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From: Ran Tavory <rantav@gmail.com>
Date: Wed, 26 May 2010 12:57:07 +0300
Message-ID: <AANLkTikffSaqfnkEqkXHuydE5lRfZYgG0r3x-IMO3Bd1@mail.gmail.com>
Subject: Re: Questions regarding batch mutates and transactions
To: user@cassandra.apache.org
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The summary of your question is: is batch_mutate atomic in the general
sense, meaning when used with multiple keys, multiple column families etc,
correct?

On Wed, May 26, 2010 at 12:45 PM, Todd Nine <todd@spidertracks.co.nz> wrote:

> Hey guys,
>   I originally asked this on the Hector group, but no one was sure of the
> answer.  Can I get some feedback on this.  I'd prefer to avoid having to use
> something like Cages if I can for most of our use cases.  Long term I can
> see we'll need to use something like Cages, especially when it comes to
> complex operations such as billing.  However for a majority of our uses, I
> think it's a bit overkill.  I've used transactions heavily in the workplace
> on SQL based app developments.  To be honest, a majority of application's
> I've built utilize optimistic locking, and only the atomic, consistent, and
> durable functionality of transactional ACID properties.
>
> To encapsulate all 3, I essentially need all writes to cassandra for a
> given business invocation to occur in a single write.  With Spring, I would
> implement my own transaction manager which simply adds all mutates and
> delete ops to a batch mutate.  When my transaction commits, I would execute
> the mutation on the given keyspace.  Now this would only work if the
> following semantics apply.  I've tried searching for details in Cassandra's
> batch mutate, but I'm not finding what I need.  Here are 2 use cases as an
> example.
>
> Case 1: Successful update : User adds new contact
>
> Transaction Start.
> Biz op 1. Row is created in  "contacts" and all data is added via batch
> mutation
>  Biz op 2. Row is created for an SMS message is created for queueing
>  through the SMS gateway
> return op 2
> return op 1
> Transaction Commit (batch mutate executed)
>
> Case 2. Failed update: User adds new contact
>
> Biz op 1. Row is created in "contacts"
> Biz op 2. Row is created for SMS message queuing.  Fails due to invalid
> international phone number format
> return op 2
> return op 1
> Transaction is rolled back (batch mutate never executed)
>
>
> Now, here is where I can't find what I need in the doc.  In case 1, if my
> mutation from biz op 2 were to fail during a batch mutate operation
> encapsulating all mutations, does the batch mutation as a whole not get
> executed, or would I still have the mutation from op 1 written to cassandra
> while the op 2 write fails?
>
> Thanks,
>

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<div dir=3D"ltr">The summary of your question is: is batch_mutate atomic in=
 the general sense, meaning when used with multiple keys, multiple column f=
amilies etc, correct?<br><br><div class=3D"gmail_quote">On Wed, May 26, 201=
0 at 12:45 PM, Todd Nine <span dir=3D"ltr">&lt;<a href=3D"mailto:todd@spide=
rtracks.co.nz">todd@spidertracks.co.nz</a>&gt;</span> wrote:<br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex;">Hey guys,<div>=C2=A0=C2=A0I originally aske=
d this on the Hector group, but no one was sure of the answer. =C2=A0Can I =
get some feedback on this. =C2=A0I&#39;d prefer to avoid having to use some=
thing like Cages if I can for most of our use cases. =C2=A0<span style=3D"f=
ont-family:arial, sans-serif;font-size:13px;border-collapse:collapse">Long =
term I can see we&#39;ll need to use something like Cages, especially when =
it comes to complex operations such as billing. =C2=A0However for a majorit=
y of our uses, I think it&#39;s a bit overkill. =C2=A0I&#39;ve used transac=
tions heavily in the workplace on SQL based app developments. =C2=A0To be h=
onest, a majority of application&#39;s I&#39;ve built utilize optimistic lo=
cking, and only the atomic, consistent, and durable functionality of transa=
ctional ACID properties. =C2=A0</span></div>


<div><span style=3D"font-family:arial, sans-serif;font-size:13px;border-col=
lapse:collapse"><div><br></div><div>To encapsulate all 3, I essentially nee=
d all writes to cassandra for a given business invocation to occur in a sin=
gle write. =C2=A0With Spring, I would implement my own transaction manager =
which simply adds all mutates and delete ops to a batch mutate. =C2=A0When =
my transaction commits, I would execute the mutation on the given keyspace.=
 =C2=A0Now this would only work if the following semantics apply. =C2=A0I&#=
39;ve tried searching for details in Cassandra&#39;s batch mutate, but I=
9;m not finding what I need. =C2=A0Here are 2 use cases as an example.</div=
>


<div><br></div><div>Case 1: Successful update :=C2=A0User adds new contact<=
/div><div><br></div><div>Transaction Start.</div><div>Biz op=C2=A01. Row is=
 created in=C2=A0=C2=A0&quot;contacts&quot; and all data is added via batch=
 mutation</div>

<div>
Biz op 2. Row is created for an SMS message is created for queueing =C2=A0t=
hrough the SMS gateway</div><div>return op 2</div><div>return op 1</div><di=
v>Transaction Commit (batch mutate executed)</div><div><br></div><div>Case =
2. Failed update: User adds new contact</div>


<div><br></div><div>Biz op 1. Row is created in &quot;contacts&quot;</div><=
div>Biz op 2. Row is created for SMS message queuing. =C2=A0Fails due to in=
valid international phone number format</div><div>return op 2</div><div>ret=
urn op 1</div>


<div>Transaction is rolled back (batch mutate never executed)</div><div><br=
></div><div><br></div><div>Now, here is where I can&#39;t find what I need =
in the doc. =C2=A0In case 1, if my mutation from biz op 2 were to fail duri=
ng a batch mutate operation encapsulating all mutations, does the batch mut=
ation as a whole not get executed, or would I still have the mutation from =
op 1 written to cassandra while the op 2 write fails?</div>


<div><br></div><div>Thanks,</div></span></div>
</blockquote></div><br></div>

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