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Posted to user@cassandra.apache.org by Rajesh Kishore <ra...@gmail.com> on 2018/04/19 05:35:49 UTC
Does Cassandra supports ACID txn
Hi,
I am bit confused by reading different articles, does recent version of
Cassandra supports ACID transaction ?
I found BATCH command , but not sure if it supports rollback, consider that
transaction I am going to perform would be on single partition.
Also, what are the limitations if any?
Thanks,
Rajesh
Re: Does Cassandra supports ACID txn
Posted by daemeon reiydelle <da...@gmail.com>.
If ACID is needed, then C* is the wrong architecture. Your architecture
needs to match to your business processes as Ben pointed out: "Ask if it’s
really needed"
There is a concept of a velocity file (modern tech is memSQL'ish) that
delivers the high performance, acid transactions of lambda architectures.
It means the architecture is designed to support ONLY those functions that
need to be acid'ic. FYI, velocity files are the ultra-fast record of ATM
transactions that "just" happened, and are slowly replicated to the
persistent account balances.
So again, design your application architecture to support your needs. C* is
BASIC. Learn to love it. It is basically your friend in big data, high
volume ANSI SQL solutions.
<======>
"When I finish a project for a client, I have ... learned their issues with
life,
their personal secrets, I have come to care about them.
Once the project is over, I lose them as if I lost family.
For the client, however, they’ve just dismissed a service worker." ...
"Thought on the Gig Economy" by Francine Brevetti
On Wed, Apr 25, 2018 at 8:33 PM, Ben Slater <be...@instaclustr.com>
wrote:
> Would be interested to hear if anyone else has any different approaches
> but my approaches would be:
> 1) Ask if it’s really needed - in the example you gave would it really
> matter that, for a small period of time, the hotel appeared in once kind of
> search but not another? (Although clearly there are examples where it might
> matter.)
> 2) Put the state that matters in a single table. In this example, have a
> hotel_enabled table. Search would have to both find the hotel in one of
> your hotel_by_* tables and then look up the hotel in hotel_enabled to
> check it is really enabled. “deleting” a hotel is then a single write to
> hotel_enabled. hotel_enabled could also be something like hotel_details so
> the other tables really are just indexes. You need to do more reads but
> whatever you do consistency doesn’t come for free.
>
> Cheers
> Ben
>
>
> On Thu, 26 Apr 2018 at 12:44 Rajesh Kishore <ra...@gmail.com>
> wrote:
>
>> Correction from previous query
>>
>>
>> Thanks Ben and all experts.
>>
>> I am almost a newbie to NoSQL world and thus I have a very general
>> question how does consumer application of Cassandra/other NoSQL
>> technologies deal with atomicity & other factors when there is need to *de-normalize
>> *data. For example:
>>
>> Let us say I have requirement for queries
>> - find all hotels by name
>> - Find all hotels by Point of Interest (POI)
>> - Find POI near by a hotel
>>
>> For these queries I would end up more or less in following tables
>> hotels_by_name(hotel_name,hotel_id,city,........) primary key -
>> hotel_name
>> hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
>> poi_name
>> poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
>> key - hotel_id
>>
>> So, If I have to add/remove a hotel from/into hotels_by_name , I may need
>> to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
>> assumption is these operations would need to be atomic( and may be
>> supporting other ACID properties) . How these kind of operations/usecases
>> being handled in Cassandra/NoSQL world?
>>
>> Appreciate your response.
>>
>> Thanks,
>> Rajesh
>>
>> On Thu, Apr 26, 2018 at 8:05 AM, Rajesh Kishore <ra...@gmail.com>
>> wrote:
>>
>>> Thanks Ben and all experts.
>>>
>>> I am almost a newbie to NoSQL world and thus I have a very general
>>> question how does consumer application of Cassandra/other NoSQL
>>> technologies deal with atomicity & other factors when there is need to
>>> normalize data. For example:
>>>
>>> Let us say I have requirement for queries
>>> - find all hotels by name
>>> - Find all hotels by Point of Interest (POI)
>>> - Find POI near by a hotel
>>>
>>> For these queries I would end up more or less in following tables
>>> hotels_by_name(hotel_name,hotel_id,city,........) primary key -
>>> hotel_name
>>> hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
>>> poi_name
>>> poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......)
>>> primary key - hotel_id
>>>
>>> So, If I have to add/remove a hotel from/into hotels_by_name , I may
>>> need to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
>>> assumption is these operations would need to be atomic( and may be
>>> supporting other ACID properties) . How these kind of operations/usecases
>>> being handled in Cassandra/NoSQL world?
>>>
>>> Appreciate your response.
>>>
>>> Thanks,
>>> Rajesh
>>>
>>>
>>>
>>> On Fri, Apr 20, 2018 at 11:07 AM, Ben Slater <ben.slater@instaclustr.com
>>> > wrote:
>>>
>>>> The second SO answer just says the partitions will be collocated (ie on
>>>> the same server) not that the two tables will use the same partition. In
>>>> any event, Cassandra does not have the kind of functionality you are
>>>> looking for. The closest is logged batch but as Sylvain said, "all that
>>>> guarantees is that if some operations of a batch are applied, then all
>>>> of them will
>>>> *eventually* get applied” and “batch have no rollback whatsoever”.
>>>>
>>>> As Cassandra won’t help you here, a potential (although admittedly more
>>>> complex) option is to do implement compensating transactions at the
>>>> application level (eg in the catch block delete the records that were
>>>> inserted). That, however, does not provide you the isolation part of ACID.
>>>>
>>>> You also tend to find that if you have properly denormalised your data
>>>> model for Cassandra there is less requirement for these type of batched
>>>> updates.
>>>>
>>>> Cheers
>>>> Ben
>>>>
>>>> On Fri, 20 Apr 2018 at 15:21 Rajesh Kishore <ra...@gmail.com>
>>>> wrote:
>>>>
>>>>> Re-framing my question:
>>>>>
>>>>> So, it means that having different tables will not result into same
>>>>> partition even though you have same partition key.
>>>>> Ex.
>>>>> TableA( Partionkey(id))
>>>>> TableB( Partionkey(id))
>>>>> TableC( Partionkey(id))
>>>>>
>>>>>
>>>>> and as part of batch operation I am somehow providing same id say "20"
>>>>> It wont be considered as Atomic as it will result into different
>>>>> partition key and there would not be any way to rollback ?
>>>>> The same is being claimed in https://stackoverflow.com/
>>>>> questions/36700859/does-the-same-partition-key-in-
>>>>> different-cassandra-tables-add-up-to-cell-theoret
>>>>>
>>>>> Now, the other forum says that how we can keep two tables in same
>>>>> partition
>>>>> https://stackoverflow.com/questions/34294830/how-to-
>>>>> keep-2-cassandra-tables-within-same-partition
>>>>>
>>>>> Which one is correct ? Please confirm
>>>>>
>>>>> Basically , our requirement is - we should be able to achieve similar
>>>>> functionality as that of JDBC
>>>>> try {
>>>>> txn.start()
>>>>> operation a
>>>>> operation b
>>>>>
>>>>> ......
>>>>> operation n
>>>>> txn.commit();
>>>>> } catch (Exception e)
>>>>> {
>>>>> txn.rollback()
>>>>> }
>>>>>
>>>>> Thanks in advance.
>>>>>
>>>>> Regards,
>>>>> Rajesh
>>>>>
>>>>> On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <
>>>>> rajesh10sinha@gmail.com> wrote:
>>>>>
>>>>>> So, it means that having different tables will not result into same
>>>>>> partition even though you have same partition key.
>>>>>> Ex.
