ISSUE #168: Release Notes for 0.5.0
Descriptions of the changes in this PR:
Release Notes for release0.5.0
Since the release is in-progress, please hold on to merge this PR.
Author: Jia Zhai <zhaijia@apache.org>
Reviewers: Khurrum Nasim <None>, Sijie Guo <sijie@apache.org>
This closes #180 from zhaijack/releasenotes_050, closes #168
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+---
+title: Apache DistributedLog 0.5.0 Release Notes
+---
+
+This is the second Apache release of DistributedLog and the first release as a sub-project of Apache BookKeeper!
+
+The 0.5.0 release upgrades BookKeeper from Twitter `4.3.7-TWTTR-OSS` version to the official Apache `4.5.0` version.
+It is a big milestone in Apache BookKeeper & DistributedLog community, converging the development efforts for
+both communities and moving the DistributedLog development on the official Apache bookkeeper release.
+
+Apache DistributedLog users are encouraged to upgrade to 0.5.0. The technical details of this release are summarized
+below.
+
+## Highlights
+
+### BookKeeper Version Upgrade
+
+The main change in 0.5.0 is BookKeeper version upgrade. We upgraded the BookKeeper version from Twitter's `4.3.7-TWTTR-OSS`
+to the official [Apache BookKeeper `4.5.0`](http://bookkeeper.apache.org/docs/4.5.0/overview/releaseNotes/) version. This upgrade brings in BookKeeper security feature and performance improvement (such as netty 4 upgrade).
+The upgrade should be straightforward, because there isn't any backward compatible issue.
+
+### Change Twitter Future to Java Future
+
+Prior to 0.5.0, the DistributedLog API heavily depends on Twitter Future library and other scala dependency. In 0.5.0, we change
+the twitter future API to a separate module and replace the core API with Java8 CompletableFuture. It reduces the dependencies introduced
+by Scala and also avoid maintaining multiple versions for different scala versions.
+
+### Better buffer/memory management
+
+After upgrading to BookKeeper 4.5.0, we update the buffer and memory management in DistributedLog to leverage netty's buffer management.
+It reduces object allocation, memory copies and improves the latency because less jvm garbage is produced.
+
+
+## Full list of changes
+
+### JIRA
+
+
+####Sub-task
+<ul>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-208'>DL-208</a>] - Update release notes about the download location
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-209'>DL-209</a>] - Update build script to build DistributedLog website under `bookkeeper.apache.org/distributedlog`
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-210'>DL-210</a>] - Update DL mailing lists
+</li>
+</ul>
+
+####Bug
+<ul>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-19'>DL-19</a>] - Can't compile thrift file
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-124'>DL-124</a>] - Use Java8 Future rather than twitter Future
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-128'>DL-128</a>] - All TODO items should have jira tickets.
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-195'>DL-195</a>] - Apache Rat Check Failures on DISCLAIMER.bin.txt
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-206'>DL-206</a>] - Delete log doesn't delete log segments
+</li>
+</ul>
+
+####Improvement
+<ul>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-204'>DL-204</a>] - Bump libthrift to latest version for distributedlog-core
+</li>
+</ul>
+
+####Task
+<ul>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-2'>DL-2</a>] - DistributedLog should work with the official apache bookkeeper
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-81'>DL-81</a>] - Build the distributedlog release procedure
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-82'>DL-82</a>] - Automatically build and update the website
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-199'>DL-199</a>] - Be able to support filesystem-path like name
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-205'>DL-205</a>] - Remove StatusCode dependency on DLException
+</li>
+<li>[<a href='https://issues.apache.org/jira/browse/DL-207'>DL-207</a>] - DL Graduation Item
+</li>
+</ul>
+
+
+### Github
+
+- [https://github.com/apache/distributedlog/milestone/1](https://github.com/apache/distributedlog/milestone/1?closed=1)
