Re: Cassandra Supports multi tenant or not
please refer following url, if you'd like to know about multi-tenancy with Cassandra. http://wiki.apache.org/cassandra/MultiTenant And, Hector supports multi tenant datamodel on cassandra. https://github.com/hector-client/hector/wiki/Virtual-Keyspaces Recently, I have disscussed about multi tenant datamodel on cassandra. please refere following archive. http://mail-archives.apache.org/mod_mbox/cassandra-user/201206.mbox/browser Toru. On Mon, 11 Jun 2012 14:45:32 +0900, MOHD ARSHAD SALEEM marshadsal...@tataelxsi.co.in wrote: Hi All, I wanted to know cassandra supports multi tenant features or not. if cassandra not supported multi tenant is there any other database which supports multi tenant . Regards Arshad -- --- SCSK Corp. Toru Inoko tel : 03-6438-3544 mail : in...@ms.scsk.jp ---
Re: about multitenant datamodel
See virtual keyspaces in Hector. Yes, at first, I tried to desigen data model like POD architecture (http://goo.gl/Uw1yD) with this. But, it is problem for me that strong consistency isn't guaranteed among metadata schemas. Every CF has a certain amount of overhead in memory. It's just not how Cassandra is designed to be used. Thanks. I'll try to design meta schma data model again which has strong consistency. Thank you for your advices! On Wed, 06 Jun 2012 03:35:40 +0900, aaron morton aa...@thelastpickle.com wrote: With an abstraction layer you can store practically anything in Cassandra. See virtual keyspaces in Hector. why do you think so? I'll let users create ristricted CFs, and limit a number of CFs which users create. is it still a bad one? Depends what your limits are, but in general still yes. If someone creates a CF with 10 secondary indexes they will use more resources than someone who creates a CF with none. Same thing would happen in a multitenant RDBMS server. If you have 200 CF's in a cluster it will use more memory than one with 20 CF's. The extra memory use will result in more disk IO. Cheers - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 5/06/2012, at 7:52 PM, R. Verlangen wrote: Every CF has a certain amount of overhead in memory. It's just not how Cassandra is designed to be used. Maybe you could think of a way to smash data down to indices and entities. With an abstraction layer you can store practically anything in Cassandra. 2012/6/5 Toru Inoko in...@ms.scsk.jp IMHO a model that allows external users to create CF's is a bad one. why do you think so? I'll let users create ristricted CFs, and limit a number of CFs which users create. is it still a bad one? On Thu, 31 May 2012 06:44:05 +0900, aaron morton aa...@thelastpickle.com wrote: - Do a lot of keyspaces cause some problems? (If I have 1,000 users, cassandra creates 1,000 keyspaces…) It's not keyspaces, but the number of column families. Without storing any data each CF uses about 1MB of ram. When they start storing and reading data they use more. IMHO a model that allows external users to create CF's is a bad one. Hope that helps. - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 25/05/2012, at 12:52 PM, Toru Inoko wrote: Hi, all. I'm designing data api service(like cassandra.io but not using dedicated server for each user) on cassandra 1.1 on which users can do DML/DDL method like cql. Followings are api which users can use( almost same to cassandra api). - create/read/delete ColumnFamilies/Rows/Columns Now I'm thinking about multitenant datamodel on that. My data model like the following. I'm going to prepare a keyspace for each user as a user's tenant space. | keyspace1 | --- | column family | |(for user1)| | ... | keyspace2 | --- | column family | |(for user2)| | ... Followings are my question! - Is this data model a good for multitenant? - Do a lot of keyspaces cause some problems? (If I have 1,000 users, cassandra creates 1,000 keyspaces...) please, help. thank you in advance. Toru Inoko. -- With kind regards, Robin Verlangen Software engineer W http://www.robinverlangen.nl E ro...@us2.nl Disclaimer: The information contained in this message and attachments is intended solely for the attention and use of the named addressee and may be confidential. If you are not the intended recipient, you are reminded that the information remains the property of the sender. You must not use, disclose, distribute, copy, print or rely on this e-mail. If you have received this message in error, please contact the sender immediately and irrevocably delete this message and any copies. -- --- SCSK Corp. Toru Inoko tel : 03-6438-3544 mail : in...@ms.scsk.jp ---