>>>>>> TableA( Partionkey(id))
>>>>>> TableB( Partionkey(id))
>>>>>> TableC( Partionkey(id))
>>>>>>
>>>>>>
>>>>>> and as part of batch operation I am somehow providing same id say "20"
>>>>>> It wont be considered as Atomic as it will result into different
>>>>>> partition key and there would not be any way to rollback ?
>>>>>> The same is being claimed in https://stackoverflow.com/
>>>>>> questions/36700859/does-the-same-partition-key-in-
>>>>>> different-cassandra-tables-add-up-to-cell-theoret
>>>>>>
>>>>>> Please confirm
>>>>>>
>>>>>> Thanks in advance.
>>>>>>
>>>>>> Regards,
>>>>>> Rajesh
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
>>>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>>>
>>>>>>> When using BATCH on multiple tables you’ll need to use a LOGGED
>>>>>>> batch. When you send the request, it will be written to the batch log of
>>>>>>> all (relevant) nodes, when this write is successful it will be “
>>>>>>> accepted” and nodes will try to apply the batch operations. If for
>>>>>>> any reason a statement fails the node will keep retrying forever. In that
>>>>>>> case you may see partially applied batch until it’s fixed.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Note that you can’t mix BATCH and LWT on different
>>>>>>> tables/partitions.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> You can get more details here:
>>>>>>>
>>>>>>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>>>>>>
>>>>>>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>>>>>>
>>>>>>> *--*
>>>>>>>
>>>>>>> *Jacques-Henri Berthemet*
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>>>>>>> *Sent:* Thursday, April 19, 2018 11:13 AM
>>>>>>> *To:* user@cassandra.apache.org
>>>>>>>
>>>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Thanks for the response. Let me put my question again wrt a example
>>>>>>>
>>>>>>> I want to perform a atomic txn say insert/delete/update on a set of
>>>>>>> tables
>>>>>>>
>>>>>>> TableA
>>>>>>>
>>>>>>> TableB
>>>>>>>
>>>>>>> TableC
>>>>>>>
>>>>>>> When these are performed as batch operations and let us say
>>>>>>> something goes wrong while doing operation at TableC
>>>>>>>
>>>>>>> Would the system rollback the operations done for TableA TableB ?
>>>>>>>
>>>>>>> -Rajesh
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>>>>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>>>>
>>>>>>> Cassandra support LWT (Lightweight transactions), you may find this
>>>>>>> doc interesting:
>>>>>>>
>>>>>>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/
>>>>>>> dmlDataConsistencyTOC.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> In any case, LWT or BATCH you won’t have external control on the
>>>>>>> tx, it’s either done or not done. In case of timeout you won’t have
>>>>>>> a way to know if it worked or not.
>>>>>>>
>>>>>>> There is no way to rollback a statement/batch, the only way is to
>>>>>>> send an update to modify the partition to its previous state.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> *--*
>>>>>>>
>>>>>>> *Jacques-Henri Berthemet*
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>>>>>>> *Sent:* Thursday, April 19, 2018 9:10 AM
>>>>>>> *To:* user <us...@cassandra.apache.org>
>>>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> No ACID transaction any soon in Cassandra
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <
>>>>>>> rajesh10sinha@gmail.com> wrote:
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I am bit confused by reading different articles, does recent version
>>>>>>> of Cassandra supports ACID transaction ?
>>>>>>>
>>>>>>> I found BATCH command , but not sure if it supports rollback,
>>>>>>> consider that transaction I am going to perform would be on single
>>>>>>> partition.
>>>>>>>
>>>>>>> Also, what are the limitations if any?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Rajesh
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>> --
>>>>
>>>>
>>>> *Ben Slater*
>>>>
>>>> *Chief Product Officer <https://www.instaclustr.com/>*
>>>>
>>>> <https://www.facebook.com/instaclustr>
>>>> <https://twitter.com/instaclustr>
>>>> <https://www.linkedin.com/company/instaclustr>
>>>>
>>>> Read our latest technical blog posts here
>>>> <https://www.instaclustr.com/blog/>.
>>>>
>>>> This email has been sent on behalf of Instaclustr Pty. Limited
>>>> (Australia) and Instaclustr Inc (USA).
>>>>
>>>> This email and any attachments may contain confidential and legally
>>>> privileged information. If you are not the intended recipient, do not copy
>>>> or disclose its content, but please reply to this email immediately and
>>>> highlight the error to the sender and then immediately delete the message.
>>>>
>>>
>>>
>> --
>
>
> *Ben Slater*
>
> *Chief Product Officer <https://www.instaclustr.com/>*
>
> <https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr>
> <https://www.linkedin.com/company/instaclustr>
>
> Read our latest technical blog posts here
> <https://www.instaclustr.com/blog/>.
>
> This email has been sent on behalf of Instaclustr Pty. Limited (Australia)
> and Instaclustr Inc (USA).
>
> This email and any attachments may contain confidential and legally
> privileged information. If you are not the intended recipient, do not copy
> or disclose its content, but please reply to this email immediately and
> highlight the error to the sender and then immediately delete the message.
>
Re: Does Cassandra supports ACID txn
Posted by Ben Slater <be...@instaclustr.com>.
Would be interested to hear if anyone else has any different approaches but
my approaches would be:
1) Ask if it’s really needed - in the example you gave would it really
matter that, for a small period of time, the hotel appeared in once kind of
search but not another? (Although clearly there are examples where it might
matter.)
2) Put the state that matters in a single table. In this example, have a
hotel_enabled table. Search would have to both find the hotel in one of
your hotel_by_* tables and then look up the hotel in hotel_enabled to
check it is really enabled. “deleting” a hotel is then a single write to
hotel_enabled. hotel_enabled could also be something like hotel_details so
the other tables really are just indexes. You need to do more reads but
whatever you do consistency doesn’t come for free.
Cheers
Ben
On Thu, 26 Apr 2018 at 12:44 Rajesh Kishore <ra...@gmail.com> wrote:
> Correction from previous query
>
>
> Thanks Ben and all experts.
>
> I am almost a newbie to NoSQL world and thus I have a very general
> question how does consumer application of Cassandra/other NoSQL
> technologies deal with atomicity & other factors when there is need to *de-normalize
> *data. For example:
>
> Let us say I have requirement for queries
> - find all hotels by name
> - Find all hotels by Point of Interest (POI)
> - Find POI near by a hotel
>
> For these queries I would end up more or less in following tables
> hotels_by_name(hotel_name,hotel_id,city,........) primary key - hotel_name
> hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
> poi_name
> poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
> key - hotel_id
>
> So, If I have to add/remove a hotel from/into hotels_by_name , I may need
> to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
> assumption is these operations would need to be atomic( and may be
> supporting other ACID properties) . How these kind of operations/usecases
> being handled in Cassandra/NoSQL world?
>
> Appreciate your response.
>
> Thanks,
> Rajesh
>
> On Thu, Apr 26, 2018 at 8:05 AM, Rajesh Kishore <ra...@gmail.com>
> wrote:
>
>> Thanks Ben and all experts.
>>
>> I am almost a newbie to NoSQL world and thus I have a very general
>> question how does consumer application of Cassandra/other NoSQL
>> technologies deal with atomicity & other factors when there is need to
>> normalize data. For example:
>>
>> Let us say I have requirement for queries
>> - find all hotels by name
>> - Find all hotels by Point of Interest (POI)
>> - Find POI near by a hotel
>>
>> For these queries I would end up more or less in following tables
>> hotels_by_name(hotel_name,hotel_id,city,........) primary key - hotel_name
>> hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
>> poi_name
>> poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
>> key - hotel_id
>>
>> So, If I have to add/remove a hotel from/into hotels_by_name , I may need
>> to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
>> assumption is these operations would need to be atomic( and may be
>> supporting other ACID properties) . How these kind of operations/usecases
>> being handled in Cassandra/NoSQL world?
