Use a unified namespace to implement cache-based acceleration - E-MapReduce

JindoCache can cache data from various data sources to accelerate data access. JindoCache also allows you to mount the data sources to a unified namespace for centralized management and access.

Prerequisites

JindoCache is configured. For more information, see Use the transparent caching feature of JindoCache to accelerate access to OSS-HDFS and Use the transparent caching feature of JindoCache to accelerate access to OSS.

Mount data sources

Mount an OSS data source

You can mount a specific directory of an Object Storage Service (OSS) bucket to the /oss directory in the Jindo file system. This way, you can use the Jindo file system to access and perform operations on objects in OSS. You can also mount multiple OSS buckets to different paths.

jindocache -mount /oss oss://<bucket>/<dir>

Mount an OSS-HDFS data source

You can mount a specific directory of an OSS-HDFS bucket to the /oss-hdfs directory in the Jindo file system. This way, you can use the Jindo file system to access and perform operations on files in OSS-HDFS.

jindocache -mount /oss-hdfs oss://<bucket>/<dir>

You can also mount multiple OSS-HDFS buckets to different paths.

Mount an on-premises NAS data source

You can mount a specific directory of File Storage NAS to the /nas directory in the Jindo file system. This way, you can use the Jindo file system to access and perform operations on on-premises NAS files.

jindocache -mount /nas local:///mnt/nas

You can also mount multiple on-premises NAS file directories to different paths.

Use a unified namespace to access the Jindo file system

A specific directory of an OSS bucket is mounted to the /oss directory in the Jindo file system.

Run the following command to view the files and directories in the root directory of the Jindo file system:
```
hadoop fs -ls jindo://master-1-1:8101/
```
The /oss directory is returned.
```
bashdrwxrwxr-x   - root root          0 1970-01-01 00:00 jindo:///oss
```

Run the following command to view the details of files and directories in the /oss path:

hadoop fs -ls jindo://master-1-1:8101/oss/

The following information is returned:

drwxrwxr-x   - root root          0 1970-01-01 00:00 jindo:///oss/test_a_dir
-rwxrwxr-x   0 root root   19564111 2022-04-11 10:25 jindo:///oss/tmp.txt

View all mount points of the current system

You can run the following command to view all mount points in the current system. For information about the jindocache command, see JindoCache CLI usage notes.

jindocache -mount