13 May 2008: ehcache-1.5.0-beta1 release

Ehcache 1.5.0-beta1 provides a host of new features and a few bug fixes:

1 March 2008: ehcache is SourceForge project of the month

Ehcache has been honoured as the February 2008 SourceForge project of the month. See http://sourceforge.net/community/index.php/potm-200802/.

21 February 2008: ehcache-1.4.1 maintenance release

The version of ehcache is a minor maintenance release. The main reason for the release was to include ehcache-failsafe.xml which was omitted from the public maven repository version. See the changelog for complete details.

31 January 2008: ehcache-1.4.0 released

The final version of ehcache-1.4.0 is available on sourceforge and the Maven central repository.

This version significantly enrichens the ehcache API and enhances extension of ehcache. The new features are:

• You can now define CacheLoaders in the ehcache core API. They supplement the existing SelfPopulatingCache. They can be configured in ehcache.xml or programmatically. They can be used for cache warming, and simple pull-through caching. See the Cache Loaders chapter in the documentation for more details.
• You can now define a CacheExceptionHandler and register it progammatically or in ehcache.xml. This enables an exception handler to be registered with a cache so that it is called on exception rather than the exception being thrown. See the Cache Exception Handler chapter in the documentation for more details.
• You can now define CacheExtensions and register them progammatically or in ehcache.xml. A CacheExtension is a generic facility which holds a reference to a cache and is bound to the cache lifecycle, making possible a wide variety of extensions to behaviour. Usage examples are a cache refresh timer or a file monitoring mechanism. See the Cache Extensions chapter in the documentation for more details.

  This final release follows the second beta release by a month and fixes a few minor issues. See changelog for complete details.

  A new Book has been released to coincide with ehcache-1.4.0.

1 January 2008: ehcache-1.4-beta2 released

The beta 2 version of ehcache-1.4 is available on sourceforge and the Maven central repository.

The second beta release fixes 10 bugs, most of them in the new features being introduced in 1.4.0, reported by beta testers. See the changelog for complete details.

30 November 2007: Ehcache book available

Ehcache Guide and Reference for the forthcoming 1.4.0 release is available as a book. The price for the high quality bound edition is USD49.95 plus shipping. The price for the downloadable print-ready version is USD37.50. The book has 154 pages.

Many people have asked for a format for the documentation where it can be printed out as a book and even where they can get it. Of course, full documentation in html will always remain available online at http://ehcache.sf.net.

Buy it from the Ehcache Storefront at Lulu Books.

26 August 2007: ehcache-1.4-beta released

The beta version of ehcache-1.4 is available on sourceforge and the Maven central repository.

This version significantly enrichens the ehcache API and enhances extension of ehcache. The new features are:

• You can now define CacheLoaders in the ehcache core API. They supplement the existing SelfPopulatingCache. They can be configured in ehcache.xml or programmatically. They can be used for cache warming, and simple pull-through caching. See the Cache Loaders chapter in the documentation for more details.
• You can now define a CacheExceptionHandler and register it progammatically or in ehcache.xml. The enable an exception handler to be registered with a cache so that it is called on exception rather than the exception being thrown. See the Cache Exception Handler chapter in the documentation for more details.
• You can now define CacheExtensions and register them progammatically or in ehcache.xml. A CacheExtension is a generic facility which holds a reference to a cache and is bound to the cache lifecycle, making possible a wide variety of extensions to behaviour. Usage examples are a cache refresh timer or a file monitoring mechanism. See the Cache Extensions chapter in the documentation for more details.

  There are 5 minor bug fixes in the release. At the time of release there are no open bugs in ehcache.

  See the changelog for complete details.

11 June 2007: ehcache-1.3 released

The next major version of ehcache has been released.

This version contains the following major new features over 1.2.4:

• A draft JCache API (JSR107) package.
• JMX instrumentation. Register a variety of MBeans from your ehcache instance with your MBeanServer of choice. Care has been taken to make this implementation friendly to a wide variety of JMX NMSs.