>>
>> Appreciate your response.
>>
>> Thanks,
>> Rajesh
>>
>>
>>
>> On Fri, Apr 20, 2018 at 11:07 AM, Ben Slater <be...@instaclustr.com>
>> wrote:
>>
>>> The second SO answer just says the partitions will be collocated (ie on
>>> the same server) not that the two tables will use the same partition. In
>>> any event, Cassandra does not have the kind of functionality you are
>>> looking for. The closest is logged batch but as Sylvain said, "all that
>>> guarantees is that if some operations of a batch are applied, then all
>>> of them will
>>> *eventually* get applied” and “batch have no rollback whatsoever”.
>>>
>>> As Cassandra won’t help you here, a potential (although admittedly more
>>> complex) option is to do implement compensating transactions at the
>>> application level (eg in the catch block delete the records that were
>>> inserted). That, however, does not provide you the isolation part of ACID.
>>>
>>> You also tend to find that if you have properly denormalised your data
>>> model for Cassandra there is less requirement for these type of batched
>>> updates.
>>>
>>> Cheers
>>> Ben
>>>
>>> On Fri, 20 Apr 2018 at 15:21 Rajesh Kishore <ra...@gmail.com>
>>> wrote:
>>>
>>>> Re-framing my question:
>>>>
>>>> So, it means that having different tables will not result into same
>>>> partition even though you have same partition key.
>>>> Ex.
>>>> TableA( Partionkey(id))
>>>> TableB( Partionkey(id))
>>>> TableC( Partionkey(id))
>>>>
>>>>
>>>> and as part of batch operation I am somehow providing same id say "20"
>>>> It wont be considered as Atomic as it will result into different
>>>> partition key and there would not be any way to rollback ?
>>>> The same is being claimed in
>>>> https://stackoverflow.com/questions/36700859/does-the-same-partition-key-in-different-cassandra-tables-add-up-to-cell-theoret
>>>>
>>>> Now, the other forum says that how we can keep two tables in same
>>>> partition
>>>>
>>>> https://stackoverflow.com/questions/34294830/how-to-keep-2-cassandra-tables-within-same-partition
>>>>
>>>> Which one is correct ? Please confirm
>>>>
>>>> Basically , our requirement is - we should be able to achieve similar
>>>> functionality as that of JDBC
>>>> try {
>>>> txn.start()
>>>> operation a
>>>> operation b
>>>>
>>>> ......
>>>> operation n
>>>> txn.commit();
>>>> } catch (Exception e)
>>>> {
>>>> txn.rollback()
>>>> }
>>>>
>>>> Thanks in advance.
>>>>
>>>> Regards,
>>>> Rajesh
>>>>
>>>> On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <
>>>> rajesh10sinha@gmail.com> wrote:
>>>>
>>>>> So, it means that having different tables will not result into same
>>>>> partition even though you have same partition key.
>>>>> Ex.
>>>>> TableA( Partionkey(id))
>>>>> TableB( Partionkey(id))
>>>>> TableC( Partionkey(id))
>>>>>
>>>>>
>>>>> and as part of batch operation I am somehow providing same id say "20"
>>>>> It wont be considered as Atomic as it will result into different
>>>>> partition key and there would not be any way to rollback ?
>>>>> The same is being claimed in
>>>>> https://stackoverflow.com/questions/36700859/does-the-same-partition-key-in-different-cassandra-tables-add-up-to-cell-theoret
>>>>>
>>>>> Please confirm
>>>>>
>>>>> Thanks in advance.
>>>>>
>>>>> Regards,
>>>>> Rajesh
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
>>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>>
>>>>>> When using BATCH on multiple tables you’ll need to use a LOGGED
>>>>>> batch. When you send the request, it will be written to the batch log of
>>>>>> all (relevant) nodes, when this write is successful it will be “
>>>>>> accepted” and nodes will try to apply the batch operations. If for
>>>>>> any reason a statement fails the node will keep retrying forever. In that
>>>>>> case you may see partially applied batch until it’s fixed.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Note that you can’t mix BATCH and LWT on different tables/partitions.
>>>>>>
>>>>>>
>>>>>>
>>>>>> You can get more details here:
>>>>>>
>>>>>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>>>>>
>>>>>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>>>>>
>>>>>> *--*
>>>>>>
>>>>>> *Jacques-Henri Berthemet*
>>>>>>
>>>>>>
>>>>>>
>>>>>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>>>>>> *Sent:* Thursday, April 19, 2018 11:13 AM
>>>>>> *To:* user@cassandra.apache.org
>>>>>>
>>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>>
>>>>>>
>>>>>>
>>>>>> Thanks for the response. Let me put my question again wrt a example
>>>>>>
>>>>>> I want to perform a atomic txn say insert/delete/update on a set of
>>>>>> tables
>>>>>>
>>>>>> TableA
>>>>>>
>>>>>> TableB
>>>>>>
>>>>>> TableC
>>>>>>
>>>>>> When these are performed as batch operations and let us say something
>>>>>> goes wrong while doing operation at TableC
>>>>>>
>>>>>> Would the system rollback the operations done for TableA TableB ?
>>>>>>
>>>>>> -Rajesh
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>>>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>>>
>>>>>> Cassandra support LWT (Lightweight transactions), you may find this
>>>>>> doc interesting:
>>>>>>
>>>>>>
>>>>>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html
>>>>>>
>>>>>>
>>>>>>
>>>>>> In any case, LWT or BATCH you won’t have external control on the tx,
>>>>>> it’s either done or not done. In case of timeout you won’t have a
>>>>>> way to know if it worked or not.
>>>>>>
>>>>>> There is no way to rollback a statement/batch, the only way is to
>>>>>> send an update to modify the partition to its previous state.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> *--*
>>>>>>
>>>>>> *Jacques-Henri Berthemet*
>>>>>>
>>>>>>
>>>>>>
>>>>>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>>>>>> *Sent:* Thursday, April 19, 2018 9:10 AM
>>>>>> *To:* user <us...@cassandra.apache.org>
>>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>>
>>>>>>
>>>>>>
>>>>>> No ACID transaction any soon in Cassandra
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <
>>>>>> rajesh10sinha@gmail.com> wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I am bit confused by reading different articles, does recent version
>>>>>> of Cassandra supports ACID transaction ?
>>>>>>
>>>>>> I found BATCH command , but not sure if it supports rollback,
>>>>>> consider that transaction I am going to perform would be on single
>>>>>> partition.
>>>>>>
>>>>>> Also, what are the limitations if any?
>>>>>>
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Rajesh
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>> --
>>>
>>>
>>> *Ben Slater*
>>>
>>> *Chief Product Officer <https://www.instaclustr.com/>*
>>>
>>> <https://www.facebook.com/instaclustr>
>>> <https://twitter.com/instaclustr>
>>> <https://www.linkedin.com/company/instaclustr>
>>>
>>> Read our latest technical blog posts here
>>> <https://www.instaclustr.com/blog/>.
>>>
>>> This email has been sent on behalf of Instaclustr Pty. Limited
>>> (Australia) and Instaclustr Inc (USA).
>>>
>>> This email and any attachments may contain confidential and legally
>>> privileged information. If you are not the intended recipient, do not copy
>>> or disclose its content, but please reply to this email immediately and
>>> highlight the error to the sender and then immediately delete the message.
>>>
>>
>>
> --
*Ben Slater*
*Chief Product Officer <https://www.instaclustr.com/>*
<https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr>
<https://www.linkedin.com/company/instaclustr>
Read our latest technical blog posts here
<https://www.instaclustr.com/blog/>.
This email has been sent on behalf of Instaclustr Pty. Limited (Australia)
and Instaclustr Inc (USA).
