I put together a tool that leverages Tom White's work. Here is a review for it: https://reviews.apache.org/r/10361/
It will diff the public java api definitions of hbase in two git repos and generate an HTML report. The tool will reside in the /dev-support folder. The documentation is inline in the file. I'd appreciate your input in how I can make it more useful and usable for us. Once we agree on the definitions of what classes are indeed public, we can fine-tune this tool to ignore everything else. -Aleks S. On Mon, Apr 8, 2013 at 3:55 PM, Todd Lipcon <t...@cloudera.com> wrote: > The advantage of the annotations is that Tom White already did the work for > jdiff to ignore non-public classes over in Hadoop land. We could leverage > that work, whether we re-use the o.a.h.classification annotations or add > our own copies in org.apache.hbase.*. > > -Todd > > On Mon, Apr 8, 2013 at 3:08 PM, lars hofhansl <la...@apache.org> wrote: > > > It seems we could just generally document that: > > - no RPC incompatibilities > > - no API breaking changes to any user facing classes (now we'll pay > better > > attention to this) > > - best effort to keep coprocessor API changes backward compatible > > > > If - on the other hand - we wanted to automate API checks then we'd need > > tagging (either in form of an annotation or Javadoc) > > > > +1 on the javadoc tagging if you're willing to take than on. As other > have > > said -1 on pulling Interface Audience in. > > Your set of classes looks good. > > > > -- Lars > > > > > > > > ________________________________ > > From: Elliott Clark <ecl...@apache.org> > > To: "dev@hbase.apache.org" <dev@hbase.apache.org> > > Sent: Monday, April 8, 2013 1:49 PM > > Subject: Re: Declaring HBase Public API in 0.94 > > > > Please don't pull in @InterfaceAudience. Keeping 0.2x compatibility was > > something that was hard won in 0.94, it would be a real shame to loose > that > > now. > > > > > > On Mon, Apr 8, 2013 at 11:07 AM, Aleksandr Shulman <al...@cloudera.com > > >wrote: > > > > > Hi everyone, > > > > > > In light of all the conversation on compatibility, I wanted to float > the > > > idea of documenting which Java packages, classes, and methods we want > to > > > declare as being API compatible in 0.94.x. I'd like your input on: > > > 1. JavaDoc vs. using AudienceInterface > > > 2. What the javadoc notation should look like > > > 3. Which pieces of code should be tagged > > > > > > What do I mean by documenting API compatibility? That means that we > > suggest > > > the anyone building applications use specific methods because they > would > > > continue to be both binary and RPC-compatible going forward. Any > > > application written, either running on a node of a cluster or on a > remote > > > machine, would continue to work properly without recompile for all > > versions > > > of 0.94.x running on the cluster. > > > > > > *Benefits:* > > > It would prevent developers from using calls that are subject to > change. > > > This would give developers more confidence in using the platform, which > > > will encourage more development on our platform. > > > 0.94 will still be with us for some time and I think the > > > better-late-than-never approach will save us pain down the road. > Finally, > > > it would allow us to more easily verify that we are in fact API > > compatible. > > > > > > *Can we use AudienceInterface?* > > > HBase 0.94 can be compiled against both hadoop 0.2x, 1.x, and 2.0.x. In > > the > > > case of 0.2x, the AudienceInterface classes were not bundled. > Therefore, > > we > > > cannot expect HBase 0.94 to support it. For that reason, I think > JavaDoc > > > might be better. > > > On the other hand, perhaps we might just want to bundle > AudienceInterface > > > with 0.94 going forward? Then we can have consistent annotations in > 0.94, > > > 0.95, and 0.96 without worrying about the hadoop version. > > > > > > Please correct me if I'm wrong about any of the above. > > > > > > *Clarification of RPC compatibility:* > > > We care about RPC compatibility when we create clients that bundle > their > > > dependency jars with them. These jars are used to form a request that > is > > > executed on a remote machine (i.e. the cluster). If the cluster is > > upgraded > > > and no longer recognizes the command, then this will break RPC > > > compatibility. > > > > > > *Clarification of Binary compatibility:* > > > We care about binary compatibility when a client is created and > compiled, > > > and the jars on which is depends change. It should still be able to > form > > > requests using those jars. If the cluster is upgraded and the compiled > > > client code cannot find a method it was depending on to be there, we > > break > > > binary compatibility. A recent example is in 0.94.2, where the return > > type > > > of HColumnDescriptor.setMaximumVersions was changed and those who > > upgraded > > > received this error: > > > > > > java.lang.NoSuchMethodError: org.apache.hadoop.hbase.** > > > HColumnDescriptor.**setMaxVersions(I)V > > > > > > *What we currently have:* > > > We have an @audience annotation set up in 0.95/0.96. In 0.94, I suggest > > > either adding JavaDoc or pulling in the AudienceInterface annotation. > > > > > > *Suggested Javadoc language:* > > > @custom.94_api > > > > > > *Granularity:* > > > Just to the class level. The native java access level (e.g. public, > > > protected, etc.) should indicate what should be kept compatible. > > > > > > *Suggested classes:* > > > Here is a first-cut of things that should be declared and documented as > > > public APIs. This list was obtained from looking at some MapReduce over > > > HBase example code. > > > > > > *JAVA API:* > > > > > > *org.apache.hadoop.hbase (some selected classes, see below) > > > org.apache.hadoop.hbase.client.* > > > org.apache.hadoop.hbase.filter.* > > > org.apache.hadoop.hbase.io.hfile.Compression.Algorithm > > > org.apache.hadoop.hbase.util.* > > > org.apache.hadoop.hbase.mapreduce.** > > > > > > *REST API: > > > org.apache.hadoop.hbase.rest.client.** > > > > > > *Thrift API: > > > All methods defined in: > > > /hbase/src/main/resources/org/apache/hadoop/hbase/thrift/Hbase.thrift* > > > > > > *Selected classes in org.apache.hadoop.hbase:* > > > > > > *import org.apache.hadoop.hbase.ClusterStatus; > > > import org.apache.hadoop.hbase.HBaseConfiguration; > > > import org.apache.hadoop.hbase.HColumnDescriptor; > > > import org.apache.hadoop.hbase.HRegionInfo; > > > import org.apache.hadoop.hbase.HRegionLocation; > > > import org.apache.hadoop.hbase.HServerAddress; > > > import org.apache.hadoop.hbase.HTableDescriptor; > > > import org.apache.hadoop.hbase.KeyValue;* > > > > > > -- > > > Best Regards, > > > > > > Aleks Shulman > > > 847.814.5804 > > > Cloudera > > > > > > > > > -- > Todd Lipcon > Software Engineer, Cloudera > -- Best Regards, Aleks Shulman 847.814.5804 Cloudera