  In terms of minor features:

• A new cache attribute, diskSpoolBufferSizeMB, can be set to control the amount of memory that can be used for spooling to DiskStore
• The ehcache shutdown hook is now off by default. Ehcache is typically used in scenarios where someone else has a shutdown hook. It can be re-enabled by setting net.sf.ehcache.enableShutdownHook=true

  The distributed caching feature of ehcache is now in wide-spread use in wide ranging environments. All of this field experience unearthed the need for further documentation, clarificationa and bug fixes, particularly for dirty or mis-configured networks, which have been provided in 1.3. Excellent performance has been reported for clusters with up to 20 nodes.

  A new Tomcat chapter in the documentation provides specific information on configuring Tomcat with ehcache.

  See the changelog for complete details.

  Work on new features will now start on a new 1.4 branch. See the Roadmap for details. 1.3 will be maintained as the new stable branch.

27 May 2007: ehcache-1.3 beta 3 released

This release fixes two bugs and has some minor changes to support third parties who are making extensions to ehcache. See See the changelog for details. A final release should be out in the next few weeks.

22 May 2007: Ehcache Maven repository

Ehcache has a Maven repository for releases at http://ehcache.sourceforge.net/repository. It is synchronized with the Maven central repository. New releases will now appear in the Maven repository without delay.

16 May 2007: JSR107 (JCACHE) News

At JavaOne, Greg Luck, the maintainer of ehcache, was appointed as co Spec Lead of JSR107, JCACHE.

The expert group has been reenergised and is making progress towards getting a spec done. Everyone is welcome to monitor technical discussion on JCACHE at the new mailing list - jsr107 AT jsr107.dev.java.net.

9 May 2007: JavaOne Talk

TS-6175 - Distributed Caching, Using the JCACHE API and ehcache, Including a Case Study was attended by around 1200 people. About 50 people had question. There was so much interest that an impromptu Q&A session was held later that day. It appears that interest in caching and ehcache in particular remain very strong in the Java community.

4 May 2007: ehcache-1.3 beta 2 released

Ehcache-1.3-beta2 has 7 fixes over beta 1. See the changelog for details.

9 March 2007: ehcache-1.3 beta released

New features in 1.3 are:

• JCACHE implementation. This is a full implementation of JSR107.
• JMX instrumentation. Register a variety of MBeans from your ehcache instance with your MBeanServer of choice. Care has been taken to make this implementation friendly to a wide variety of JMX NMSs.

  In adding these new packages care has been taken not to disturb the existing packages. Only bug fixes have been applied to those. 8 bug fixes, representing all those reported since 1.2.4 have been fixed. Ehcache has no open bugs or patches at the time of release. See the changelog for details.

22 February 2007: JavaOne Session.

For anyone attending JavaOne 2007 at the Moscone Centre in San Francisco, the maintainer of ehcache, Greg Luck, will be presenting a session entitled "Distributed Caching, Using the JCACHE API and ehcache, Including a Case Study". This will be a practical session covering much of the recent features added to ehcache.

2 December 2006: ehcache-1.2.4 released

This is a candidate for a maintenance release.

It contains four feature and fifteen bug fixes received in the two months since ehcache-1.2.3 was released. See the changelog for details.

Eight of the changes in this release are scalability improvements contributed by users running very large ehcache deployments. The distributed caching changes stem from a user who is using ehcache in a multi-subnet cluster of 20 nodes.

The Caching and Gzip filters in the web package have been updated to work on Glassfish and Tomcat.

The distributed caching functionality in ehcache is now 6 months ago.

The maintainer has now been running ehcache distributed in production for four months without incident.

Ehcache has no open bugs or patches at the time of release.

2 September 2006: ehcache-1.2.3 released

This is a maintenance release. It contains eight feature requests and 6 bug fixes received in the two months since ehcache-1.2.2 was released. See the changelog for details.

All of the feature changes come from the suggestions of people with practical experience using ehcache-1.2. The changes are all fine tuning of the distributed caching functionality rather than large changes.

The distributed caching functionality was released four months ago. There are many production sites running this now, including that of the maintainers.

One of the more difficult aspects of getting distributed caching going is getting past network configurations that swallow multicast. A tool, ehcache-1.2.3-remote-debugger.jar is now included in the distribution so that distributed traffic can be listened in on.

