Configure Searchable Attributes for Data Structures in Cache

Note

This feature is only available in NCache Enterprise Edition.

A Data type can also be associated with searchable attributes such as:

Groups
Tags
Named Tags

These searchable attributes can be used to query all associated items, as explained in Querying Data Structures. For example, a CacheItem and HashSet can belong to the same group. These attributes are specified using the DataTypeAttributes class.

Warning

These attributes can not be modified once a data type is created, however the data type itself can be modified.

Pre-requisites

Install the following NuGet packages:
- Alachisoft.NCache.SDK.
Include the following namespaces in your application:
- Alachisoft.NCache.Client.DataTypes
- Alachisoft.NCache.Client
- Alachisoft.NCache.Runtime.Exceptions
The application must be connected to cache before performing the operation.
Cache must be running.
For API details, refer to: ICache, Contains, Count, DataTypeAttributes.
Make sure that the data being added is serializable.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Add the following Maven dependencies in your pom.xml file:

<dependency>
    <groupId>com.alachisoft.ncache</groupId>
    <artifactId>ncache-client</artifactId>
    <version>5.2.0</version>
</dependency>

Import the following packages in your application:
- import com.alachisoft.ncache.client.*;
- import com.alachisoft.ncache.runtime.exceptions.*;
- import com.alachisoft.ncache.client.*;
- import com.alachisoft.ncache.client.datastructures.*;
The application must be connected to cache before performing the operation.
Cache must be running.
For API details, refer to: Cache, contains, getCount, DataStructureAttributes.
Make sure that the data being added is serializable.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Include the following modules in your application
- const ncache = require('ncache-client')
The application must be connected to cache before performing the operation.
Cache must be running.
For API details, refer to: Cache, contains, getCount, DataStructureAttributes.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

The following code sample creates a HashSet ProductIDSet of int type and specifies group Electronics, tags and a Named Tag to it using DataTypeAttributes. ProductIDs are then fetched and added to this HashSet. You can query on these set values.

Tip

One quick way to verify whether data type has been created is to use either properties of the Cache class:

Count returns the number of items present in the cache.
Contains verifies if the specified key of the data type exists in the cache.

try
{
    // Pre-condition: Cache must be connected
    // Specify unique cache key for set
    string key = "ProductIDSet";

    // Specify attributes for hashset
    var attributes = new DataTypeAttributes();

    // Specify group "Electronics"
    attributes.Group = "Electronics";

    // Specify tags
    Tag[] tags = new Tag[2];
    tags[0] = new Tag("2 Year Warranty");
    tags[1] = new Tag("Stainless Steel");
    attributes.Tags = tags;

    // Specify Named Tag
    var namedTag = new NamedTagsDictionary();
    namedTag.Add("Discount", 0.4);
    attributes.NamedTags = namedTag;

    // Create hashset with attributes
    IDistributedHashSet<int> hashSet = cache.DataTypeManager.CreateHashSet<int>(key, attributes);

    // Adding Product IDs to Set
    int[] productIDs = FetchProductIDs();

    foreach(var productID in productIDs)
    {
        // Add product IDs to set
        hashSet.Add(productID);
    }

    // You can query on this hashset using these attributes
}
catch (OperationFailedException ex)
{
    // NCache specific exception

    if(ex.ErrorCode == NCacheErrorCodes.KEY_ALREADY_EXISTS)
    {       
        // An item with the same key already exists
    }
    else if (ex.ErrorCode == NCacheErrorCodes.CACHEITEM_IN_DATA_STRUCTURES)
    {
        // Data structures cannot be of CacheItem type
        // CacheItems cannot be added in data structures
    }
    else
    {
        // NCache specific exception
        // Exception can occur due to:
        // Connection Failures
        // Operation Timeout
        // Operation performed during state transfer
    }
}
catch (Exception ex)
{
    // Any generic exception like ArgumentNullException or ArgumentException
}

try
{
    // Pre-condition: Cache must be connected
    // Specify unique cache key for set
    String key = "ProductIDSet";

    // Specify attributes for hashset
    var attributes = new DataStructureAttributes();

    // Specify group "Electronics"
    attributes.setGroup("Electronics");

    // Specify tags
    Tag[] tags = new Tag[2];
    tags[0] = new Tag("2 Year Warranty");
    tags[1] = new Tag("Stainless Steel");
    attributes.setTags(Arrays.asList(tags));

    // Specify Named Tag
    var namedTag = new NamedTagsDictionary();
    namedTag.add("Discount", 0.4);
    attributes.setNamedTags(namedTag);

    var writeThruOptions = null;

    // Create hashset with attributes
    DistributedHashSet hashSet = cache.getDataStructuresManager().createHashSet(key,attributes,writeThruOptions,Integer.class);

    // Adding Product IDs to Set
    int[] productIDs = fetchProductIDs();

    for(var productID : productIDs)
    {
        // Add product IDs to set
        hashSet.add(productID);
    }

    // You can query on this hashset using these attributes
}
catch (OperationFailedException ex)
{
    // NCache specific exception

    if(ex.getErrorCode() == NCacheErrorCodes.KEY_ALREADY_EXISTS)
    {       
        // An item with the same key already exists
    }
    else if (ex.getErrorCode() == NCacheErrorCodes.CACHEITEM_IN_DATA_STRUCTURES)
    {
        // Data structures cannot be of CacheItem type
        // CacheItems cannot be added in data structures
    }
    else
    {
        // NCache specific exception
        // Exception can occur due to:
        // Connection Failures
        // Operation Timeout
        // Operation performed during state transfer
    }
}
catch (Exception ex)
{
    // Any generic exception like IllegalArgumentException or NullPointerException
}

// This is an async method
try
{
    // Pre-condition: Cache must be connected
    // Specify unique cache key for set
    var key = "ProductIDSet";

    // Specify attributes for hashset
    var attributes = new ncache.DataStructureAttributes();

    // Specify group "Electronics"
    attributes.setGroup("Electronics");

    // Specify tags
    var tags = [new ncache.Tag("2 Year Warranty"), new ncache.Tag("Stainless Steel")]

    attributes.setTags(tag);

    // Specify Named Tag
    var namedTag = new ncache.NamedTagsDictionary();
    namedTag.add("Discount", 0.4);
    attributes.setNamedTags(namedTag);

    // Create list with attributes
    var list = await (await this.cache.getDataStructuresManager()).createList(key, Number(), attributes, null);

    // Adding Product IDs to Set
    var productIDs = this.fetchProductIDs();


    for (var productID in productIDs)
    {
        // Add product IDs to set
        list.add(productID);
    }

    // You can query on this list using these attributes
}
catch (error)
{
    // Handle errors
}

Recommendation: To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.

Configure Searchable Attributes for Data Structures in Cache

Note

Warning

Pre-requisites

Tip

See Also