 id | val
+---
  1 | %escapeme
  3 | escape%esc
(2 rows)


Prefix search

cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';

 id | val
+---
  2 | escape%me
  3 | escape%esc

Thanks,
Mikhail 

> On 13 Sep 2016, at 18:16, DuyHai Doan  wrote:
> 
> Use % to escape %
> 
> cqlsh:test> select * from escape;
> 
>  id | val
> +---
>   1 | %escapeme
>   2 | escape%me
> 
> 
> Contains search
> 
> cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';
> 
>  id | val
> +---
>   1 | %escapeme
> 
> (1 rows)
> 
> 
> Prefix search
> 
> cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';
> 
>  id | val
> +---
>   2 | escape%me
> 
> On Tue, Sep 13, 2016 at 5:06 PM, Mikhail Krupitskiy 
> mailto:mikhail.krupits...@jetbrains.com>> 
> wrote:
> Hi Cassandra guys,
> 
> I use Cassandra 3.7 and wondering how to use ‘%’ as a simple char in a search 
> pattern.
> Here is my test script:
> 
> DROP keyspace if exists kmv;
> CREATE keyspace if not exists kmv WITH REPLICATION = { 'class' : 
> 'SimpleStrategy', 'replication_factor':'1'} ;
> USE kmv;
> CREATE TABLE if not exists kmv (id int, c1 text, c2 text, PRIMARY KEY(id, 
> c1));
> CREATE CUSTOM INDEX ON kmv.kmv  ( c2 ) USING 
> 'org.apache.cassandra.index.sasi.SASIIndex' WITH OPTIONS = {
> 'analyzed' : 'true',
> 'analyzer_class' : 
> 'org.apache.cassandra.index.sasi.analyzer.NonTokenizingAnalyzer',
> 'case_sensitive' : 'false',
> 'mode' : 'CONTAINS'
> };
> 
> INSERT into kmv (id, c1, c2) values (1, 'f22', 'qwe%asd');
> INSERT into kmv (id, c1, c2) values (2, 'f22', '%asd');
> INSERT into kmv (id, c1, c2) values (3, 'f22', 'asd%');
> INSERT into kmv (id, c1, c2) values (4, 'f22', 'asd%1');
> INSERT into kmv (id, c1, c2) values (5, 'f22', 'qweasd');
> 
> SELECT c2 from kmv.kmv where c2 like ‘_pattern_';
> 
> _pattern_ '%%%' finds all columns that contain %.
> How to find columns that start form ‘%’ or ‘%a’?
> How to find columns that end with ‘%’?
> What about more complex patterns: '%qwe%a%sd%’? How to differentiate ‘%’ char 
> form % as a command symbol? (Also there is a related issue CASSANDRA-12573).
> 
> 
> Thanks,
> Mikhail
> 

Re: How to query '%' character using LIKE operator in Cassandra 3.7?

[DuyHai Doan]

CREATE CUSTOM INDEX ON test.escape(val) USING
'org.apache.cassandra.index.sasi.SASIIndex' WITH OPTIONS = {'mode':
'CONTAINS', 'analyzer_class':
'org.apache.cassandra.index.sasi.analyzer.NonTokenizingAnalyzer',
'case_sensitive': 'false'};

I don't see any problem in the results you got

SELECT * FROM escape WHERE val LIKE '%%esc%'; --> Give all results
*containing* '%esc' so *%esc*apeme is a possible match and also escape*%esc*

SELECT * FROM escape WHERE val LIKE 'escape%%' --> Give all results
*starting* with 'escape%' so *escape%*me is a valid result and also
*escape%*esc

On Tue, Sep 13, 2016 at 5:58 PM, Mikhail Krupitskiy <
mikhail.krupits...@jetbrains.com> wrote:

