Percona XtraDB Cluster 5.6.15-25.4 发布，此版本现在已在软件仓库 中提供二进制下载。
此版本是基于 Percona Server 5.6.15-63.0 的 bug 修复版本，包括里面的所有 bug 修复，当前已经发布可用的 Galera Replicator 3.3 和 Codership wsrep API 5.6.15-25.2。
Bugs fixed
Parallel Applying was not functioning which was evident from the wsrep_cert_deps_distance being 1.0 at all times. Bug fixed #1277703.
Binlog events were created for the statements for non-InnoDB tables, but they were never cleaned from transaction cache, which could lead to node crash. Bug fixed #1277986.
Percona XtraDB Cluster didn’t validate the parameters of wsrep_provider_options when node was being started. Bug fixed #1260193.
clustercheck script would mark node as down on Debian based systems if it was run with default values because it was looking for the defaults-extra-file in the wrong directory. Bug fixed #1276076.
Deadlock would happen when NULL unique key was inserted. Workaround has been implemented to support NULL keys, by using the md5 sum of full row as key value. Bug fixed #1276424
Variables innodb-log-group-home-dir and innodb-data-home-dir are now handled by default (ie., there is no need to set them up in sst_special_dirs). Bug fixed #1276904.
Builds now use system Zlib instead of bundled one. Bug fixed #1277928.
If transaction size exceeds the wsrep_max_ws_size limit, there will appear a warning message in the error log and replication is skipped. However, the transaction was committed in the master node, and cluster would be in inconsistent state. Bug fixed #1280557.
Variable wsrep_load_data_splitting defaults to OFF now, using it turned ON with autocommit set to 0 is not recommended.
Other bugs fixed: #1279844.
更多更新内容请看发行说明，安装和升级指导可以查看 在线文档。
Percona XtraDB Cluster是针对MySQL用户的高可用性和扩展性解决方案，基于Percona Server 。其包括了Write Set REPlication补丁，使用Galera 2.0库，这是一个针对事务性应用程序的同步多主机复制插件。
Percona Server是MySQL的改进版本，使用 XtraDB 存储引擎，在功能和性能上较 MySQL 有着很显著的提升，如提升了在高负载情况下的 InnoDB 的性能，为 DBA 提供了一些非常有用的性能诊断工具，另外有更多的参数和命令来控制服务器行为。
Percona XtraDB Cluster提供了：
同步复制，事务可以在所有节点上提交。
多主机复制，你可以写到任何节点。
从（slave）服务器上的并行应用事件，真正的“并行复制”。
自动节点配置。
数据一致性，不再有未同步的从服务器。
Percona XtraDB Cluster完全兼容MySQL或Percona Server，包括：
数据兼容。Percona XtraDB Cluster可在由MySQL或Percona Server创建的数据库上使用。
应用程序兼容。如果要使用Percona XtraDB Cluster，你的应用程序基本不需要作任何更改。
此次发布的Percona XtraDB Cluster为alpha版本，不建议在实际工作中使用，开发者可据此了解Percona XtraDB Cluster的特性和功能。
下载地址：http://www.percona.com/downloads/
来自:开源中国社区
