[HDFS-5512] CacheAdmin -listPools fails with NPE when user lacks permissions to view all pools

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha1
• Fix Version/s: 2.3.0
• Component/s: caching, tools
• Assignee: Andrew Wang
• Reporter: Stephen Chu
• Created: 13/Nov/13 23:29
• Updated: 12/May/16 18:18
• Resolved: 19/Nov/13 02:35

Description

https://issues.apache.org/jira/browse/HDFS-5471 (CacheAdmin -listPools fails when user lacks permissions to view all pools) was recently resolved, but on a build with this fix, I am running into another error when using cacheadmin -listPools.

Now, when the user does not have permissions to view all the pools, the cacheadmin -listPools command will throw a NullPointerException.

On a system with a single pool "root" with a mode of 750, I see this as user schu:

[schu@hdfs-c5-nfs ~]$ hdfs cacheadmin -listPools
Exception in thread "main" java.lang.NullPointerException
	at org.apache.hadoop.hdfs.tools.CacheAdmin$ListCachePoolsCommand.run(CacheAdmin.java:745)
	at org.apache.hadoop.hdfs.tools.CacheAdmin.run(CacheAdmin.java:82)
	at org.apache.hadoop.hdfs.tools.CacheAdmin.main(CacheAdmin.java:87)

After we modify the root pool to 755, then -listPools works properly.

[schu@hdfs-c5-nfs ~]$ hdfs cacheadmin -listPools
Found 1 result.
NAME  OWNER  GROUP  MODE       WEIGHT 
root  root   root   rwxr-xr-x  100    
[schu@hdfs-c5-nfs ~]$