This tutorial will guide you on how to expose data stored in Cassandra as a data service. Also, see the samples in Data Integration Samples.
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Click Add New Datasource. and enter the following details:
Datasource ID Cassandra Datasource Type Select Cassandra as the datasource. Cassandra Server Enter localhost. The rest of the datasource properties are optional. See the descriptions given below.
Expand title Properties for a Cassandra datasource The following describes the properties supported by the Cassandra datasource.
Data Source Property Description Cassandra Servers* Host names of Cassandra servers in a comma-separated list. Keyspace The default key space used by the Cassandra session. Port The port of Cassandra servers. Cluster Name The Cassandra cluster name. Compression Compression used in communication. User Name The authenticating user's username. Password The authenticating user's password. Load Balancing Policy The client load balancing policy on how calls should be made to the provided servers. Enable JMX Reporting Enable JMX statistics for the connector. Enable Metrics Enable metrics for the connector. Local Core Connections Per Host Connection pooling: Local core connections per server host. Remote Core Connections Per Host Connection pooling: Remote core connections per server host.
Local Max.Connections Per HostAnchor Max_Con_Loc_Host Max_Con_Loc_Host Connection pooling: Maximum local connections per server host.
Remote Max.Connections Per HostAnchor Rem_Max_Con_Host Rem_Max_Con_Host Connection pooling: Remote max connections per server host. Local New Connection Threshold This property determines the threshold in the connection pool, which will trigger the creation of a new connection when the connection pool has not reached the maximum capacity for local hosts. Generally, it will not be required to change the default value for this parameter. Remote New Connection Threshold This property determines the threshold in the connection pool, which will trigger the creation of a new connection when the connection pool has not reached the maximum capacity for remote hosts. Generally, it will not be required to change the default value for this parameter. Local Max Requests Per Connection This property allows you to throttle the number of concurrent requests per connection for local hosts. Remote Max Requests Per Connection This property allows you to throttle the number of concurrent requests per connection for remote hosts. Protocol Version The native protocol version to use. By default, it auto connects. "2" for Cassandra versions 2.0 and upwards, and "1" for Cassandra version 1.2.x. Consistency Level The consistency level used for queries. Fetch Size Fetch size used by queries. Serial Consistency Level The serial consistency level used for queries. Reconnection Policy The reconnection policy used for the cluster. Constant Reconnection Policy Delay If "ConstantReconnectionPolicy" is used for Reconnection Policy, this represents the constant wait time between reconnection attempts in milliseconds. Exponential Reconnection Policy Base Delay If "ExponentialReconnectionPolicy" is used for Reconnection Policy, this represents the base delay in milliseconds. Exponential Reconnection Policy Max. Delay If "ExponentialReconnectionPolicy" is used for Reconnection Policy, this represents the maximum delay in milliseconds. Retry Policy Configured the retry policy in this cluster. Connection Timeout The socket connection timeout in milliseconds. Keep Alive Set if socket keeps alive. Read Timeout Set per host socket read timeout in milliseconds. Receive Buffer Size The socket receive buffer size. Send Buffer Size Thesocketsendbuffersize. Reuse Address The socket re-use address. So Linger The socket linger on value. TCP no Delay Set socket TCP to no delay. Enable SSL Enable SSL. Enable OData In WSO2 EI OData protocol version 4 (OASIS standards) is supported, which mainly provides support for CRUD operations. You can easily expose databases as an odata service by selecting this check box. Currently, Odata service feature support is available for RDBMS datasources and Cassandra datasources. If you have enabled Odata for your data service, you can complete the data service creation process. That is, you are not required to define queries or operations for the service. This Odata service will now be accessible from the following endpoints:
- For super tenant:
http://localhost:<port>/odata/{dataserviceName}/{datasourceId}/ - For normal tenants:
http://localhost:<port>/odata/t/{tenantId}/{dataserviceName}/{datasourceId}/
Disable Native Batch Requests Disables native Cassandrabatchrequests,and reverts to emulated batch requests. * Mandatory fields.
- For super tenant:
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Finish creating the data service
Once you have defined the operation, click Finish to complete the data service creation process. You will now be taken to the Deployed Services screen, which shows all the data services deployed on the server.
Invoking your data service using SOAP
You can try the data service you created by using the TryIt tool that is in your product by default.
- Go to the Deployed Services screen.
- Click the Try this service link for the Cassandra data service. The TryIt Tool will open with the data service.
Create the Keyspace
Select the createKSOp operation you created earlier.
Click Send.
Create the table in the Keyspace
Select the createTableOp operation you created earlier.
Click Send.
Post new data
- Select the addUsersOp operation you created earlier.
You need to provide the user details. . Be sure to enter a UUID value as the user ID.
Click Send.
Get data
- Select the getUsersbyIDop operation you created earlier.
Click Send to see the details of the user you added previously.
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Invoking your data service using REST The HTTP requests sent for each of the resources using cURL would be as follows: Post new data
Get data The service can be invoked in REST-style via curl (http://curl.haxx.se). Shown below is the curl command to invoke the GET resource:
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