> Thanks for the reply.
> Could you please provide what index definition did you use?
> With the index from my script I get the following results:
>
> cqlsh:test> select * from escape;
>
>  id | val
> +---
>   1 | %escapeme
>   2 | escape%me
> *  3 | escape%esc*
>
> Contains search
>
> cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';
>
>  id | val
> +---
>   1 | %escapeme
>   3
> * | escape%esc*(2 rows)
>
>
> Prefix search
>
> cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';
>
>  id | val
> +---
>   2 | escape%me
>   3
> * | escape%esc*
>
> Thanks,
> Mikhail
>
> On 13 Sep 2016, at 18:16, DuyHai Doan  wrote:
>
> Use % to escape %
>
> cqlsh:test> select * from escape;
>
>  id | val
> +---
>   1 | %escapeme
>   2 | escape%me
>
>
> Contains search
>
> cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';
>
>  id | val
> +---
>   1 | %escapeme
>
> (1 rows)
>
>
> Prefix search
>
> cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';
>
>  id | val
> +---
>   2 | escape%me
>
> On Tue, Sep 13, 2016 at 5:06 PM, Mikhail Krupitskiy <
> mikhail.krupits...@jetbrains.com> wrote:
>
>> Hi Cassandra guys,
>>
>> I use Cassandra 3.7 and wondering how to use ‘%’ as a simple char in a
>> search pattern.
>> Here is my test script:
>>
>> DROP keyspace if exists kmv;
>> CREATE keyspace if not exists kmv WITH REPLICATION = { 'class' :
>> 'SimpleStrategy', 'replication_factor':'1'} ;
>> USE kmv;
>> CREATE TABLE if not exists kmv (id int, c1 text, c2 text, PRIMARY KEY(id,
>> c1));
>> CREATE CUSTOM INDEX ON kmv.kmv  ( c2 ) USING '
>> org.apache.cassandra.index.sasi.SASIIndex' WITH OPTIONS = {
>> 'analyzed' : 'true',
>> 'analyzer_class' : 'org.apache.cassandra.index.sa
>> si.analyzer.NonTokenizingAnalyzer',
>> 'case_sensitive' : 'false',
>> 'mode' : 'CONTAINS'
>> };
>>
>> INSERT into kmv (id, c1, c2) values (1, 'f22', 'qwe%asd');
>> INSERT into kmv (id, c1, c2) values (2, 'f22', '%asd');
>> INSERT into kmv (id, c1, c2) values (3, 'f22', 'asd%');
>> INSERT into kmv (id, c1, c2) values (4, 'f22', 'asd%1');
>> INSERT into kmv (id, c1, c2) values (5, 'f22', 'qweasd');
>>
>> SELECT c2 from kmv.kmv where c2 like ‘_pattern_';
>>
>> _pattern_ '%%%' finds all columns that contain %.
>> How to find columns that start form ‘%’ or ‘%a’?
>> How to find columns that end with ‘%’?
>> What about more complex patterns: '%qwe%a%sd%’? How to differentiate ‘%’
>> char form % as a command symbol? (Also there is a related issue
>> CASSANDRA-12573).
>>
>>
>> Thanks,
>> Mikhail
>
>
>
>

Re: How to query '%' character using LIKE operator in Cassandra 3.7?

[Mikhail Krupitskiy]

Looks like we have different understanding of what results are expected.
I based my understanding on 
http://docs.datastax.com/en/cql/3.3/cql/cql_using/useSASIIndex.html 

According to the doc ‘esc’ is a pattern for exact match and I guess that there 
is no semantical difference between two LIKE patterns (both of patterns should 
be treated as ‘exact match'): ‘%%esc’ and ‘esc’.

> SELECT * FROM escape WHERE val LIKE '%%esc%'; --> Give all results containing 
> '%esc' so %escapeme is a possible match and also escape%esc
Why ‘containing’? I expect that it should be ’starting’..
> 
> SELECT * FROM escape WHERE val LIKE 'escape%%' --> Give all results starting 
> with 'escape%' so escape%me is a valid result and also escape%esc
Why ’starting’? I expect that it should be ‘exact matching’.

Also I expect that “ LIKE ‘%s%sc%’ ” will return ‘escape%esc’ but it returns 
nothing (CASSANDRA-12573).

What I’m missing?