This email and any attachments may contain confidential and legally
privileged information. If you are not the intended recipient, do not copy
or disclose its content, but please reply to this email immediately and
highlight the error to the sender and then immediately delete the message.
Re: Does Cassandra supports ACID txn
Posted by Rajesh Kishore <ra...@gmail.com>.
Correction from previous query
Thanks Ben and all experts.
I am almost a newbie to NoSQL world and thus I have a very general question
how does consumer application of Cassandra/other NoSQL technologies deal
with atomicity & other factors when there is need to *de-normalize *data.
For example:
Let us say I have requirement for queries
- find all hotels by name
- Find all hotels by Point of Interest (POI)
- Find POI near by a hotel
For these queries I would end up more or less in following tables
hotels_by_name(hotel_name,hotel_id,city,........) primary key - hotel_name
hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
poi_name
poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
key - hotel_id
So, If I have to add/remove a hotel from/into hotels_by_name , I may need
to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
assumption is these operations would need to be atomic( and may be
supporting other ACID properties) . How these kind of operations/usecases
being handled in Cassandra/NoSQL world?
Appreciate your response.
Thanks,
Rajesh
On Thu, Apr 26, 2018 at 8:05 AM, Rajesh Kishore <ra...@gmail.com>
wrote:
> Thanks Ben and all experts.
>
> I am almost a newbie to NoSQL world and thus I have a very general
> question how does consumer application of Cassandra/other NoSQL
> technologies deal with atomicity & other factors when there is need to
> normalize data. For example:
>
> Let us say I have requirement for queries
> - find all hotels by name
> - Find all hotels by Point of Interest (POI)
> - Find POI near by a hotel
>
> For these queries I would end up more or less in following tables
> hotels_by_name(hotel_name,hotel_id,city,........) primary key - hotel_name
> hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
> poi_name
> poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
> key - hotel_id
>
> So, If I have to add/remove a hotel from/into hotels_by_name , I may need
> to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
> assumption is these operations would need to be atomic( and may be
> supporting other ACID properties) . How these kind of operations/usecases
> being handled in Cassandra/NoSQL world?
>
> Appreciate your response.
>
> Thanks,
> Rajesh
>
>
>
> On Fri, Apr 20, 2018 at 11:07 AM, Ben Slater <be...@instaclustr.com>
> wrote:
>
>> The second SO answer just says the partitions will be collocated (ie on
>> the same server) not that the two tables will use the same partition. In
>> any event, Cassandra does not have the kind of functionality you are
>> looking for. The closest is logged batch but as Sylvain said, "all that
>> guarantees is that if some operations of a batch are applied, then all
>> of them will
>> *eventually* get applied” and “batch have no rollback whatsoever”.
>>
>> As Cassandra won’t help you here, a potential (although admittedly more
>> complex) option is to do implement compensating transactions at the
>> application level (eg in the catch block delete the records that were
>> inserted). That, however, does not provide you the isolation part of ACID.
>>
>> You also tend to find that if you have properly denormalised your data
>> model for Cassandra there is less requirement for these type of batched
>> updates.
>>
>> Cheers
>> Ben
>>
>> On Fri, 20 Apr 2018 at 15:21 Rajesh Kishore <ra...@gmail.com>
>> wrote:
>>
>>> Re-framing my question:
>>>
>>> So, it means that having different tables will not result into same
>>> partition even though you have same partition key.
>>> Ex.
>>> TableA( Partionkey(id))
>>> TableB( Partionkey(id))
>>> TableC( Partionkey(id))
>>>
>>>
>>> and as part of batch operation I am somehow providing same id say "20"
>>> It wont be considered as Atomic as it will result into different
>>> partition key and there would not be any way to rollback ?
>>> The same is being claimed in https://stackoverflow.com/ques
>>> tions/36700859/does-the-same-partition-key-in-different-
>>> cassandra-tables-add-up-to-cell-theoret
>>>
>>> Now, the other forum says that how we can keep two tables in same
>>> partition
>>> https://stackoverflow.com/questions/34294830/how-to-keep-2-
>>> cassandra-tables-within-same-partition
>>>
>>> Which one is correct ? Please confirm
>>>
>>> Basically , our requirement is - we should be able to achieve similar
>>> functionality as that of JDBC
>>> try {
>>> txn.start()
>>> operation a
>>> operation b
>>>
>>> ......
>>> operation n
>>> txn.commit();
>>> } catch (Exception e)
>>> {
>>> txn.rollback()
>>> }
>>>
>>> Thanks in advance.
>>>
>>> Regards,
>>> Rajesh
>>>
>>> On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <rajesh10sinha@gmail.com
>>> > wrote:
>>>
>>>> So, it means that having different tables will not result into same
>>>> partition even though you have same partition key.
>>>> Ex.
>>>> TableA( Partionkey(id))
>>>> TableB( Partionkey(id))
>>>> TableC( Partionkey(id))
>>>>
>>>>
>>>> and as part of batch operation I am somehow providing same id say "20"
>>>> It wont be considered as Atomic as it will result into different
>>>> partition key and there would not be any way to rollback ?
>>>> The same is being claimed in https://stackoverflow.com/ques
>>>> tions/36700859/does-the-same-partition-key-in-different-
>>>> cassandra-tables-add-up-to-cell-theoret
>>>>
>>>> Please confirm
>>>>
>>>> Thanks in advance.
>>>>
>>>> Regards,
>>>> Rajesh
>>>>
>>>>
>>>>
>>>> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>
>>>>> When using BATCH on multiple tables you’ll need to use a LOGGED
>>>>> batch. When you send the request, it will be written to the batch log of
>>>>> all (relevant) nodes, when this write is successful it will be “
>>>>> accepted” and nodes will try to apply the batch operations. If for
>>>>> any reason a statement fails the node will keep retrying forever. In that
>>>>> case you may see partially applied batch until it’s fixed.
>>>>>
>>>>>
>>>>>
>>>>> Note that you can’t mix BATCH and LWT on different tables/partitions.
>>>>>
>>>>>
>>>>>
>>>>> You can get more details here:
>>>>>
>>>>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>>>>
>>>>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>>>>
>>>>> *--*
>>>>>
>>>>> *Jacques-Henri Berthemet*
>>>>>
>>>>>
>>>>>
>>>>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>>>>> *Sent:* Thursday, April 19, 2018 11:13 AM
>>>>> *To:* user@cassandra.apache.org
>>>>>
>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>
>>>>>
>>>>>
>>>>> Thanks for the response. Let me put my question again wrt a example
>>>>>
>>>>> I want to perform a atomic txn say insert/delete/update on a set of
>>>>> tables
>>>>>
>>>>> TableA
>>>>>
>>>>> TableB
>>>>>
>>>>> TableC
>>>>>
>>>>> When these are performed as batch operations and let us say something
>>>>> goes wrong while doing operation at TableC
>>>>>
>>>>> Would the system rollback the operations done for TableA TableB ?
>>>>>
>>>>> -Rajesh
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>>
>>>>> Cassandra support LWT (Lightweight transactions), you may find this
>>>>> doc interesting:
>>>>>
>>>>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dml
>>>>> DataConsistencyTOC.html
>>>>>
>>>>>
>>>>>
>>>>> In any case, LWT or BATCH you won’t have external control on the tx,
>>>>> it’s either done or not done. In case of timeout you won’t have a way
>>>>> to know if it worked or not.
>>>>>
>>>>> There is no way to rollback a statement/batch, the only way is to send
>>>>> an update to modify the partition to its previous state.
