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https://issues.apache.org/jira/browse/MAPREDUCE-323?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Dick King updated MAPREDUCE-323:
--------------------------------
Attachment: MR323--2010-08-25--1632.patch
This file is a new patch incorporating some of the review comments by Krishna .
What follows is a suggested release notes:
This patch does four things:
* it changes the directory structure of the done directory that holds
history logs for jobs that are completed,
* it builds toy databases for completed jobs, so we no longer have to scan
2N files on DFS to find out facts about the N jobs that have completed since
the job tracker started [which can be hundreds of thousands of files in
practical cases],
* it changes the job history browser to display more information and allow
more filtering criteria, and
* it creates a new programmatic interface for finding files matching
user-chosen criteria. This allows users to no longer be concerned with our
methods of storing them, in turn allowing us to change those at will.
The new API described above, which can be used to programmatically obtain
history file PATHs given search criteria, is described below:
{noformat}
package org.apache.hadoop.mapreduce.jobhistory;
...
// within JobHistory:
// holds information about one job hostory log in the done
// job history logs
public static class JobHistoryJobRecord {
public Path getPath() { ... }
public String getJobIDString() { ... }
public long getSubmitTime() { ... }
public String getUserName() { ... }
public String getJobName() { ... }
}
public class JobHistoryRecordRetriever implements
Iterator<JobHistoryJobRecord> {
// usual Interface methods -- remove() throws
UnsupportedOperationException
// returns the number of calls to next() that will succeed
public int numMatches() { ... }
}
// returns a JobHistoryRecordRetriever that delivers all Path's of job
matching job history files,
// in no particular order. Any criterion that is null or the empty string
does not constrain.
// All criteria that are specified are applied conjunctively, except that
if there's more than
// one date you retrieve all Path's matching ANY date.
// soughtUser and soughtJobid must match exactly.
// soughtJobName can match the entire job name or any substring.
// dates must be in the format exactly MM/DD/YYYY .
// Dates' leading digits must be 2's . We're incubating a Y3K problem.
public JobHistoryRecordRetriever
(String soughtUser, String soughtJobName, String[] dateStrings, String
soughtJobid)
throws IOException
{noformat}
> Improve the way job history files are managed
> ---------------------------------------------
>
> Key: MAPREDUCE-323
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-323
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: jobtracker
> Affects Versions: 0.21.0, 0.22.0
> Reporter: Amar Kamat
> Assignee: Dick King
> Priority: Critical
> Attachments: MR323--2010-08-20--1533.patch,
> MR323--2010-08-25--1632.patch
>
>
> Today all the jobhistory files are dumped in one _job-history_ folder. This
> can cause problems when there is a need to search the history folder
> (job-recovery etc). It would be nice if we group all the jobs under a _user_
> folder. So all the jobs for user _amar_ will go in _history-folder/amar/_.
> Jobs can be categorized using various features like _jobid, date, jobname_
> etc but using _username_ will make the search much more efficient and also
> will not result into namespace explosion.
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