Sqoop 2 MapReduce Job
一个作业初始化的工作:
作业映射阶段：
下面的图表对工作的减少阶段进行了描述;
,------------. ,---------------------.
|SqoopReducer| |SqoopNullOutputFormat|
`---+--------' `----------+----------'
| | ,-----------------------------.
| |-> |SqoopOutputFormatLoadExecutor|
| | `--------------+--------------' |
| | | |
| | | ,-----------------. ,-------------.
| | |-> |SqoopRecordWriter|-->|SqoopWritable|
getRecordWriter | | `--------+--------' `---+---------'
----------------------->| getRecordWriter | | |
| |----------------->| | | ,--------------.
| | |---------------------------------->|ConsumerThread|
| | | | | `------+-------'
| |<- - - - - - - - -| | | | ,------.
<- - - - - - - - - - - -| | | | |--->|Loader|
| | | | | | `--+---'
| | | | | | |
| | | | | | load |
run | | | | | |------>|
----->| | write | | | | |
|------------------------------------------------>| setContent | | read* |
| | | |--------------->| getContent |<------|
| | | | |<-----------| |
| | | | | | - - ->|
| | | | | | | write into Data Source
| | | | | | |----------------------->