The number of lines of code in ehcache is now three times bigger than ehcache-1.0. They have increased as the features of ehcache have increased. To complement this increase in complexity, commercial support is now available for ehcache. Contact kluck@gregluck.com for details.

1 September 2006: Ehcache three years old and going strong

Ehcache had more than 4000 downloads per month for the last three months in a row. This is up from the 1500 downloads per month it was running at for the two years before then.

The result is there is now a much larger user community who use ehcache directly, rather than through one of the popular frameworks. This places new demands on the project but also means that most of the code paths and API are being utilised, leading to fewer undiscovered bugs and a continuing evolution of features.

17 July 2006: ehcache-1.2.2 released

This is a minor maintenance release to ehcache-1.2.1. It clears all bug reports and feature requests received since ehcache-1.2.1 was released. It also includes the fix in ehcache-1.2.0_02 to reduce memory consumption.

See the release notes and changelog for details.

16 July 2006: ehcache-1.2.0-02 released

Contains a fix to quickly hand back memory when spooling to disk. See http://gregluck.com/blog/archives/2006/07/tuning_memory_u.html for details on the effect of this change.

3 July 2006: ehcache-1.2.1 released

ehcache-1.2.1 is mostly a maintenance release of ehcache. It focuses on simplifying usage of new features and easing the migration path between ehcache-1.1 and ehcache-1.2. While ehcache-1.2 is backward compatible, some typical usage scenarios in Hibernate and Spring are not.

See the separate news item on ehcache-1.2.1RC to get the full picture. Changes above ehcache-1.2.1RC are:

3 July 2006: ehcache-1.2.0-01 released

Ehcache-1.2.0-01 is a backport of the thread hardening changes to the 1.2.0 branch. The 1.2.0 release will be supported with backports of other important fixes.

27 June 2006: ehcache maintainer added to JSR-107 expert group

Greg Luck, the maintainer of ehcache, has been added to the JSR-107 expert group. The plan is to add a JSR-107 compatibility API to ehcache. The benefit to users is that they can switch to and from ehcache with almost zero code cost, when using the JSR-107 API.

Enabling changes to the ehcache codebase have been made in the ehcache-1.2.1 branch (released 3 July). Work on the compatibility API will occur in the 1.3 branch.

4 June 2006: ehcache-1.2.1RC released.

This is a release candidate for ehcache-1.2.1. There are a few very minor bug fixes in this release. The main focus is to resolve upgrade difficulties with client libraries which expect ehcache CacheManagers to be singletons as they were in ehcache-1.1. In ehcache-1.2 any attempt to have two CacheManagers sharing the same configuration resulted in a CacheException being thrown. The check was made on diskStorePath. In ehcache-1.2.1RC multiple CacheManagers sharing the same ehcache.xml configuration is permitted.

To resolve conflicts with DiskStore paths, the second and subsequent CacheManagers create their data files in a unique subdirectory under the first CacheManager's diskStore path.

The other potential conflict is in CacheManagerPeerListeners. In the default implementation the conflict is with RMI listener ports. To resolve this conflict the second and subsequent CacheManagers use a free port to listen on.

For both, warning messages are logged encouraging clients to migrate over to their own ehcache.xml.

There are also a number of enhancements/new features as follows:

• New SingletonEhCacheProvider for use by Hibernate in situations where code has been written which relies on the singleton behaviour of ehcache-1.1 and earlier. Most code bases using Hibernate should not require this.
• Allow cacheEventListenerFactory elements to be added to defaultCache in ehcache.xml. This allows caches created with CacheManager.a ddCache(String cacheName) to receive events. This can be used for example to set default replication settings in defaultCache.
• To complement full support foe default cache (above), added support for programmatic addition of caches which include CacheReplicators. Also support for removal of these caches with CacheManager.remove(String cacheName).
• Andy McNutt's JNDI-based manual RMI replication added. See ehcache.xml example for how to use.
• Support tomcat 5.5 for the servlet filters. Tomcat integration testing, in addition to the Orion one, is also added to the full JUnit test process. Tomcat relies on Servlet 2.4 dispatcher INCLUDE and FORWARD directives for page fragment caching.
• Support runtime setting of individual Element time to lives (TTLs), time to idles(TTIs) and eternal overrides. If an override is set, the Element expiry ignores the Cache default.
• Add a cache bootstrap mechanism. This is used to populate a cache when it is first initialized. An abstract factory, BootstrapCacheLoaderFactory has been defined along with an interface BootstrapCacheLoader. The initial concrete implementations are for RMI, so that a new cache entering a cluster gets bootstrapped from a randomly chosen peer.

