Apache Kudu 0.10.0 发布了。 Apache Kudu 简介 为了应对先前发现的这些趋势，有两种不同的方式：持续更新现有的Hadoop工具或者重新设计开发一个新的组件。其目标是： 对数据扫描(scan)和随机访问(random access)同时具有高性能，简化用户复杂的混合架构； 高CPU效率，最大化先进处理器的效能； 高IO性能，充分利用先进永久存储介质； 支持数据的原地更新，避免额外的数据处理、数据移动 我们为了实现这些目标，首先在现有的开源项目上实现原型，但是最终我们得出结论：需要从架构层作出重大改变。而这些改变足以让我们重新开发一个全新的数据存储系统。于是3年前开始开发，直到如今我们终于可以分享多年来的努力成果：Kudu，一个新的数据存储系统。 更新如下： Incompatible changes 0.8.0 clients are not fully compatible with servers running Kudu 0.7.1 or lower. In particular, scans that specify column predicates will fail. To work around this issue, upgrade all Kudu servers before upgrading clients. New features KUDU-431 A simple Flume sink has been implemented. Improvements KUDU-839 Java RowError now uses an enum error code. Gerrit 2138 The handling of column predicates has been re-implemented in the server and clients. KUDU-1379 Partition pruning has been implemented for C++ clients (but not yet for the Java client). This feature allows you to avoid reading a tablet if you know it does not serve the row keys you are querying. Gerrit 2641 Kudu now uses earliest-deadline-first RPC scheduling and rejection. This changes the behavior of the RPC service queue to prevent unfairness when processing a backlog of RPC threads and to increase the likelihood that an RPC will be processed before it can time out. Fixed Issues KUDU-1337 Tablets from tables that were deleted might be unnecessarily re-bootstrapped when the leader gets the notification to delete itself after the replicas do. KUDU-969 If a tablet server shuts down while compacting a rowset and receiving updates for it, it might immediately crash upon restart while bootstrapping that rowset’s tablet. KUDU-1354 Due to a bug in Kudu’s MVCC implementation where row locks were released before the MVCC commit happened, flushed data would include out-of-order transactions, triggering a crash on the next compaction. KUDU-1322 The C++ client now retries write operations if the tablet it is trying to reach has already been deleted. Gerrit 2571 Due to a bug in the Java client, users were unable to close the kudu-spark shell because of lingering non-daemon threads. Other noteworthy changes Gerrit 2239 The concept of "feature flags" was introduced in order to manage compatibility between different Kudu versions. One case where this is helpful is if a newer client attempts to use a feature unsupported by the currently-running tablet server. Rather than receiving a cryptic error, the user gets an error message that is easier to interpret. This is an internal change for Kudu system developers and requires no action by users of the clients or API. 完整更新说明：http://kudu.apache.org/releases/0.8.0/docs/release_notes.html 下载： Kudu 0.8.0 source tarball (SHA1, MD5, Signature) Apache Kudu 0.10.0 发布，Hadoop 存储系统下载地址
