Configure JSON Query Indexes

JSON (JavaScript Object Notation) is an open standard file format and data interchange format. It consists of attribute value pairs which are in human-readable format.

Note

This feature is also available in NCache Professional.

Important

For Java, before deploying your JAR files, you need to make sure that:

  • You have JDK 17 installed.
  • Your Environment Variable for Java Home is set.

NCache allows you to specify attributes that need to be indexed within a JSON document. These attributes can be configured in the following ways:

Add JSON Query Indexes

Using the NCache Management Center

  • Launch the NCache Management Center by browsing to http://localhost:8251 or <server-ip>:8251 for Windows and Linux.

  • In the left navigation bar, click on Clustered Caches or Local Caches, based on the cache to which the query index will be added. Against the cache name, click on View Details.

Note

Make sure the cache is stopped.

Cache View Details

  • This opens up the detailed configuration page for the cache. Go to the Advanced Settings tab and click on Query Indexes in the left bar.

  • This opens up the Query Indexes page, click on Add.

Select Classes Web

  • On the next page, select the JSON file that contains the classes that you want to store in the cache for querying by clicking on the Browse button.

  • In the Selected Assemblies box, all serialized classes are displayed. Check the ones you want to index, and click on Add Selected Classes.

Important

Make sure the Index_Class attribute in your JSON file is defined. You should assign the FQN of your class as a value to this attribute

Add Json Classes

  • The added classes will be displayed in the list of selected classes. Here you can select the attributes that you want to index. Their type is also parsed from the JSON file but, you also have the option to assign your attributes a different type from the dropdown menu placed next to them.

JSON query index selected attributes

  • You can also remove any classes from the List of selected classes by clicking on the Remove Selected Classes button.

  • Once you are done, click on the OK button.

Save Changes

  • The added query indexes will be displayed on the Query Indexes page. Click on Save Changes to apply this configuration to the cache.

Using Command Line Tools

The add-queryindex tool enables the user to add query indexes for the objects to be added to the cache.

The following command adds productID, productName, category, unitPrice, unitsInStock, and isContinued attributes from the class com.alachisoft.Data.Product in query indexes fordemoCache.

add-queryindex -cachename demoCache -assemblypath /user/product.json -class Data.Product –attributelist "productID'$'productName'$'category'$'unitPrice'$'unitsInStock'$'isContinued"

Manually Editing NCache Configuration

Important

Make sure the cache is stopped before making any configuration changes.

  • Specify the query indexes through config.ncconf by adding the <query-indexes> and <query-class> tags under the <cache-settings> tag. The following example adds attributes of a class Product as indexes:
<cache-settings ...>
    <query-indexes>
        <query-class id="Data.Product" name="Data.Product">
            <query-attributes id="unitPrice" name="unitPrice" data-type="System.Int32"/>
            <query-attributes id="unitsInStock" name="unitsInStock" data-type="System.Int32"/>
            <query-attributes id="productID" name="productID" data-type="System.Int32"/>
            <query-attributes id="productName" name="productName" data-type="System.String"/>
            <query-attributes id="category" name="category" data-type="System.String"/>
            <query-attributes id="isContinued" name="isContinued" data-type="System.Boolean"/>
        </query-class>
    </query-indexes>
</cache-settings>
  • Once changes are made, start the cache and restart the NCache Service.

Removing JSON Query Indexes

Pre-defined query indexes can be removed by the user using the following steps.

Using the NCache Management Center

  • Launch the NCache Management Center by browsing to <server-ip>:8251 (Linux) or http://localhost:8251 (Windows).

  • In the left navigation bar, click on Clustered Caches or Local Caches, based on the cache to which the query index will be added. Against the cache name, click on View Details.

Remove Query Indexes Web

  • This opens up the detailed configuration page for the cache. Go to the Advanced Settings tab and click on Query Indexes in the left bar.

  • This opens up the Query Indexes page which shows existing classes for query indexes.

  • Select the classes to remove and click on Remove.

Remove JSON Query Indexes

  • Click on Save Changes to apply this configuration to the cache.

Using Command Line Tools

The remove-queryindex tool enables the user to remove pre-defined query indexes for the objects to be added to the cache.

The following command removes query indexing for the class Product from the cache demoCache.

remove-queryindex -cachename demoCache -class Data.Product

See Also

Configure Caches
Configure Query Indexes