Re: about multitenant datamodel
IMHO a model that allows external users to create CF's is a bad one. why do you think so? I'll let users create ristricted CFs, and limit a number of CFs which users create. is it still a bad one? On Thu, 31 May 2012 06:44:05 +0900, aaron morton aa...@thelastpickle.com wrote: - Do a lot of keyspaces cause some problems? (If I have 1,000 users, cassandra creates 1,000 keyspaces…) It's not keyspaces, but the number of column families. Without storing any data each CF uses about 1MB of ram. When they start storing and reading data they use more. IMHO a model that allows external users to create CF's is a bad one. Hope that helps. - Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 25/05/2012, at 12:52 PM, Toru Inoko wrote: Hi, all. I'm designing data api service(like cassandra.io but not using dedicated server for each user) on cassandra 1.1 on which users can do DML/DDL method like cql. Followings are api which users can use( almost same to cassandra api). - create/read/delete ColumnFamilies/Rows/Columns Now I'm thinking about multitenant datamodel on that. My data model like the following. I'm going to prepare a keyspace for each user as a user's tenant space. | keyspace1 | --- | column family | |(for user1)| | ... | keyspace2 | --- | column family | |(for user2)| | ... Followings are my question! - Is this data model a good for multitenant? - Do a lot of keyspaces cause some problems? (If I have 1,000 users, cassandra creates 1,000 keyspaces...) please, help. thank you in advance. Toru Inoko. -- --- SCSK株式会社 技術・品質・情報グループ 技術開発部 先端技術課 猪子 徹(Toru Inoko) tel : 03-6438-3544 mail : in...@ms.scsk.jp ---
Re: How to use Hector to retrieve data from Cassandra
Please refer following url. You can find some example of how to use hector https://github.com/zznate/hector-examples/tree/master/src/main/java/com/riptano/cassandra/hector/example Toru On Tue, 05 Jun 2012 13:08:31 +0900, Prakrati Agrawal prakrati.agra...@mu-sigma.com wrote: Dear all, I am unable to find a good elaborate example on how to use Hector to get data stored in Cassandra. Please help me. Thanks and Regards Prakrati Agrawal | Developer - Big Data(ID)| 9731648376 | www.mu-sigma.com This email message may contain proprietary, private and confidential information. The information transmitted is intended only for the person(s) or entities to which it is addressed. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited and may be illegal. If you received this in error, please contact the sender and delete the message from your system. Mu Sigma takes all reasonable steps to ensure that its electronic communications are free from viruses. However, given Internet accessibility, the Company cannot accept liability for any virus introduced by this e-mail or any attachment and you are advised to use up-to-date virus checking software. -- --- SCSK Corporation Toru Inoko tel : 03-6438-3544 mail : in...@ms.scsk.jp ---
about multitenant datamodel
Hi, all. I'm designing data api service(like cassandra.io but not using dedicated server for each user) on cassandra 1.1 on which users can do DML/DDL method like cql. Followings are api which users can use( almost same to cassandra api). - create/read/delete ColumnFamilies/Rows/Columns Now I'm thinking about multitenant datamodel on that. My data model like the following. I'm going to prepare a keyspace for each user as a user's tenant space. | keyspace1 | --- | column family | |(for user1)| | ... | keyspace2 | --- | column family | |(for user2)| | ... Followings are my question! - Is this data model a good for multitenant? - Do a lot of keyspaces cause some problems? (If I have 1,000 users, cassandra creates 1,000 keyspaces...) please, help. thank you in advance. Toru Inoko.
