Appengine Mapreduce 受限类管理工厂

Question

当我使用 Appengine-mapreduce 库触发 mapreduce 作业时出现受限类异常。我使用的是 appengine sdk 版本 1.8.8。错误似乎是因为 appengine-mapper 代码内部使用了 hadoop-0.20.2。

java.lang.NoClassDefFoundError: java.lang.management.ManagementFactory is a restricted class. Please see the Google App Engine developer's guide for more details.
    at com.google.apphosting.runtime.security.shared.stub.java.lang.management.ManagementFactory.<clinit>(ManagementFactory.java)
    at org.apache.hadoop.util.ReflectionUtils.<clinit>(ReflectionUtils.java:121)
    at org.apache.hadoop.io.serializer.SerializationFactory.add(SerializationFactory.java:64)
    at org.apache.hadoop.io.serializer.SerializationFactory.<init>(SerializationFactory.java:54)
    at com.google.appengine.tools.mapreduce.SerializationUtil.serializeToByteArrayOutputStream(SerializationUtil.java:46)
    at com.google.appengine.tools.mapreduce.SerializationUtil.serializeToByteArray(SerializationUtil.java:60)
    at com.google.appengine.tools.mapreduce.v2.impl.ShardState.setInputSplit(ShardState.java:215)
    at com.google.appengine.tools.mapreduce.v2.impl.handlers.Worker.scheduleShards(Worker.java:218)
    at com.google.appengine.tools.mapreduce.v2.impl.handlers.Controller.handleStart(Controller.java:133)

触发代码：

MapReduceXml mrXml = MapReduceXml.getMapReduceXmlFromFile();
Configuration configuration = mrXml.instantiateConfiguration( configName, params );

jobId = Controller.handleStart(configuration, configName, "/mapreduce/");

请指教！！

Answer 1

使用 appengine-mapper 随附的 hadoop-0.20.2-core.jar 后，此问题得到解决。它似乎不喜欢来自 maven 的 hadoop-core-0.20.2 文件。