Question

我刚刚在spark中发现了类序列化的错误。

=＆GT;现在，我想进行单元测试，但我不知道怎么做？

注意：

故障附加在已经广播的（反）序列化对象中。
我想测试一下spark会做什么，断言它一旦部署就会起作用
要序列化的类是扩展Serializer

Answer 1

研究火花广播代码，我找到了一种方法。但它使用私有火花代码，因此如果火花内部发生变化，它可能会变得无效。但它仍然有效。

在以org.apache.spark开头的包中添加测试类，例如：

package org.apache.spark.my_company_tests

// [imports]

/**
 * test data that need to be broadcast in spark (using kryo)
 */
class BroadcastSerializationTests extends FlatSpec with Matchers {

  it should "serialize a transient val, which should be lazy" in {

    val data = new MyClass(42) // data to test
    val conf = new SparkConf()


    // Serialization
    //   code found in TorrentBroadcast.(un)blockifyObject that is used by TorrentBroadcastFactory
    val blockSize = 4 * 1024 * 1024 // 4Mb
    val out = new ChunkedByteBufferOutputStream(blockSize, ByteBuffer.allocate)
    val ser = new KryoSerializer(conf).newInstance() // Here I test using KryoSerializer, you can use JavaSerializer too
    val serOut = ser.serializeStream(out)

    Utils.tryWithSafeFinally { serOut.writeObject(data) } { serOut.close() }

    // Deserialization
    val blocks = out.toChunkedByteBuffer.getChunks()
    val in = new SequenceInputStream(blocks.iterator.map(new ByteBufferInputStream(_)).asJavaEnumeration)
    val serIn = ser.deserializeStream(in)

    val data2 = Utils.tryWithSafeFinally { serIn.readObject[MyClass]() } { serIn.close() }

    // run test on data2
    data2.yo shouldBe data.yo
  }
}

class MyClass(i: Int) extends Serializable {
  @transient val yo = 1 to i // add lazy to make the test pass: not lazy transient val are not recomputed after deserialization
}

如何对一个类进行单元测试是可序列化的？

1 个答案: