1
我有大量的數據存儲在HDFS中，我們想索引到Elasticsearch。微不足道的想法是使用Elasticsearch-hadoop庫。如何使用hadoop map-reduce和es-hadoop將json索引到elasticsearch？
我遵循this video的概念，這裏是我爲這項工作寫的代碼。
public class TestOneFileJob extends Configured implements Tool {
public static class Tokenizer extends MapReduceBase
implements Mapper<LongWritable, Text, LongWritable, MapWritable> {
private final MapWritable map = new MapWritable();
private final Text key = new Text("test");
@Override
public void map(LongWritable arg0, Text value, OutputCollector<LongWritable, MapWritable> output, Reporter reporter)
throws IOException {
map.put(key, value);
output.collect(arg0, map);
}
}
@Override
public int run(String[] args) throws Exception {
JobConf job = new JobConf(getConf(), TestOneFileJob.class);
job.setJobName("demo.mapreduce");
job.setInputFormat(TextInputFormat.class);
job.setOutputFormat(EsOutputFormat.class);
job.setMapperClass(Tokenizer.class);
job.setMapOutputValueClass(MapWritable.class);
job.setSpeculativeExecution(false);
FileInputFormat.setInputPaths(job, new Path(args[1]));
job.set("es.resource", args[2]);
JobClient.runJob(job);
return 0;
}
public static void main(String[] args) throws Exception {
System.exit(ToolRunner.run(new TestOneFileJob(), args));
}
}
作業工作得很好，但整個JSON是投入在Elasticsearch名爲test一個字段。很顯然，字段名稱是這一行private final Text key = new Text("test");中的關鍵，但我需要整個json字段。
以下是文檔在Elasticsearch中的顯示方式。
{
"_index": "test",
"_type": "test",
"_id": "AVEzNbg4XbZ07JYtWKzv",
"_score": 1,
"_source": {
"test": "{\"id\":\"tag:search.twitter.com,2005:666560492832362496\",\"objectType\":\"activity\",\"actor\":{\"objectType\":\"person\",\"id\":\"id:twitter.com:2305228178\",\"link\":\"http://www.twitter.com/alert01\",\"displayName\":\"Himanshu\",\"postedTime\":\"2014-01-22T17:49:57.000Z\",\"image\":\"https://pbs.twimg.com/profile_images/468092875440275456/jJkHRnQF_normal.jpeg\",\"summary\":\"A Proud Indian ; A Nationalist ; Believe in India First\",\"links\":[{\"href\":null,\"rel\":\"me\"}],\"friendsCount\":385,\"followersCount\":2000,\"listedCount\":83,\"statusesCount\":103117,\"twitterTimeZone\":\"New Delhi\",\"verified\":false,\"utcOffset\":\"19800\",\"preferredUsername\":\"alert01\",\"languages\":[\"en-gb\"],\"favoritesCount\":10},\"verb\":\"share\",\"postedTime\":\"2015-11-17T10:16:20.000Z\",\"generator\":{\"displayName\":\"Twitter for Android\",\"link\":\"http://twitter.com/download/android\"},\"provider\":{\"objectType\":\"service\",\"displayName\":\"Twitter\",\"link\":\"http://www.twitter.com\"},\"link\":\"http://twitter.com/alert01/statuses/666560492832362496\",\"body\":\"RT @UnSubtleDesi: Raje didnt break rules bt Media hounded her for weeks demndng resignatn on \\\"moral ground\\\".A massve dynasty scam unfoldng …\",\"object\":{\"id\":\"tag:search.twitter.com,2005:666559923673653248\",\"objectType\":\"activity\",\"actor\":{\"objectType\":\"person\",\"id\":\"id:twitter.com:17741799\",\"link\":\"http://www.twitter.com/UnSubtleDesi\",\"displayName\":\"Vande Mataram\",\"postedTime\":\"2008-11-29T21:12:05.000Z\",\"image\":\"https://pbs.twimg.com/profile_images/648362451717648384/-7oGuhfN_normal.jpg\",\"summary\":\"I apologise if I end up offending u unintentionally. In all probability, it was acutely intentional. http://saffronscarf.blogspot.in\",\"links\":[{\"href\":null,\"rel\":\"me\"}],\"friendsCount\":786,\"followersCount\":25198,\"listedCount\":155,\"statusesCount\":71853,\"twitterTimeZone\":null,\"verified\":false,\"utcOffset\":null,\"preferredUsername\":\"UnSubtleDesi\",\"languages\":[\"en\"],\"favoritesCount\":21336},\"verb\":\"post\",\"postedTime\":\"2015-11-17T10:14:04.000Z\",\"generator\":{\"displayName\":\"Twitter for Android\",\"link\":\"http://twitter.com/download/android\"},\"provider\":{\"objectType\":\"service\",\"displayName\":\"Twitter\",\"link\":\"http://www.twitter.com\"},\"link\":\"http://twitter.com/UnSubtleDesi/statuses/666559923673653248\",\"body\":\"Raje didnt break rules bt Media hounded her for weeks demndng resignatn on \\\"moral ground\\\".A massve dynasty scam unfoldng here. Eerie silence\",\"object\":{\"objectType\":\"note\",\"id\":\"object:search.twitter.com,2005:666559923673653248\",\"summary\":\"Raje didnt break rules bt Media hounded her for weeks demndng resignatn on \\\"moral ground\\\".A massve dynasty scam unfoldng here. Eerie silence\",\"link\":\"http://twitter.com/UnSubtleDesi/statuses/666559923673653248\",\"postedTime\":\"2015-11-17T10:14:04.000Z\"},\"inReplyTo\":{\"link\":\"http://twitter.com/UnSubtleDesi/statuses/666554154169446400\"},\"favoritesCount\":5,\"twitter_entities\":{\"hashtags\":[],\"urls\":[],\"user_mentions\":[],\"symbols\":[]},\"twitter_filter_level\":\"low\",\"twitter_lang\":\"en\"},\"favoritesCount\":0,\"twitter_entities\":{\"hashtags\":[],\"urls\":[],\"user_mentions\":[{\"screen_name\":\"UnSubtleDesi\",\"name\":\"Vande Mataram\",\"id\":17741799,\"id_str\":\"17741799\",\"indices\":[3,16]}],\"symbols\":[]},\"twitter_filter_level\":\"low\",\"twitter_lang\":\"en\",\"retweetCount\":9,\"gnip\":{\"matching_rules\":[{\"tag\":\"ISIS40\"}],\"klout_score\":54,\"language\":{\"value\":\"en\"}}}"
}
}
一種選擇是手動解析JSON和用於在JSON每個鍵分配字段。
還有其他的選擇嗎？