This will activate the Enterprise Library Configuration Manager. The application configuration file typically named either App. A new application configuration file can be created or an existing one can be opened where Caching related settings will be stored. Right-click the application root node, point to New , and click Caching Application Block Configuration.
This generates a Caching subtree. This subnode can be configured to add multiple instances of the Cache Manager with each instance referencing either an in-memory cache, a Database or an Isolated Storage. Each Cache Manager Instance has the following attributes ExpirationPollFrequencyInSecond: Represents value in seconds to set the frequency of the timer that regulates how frequently BackgroundScheduler checks for expired items.
The minimum time is 1 second and the default time is 60 seconds MaximumElementsInCacheBeforeScavenging Sets the maximum number of elements that can be in the cache before scavenging begins. Default is elements. Default is 10 elements. Each cache manager can either be configured to store data only in memory, or it can be configured to store data both in memory and in persistent storage.
Note: Since isolated storage is always segregated by user, server applications must impersonate the user making a request to the application Isolated storage is appropriate in the following situations: Persistent storage is required and the number of users is small. The overhead of using a database is significant or No database facility exists.
Scenarios where Isolated Storage should not be used: Isolated storage should not be used to store high-value secrets, such as unencrypted keys or passwords. Isolated storage should not be used to store configuration and deployment settings, which administrators control.
FromMinutes 5 ; Note: Defaults Scavenging priority: Normal No expiration When adding a second item with the same key as an existing item replaces the existing item When configured to use a persistent backing store, objects added to the cache must be serializable Flushing the Cache The following code shows how to use the Flush method.
Remove order. GetData 12 ; Loading the Cache There are two methods you can use for loading data: Proactive loading. This method retrieves all the required data and caches it for the lifetime of the application.
Advantages Application performance improves because cache operations are optimized Application response times also improve because all the data is cached Disadvantages Does not result in most optimized since much of the state is cached even though it may not all be required The Implementation could turn out to be more complex than conventional techniques Reactive loading.
This method retrieves data only when requested by the application and then caches it for future requests. Advantages System resources are not misused. Results in an optimized caching system since requested items are only stored.
Checks need to be made every time to ensure the item is in cache The Expiration Policies The Caching Application Block's expiration process is performed by the BackgroundScheduler. Expirations; Following are the Expiration policies Time-based expirations You should use time-based expiration when volatile cache items-such as those that have regular data refreshes or those that are valid for only a set amount of time-are stored in a cache.
Time Based Expirations are of three types Absolute. Allows you to define the lifetime of an item by specifying the absolute time for an item to expire. Simple-You define the lifetime of an item by setting a specific date and time for the item to expire. Extended-You define the lifetime of an item by specifying expressions such as every minute, every Sunday, expire at AM on the 15th of every month, and so on. Allows you to define the lifetime of an item by specifying the interval between the item being accessed and the policy defining it as expired.
This means the item expires after the specified time has elapsed from when the item was last accessed. Normal, null, expireTime ; Extended format. This allows you to be very detailed about when an item expires. For example, you can specify that an item expire every Saturday night at PM, or on the third Tuesday of the month. Extended formats are listed in the ExtendedFormat. If a dependency changes, the cached item is invalidated and removed from the cache. File dependency. This means the item expires after a specific file has been modified.
The following can be configured Removal of expired items occurs on a background thread You can set the frequency of how often this thread will run looking for expired items Count of the cached items to remove during the scavenging process. The BackGroundScheduler performs a: major sort on priority minor sort on LTA Scavenging is done in one single pass Expiration is a two-part process Marking A copy of the hash table is made.
Every CachedItem is checked for expiry. If item is to be expired, it is flagged. Sweeping Every flagged item is checked if it has been accessed in the mean time. If accessed it is kept in cache. If not, it is removed. The concrete implementation needs to ensure that the backing store remains intact and functional when any operation that accesses the backing store causes any exceptions.
Add a new Expiration Policy The following interfaces need to be implemented in case one needs to provide custom expiration policies ICacheItemExpiration: This interface represents an application-defined rule governing how and when a CacheItem object can expire. ICacheRefreshAction: This interface refreshes an expired cache item.
NOTE: If you want to add new features to the application block, you can do so by modifying the source code the installer includes both the source code and the binaries Instrumenting the Caching Application Block The Caching Application block also incorporates the following instrumentation: Caching Application Block Performance Counters.
The Caching Application Blocks records key metrics by writing to the Microsoft Windows operating system performance counters. This performance counter shows the number of entries in the cache.
This performance counter shows the number of cache hits per second. This performance counter shows the number of cache misses per second. Cache Hit Ratio.
This performance counter shows the ratio of hits from all cache calls. Cache Total Turnover Rate. This performance counter shows the number of additions and removals to the total cache per second. It signifies that an internal failure has occurred. It includes the string property ConfigurationFilePaththat contains the path of the main configuration file. Next Recommended Reading.
Net Core 6. Create A. Understanding Thread Starvation in. A download manager is recommended for downloading multiple files. Would you like to install the Microsoft Download Manager? Generally, a download manager enables downloading of large files or multiples files in one session. Many web browsers, such as Internet Explorer 9, include a download manager.
Stand-alone download managers also are available, including the Microsoft Download Manager. The Microsoft Download Manager solves these potential problems. It gives you the ability to download multiple files at one time and download large files quickly and reliably. It also allows you to suspend active downloads and resume downloads that have failed.
Microsoft Download Manager is free and available for download now. Warning: This site requires the use of scripts, which your browser does not currently allow. See how to enable scripts. Download Microsoft Enterprise Library 5. Microsoft Enterprise Library 5. This release of Enterprise Library in October is a service release that includes the following:. The Application Block Software Factory and the Strong Naming Guidance Package are not included in this release but are available as a separate download.
In May , Enterprise Library 3. In April , Enterprise Library 3. It contains new Application Blocks, a new Application Block Software factory designed to simplify the development of new Application Blocks and extensions, and new features providing better integration with.
NET Framework 3. The 3. In January , a new version of Enterprise Library was released that targeted. NET Framework 2.
The most significant change in this release was that the Configuration Application Block was removed, and the blocks were updated to use. NET's improved System. Configuration capabilities. This release also included significant improvements to the Logging Application Block, and much of the Security Application Block was removed due to similar capabilities provided in. NET 2.
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