For me it wouldn’t help I guess, because those newer classes would still be loaded by different classloader. What did work for me with 1.3.1 – removing of those classes from Spark’s jar completely, so they get loaded from external Guava (the version I prefer) and by the classloader I expect. That’s why I proposed to put them into separate maven artifact where they could be just excluded in the build of the app that depends on Spark.
From: Marcelo Vanzin [mailto:van...@cloudera.com] Sent: Friday, May 15, 2015 11:55 AM To: Anton Brazhnyk Cc: user@spark.apache.org Subject: Re: Spark's Guava pieces cause exceptions in non-trivial deployments Ah, I see. yeah, it sucks that Spark has to expose Optional (and things it depends on), but removing that would break the public API, so... One last thing you could try is do add your newer Guava jar to "spark.driver.extraClassPath" and "spark.executor.extraClassPath". Those settings will place your jars before Spark's in the classpath, so you'd actually be using the newer versions of the conflicting classes everywhere. It does require manually distributing the Guava jar to the same location on all nodes in the cluster, though. If that doesn't work. Thomas's suggestion of shading Guava in your app can be used as a last resort. On Thu, May 14, 2015 at 7:38 PM, Anton Brazhnyk <anton.brazh...@genesys.com<mailto:anton.brazh...@genesys.com>> wrote: The problem is with 1.3.1 It has Function class (mentioned in exception) in spark-network-common_2.10-1.3.1.jar. Our current resolution is actually backport to 1.2.2, which is working fine. From: Marcelo Vanzin [mailto:van...@cloudera.com<mailto:van...@cloudera.com>] Sent: Thursday, May 14, 2015 6:27 PM To: Anton Brazhnyk Cc: user@spark.apache.org<mailto:user@spark.apache.org> Subject: Re: Spark's Guava pieces cause exceptions in non-trivial deployments What version of Spark are you using? The bug you mention is only about the Optional class (and a handful of others, but none of the classes you're having problems with). All other Guava classes should be shaded since Spark 1.2, so you should be able to use your own version of Guava with no problems (aside from the Optional classes). Also, Spark 1.3 added some improvements to how shading is done, so if you're using 1.2 I'd recommend trying 1.3 before declaring defeat. On Thu, May 14, 2015 at 4:52 PM, Anton Brazhnyk <anton.brazh...@genesys.com<mailto:anton.brazh...@genesys.com>> wrote: Greetings, I have a relatively complex application with Spark, Jetty and Guava (16) not fitting together. Exception happens when some components try to use “mix” of Guava classes (including Spark’s pieces) that are loaded by different classloaders: java.lang.LinkageError: loader constraint violation: when resolving method "com.google.common.collect.Iterables.transform(Ljava/lang/Iterable;Lcom/google/common/base/Function;)Ljava/lang/Iterable;" the class loader (instance of org/eclipse/jetty/webapp/WebAppClassLoader) of the current class, org/apache/cassandra/db/ColumnFamilyStore, and the class loader (instance of java/net/URLClassLoader) for resolved class, com/google/common/collect/Iterables, have different Class objects for the type e;Lcom/google/common/base/Function;)Ljava/lang/Iterable; used in the signature According to https://issues.apache.org/jira/browse/SPARK-4819 it’s not going to be fixed at least until Spark 2.0, but maybe some workaround is possible? Those classes are pretty simple and have low chances to be changed in Guava significantly, so any “external” Guava can provide them. So, could such problems be fixed if those Spark’s pieces of Guava would be in separate jar and could be excluded from the mix (substituted by “external” Guava)? Thanks, Anton -- Marcelo -- Marcelo