>>>>>
>>>>>
>>>>>
>>>>> Regards,
>>>>>
>>>>> *--*
>>>>>
>>>>> *Jacques-Henri Berthemet*
>>>>>
>>>>>
>>>>>
>>>>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>>>>> *Sent:* Thursday, April 19, 2018 9:10 AM
>>>>> *To:* user <us...@cassandra.apache.org>
>>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>>
>>>>>
>>>>>
>>>>> No ACID transaction any soon in Cassandra
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <
>>>>> rajesh10sinha@gmail.com> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> I am bit confused by reading different articles, does recent version
>>>>> of Cassandra supports ACID transaction ?
>>>>>
>>>>> I found BATCH command , but not sure if it supports rollback, consider
>>>>> that transaction I am going to perform would be on single partition.
>>>>>
>>>>> Also, what are the limitations if any?
>>>>>
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Rajesh
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>> --
>>
>>
>> *Ben Slater*
>>
>> *Chief Product Officer <https://www.instaclustr.com/>*
>>
>> <https://www.facebook.com/instaclustr>
>> <https://twitter.com/instaclustr>
>> <https://www.linkedin.com/company/instaclustr>
>>
>> Read our latest technical blog posts here
>> <https://www.instaclustr.com/blog/>.
>>
>> This email has been sent on behalf of Instaclustr Pty. Limited
>> (Australia) and Instaclustr Inc (USA).
>>
>> This email and any attachments may contain confidential and legally
>> privileged information. If you are not the intended recipient, do not copy
>> or disclose its content, but please reply to this email immediately and
>> highlight the error to the sender and then immediately delete the message.
>>
>
>
Re: Does Cassandra supports ACID txn
Posted by Rajesh Kishore <ra...@gmail.com>.
Thanks Ben and all experts.
I am almost a newbie to NoSQL world and thus I have a very general question
how does consumer application of Cassandra/other NoSQL technologies deal
with atomicity & other factors when there is need to normalize data. For
example:
Let us say I have requirement for queries
- find all hotels by name
- Find all hotels by Point of Interest (POI)
- Find POI near by a hotel
For these queries I would end up more or less in following tables
hotels_by_name(hotel_name,hotel_id,city,........) primary key - hotel_name
hotels_by_poi(poi_name,poi_id,hotel_id,hotel_name,......) primary key -
poi_name
poi_by_hotel(hotel_id,poi_name,poi_id,poi_loc,hotel_name,......) primary
key - hotel_id
So, If I have to add/remove a hotel from/into hotels_by_name , I may need
to add/remove into/from tables hotels_by_poi/poi_by_hotel. So, here my
assumption is these operations would need to be atomic( and may be
supporting other ACID properties) . How these kind of operations/usecases
being handled in Cassandra/NoSQL world?
Appreciate your response.
Thanks,
Rajesh
On Fri, Apr 20, 2018 at 11:07 AM, Ben Slater <be...@instaclustr.com>
wrote:
> The second SO answer just says the partitions will be collocated (ie on
> the same server) not that the two tables will use the same partition. In
> any event, Cassandra does not have the kind of functionality you are
> looking for. The closest is logged batch but as Sylvain said, "all that
> guarantees is that if some operations of a batch are applied, then all of
> them will
> *eventually* get applied” and “batch have no rollback whatsoever”.
>
> As Cassandra won’t help you here, a potential (although admittedly more
> complex) option is to do implement compensating transactions at the
> application level (eg in the catch block delete the records that were
> inserted). That, however, does not provide you the isolation part of ACID.
>
> You also tend to find that if you have properly denormalised your data
> model for Cassandra there is less requirement for these type of batched
> updates.
>
> Cheers
> Ben
>
> On Fri, 20 Apr 2018 at 15:21 Rajesh Kishore <ra...@gmail.com>
> wrote:
>
>> Re-framing my question:
>>
>> So, it means that having different tables will not result into same
>> partition even though you have same partition key.
>> Ex.
>> TableA( Partionkey(id))
>> TableB( Partionkey(id))
>> TableC( Partionkey(id))
>>
>>
>> and as part of batch operation I am somehow providing same id say "20"
>> It wont be considered as Atomic as it will result into different
>> partition key and there would not be any way to rollback ?
>> The same is being claimed in https://stackoverflow.com/
>> questions/36700859/does-the-same-partition-key-in-
>> different-cassandra-tables-add-up-to-cell-theoret
>>
>> Now, the other forum says that how we can keep two tables in same
>> partition
>> https://stackoverflow.com/questions/34294830/how-to-
>> keep-2-cassandra-tables-within-same-partition
>>
>> Which one is correct ? Please confirm
>>
>> Basically , our requirement is - we should be able to achieve similar
>> functionality as that of JDBC
>> try {
>> txn.start()
>> operation a
>> operation b
>>
>> ......
>> operation n
>> txn.commit();
>> } catch (Exception e)
>> {
>> txn.rollback()
>> }
>>
>> Thanks in advance.
>>
>> Regards,
>> Rajesh
>>
>> On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <ra...@gmail.com>
>> wrote:
>>
>>> So, it means that having different tables will not result into same
>>> partition even though you have same partition key.
>>> Ex.
>>> TableA( Partionkey(id))
>>> TableB( Partionkey(id))
>>> TableC( Partionkey(id))
>>>
>>>
>>> and as part of batch operation I am somehow providing same id say "20"
>>> It wont be considered as Atomic as it will result into different
>>> partition key and there would not be any way to rollback ?
>>> The same is being claimed in https://stackoverflow.com/
>>> questions/36700859/does-the-same-partition-key-in-
>>> different-cassandra-tables-add-up-to-cell-theoret
>>>
>>> Please confirm
>>>
>>> Thanks in advance.
>>>
>>> Regards,
>>> Rajesh
>>>
>>>
>>>
>>> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
>>> jacques-henri.berthemet@genesys.com> wrote:
>>>
>>>> When using BATCH on multiple tables you’ll need to use a LOGGED batch.
>>>> When you send the request, it will be written to the batch log of all
>>>> (relevant) nodes, when this write is successful it will be “accepted”
>>>> and nodes will try to apply the batch operations. If for any reason a
>>>> statement fails the node will keep retrying forever. In that case you may
>>>> see partially applied batch until it’s fixed.
>>>>
>>>>
>>>>
>>>> Note that you can’t mix BATCH and LWT on different tables/partitions.
>>>>
>>>>
>>>>
>>>> You can get more details here:
>>>>
>>>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>>>
>>>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>>>
>>>> *--*
>>>>
>>>> *Jacques-Henri Berthemet*
>>>>
>>>>
>>>>
>>>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>>>> *Sent:* Thursday, April 19, 2018 11:13 AM
>>>> *To:* user@cassandra.apache.org
>>>>
>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>
>>>>
>>>>
>>>> Thanks for the response. Let me put my question again wrt a example
>>>>
>>>> I want to perform a atomic txn say insert/delete/update on a set of
>>>> tables
>>>>
>>>> TableA
>>>>
>>>> TableB
>>>>
>>>> TableC
>>>>
>>>> When these are performed as batch operations and let us say something
>>>> goes wrong while doing operation at TableC
>>>>
>>>> Would the system rollback the operations done for TableA TableB ?
>>>>
>>>> -Rajesh
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>>>> jacques-henri.berthemet@genesys.com> wrote:
>>>>
>>>> Cassandra support LWT (Lightweight transactions), you may find this doc
>>>> interesting:
>>>>
>>>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/
>>>> dmlDataConsistencyTOC.html
>>>>
>>>>
>>>>
>>>> In any case, LWT or BATCH you won’t have external control on the tx, it
>>>> ’s either done or not done. In case of timeout you won’t have a way to
>>>> know if it worked or not.
>>>>
>>>> There is no way to rollback a statement/batch, the only way is to send
>>>> an update to modify the partition to its previous state.