Thanks,
Mikhail

> On 13 Sep 2016, at 19:31, DuyHai Doan  wrote:
> 
> CREATE CUSTOM INDEX ON test.escape(val) USING 
> 'org.apache.cassandra.index.sasi.SASIIndex' WITH OPTIONS = {'mode': 
> 'CONTAINS', 'analyzer_class': 
> 'org.apache.cassandra.index.sasi.analyzer.NonTokenizingAnalyzer', 
> 'case_sensitive': 'false'};
> 
> I don't see any problem in the results you got
> 
> SELECT * FROM escape WHERE val LIKE '%%esc%'; --> Give all results containing 
> '%esc' so %escapeme is a possible match and also escape%esc
Why ‘containing’? I expect that it should be ’starting’..
> 
> SELECT * FROM escape WHERE val LIKE 'escape%%' --> Give all results starting 
> with 'escape%' so escape%me is a valid result and also escape%esc
Why ’starting’? I expect that it should be ‘exact matching’.
> 
> On Tue, Sep 13, 2016 at 5:58 PM, Mikhail Krupitskiy 
> mailto:mikhail.krupits...@jetbrains.com>> 
> wrote:
> Thanks for the reply.
> Could you please provide what index definition did you use?
> With the index from my script I get the following results:
> 
> cqlsh:test> select * from escape;
> 
>  id | val
> +---
>   1 | %escapeme
>   2 | escape%me
>   3 | escape%esc
> 
> Contains search
> 
> cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';
> 
>  id | val
> +---
>   1 | %escapeme
>   3 | escape%esc
> (2 rows)
> 
> 
> Prefix search
> 
> cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';
> 
>  id | val
> +---
>   2 | escape%me
>   3 | escape%esc
> 
> Thanks,
> Mikhail 
> 
>> On 13 Sep 2016, at 18:16, DuyHai Doan > > wrote:
>> 
>> Use % to escape %
>> 
>> cqlsh:test> select * from escape;
>> 
>>  id | val
>> +---
>>   1 | %escapeme
>>   2 | escape%me
>> 
>> 
>> Contains search
>> 
>> cqlsh:test> SELECT * FROM escape WHERE val LIKE '%%esc%';
>> 
>>  id | val
>> +---
>>   1 | %escapeme
>> 
>> (1 rows)
>> 
>> 
>> Prefix search
>> 
>> cqlsh:test> SELECT * FROM escape WHERE val LIKE 'escape%%';
>> 
>>  id | val
>> +---
>>   2 | escape%me
>> 
>> On Tue, Sep 13, 2016 at 5:06 PM, Mikhail Krupitskiy 
>> mailto:mikhail.krupits...@jetbrains.com>> 
>> wrote:
>> Hi Cassandra guys,
>> 
>> I use Cassandra 3.7 and wondering how to use ‘%’ as a simple char in a 
>> search pattern.
>> Here is my test script:
>> 
>> DROP keyspace if exists kmv;
>> CREATE keyspace if not exists kmv WITH REPLICATION = { 'class' : 
>> 'SimpleStrategy', 'replication_factor':'1'} ;
>> USE kmv;
>> CREATE TABLE if not exists kmv (id int, c1 text, c2 text, PRIMARY KEY(id, 
>> c1));
>> CREATE CUSTOM INDEX ON kmv.kmv  ( c2 ) USING 'org.apache.cassandra.index.sa 
>> si.SASIIndex' WITH OPTIONS = {
>> 'analyzed' : 'true',
>> 'analyzer_class' : 'org.apache.cassandra.index.sa 
>> si.analyzer.NonTokenizingAnalyzer',
>> 'case_sensitive' : 'false',
>> 'mode' : 'CONTAINS'
>> };
>> 
>> INSERT into kmv (id, c1, c2) values (1, 'f22', 'qwe%asd');
>> INSERT into kmv (id, c1, c2) values (2, 'f22', '%asd');
>> INSERT into kmv (id, c1, c2) values (3, 'f22', 'asd%');
>> INSERT into kmv (id, c1, c2) values (4, 'f22', 'asd%1');
>> INSERT into kmv (id, c1, c2) values (5, 'f22', 'qweasd');
>> 
>> SELECT c2 from kmv.kmv where c2 like ‘_pattern_';
>> 
>> _pattern_ '%%%' finds all columns that contain %.
>> How to find columns that start form ‘%’ or ‘%a’?
>> How to find columns that end with ‘%’?
>> What about more complex patterns: '%qwe%a%sd%’? How to differentiate ‘%’ 
>> char form % as a command symbol? (Also there is a related issue 
>> CASSANDRA-12573).
>> 
>> 
>> Thanks,
>> Mikhail
>> 
> 
> 

Re : Cluster performance after enabling SSL

[sai krishnam raju potturi]

hi;
  will enabling SSL (node-to-node) cause an overhead in the performance of
Cassandra? We have tried it out on a small test cluster while running
Cassandra-stress tool, and did not see much difference in terms of read and
write latencies.
 Could somebody throw some light regarding any impact SSL will have on
large clusters in terms of performance. Thanks in advance.

Cassandra-version (2.1.15)

thanks
Sai

Re: Re : Cluster performance after enabling SSL

[Surbhi Gupta]

We have seen a little overhead in latencies while enabling the
client_encryption.
Our cluster gets around 40-50K reads and writes per second.

On 13 September 2016 at 12:01, sai krishnam raju potturi <
pskraj...@gmail.com> wrote:

> hi;
>   will enabling SSL (node-to-node) cause an overhead in the performance of
> Cassandra? We have tried it out on a small test cluster while running
> Cassandra-stress tool, and did not see much difference in terms of read and
> write latencies.
>  Could somebody throw some light regarding any impact SSL will have on
> large clusters in terms of performance. Thanks in advance.
>
> Cassandra-version (2.1.15)
>
> thanks
> Sai
>

Re: Re : Cluster performance after enabling SSL

[G P]

Read this:

http://www.aifb.kit.edu/images/5/58/IC2E2014-Performance_Overhead_TLS.pdf

It can cause bigger variances in latencies, but not much.

Terça-feira, 13 Setembro 2016, 08:01PM +01:00 de sai krishnam raju potturi 
pskraj...@gmail.com:

hi;
  will enabling SSL (node-to-node) cause an overhead in the performance of 
Cassandra? We have tried it out on a small test cluster while running 
Cassandra-stress tool, and did not see much difference in terms of read and 
write latencies.
 Could somebody throw some light regarding any impact SSL will have on 
large clusters in terms of performance. Thanks in advance.

Cassandra-version (2.1.15)

thanks
Sai