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Posted to common-issues@hadoop.apache.org by "John Carrino (JIRA)" <ji...@apache.org> on 2011/04/14 06:36:05 UTC
[jira] [Created] (HADOOP-7226) CLONE - DataNode.setNewStorageID
pulls entropy from /dev/random
CLONE - DataNode.setNewStorageID pulls entropy from /dev/random
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Key: HADOOP-7226
URL: https://issues.apache.org/jira/browse/HADOOP-7226
Project: Hadoop Common
Issue Type: Bug
Components: fs
Affects Versions: 0.17.0
Environment: linux
Reporter: John Carrino
Priority: Minor
DataNode.setNewStorageID uses SecureRandom.getInstance("SHA1PRNG") which always pulls fresh entropy.
It wouldn't be so bad if this were only the 120 bits needed by sha1, but the default impl of SecureRandom actually uses a BufferedInputStream around /dev/random and pulls 1024 bits of entropy for this one call.
If you are on a system without much entropy coming in, this call can block and block others.
Can we just change this to use "new SecureRandom().nextInt(Integer.MAX_VALUE)" instead?
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[jira] [Resolved] (HADOOP-7226) CLONE - DataNode.setNewStorageID
pulls entropy from /dev/random
Posted by "John Carrino (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/HADOOP-7226?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
John Carrino resolved HADOOP-7226.
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Resolution: Duplicate
Sorry, ignore this. I was trying to clone it to the HDFS project, but it resulted in this duplicate ticket.
> CLONE - DataNode.setNewStorageID pulls entropy from /dev/random
> ---------------------------------------------------------------
>
> Key: HADOOP-7226
> URL: https://issues.apache.org/jira/browse/HADOOP-7226
> Project: Hadoop Common
> Issue Type: Bug
> Components: fs
> Affects Versions: 0.17.0
> Environment: linux
> Reporter: John Carrino
> Priority: Minor
> Original Estimate: 10m
> Remaining Estimate: 10m
>
> DataNode.setNewStorageID uses SecureRandom.getInstance("SHA1PRNG") which always pulls fresh entropy.
> It wouldn't be so bad if this were only the 120 bits needed by sha1, but the default impl of SecureRandom actually uses a BufferedInputStream around /dev/random and pulls 1024 bits of entropy for this one call.
> If you are on a system without much entropy coming in, this call can block and block others.
> Can we just change this to use "new SecureRandom().nextInt(Integer.MAX_VALUE)" instead?
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