  Finally, the ehcache-constructs package has been merged into the ehcache module so that there is only one jar to download and install to get all functionaliy. Ehcache-constructs contains Java EE Caching filters and other useful applied caching solutions.

  See the change log for more details.

  The plan is to rapidly release ehcache-1.2.1 within a week or so. Please report any issues with ehcache-1.2.1RC promptly. Documentation of the new features will be complete during this time.

3 June 2006: Printable PDF User Guide for ehcache available

Some people have requested a printable manual for ehcache. Please seeEhcacheUserGuide.pdf

25 April 2006: ehcache-1.2 released.

After 10 months of development, ehcache-1.2 is released. Thanks to all the developers who contributed to the release through feature requests, bug reports and patches during the beta program.

The 1.2 release of ehcache has many new features including:

• Flexible, extensible, high performance distributed caching. The default implementation supports cache discovery via multicast or manual configuration. Updates are delivered either asynchronously or synchronously via custom RMI connections. Additional discovery or delivery schemes can be plugged in by third parties.
• New FIFO and LFU caching policies in addition to the standard LRU.
• Introduced CacheManagerEventListener and CacheEventListener interfaces and default implementations.
• Multiple CacheManagers per virtual machine.
• Programmatic flushing of application state to persistent caches
• Significant (up to 7 fold) DiskStore performance increases.
• API for Objects in addition to Serializable. Non-serializable Objects can use all parts of ehcache except for DiskStore and replication. Two new methods on Element: getObjectValue and getKeyValue are the only API differences between the Serializable and Object APIs.
• Backward Compatibility with ehcache-1.1. All users of ehcache-1.1 should be able to upgrade to ehcache-1.2.
• Tested with Hibernate2.1.8 and Hibernate3.1.3, which can utilise all of the new features except for Object API and multiple session factories each using a different ehcache CacheManager. A new net.sf.ehcache.hibernate.EhCacheProvider makes those additional features available to Hibernate-3.1.3. A version of the new provider should make it into the Hibernate3.2 release.
• Tested with ehcache-constructs.
• Apache 2.0 license

At time of release, there are no open bugs against the ehcache-1.2. 21 bugs have been fixed in this release. Most of those were raised against the 1.2 beta releases.

See the changelog for more details on this release.

20 April 2006: Development Roadmap Updated

The roadmap for new development has been updated here.

17 April 2006: ehcache-1.2rc1 released

Released ehcache-1.2rc1 to give testers a chance to test recent fixes and fine tuning before a final release.

At this point all bugs, support requests and feature requests are closed. Final testing is focusing on the distributed caching area.

8 April 2006: Elements are no longer required to be Serializable

Following many requests, ehcache no longer requires that Elements contain Serializable keys and values. Ehcache will gracefully degrade for those operations which require Serialization.

In particular the MemoryStore and event listeners can be used with Non Serializable elements.

WARNING error messages are logged when an operation cannot be completed because the key or value is not Serializable.

28 March 2006: License changed from Apache 1.1 to Apache 2.0

The ehcache 1.2 series from beta5 is released under the Apache 2.0 license.

26 March 2006: 1.2 beta 5 released.

This is a bug fix release which fixes all reported issues in the new 1.2 features. Developers should be testing this version.

25 March 2006: Subversion

Ehcache is now on Subversion. See the source repository page for details.

17 March 2006: New Site Redesign

Ehcache has outgrown its old web design. This new one is produced using Maven 2. Please send any feedback on the new site to the team.

14 March 2006: New Mailing List

A new mailing list, ehcache-list@lists.sourceforge.net, has been created for ehcache users and developers. Go here to subscribe or to search the archive.