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>> *--*
>>>>
>>>> *Jacques-Henri Berthemet*
>>>>
>>>>
>>>>
>>>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>>>> *Sent:* Thursday, April 19, 2018 9:10 AM
>>>> *To:* user <us...@cassandra.apache.org>
>>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>>
>>>>
>>>>
>>>> No ACID transaction any soon in Cassandra
>>>>
>>>>
>>>>
>>>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <
>>>> rajesh10sinha@gmail.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> I am bit confused by reading different articles, does recent version of
>>>> Cassandra supports ACID transaction ?
>>>>
>>>> I found BATCH command , but not sure if it supports rollback, consider
>>>> that transaction I am going to perform would be on single partition.
>>>>
>>>> Also, what are the limitations if any?
>>>>
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Rajesh
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>> --
>
>
> *Ben Slater*
>
> *Chief Product Officer <https://www.instaclustr.com/>*
>
> <https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr>
> <https://www.linkedin.com/company/instaclustr>
>
> Read our latest technical blog posts here
> <https://www.instaclustr.com/blog/>.
>
> This email has been sent on behalf of Instaclustr Pty. Limited (Australia)
> and Instaclustr Inc (USA).
>
> This email and any attachments may contain confidential and legally
> privileged information. If you are not the intended recipient, do not copy
> or disclose its content, but please reply to this email immediately and
> highlight the error to the sender and then immediately delete the message.
>
Re: Does Cassandra supports ACID txn
Posted by Ben Slater <be...@instaclustr.com>.
The second SO answer just says the partitions will be collocated (ie on the
same server) not that the two tables will use the same partition. In any
event, Cassandra does not have the kind of functionality you are looking
for. The closest is logged batch but as Sylvain said, "all that guarantees
is that if some operations of a batch are applied, then all of them will
*eventually* get applied” and “batch have no rollback whatsoever”.
As Cassandra won’t help you here, a potential (although admittedly more
complex) option is to do implement compensating transactions at the
application level (eg in the catch block delete the records that were
inserted). That, however, does not provide you the isolation part of ACID.
You also tend to find that if you have properly denormalised your data
model for Cassandra there is less requirement for these type of batched
updates.
Cheers
Ben
On Fri, 20 Apr 2018 at 15:21 Rajesh Kishore <ra...@gmail.com> wrote:
> Re-framing my question:
>
> So, it means that having different tables will not result into same
> partition even though you have same partition key.
> Ex.
> TableA( Partionkey(id))
> TableB( Partionkey(id))
> TableC( Partionkey(id))
>
>
> and as part of batch operation I am somehow providing same id say "20"
> It wont be considered as Atomic as it will result into different partition
> key and there would not be any way to rollback ?
> The same is being claimed in
> https://stackoverflow.com/questions/36700859/does-the-same-partition-key-in-different-cassandra-tables-add-up-to-cell-theoret
>
> Now, the other forum says that how we can keep two tables in same partition
>
> https://stackoverflow.com/questions/34294830/how-to-keep-2-cassandra-tables-within-same-partition
>
> Which one is correct ? Please confirm
>
> Basically , our requirement is - we should be able to achieve similar
> functionality as that of JDBC
> try {
> txn.start()
> operation a
> operation b
>
> ......
> operation n
> txn.commit();
> } catch (Exception e)
> {
> txn.rollback()
> }
>
> Thanks in advance.
>
> Regards,
> Rajesh
>
> On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <ra...@gmail.com>
> wrote:
>
>> So, it means that having different tables will not result into same
>> partition even though you have same partition key.
>> Ex.
>> TableA( Partionkey(id))
>> TableB( Partionkey(id))
>> TableC( Partionkey(id))
>>
>>
>> and as part of batch operation I am somehow providing same id say "20"
>> It wont be considered as Atomic as it will result into different
>> partition key and there would not be any way to rollback ?
>> The same is being claimed in
>> https://stackoverflow.com/questions/36700859/does-the-same-partition-key-in-different-cassandra-tables-add-up-to-cell-theoret
>>
>> Please confirm
>>
>> Thanks in advance.
>>
>> Regards,
>> Rajesh
>>
>>
>>
>> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
>> jacques-henri.berthemet@genesys.com> wrote:
>>
>>> When using BATCH on multiple tables you’ll need to use a LOGGED batch.
>>> When you send the request, it will be written to the batch log of all
>>> (relevant) nodes, when this write is successful it will be “accepted”
>>> and nodes will try to apply the batch operations. If for any reason a
>>> statement fails the node will keep retrying forever. In that case you may
>>> see partially applied batch until it’s fixed.
>>>
>>>
>>>
>>> Note that you can’t mix BATCH and LWT on different tables/partitions.
>>>
>>>
>>>
>>> You can get more details here:
>>>
>>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>>
>>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>>
>>> *--*
>>>
>>> *Jacques-Henri Berthemet*
>>>
>>>
>>>
>>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>>> *Sent:* Thursday, April 19, 2018 11:13 AM
>>> *To:* user@cassandra.apache.org
>>>
>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>
>>>
>>>
>>> Thanks for the response. Let me put my question again wrt a example
>>>
>>> I want to perform a atomic txn say insert/delete/update on a set of
>>> tables
>>>
>>> TableA
>>>
>>> TableB
>>>
>>> TableC
>>>
>>> When these are performed as batch operations and let us say something
>>> goes wrong while doing operation at TableC
>>>
>>> Would the system rollback the operations done for TableA TableB ?
>>>
>>> -Rajesh
>>>
>>>
>>>
>>>
>>>
>>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>>> jacques-henri.berthemet@genesys.com> wrote:
>>>
>>> Cassandra support LWT (Lightweight transactions), you may find this doc
>>> interesting:
>>>
>>>
>>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html
>>>
>>>
>>>
>>> In any case, LWT or BATCH you won’t have external control on the tx, it’s
>>> either done or not done. In case of timeout you won’t have a way to
>>> know if it worked or not.
>>>
>>> There is no way to rollback a statement/batch, the only way is to send
>>> an update to modify the partition to its previous state.
>>>
>>>
>>>
>>> Regards,
>>>
>>> *--*
>>>
>>> *Jacques-Henri Berthemet*
>>>
>>>
>>>
>>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>>> *Sent:* Thursday, April 19, 2018 9:10 AM
>>> *To:* user <us...@cassandra.apache.org>
>>> *Subject:* Re: Does Cassandra supports ACID txn
>>>
>>>
>>>
>>> No ACID transaction any soon in Cassandra
>>>
>>>
>>>
>>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
>>> wrote:
>>>
>>> Hi,
>>>
>>> I am bit confused by reading different articles, does recent version of
>>> Cassandra supports ACID transaction ?
>>>
>>> I found BATCH command , but not sure if it supports rollback, consider
>>> that transaction I am going to perform would be on single partition.
>>>
>>> Also, what are the limitations if any?
>>>
>>>
>>>
>>> Thanks,
>>>
>>> Rajesh
>>>
>>>
>>>
>>>
>>>
>>
>>
> --
*Ben Slater*
*Chief Product Officer <https://www.instaclustr.com/>*
<https://www.facebook.com/instaclustr> <https://twitter.com/instaclustr>
<https://www.linkedin.com/company/instaclustr>
Read our latest technical blog posts here
<https://www.instaclustr.com/blog/>.
This email has been sent on behalf of Instaclustr Pty. Limited (Australia)
and Instaclustr Inc (USA).
This email and any attachments may contain confidential and legally
privileged information. If you are not the intended recipient, do not copy
or disclose its content, but please reply to this email immediately and
highlight the error to the sender and then immediately delete the message.
Re: Does Cassandra supports ACID txn
Posted by Rajesh Kishore <ra...@gmail.com>.
Re-framing my question:
So, it means that having different tables will not result into same
partition even though you have same partition key.
