Remove Named Tags From Cache Data

Note

This feature is only available in NCache Enterprise Edition.

The items added with Named Tags to the cache can also be removed from the cache using the same named tag.

Similar to updating Named Tags; they can also be removed via CacheItem. This is a custom class provided by NCache which can be used to add data to the cache. In order to remove Named Tag via CacheItem the Named Tag property of the CacheItem is set as null.

Pre-Requisites

Install the following NuGet packages:
- Alachisoft.NCache.SDK.
Include the following namespace in your application:
- Alachisoft.NCache.Client
- Alachisoft.NCache.Runtime.Caching
- Alachisoft.NCache.Runtime.Exceptions
The application must be connected to cache before performing the operation.
Cache must be running.
For API details, refer to: CacheItem, NamedTags.
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.runtime.caching.NamedTagsDictionary.*;
The application must be connected to cache before performing the operation.
Cache must be running.
For API details, refer to: CacheItem, NamedTags.
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: CacheItem, NamedTags.
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 example removes the Named Tags via CacheItem.

try
{
    // Pre-condition: Cache is already connected
    // CacheItem is already added in the cache with named tags with this key
    string key = "Product:1001";

    // Retrieve the CacheItem using the key
    CacheItem cacheItem = cache.GetCacheItem(key);

    // Set the named tag property of the cacheItem as null
    cacheItem.NamedTags = null;

    // Re-insert the cacheItem in the cache with named tags removed
    cache.Insert(key, cacheItem);

    // CacheItem is successfully re-inserted in cache with removed named tags
}
catch (OperationFailedException ex)
{
    // Exception can occur due to:
    // Connection Failures 
    // Operation Timeout
    // Operation performed during state transfer
}
catch (Exception ex)
{
    // Any other generic exception like ArgumentNullException or ArgumentException
}

try
{
    // Pre-condition: Cache is already connected
    // CacheItem is already added in the cache with named tags with this key
    String key = "Product:1001";

    // Retrieve the CacheItem using the key
    CacheItem cacheItem = cache.getCacheItem(key);

    // Set the named tag property of the cacheItem as null
    cacheItem.setNamedTags(null);

    // Re-insert the cacheItem in the cache with named tags removed
    cache.insert(key, cacheItem);

    // CacheItem is successfully re-inserted in cache with removed named tags
}
catch (OperationFailedException ex)
{
    // 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 is already connected
    // CacheItem is already added in the cache with named tags with this key
    var key = "Product:1001";

    // Retrieve the CacheItem using the key
    var cacheItem = await this.cache.getCacheItem(key);

    // Set the named tag property of the cacheItem as null
    cacheItem.setNamedTags(null);

    // Re-insert the cacheItem in the cache with named tags removed
    await this.cache.insert(key, cacheItem);

    // CacheItem is successfully re-inserted in cache with removed named tags
}
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.

Note

cacheItem.NamedTags.Remove(tagName) method will remove the Named Tag associated with the tag name tagName. If all Named Tags are removed from the Named Tags dictionary and the cache item is then inserted into cache, Named Tags will be removed from that cache item since empty Named Tags dictionary indicates no Named Tags.

Additional Resources

NCache provides sample application for Tags on GitHub.

Remove Named Tags From Cache Data

Note

Pre-Requisites

Note

Additional Resources

See also