7 February 2006: Whats New in 1.2

Ehcache-1.2, currently at beta 5, has many new features:

• Introduced new caching policies in addition to the standard LRU. FIFO and LFU were added. LRU remains the default unless explicitly set in each cache's configuration. Thanks to Surya Suravarapu for working with me on these. The documentation has a new section on caching policies and when to use what.
• Introduced CacheManagerEventListener and CacheEventListener interfaces and default implementations. These can be configured in ehcache.xml or set programmatically. Thanks to steve at jofti dot com for help with the specification for these.
• After requests from Jo Walnes, Paul Hammant and others, I have added normal instance constructers to CacheManager which do not act as singletons. The factory singleton methods remain for backward compatibility. CacheManager can now be constructed with a Configuration object programmatically.
• Since version 1.1, ehcache has had a persistent diskStore, which makes it suitable for storing application state. Added a flush method so that, if the cache is diskPersistent, it can be programmatically flushed, in addition to the automatic flush which happens at shutdown.
• Pluggable Distributed Caching. The default implementation supports cache discovery via multicast or manual configuration. Updates are delivered asynchronously or synchronously via custom RMI connections. Additional discovery or delivery schemes can be plugged in by third parties.
• Significant (up to 7 fold) DiskStore performance increases, after introduction of finer grained threading. Thanks to Robert Watkins for reporting on the performance limits.
• Backward Compatibility

Ehcache-1.2 is mostly backward compatible with ehcache-1.1. Ehcache-1.1 ehcache.xml configurations are compatible. There have been a few small API changes to the ehcache-1.1 API.

See the changelog for more details on the release.

8 February 2006 Announcing ehcache-1.2beta4.

This fixes most reported bugs and has fairly complete documentation.

27 January 2006 Announcing ehcache-1.2 beta 3.

New features over beta2 are:

• Pluggable Distributed Caching. The default implementation supports cache discovery via multicast or manual configuration. Updates are delivered asynchronously or synchronously via custom RMI connections. Additional discovery or delivery schemes can be plugged in by third parties.
• After requests from Jo Walnes, Paul Hammant and others, I have added normal instance constructers to CacheManager which do not act as singletons. The factory singleton methods remain for backward compatibility. CacheManager can now be constructed with a Configuration object programmatically.
• Significant (up to 7 fold) DiskStore performance increases, after introduction of finer grained threading. Thanks to Robert Watkins for reporting on the performance limits.

This release also contains 5 bug fixes and increased test coverage. This version has been comprehensively tested, but has limited production use.

This will be the last pre release of ehcache-1.2 which adds major features. The focus will now shift to addressing any bugs or issues raised by those using this version. Basic documentation of the new features has been completed. Work will also continue on providing  configuration and coding examples to use  em.  Please promptly report any bugs found.

16 October 2005 Announcing ehcache-1.2 beta 2.

New features over beta1 are:

• Introduced CacheManagerEventListener and CacheEventListener interfaces and default implementations. These can be configured in ehcache.xml or set programmatically. Thanks to steve at jofti dot com for help with the specification for these.
• Added normal instance constructers to CacheManager which do not act as singletons. The factory singleton methods remain for backward compatibility. CacheManager can now be constructed with a Configuration object programmatically.
• ehcache has a persistent diskStore, which makes it suitable for storing application state. Added a flush method so that, if the cache is diskPersistent, it can be programmatically flushed, in addition to the automatic flush which happens at shutdown.

This release also contains 5 bug fixes and increased test coverage.

This version has been comprehensively tested, but has limited production use. It is recommended for development usage and testing.

28 August 2005 Announcing ehcache-1.2 beta 1.

New in this version are two new cache eviction policies: Less Frequently Used (LFU) and First In First Out (FIFO). There are also a few minor bug fixes. Thanks to Surya Suravarapu for work on these new policies.

This version of ehcache should be backwardly compatible with ehcache 1.1 except for a dependency on commons-collections 3.1, up from version 2.1. This version has been comprehensively tested, but has limited production use. It is recommended for development usage only.

15 August 2005 Announcing ehcache-constructs-0.6.

A subproject of ehcache, ehcache-constructs builds on top of ehcache to create implementations for common caching patterns. All implementations use ehcache as the backing cache. They also share a common purpose - to create very high performance Java applications. New in this version is a fault-tolerant AsynchronousCommandExecutor, which will asynchronously execute arbitrary commands, optionally retrying on a defined array of Exception types a defined number of times at a defined interval.

