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Subject: Re: Need help in cassandra data model..
From: aaron morton <aaron@thelastpickle.com>
In-Reply-To: <AANLkTikL-M-cRZUOh=8JGgTOPC7G6GfkeGvqxe8eLPc2@mail.gmail.com>
Date: Wed, 1 Sep 2010 20:32:26 +1200
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References: <AANLkTikL-M-cRZUOh=8JGgTOPC7G6GfkeGvqxe8eLPc2@mail.gmail.com>
To: user@cassandra.apache.org

=46rom what you have described that sounds OK (am assuming there is not =
millions of events per transaction). When designing the model consider =
all the ways you will want to read the data back and then dernomalize =
the data appropriately. Ideally each request for data from cassandra =
should be handled by single CF.=20

When storing the time of the event, you could use either a Long as the =
seconds since epoch or an ASCII string with the time formatted using the =
ISO format.=20

Aaron

On 1 Sep 2010, at 19:09, Manikandan R wrote:

> Hello Everyone,
>=20
> I am doing study on cassandra to make use of it for the below problem =
-=20
>=20
> My current system has many components. To complete any =
transaction(request), it has to pass through all the components. While =
it passes through, there is no clear visibility to know what is =
happening behind each component at any given point.
>=20
> Trying to create a new component using cassandra, which receives the =
status of the transaction(request) from other components for any given =
transaction(request) id, so that it can viewed online in real time.
>=20
> Here is the model, I have in my mind:
>=20
> Transactions: {
>=20
>     100: { //transaction id as key
>=20
>          t1: { //Say, at time t1
>=20
>               status: "Received the request. Doing validation";
>               mode: "debug";
>          };
>=20
>          t2 : { // Say, at time t2
>          =20
>              status: "dropped:1000|absent=3D2000";
>              dropped: 1000;
>              absent: 2000;
>              mode: "info";
>          };
>=20
>=20
>=20
>     101: { //transaction id as key
>=20
>          t1: { //Say, at time t1
>=20
>               status: "Doing External Verification..."
>               mode: "debug";
>          };
>=20
>          t2 : { // Say, at time t2
>          =20
>              status: "valid:2000|invalid:1000";
>              valid: 1000;
>              invalid: 1000;
>              mode: "info";
>          };
> }
>=20
> Status can delivered to the users depending on the SLA. Based on the =
mode, it can be displayed to users. Users who has access to see detailed =
status, can see all the mode's status, where as, user who want to see =
only reports, can see the mode with "info".=20
>=20
> Please let me know your thoughts.
>=20
> Thanks,
> Mani