1. 下载
wget http://repo1.maven.org/maven2/org/mongodb/mongo-hadoop/mongo-hadoop-hive/2.0.2/mongo-hadoop-hive-2.0.2.jar
wget http://repo1.maven.org/maven2/org/mongodb/mongo-hadoop/mongo-hadoop-core/2.0.2/mongo-hadoop-core-2.0.2.jar
wget http://repo1.maven.org/maven2/org/mongodb/mongo-hadoop/mongo-hadoop-core/2.0.2/mongo-hadoop-core-2.0.2.jar
2. 放入hive的lib目录
因为本人搭建的是CDH版本的hadoop集群，所以hive的lib目录在：
/opt/cloudera/parcels/CDH/lib/hive/lib
把上面三个jar包分别放入集群每个节点上的目录中。然后做成软链接，如下：
ln -s mongo-hadoop-hive-2.0.2.jar mongo-hadoop-hive.jar
ln -s mongo-hadoop-core-2.0.2.jar mongo-hadoop-core.jar
如图：
3. mongdb中插入一些测试数据：
db.student.insert({"name":"张三","age":"22","sex":"男","class":"计算机2班"});//如果数据库中不存在集合，就创建
db.student.insert({"name":"李四","age":"23","sex":"女","class":"计算机3班"});
db.student.insert({"name":"王五","age":"24","sex":"男","class":"计算机2班"});
db.student.insert({"name":"刘六","age":"25","sex":"男","class":"计算机3班"});
db.student.insert({"name":"赵七","age":"26","sex":"女","class":"计算机3班"});
db.student.insert({"name":"吴八","age":"28","sex":"女","class":"计算机2班"});
4. hive 中创建表
create external table student
( id string,
name string,
age string,
sex string,
class string
)
stored by 'com.mongodb.hadoop.hive.MongoStorageHandler'
with serdeproperties('mongo.columns.mapping'='{"id":"_id","name":"name","age":"age","sex":"sex","class":"class"}')
tblproperties('mongo.uri'='mongodb://root:e19ee8c4@192.168.0.12:40000/test_v3.student');
查询数据如下：
select * from student;
数据是实时同步的：
mongodb中插入一条数据如下：
db.student.insert({"name":"杨十","age":"28","sex":"男","class":"计算机3班"});
在做查询：
mongodb中修改一条数据如下：
db.student.update({"name":"张三"},{$set:{"name":"张无忌"}});#只想改某个key的value使用set
mongodb中删除一条数据如下：
db.student.remove({"name":"张无忌"});#删除
看张无忌大哥已经不在了，缅怀一下下。
mongodb中做统计：
注意在做统计及用到MR的时候会报错，具体如下：
发现是jar包没有引入成功，可是我已经把三个jar都放到指定的地方了，可是还是不行，所以我就在hive里直接引用这三个jar包，然后在测试：
add jar /opt/cloudera/parcels/CDH/lib/hive/lib/mongo-hadoop-core-2.0.2.jar
add jar /opt/cloudera/parcels/CDH/lib/hive/lib/mongo-hadoop-hive-2.0.2.jar
add jar /opt/cloudera/parcels/CDH/lib/hive/lib/mongo-java-driver-3.2.2.jar
然后看是否能正常统计了：
select sun(age) from student;
直接看结果：
成功了，接下来就要研究放入到CDH hive jar里使之生效。