23 November 2004 ehcache 1.1 released.

This version splits out the constructs package into a separate sub-project. This simplifies ehcache for those using it in Hibernate or directly. It also moves the constructs to a separate jar and release cycle. There is only 1 minor bug fix but then there was only one bug reported.

See the release notes and full changelog here.

23 November 2004 Announcing ehcache-constructs-0.5

A subproject of ehcache, ehcache-constructs builds on top of ehcache to create implementations for common caching patterns. All implementations use ehcache as the backing cache. They also share a common purpose - to create very high performance Java applications.

At present ehcache-constructs contains:

• General Purpose Caching
  • BlockingCache - a cache which blocks subsequent threads until the first read thread populates a cache entry * SelfPopulatingCache - a read-through cache. A cache that populates elements as they are requested without requiring the caller to know how the entries are populated. It also enables refreshes of cache entries without blocking reads on the same entries.
  • UpdatingSelfPopulatingCache - a read-through cache. A cache that populates elements as they are requested without requiring the caller to know how the entries are populated. The cache entry is automatically updated on subsequent reads.
  • SelfPopulatingCollectionsCache - a SelfPopulatingCache that adds threading safety where it is known in advance that all entries will be collections.
• Web Caching

  Servlet 2.3 caching filters that cache HTTP/S responses:

  • CachingFilter - an abstract, extensible caching filter.
  • SimplePageCachingFilter - a concrete implementation which caches pages based on the request URI and Query String.
  • SimplePageFragmentCachingFilter - a concrete implementation which caches page fragments based on the request URI and Query String.

  See the ehcache-constructs subsite for and overview, documentation, javadoc, clover test coverage and more.

28 September 2004 ehcache 1.0 released.

This is a major milestone for ehcache - the 1.0 release. It has several bug fixes and a few important new features. They are:

• Added SelfPopulatingCacheManager to the constructs package.
• Added a new diskExpiryThreadIntervalSeconds configuration option to ehcache.xml, to allow tuning of the expiry thread per cache.
• Added a new persistent option for the DiskStore. When enabled, diskPersistent makes Caches persistent between JVM restarts. It enables very long held caches to be configured, useful for very expensive and/or long lived cache entries.
• Improved code coverage. See clover coverage report.
• New checkstyle rules, using checkstyle 3.4. Many additional checks have been added and code cleanups done to make ehcache more standards compliant and understandable than ever.

See the release notes and full changelog here.

15 July 2004 ehcache 0.9 released

This is a large release. It fixes several bugs and adds many new features including:

• ehcache.xml cache definitions can now omit timeToIdle and/or timeToLive, which have been made optional attributes. This will make cache config easier to read for eternal caches. Either omitting the attributes or setting them to 0 causes them not to be considered when calculating expiry. Earlier versions of ehcache would have immediately expired all elements if either attribute was set to 0, so this change should not break any existing code.
• Added getQuiet and putQuiet methods to Cache. These methods are the same as get and put but do not affect statistics.
• Implemented an Element clone method.
• Added calculateInMemorySize() method to Cache to measure the approximate size of a cache's memory footprint.
• Added a new constructs package.

Blocking, self populating and self populating collections cache implementations are provided. They are useful where the cost of creating a cache entry is high, and you want to make request threads block until the first one creates the entry. While new to ehcache, the package is based on code that has been in production for almost a year, and is now ready for a wider audience.

See the release notes and full changelog here.

15 May 2004 ehcache 0.8 released.

Changes include:

• Fix to a rare null pointer exception.
• Added Clover test coverage. Many thanks to cortex for the free license. Note that Clover is not included in the packaged binary code and no license is required to use EHCache. It is a development tool only.
• Modifed some errors in the Apache license to enable its inclusion in the Apache Cocoon project.

2 Jan 2004 ehcache 0.7 released.

Bug fixes.

11 Dec 2003 EHCache is made the recommended process cache for Hibernate 2.1

8 Dec 2003 ehcache 0.6 released.

Bug fixes.

18 Nov 2003 ehcache 0.5 released

Now supports JDK1.2 and JDK1.3 as well as JKD1.4

13 Nov 2003 ehcache 0.4 released.