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https://issues.apache.org/jira/browse/HADOOP-12436?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14905231#comment-14905231
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Matthew Paduano commented on HADOOP-12436:
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Propose switching the java.util.regex library for com.google.re2j.
One possible concern: The public interface of GlobPattern does permit
users to obtain a reference to the Pattern objects. re2j does not claim
to be a drop in replacement, so this might break something somewhere.
Please find proposed patchfile attached.
> GlobPattern regex library has performance issues with wildcard characters
> -------------------------------------------------------------------------
>
> Key: HADOOP-12436
> URL: https://issues.apache.org/jira/browse/HADOOP-12436
> Project: Hadoop Common
> Issue Type: Improvement
> Components: fs
> Affects Versions: 2.2.0, 2.7.1
> Reporter: Matthew Paduano
> Assignee: Matthew Paduano
>
> java.util.regex classes have performance problems with certain wildcard
> patterns. Namely, consecutive * characters in a file name (not properly
> escaped as literals) will cause commands such as "hadoop fs -ls
> file******name" to consume 100% CPU and probably never return in a reasonable
> time (time scales with number of *'s).
> Here is an example:
> {noformat}
> hadoop fs -touchz
> /user/mattp/job_1429571161900_4222-1430338332599-tda%2D%2D\\\+\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\*\\\+\\\+\\\+...%270%27%28Stage-1430338580443-39-2000-SUCCEEDED-production%2Dhigh-1430338340360.jhist
> hadoop fs -ls
> /user/mattp/job_1429571161900_4222-1430338332599-tda%2D%2D+******************************+++...%270%27%28Stage-1430338580443-39-2000-SUCCEEDED-production%2Dhigh-1430338340360.jhist
> {noformat}
> causes:
> {noformat}
> PID COMMAND %CPU TIME
> 14526 java 100.0 01:18.85
> {noformat}
> Not every string of *'s causes this, but the above filename reproduces this
> reliably.
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