Ex.
TableA( Partionkey(id))
TableB( Partionkey(id))
TableC( Partionkey(id))
and as part of batch operation I am somehow providing same id say "20"
It wont be considered as Atomic as it will result into different partition
key and there would not be any way to rollback ?
The same is being claimed in https://stackoverflow.com/
questions/36700859/does-the-same-partition-key-in-
different-cassandra-tables-add-up-to-cell-theoret
Now, the other forum says that how we can keep two tables in same partition
https://stackoverflow.com/questions/34294830/how-to-keep-2-cassandra-tables-within-same-partition
Which one is correct ? Please confirm
Basically , our requirement is - we should be able to achieve similar
functionality as that of JDBC
try {
txn.start()
operation a
operation b
......
operation n
txn.commit();
} catch (Exception e)
{
txn.rollback()
}
Thanks in advance.
Regards,
Rajesh
On Fri, Apr 20, 2018 at 9:38 AM, Rajesh Kishore <ra...@gmail.com>
wrote:
> So, it means that having different tables will not result into same
> partition even though you have same partition key.
> Ex.
> TableA( Partionkey(id))
> TableB( Partionkey(id))
> TableC( Partionkey(id))
>
>
> and as part of batch operation I am somehow providing same id say "20"
> It wont be considered as Atomic as it will result into different partition
> key and there would not be any way to rollback ?
> The same is being claimed in https://stackoverflow.com/
> questions/36700859/does-the-same-partition-key-in-
> different-cassandra-tables-add-up-to-cell-theoret
>
> Please confirm
>
> Thanks in advance.
>
> Regards,
> Rajesh
>
>
>
> On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
> jacques-henri.berthemet@genesys.com> wrote:
>
>> When using BATCH on multiple tables you’ll need to use a LOGGED batch.
>> When you send the request, it will be written to the batch log of all
>> (relevant) nodes, when this write is successful it will be “accepted”
>> and nodes will try to apply the batch operations. If for any reason a
>> statement fails the node will keep retrying forever. In that case you may
>> see partially applied batch until it’s fixed.
>>
>>
>>
>> Note that you can’t mix BATCH and LWT on different tables/partitions.
>>
>>
>>
>> You can get more details here:
>>
>> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>>
>> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>>
>> *--*
>>
>> *Jacques-Henri Berthemet*
>>
>>
>>
>> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
>> *Sent:* Thursday, April 19, 2018 11:13 AM
>> *To:* user@cassandra.apache.org
>>
>> *Subject:* Re: Does Cassandra supports ACID txn
>>
>>
>>
>> Thanks for the response. Let me put my question again wrt a example
>>
>> I want to perform a atomic txn say insert/delete/update on a set of tables
>>
>> TableA
>>
>> TableB
>>
>> TableC
>>
>> When these are performed as batch operations and let us say something
>> goes wrong while doing operation at TableC
>>
>> Would the system rollback the operations done for TableA TableB ?
>>
>> -Rajesh
>>
>>
>>
>>
>>
>> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
>> jacques-henri.berthemet@genesys.com> wrote:
>>
>> Cassandra support LWT (Lightweight transactions), you may find this doc
>> interesting:
>>
>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dml
>> DataConsistencyTOC.html
>>
>>
>>
>> In any case, LWT or BATCH you won’t have external control on the tx, it’s
>> either done or not done. In case of timeout you won’t have a way to know
>> if it worked or not.
>>
>> There is no way to rollback a statement/batch, the only way is to send an
>> update to modify the partition to its previous state.
>>
>>
>>
>> Regards,
>>
>> *--*
>>
>> *Jacques-Henri Berthemet*
>>
>>
>>
>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>> *Sent:* Thursday, April 19, 2018 9:10 AM
>> *To:* user <us...@cassandra.apache.org>
>> *Subject:* Re: Does Cassandra supports ACID txn
>>
>>
>>
>> No ACID transaction any soon in Cassandra
>>
>>
>>
>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
>> wrote:
>>
>> Hi,
>>
>> I am bit confused by reading different articles, does recent version of
>> Cassandra supports ACID transaction ?
>>
>> I found BATCH command , but not sure if it supports rollback, consider
>> that transaction I am going to perform would be on single partition.
>>
>> Also, what are the limitations if any?
>>
>>
>>
>> Thanks,
>>
>> Rajesh
>>
>>
>>
>>
>>
>
>
Re: Does Cassandra supports ACID txn
Posted by Rajesh Kishore <ra...@gmail.com>.
So, it means that having different tables will not result into same
partition even though you have same partition key.
Ex.
TableA( Partionkey(id))
TableB( Partionkey(id))
TableC( Partionkey(id))
and as part of batch operation I am somehow providing same id say "20"
It wont be considered as Atomic as it will result into different partition
key and there would not be any way to rollback ?
The same is being claimed in
https://stackoverflow.com/questions/36700859/does-the-same-partition-key-in-different-cassandra-tables-add-up-to-cell-theoret
Please confirm
Thanks in advance.
Regards,
Rajesh
On Thu, Apr 19, 2018 at 3:10 PM, Jacques-Henri Berthemet <
jacques-henri.berthemet@genesys.com> wrote:
> When using BATCH on multiple tables you’ll need to use a LOGGED batch.
> When you send the request, it will be written to the batch log of all
> (relevant) nodes, when this write is successful it will be “accepted” and
> nodes will try to apply the batch operations. If for any reason a statement
> fails the node will keep retrying forever. In that case you may see
> partially applied batch until it’s fixed.
>
>
>
> Note that you can’t mix BATCH and LWT on different tables/partitions.
>
>
>
> You can get more details here:
>
> http://cassandra.apache.org/doc/latest/cql/dml.html#batch
>
> https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
>
> *--*
>
> *Jacques-Henri Berthemet*
>
>
>
> *From:* Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
> *Sent:* Thursday, April 19, 2018 11:13 AM
> *To:* user@cassandra.apache.org
>
> *Subject:* Re: Does Cassandra supports ACID txn
>
>
>
> Thanks for the response. Let me put my question again wrt a example
>
> I want to perform a atomic txn say insert/delete/update on a set of tables
>
> TableA
>
> TableB
>
> TableC
>
> When these are performed as batch operations and let us say something goes
> wrong while doing operation at TableC
>
> Would the system rollback the operations done for TableA TableB ?
>
> -Rajesh
>
>
>
>
>
> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
> jacques-henri.berthemet@genesys.com> wrote:
>
> Cassandra support LWT (Lightweight transactions), you may find this doc
> interesting:
>
> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/
> dmlDataConsistencyTOC.html
>
>
>
> In any case, LWT or BATCH you won’t have external control on the tx, it’s
> either done or not done. In case of timeout you won’t have a way to know
> if it worked or not.
>
> There is no way to rollback a statement/batch, the only way is to send an
> update to modify the partition to its previous state.
>
>
>
> Regards,
>
> *--*
>
> *Jacques-Henri Berthemet*
>
>
>
> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
> *Sent:* Thursday, April 19, 2018 9:10 AM
> *To:* user <us...@cassandra.apache.org>
> *Subject:* Re: Does Cassandra supports ACID txn
>
>
>
> No ACID transaction any soon in Cassandra
>
>
>
> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
> wrote:
>
> Hi,
>
> I am bit confused by reading different articles, does recent version of
> Cassandra supports ACID transaction ?
>
> I found BATCH command , but not sure if it supports rollback, consider
> that transaction I am going to perform would be on single partition.
>
> Also, what are the limitations if any?
>
>
>
> Thanks,
>
> Rajesh
>
>
>
>
>
RE: Does Cassandra supports ACID txn
Posted by Jacques-Henri Berthemet <ja...@genesys.com>.
