HBase MapReduce

Question

If I want to write the Reducer output into HBase, I just need to use:

context.write(key,put);

My question is about the first parameter "key"; whatever value I set to "key", it will not be showed in HBase when I use HBase Shell to check, even though I set it to "null". So what should I set to this "key" on earth?

Answer 1

您应该将其设置为null-从HBase角度看，放置值同时包含键和值，并且如您所正确指出的那样，未使用上下文的键

Answer 2

您应该将密钥设置为一个名为NullWriteable.get（）的实例。