迁移OSS上的数据到LindormDFS_云原生多模数据库 Lindorm(Lindorm)-阿里云帮助中心

本章节介绍如何将对象存储OSS上的数据迁移到LindormDFS。

准备工作

开通LindormDFS，详情请参见开通指南。
搭建Hadoop集群。建议您使用的Hadoop版本不低于2.7.3，本文档中使用的Hadoop版本为Apache Hadoop 2.7.3，修改Hadoop配置信息，详情参见使用开源HDFS客户端访问。
在Hadoop集群所有节点上安装JDK，本操作要求JDK版本不低于1.8。

在Hadoop集群安装OSS客户端JindoFS SDK。JindoFS SDK详细介绍请参见JindoFS SDK。

下载 jindofs-sdk.jar。

cp ./jindofs-sdk-*.jar  ${HADOOP_HOME}/share/hadoop/hdfs/lib/

为Hadoop集群所有节点创建JindoFS SDK配置文件。

添加如下环境变量到/etc/profile文件。

export B2SDK_CONF_DIR=/etc/jindofs-sdk-conf

创建OSS存储工具配置文件/etc/jindofs-sdk-conf/bigboot.cfg。

[bigboot]
logger.dir=/tmp/bigboot-log[bigboot-client]
client.oss.retry=5
client.oss.upload.threads=4
client.oss.upload.queue.size=5
client.oss.upload.max.parallelism=16
client.oss.timeout.millisecond=30000
client.oss.connection.timeout.millisecond=4000

加载环境变量使之生效。

source /etc/profile

验证是否可以在Hadoop 集群上使用OSS。

${HADOOP_HOME}/bin/hadoop fs -ls oss://<accessKeyId>:<accessKeySecret>@<bucket-name>.<endpoint>/

将对象存储OSS数据迁移到LindormDFS

检查并且确定需要迁移的数据大小。

${HADOOP_HOME}/bin/hadoop du -h oss://<accessKeyId>:<accessKeySecret>@<bucket-name>.<endpoint>/test_data

启动Hadoop MapReduce任务（DistCp）将测试数据迁移至LindormDFS。

${HADOOP_HOME}/bin/hadoop distcp  \
oss://<accessKeyId>:<accessKeySecret>@<bucket-name>.<endpoint>/test_data.txt \
hdfs://${实例Id}/

其中${实例Id}请根据您的实际情况进行修改。

参数说明如下表所示：

参数	说明
accessKeyId	访问对象存储OSS API的密钥。获取方式请参见创建AccessKey。
accessKeySecret	访问对象存储OSS API的密钥。获取方式请参见创建AccessKey。
bucket-name.endpoint	对象存储OSS的访问域名，包括存储空间（Bucket）名称和对应的地域域名（Endpoint）地址。

任务执行完成后，查看迁移结果。

如果回显包含如下类似信息，说明迁移成功。

20/09/29 12:23:59 INFO mapreduce.Job:  map 100% reduce 0%
20/09/29 12:23:59 INFO mapreduce.Job: Job job_1601195105349_0015 completed successfully
20/09/29 12:23:59 INFO mapreduce.Job: Counters: 38
 File System Counters
  FILE: Number of bytes read=0
  FILE: Number of bytes written=122343
  FILE: Number of read operations=0
  FILE: Number of large read operations=0
  FILE: Number of write operations=0
  HDFS: Number of bytes read=470
  HDFS: Number of bytes written=47047709
  HDFS: Number of read operations=15
  HDFS: Number of large read operations=0
  HDFS: Number of write operations=4
  OSS: Number of bytes read=0
  OSS: Number of bytes written=0
  OSS: Number of read operations=0
  OSS: Number of large read operations=0
  OSS: Number of write operations=0
 Job Counters
  Launched map tasks=1
  Other local map tasks=1
  Total time spent by all maps in occupied slots (ms)=5194
  Total time spent by all reduces in occupied slots (ms)=0
  Total time spent by all map tasks (ms)=5194
  Total vcore-milliseconds taken by all map tasks=5194
  Total megabyte-milliseconds taken by all map tasks=5318656
 Map-Reduce Framework
  Map input records=1
  Map output records=0
  Input split bytes=132
  Spilled Records=0
  Failed Shuffles=0
  Merged Map outputs=0
  GC time elapsed (ms)=64
  CPU time spent (ms)=2210
  Physical memory (bytes) snapshot=222294016
  Virtual memory (bytes) snapshot=2672074752
  Total committed heap usage (bytes)=110100480
 File Input Format Counters
  Bytes Read=338
 File Output Format Counters
  Bytes Written=0
 org.apache.hadoop.tools.mapred.CopyMapper$Counter
  BYTESCOPIED=47047709
  BYTESEXPECTED=47047709
  COPY=1
20/09/29 12:23:59 INFO common.AbstractJindoFileSystem: Read total statistics: oss read average -1 us, cache read average -1 us, read oss percent 0%

验证迁移结果。
查看迁移到LindormDFS的测试数据大小。
```
${HADOOP_HOME}/bin/hadoop fs -du -s -h hdfs://${实例Id}/
```