Hi squirrels, sorry I've been slow to respond to this, but I'm now testing RC1 and I'm a bit confused with this change.
So far, the easier way to run a Gelly example on a cluster was to package and submit the Gelly jar. Now, since the flink-gelly project doesn't contain the examples anymore, I tried running a Gelly example by the packaging flink-gelly-examples jar (mvn package). However, this gives me a ClassNotFoundException. e.g. for SingleSourceShortestPaths, the following: java.lang.RuntimeException: Could not look up the main(String[]) method from the class org.apache.flink.graph.examples.SingleSourceShortestPaths: org/apache/flink/graph/spargel/MessagingFunction at org.apache.flink.client.program.PackagedProgram.hasMainMethod(PackagedProgram.java:478) at org.apache.flink.client.program.PackagedProgram.<init>(PackagedProgram.java:216) at org.apache.flink.client.CliFrontend.buildProgram(CliFrontend.java:922) at org.apache.flink.client.CliFrontend.run(CliFrontend.java:301) at org.apache.flink.client.CliFrontend.parseParameters(CliFrontend.java:1189) at org.apache.flink.client.CliFrontend.main(CliFrontend.java:1239) Caused by: java.lang.NoClassDefFoundError: org/apache/flink/graph/spargel/MessagingFunction at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2531) at java.lang.Class.getMethod0(Class.java:2774) at java.lang.Class.getMethod(Class.java:1663) at org.apache.flink.client.program.PackagedProgram.hasMainMethod(PackagedProgram.java:473) ... 5 more Caused by: java.lang.ClassNotFoundException: org.apache.flink.graph.spargel.MessagingFunction at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ... 10 more What am I missing here? Thanks! -Vasia. On 26 February 2016 at 14:10, Márton Balassi <balassi.mar...@gmail.com> wrote: > Thanks, +1. > > On Fri, Feb 26, 2016 at 12:35 PM, Stephan Ewen <se...@apache.org> wrote: > > > Hi! > > > > I think it is a release blocker. > > > > That was a change to make it possible to use Flink with SBT (and make it > > easier to use it with Maven). > > Just had an offline chat with Till, and we suggest the following > solution: > > > > All libraries should be split into two projects: > > - library > > - library-examples > > > > The "library" project has the core flink dependencies as "provided" > > The "library-examples" project has both the "library" and the core flink > > dependencies with scope "compile" > > > > That way the example should run in the IDE out of the cox, and users that > > reference the libraries will still get the correct packaging (include the > > library in the user jar, but not additionally the core flink jars). > > > > Greetings, > > Stephan > > > > > > On Thu, Feb 25, 2016 at 3:45 PM, Márton Balassi < > balassi.mar...@gmail.com> > > wrote: > > > > > Issued JIRA ticket 3511 to make it referable in other discussions. [1] > > > > > > [1] https://issues.apache.org/jira/browse/FLINK-3511 > > > > > > On Thu, Feb 25, 2016 at 3:36 PM, Márton Balassi < > > balassi.mar...@gmail.com> > > > wrote: > > > > > > > Recent changes to the build [1] where many libraries got their core > > > > dependencies (the ones included in the flink-dist fat jar) moved to > the > > > > provided scope. > > > > > > > > The reasoning was that when submitting to the Flink cluster the > > > > application already has these dependencies, while when a user writes > a > > > > program against these libraries she will include the core > dependencies > > > > explicitly anyway. > > > > > > > > There is one other case of usage however, namely when someone is > trying > > > to > > > > run an application defined in these libraries depending on the core > > jars. > > > > To give an example if you were to run the Gelly ConnectedComponents > > > example > > > > [2] from an IDE after importing Flink (or running with java -jar > > without > > > > including the flink fat jar in the classpath) you would receive the > > > > following class not found exception as per the current master: > > > > > > > > Exception in thread "main" java.lang.NoClassDefFoundError: > > > > org/apache/flink/api/common/ProgramDescription > > > > at java.lang.ClassLoader.defineClass1(Native Method) > > > > at java.lang.ClassLoader.defineClass(ClassLoader.java:760) > > > > at > > > java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) > > > > at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) > > > > at java.net.URLClassLoader.access$100(URLClassLoader.java:73) > > > > at java.net.URLClassLoader$1.run(URLClassLoader.java:368) > > > > at java.net.URLClassLoader$1.run(URLClassLoader.java:362) > > > > at java.security.AccessController.doPrivileged(Native Method) > > > > at java.net.URLClassLoader.findClass(URLClassLoader.java:361) > > > > at java.lang.ClassLoader.loadClass(ClassLoader.java:424) > > > > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) > > > > at java.lang.ClassLoader.loadClass(ClassLoader.java:357) > > > > at java.lang.Class.forName0(Native Method) > > > > at java.lang.Class.forName(Class.java:264) > > > > at > com.intellij.rt.execution.application.AppMain.main(AppMain.java:122) > > > > > > > > Where the class missing in runtime is in flink-core, a transitive > > > > dependency of the jars moved to the provided scope. > > > > > > > > Funny thing is we have tests in place to run our examples, but those > > add > > > > test scope dependencies re-adding the missing classes, so it is never > > > > discovered. > > > > > > > > I agree with the original purpose of PR #1683, but also think that > the > > > > current state makes for very inconvenient user experience. > > > > > > > > I would like to open a discussion on how and when to resolve the > issue > > > > given the release of 1.0.0. > > > > > > > > 1. Is it a release blocker? > > > > 2. Should the change be reverted or is it sufficient to have proper > > > > documentation around it? Maybe a maven profile for explicitly for > > > > developing Flink without the provided scope? > > > > > > > > Note that the issue was originally reported by Gábor Gévay. > > > > > > > > [1] https://github.com/apache/flink/pull/1683 > > > > [2] > > > > > > > > > > https://github.com/apache/flink/blob/master/flink-libraries/flink-gelly/src/main/java/org/apache/flink/graph/example/ConnectedComponents.java > > > > > > > > Best, > > > > > > > > Marton > > > > > > > > > >
