Re: Create table with ID - Question

[Ken Hancock]

So I confirmed with Aleksey before firmly sticking foot in mouth, but you
CAN do this through Thrift -- Thrift has an API for sending a CQL string
via the Thrift interface..  We used to do something similar through Hector.

Not sure if this strictly fits your "is this possible via Thrift
interface"...


On Wed, Sep 28, 2016 at 12:01 PM, Aleksey Yeschenko 
wrote:

> No way to do that via Thrift I’m afraid, nor will there be one. Sorry.
>
> --
> AY
>
> On 28 September 2016 at 16:43:58, Roman Bielik (roman.bielik@
> openmindnetworks.com) wrote:
>
> Hi,
>
> in CQL it is possible to create a table with explicit ID: CREATE TABLE ...
> WITH ID='xyz'.
>
> Is something like this possible via Thrift interface?
> There is an int32 "id" field in CfDef, but it has no effect on the table
> ID.
>
> My problem is, that concurrent create table (add_column_family) requests
> for the same table name result in clash with somewhat unpredictable
> behavior.
>
> This problem was reported in:
> https://issues.apache.org/jira/browse/CASSANDRA-9933
>
> and seems to be related to changes from ticket:
> https://issues.apache.org/jira/browse/CASSANDRA-5202
>
> A workaround for me could be using the same ID in create table, however I'm
> using Thrift interface only.
>
> Thank you.
> Regards,
> Roman
>
> --
>
> 
> 
>  
>

Re: Create table with ID - Question

[Edward Capriolo]

I have a similar set of problems. I will set the stage: in the past, for a
variety of reasons I had to create tables(column families) by time range
for an event processing system.

The man reason was expiring data (TTL) did not purge easily. It was easier
to simply truncate/drop old column families than two deal with different
evolving compaction strategies.

The main loop of my program looked like this:
public void writeThisStuff(List event ){
  MutationBatch mb;
  for (Event event : events){
mb.add(event)
  }
  maybeCreateNeededTables(mb)
  executeBatch(mb);
}

public void maybeCreateNeededTables(mb){
  Set columnFamilieToCreate =
  for (mutation : batch) {
 columnFamiliesToCreate.add(extractColumnFamilyFromMutation(mutation));
  }
  for (String cf: columnFamiliesToCreate){
 if ! hectorAstyanaxFlavoroftheweekclientDoesCfExist(cf)){
hectorAstyanaxFlavoroftheweekclienCreateCf(cf);
 }
  }
}

The size of the batches were in the 5-10K range. For a given batch the
number of target cfs was typically one, but at most two. That mean worst
case scenario 1 would need to be created. Effectively this meant 1 metadata
read before write. (You could cache the already existing columns as well).
One quick read is not a huge cost when you consider the savings of batching
5K roundtrips.

Even with this type of scenario you can run into a concurrent schema
problem. But you can add whatever gizmo to confirm schema agreement here:

  for (String cf: columnFamiliesToCreate){
*waitForSchemaToSettleGizmo()*
 if ! hectorAstyanaxFlavoroftheweekclientDoesCfExist(cf)){
*waitForSchemaToSettleGizmo()*
hectorAstyanaxFlavoroftheweekclienCreateCf(cf);
 }
  }

On Wed, Sep 28, 2016 at 12:01 PM, Aleksey Yeschenko 
wrote:

> No way to do that via Thrift I’m afraid, nor will there be one. Sorry.
>
> --
> AY
>
> On 28 September 2016 at 16:43:58, Roman Bielik (roman.bielik@
> openmindnetworks.com) wrote:
>
> Hi,
>
> in CQL it is possible to create a table with explicit ID: CREATE TABLE ...
> WITH ID='xyz'.
>
> Is something like this possible via Thrift interface?
> There is an int32 "id" field in CfDef, but it has no effect on the table
> ID.
>
> My problem is, that concurrent create table (add_column_family) requests
> for the same table name result in clash with somewhat unpredictable
> behavior.
>
> This problem was reported in:
> https://issues.apache.org/jira/browse/CASSANDRA-9933
>
> and seems to be related to changes from ticket:
> https://issues.apache.org/jira/browse/CASSANDRA-5202
>
> A workaround for me could be using the same ID in create table, however I'm
> using Thrift interface only.
>
> Thank you.
> Regards,
> Roman
>
> --
>
> 
> 
>  
>

Re: Create table with ID - Question

[Aleksey Yeschenko]

No way to do that via Thrift I’m afraid, nor will there be one. Sorry.

-- 
AY

On 28 September 2016 at 16:43:58, Roman Bielik 
(roman.bie...@openmindnetworks.com) wrote:

Hi,  

in CQL it is possible to create a table with explicit ID: CREATE TABLE ...  
WITH ID='xyz'.  

Is something like this possible via Thrift interface?  
There is an int32 "id" field in CfDef, but it has no effect on the table ID.  

My problem is, that concurrent create table (add_column_family) requests  
for the same table name result in clash with somewhat unpredictable  
behavior.  

This problem was reported in:  
https://issues.apache.org/jira/browse/CASSANDRA-9933  

and seems to be related to changes from ticket:  
https://issues.apache.org/jira/browse/CASSANDRA-5202  

A workaround for me could be using the same ID in create table, however I'm  
using Thrift interface only.  

Thank you.  
Regards,  
Roman  

--  

  
  
   

Create table with ID - Question

[Roman Bielik]

Hi,

in CQL it is possible to create a table with explicit ID: CREATE TABLE ...
WITH ID='xyz'.

Is something like this possible via Thrift interface?
There is an int32 "id" field in CfDef, but it has no effect on the table ID.

My problem is, that concurrent create table (add_column_family) requests
for the same table name result in clash with somewhat unpredictable
behavior.

This problem was reported in:
https://issues.apache.org/jira/browse/CASSANDRA-9933

and seems to be related to changes from ticket:
https://issues.apache.org/jira/browse/CASSANDRA-5202

A workaround for me could be using the same ID in create table, however I'm
using Thrift interface only.

Thank you.
Regards,
Roman

--