When using BATCH on multiple tables you’ll need to use a LOGGED batch. When you send the request, it will be written to the batch log of all (relevant) nodes, when this write is successful it will be “accepted” and nodes will try to apply the batch operations. If for any reason a statement fails the node will keep retrying forever. In that case you may see partially applied batch until it’s fixed.
Note that you can’t mix BATCH and LWT on different tables/partitions.
You can get more details here:
http://cassandra.apache.org/doc/latest/cql/dml.html#batch
https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/
--
Jacques-Henri Berthemet
From: Rajesh Kishore [mailto:rajesh10sinha@gmail.com]
Sent: Thursday, April 19, 2018 11:13 AM
To: user@cassandra.apache.org
Subject: Re: Does Cassandra supports ACID txn
Thanks for the response. Let me put my question again wrt a example
I want to perform a atomic txn say insert/delete/update on a set of tables
TableA
TableB
TableC
When these are performed as batch operations and let us say something goes wrong while doing operation at TableC
Would the system rollback the operations done for TableA TableB ?
-Rajesh
On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <ja...@genesys.com>> wrote:
Cassandra support LWT (Lightweight transactions), you may find this doc interesting:
https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html<https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html>
In any case, LWT or BATCH you won’t have external control on the tx, it’s either done or not done. In case of timeout you won’t have a way to know if it worked or not.
There is no way to rollback a statement/batch, the only way is to send an update to modify the partition to its previous state.
Regards,
--
Jacques-Henri Berthemet
From: DuyHai Doan [mailto:doanduyhai@gmail.com<ma...@gmail.com>]
Sent: Thursday, April 19, 2018 9:10 AM
To: user <us...@cassandra.apache.org>>
Subject: Re: Does Cassandra supports ACID txn
No ACID transaction any soon in Cassandra
On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>> wrote:
Hi,
I am bit confused by reading different articles, does recent version of Cassandra supports ACID transaction ?
I found BATCH command , but not sure if it supports rollback, consider that transaction I am going to perform would be on single partition.
Also, what are the limitations if any?
Thanks,
Rajesh
Re: Does Cassandra supports ACID txn
Posted by Sylvain Lebresne <le...@gmail.com>.
On Thu, Apr 19, 2018 at 11:13 AM Rajesh Kishore <ra...@gmail.com>
wrote:
> Thanks for the response. Let me put my question again wrt a example
>
> I want to perform a atomic txn say insert/delete/update on a set of tables
> TableA
> TableB
> TableC
>
> When these are performed as batch operations and let us say something goes
> wrong while doing operation at TableC
> Would the system rollback the operations done for TableA TableB ?
>
No, batch have no rollback whatsoever.
Batch[1] use a distributed log however which make it so that the operation
on TableC will be retried internally until it
succeeds, so the guarantee you do get is that if some operations of a batch
are applied, then all of them will
*eventually* get applied. There is no isolation however, and you can very
well observer a state where you can read
the operations on TableA and TableB without seeing the ones on TableC
because they haven't been retried yet.
> -Rajesh
>
>
>
> On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
> jacques-henri.berthemet@genesys.com> wrote:
>
>> Cassandra support LWT (Lightweight transactions), you may find this doc
>> interesting:
>>
>>
>> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html
>>
>>
>>
>> In any case, LWT or BATCH you won’t have external control on the tx, it’s
>> either done or not done. In case of timeout you won’t have a way to know
>> if it worked or not.
>>
>> There is no way to rollback a statement/batch, the only way is to send an
>> update to modify the partition to its previous state.
>>
>>
>>
>> Regards,
>>
>> *--*
>>
>> *Jacques-Henri Berthemet*
>>
>>
>>
>> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
>> *Sent:* Thursday, April 19, 2018 9:10 AM
>> *To:* user <us...@cassandra.apache.org>
>> *Subject:* Re: Does Cassandra supports ACID txn
>>
>>
>>
>> No ACID transaction any soon in Cassandra
>>
>>
>>
>> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
>> wrote:
>>
>> Hi,
>>
>> I am bit confused by reading different articles, does recent version of
>> Cassandra supports ACID transaction ?
>>
>> I found BATCH command , but not sure if it supports rollback, consider
>> that transaction I am going to perform would be on single partition.
>>
>> Also, what are the limitations if any?
>>
>>
>>
>> Thanks,
>>
>> Rajesh
>>
>>
>>
>
>
Re: Does Cassandra supports ACID txn
Posted by Rajesh Kishore <ra...@gmail.com>.
Thanks for the response. Let me put my question again wrt a example
I want to perform a atomic txn say insert/delete/update on a set of tables
TableA
TableB
TableC
When these are performed as batch operations and let us say something goes
wrong while doing operation at TableC
Would the system rollback the operations done for TableA TableB ?
-Rajesh
On Thu, Apr 19, 2018 at 1:25 PM, Jacques-Henri Berthemet <
jacques-henri.berthemet@genesys.com> wrote:
> Cassandra support LWT (Lightweight transactions), you may find this doc
> interesting:
>
> https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/
> dmlDataConsistencyTOC.html
>
>
>
> In any case, LWT or BATCH you won’t have external control on the tx, it’s
> either done or not done. In case of timeout you won’t have a way to know
> if it worked or not.
>
> There is no way to rollback a statement/batch, the only way is to send an
> update to modify the partition to its previous state.
>
>
>
> Regards,
>
> *--*
>
> *Jacques-Henri Berthemet*
>
>
>
> *From:* DuyHai Doan [mailto:doanduyhai@gmail.com]
> *Sent:* Thursday, April 19, 2018 9:10 AM
> *To:* user <us...@cassandra.apache.org>
> *Subject:* Re: Does Cassandra supports ACID txn
>
>
>
> No ACID transaction any soon in Cassandra
>
>
>
> On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
> wrote:
>
> Hi,
>
> I am bit confused by reading different articles, does recent version of
> Cassandra supports ACID transaction ?
>
> I found BATCH command , but not sure if it supports rollback, consider
> that transaction I am going to perform would be on single partition.
>
> Also, what are the limitations if any?
>
>
>
> Thanks,
>
> Rajesh
>
>
>
RE: Does Cassandra supports ACID txn
Posted by Jacques-Henri Berthemet <ja...@genesys.com>.
Cassandra support LWT (Lightweight transactions), you may find this doc interesting:
https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlDataConsistencyTOC.html
In any case, LWT or BATCH you won’t have external control on the tx, it’s either done or not done. In case of timeout you won’t have a way to know if it worked or not.
There is no way to rollback a statement/batch, the only way is to send an update to modify the partition to its previous state.
Regards,
--
Jacques-Henri Berthemet
From: DuyHai Doan [mailto:doanduyhai@gmail.com]
Sent: Thursday, April 19, 2018 9:10 AM
To: user <us...@cassandra.apache.org>
Subject: Re: Does Cassandra supports ACID txn
No ACID transaction any soon in Cassandra
On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>> wrote:
Hi,
I am bit confused by reading different articles, does recent version of Cassandra supports ACID transaction ?
I found BATCH command , but not sure if it supports rollback, consider that transaction I am going to perform would be on single partition.
Also, what are the limitations if any?
Thanks,
Rajesh
Re: Does Cassandra supports ACID txn
Posted by DuyHai Doan <do...@gmail.com>.
No ACID transaction any soon in Cassandra
On Thu, Apr 19, 2018 at 7:35 AM, Rajesh Kishore <ra...@gmail.com>
wrote:
> Hi,
>
> I am bit confused by reading different articles, does recent version of
> Cassandra supports ACID transaction ?
>
> I found BATCH command , but not sure if it supports rollback, consider
> that transaction I am going to perform would be on single partition.
>
> Also, what are the limitations if any?
>
> Thanks,
> Rajesh
>