hadoop-common-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew Sherman (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HADOOP-14701) Configuration can log misleading warnings about an attempt to override final parameter
Date Fri, 28 Jul 2017 22:38:00 GMT
Andrew Sherman created HADOOP-14701:
---------------------------------------

             Summary: Configuration can log misleading warnings about an attempt to override
final parameter
                 Key: HADOOP-14701
                 URL: https://issues.apache.org/jira/browse/HADOOP-14701
             Project: Hadoop Common
          Issue Type: Bug
          Components: conf
            Reporter: Andrew Sherman


The class Configuration (in hadoop-common-project) is used to hold configuration properties.


The method loadResources() is used to load properties from a list of default resources into
a parameter called  “properties” (which happens to always be the field called “properties”).


This is done by calling the method loadResource() which is used to load properties from a
single resource into a parameter called  “properties” (which happens to always be the
field called “properties”). 

This is done by calling loadProperty() which is used to load a single property into a parameter
called  “properties” (which is sometimes, but not always, the field called “properties”).


In loadProperty()  there is some logic for dealing with properties that are marked as final.
(1) a final property is not set into the “properties” parameter.
(2) a warning is printed for a final property if the value of the property with the same name
in the “properties” parameter is not equal to the new value, and the property name is
in the finalParameters field.

When loadResource() is reading properties from a stream it creates a temporary Properties
object that it populates by calling loadProperty(). This is the case where  loadProperty()
has a  parameter called “properties” which is not the same as the field called “properties”).

When loadProperty() is called on a final property then because of (1) it is not set into the
“properties” parameter. But sometimes the property name is already in the finalParameters
field and now (2) the warning is triggered because the property is not present in the “properties”
parameter (although it IS present in the “properties” field). The warning is misleading
and confusing. 

h3. Possible Fix

One way of looking at the problem is that loadProperty is using the finalParameters field
in combination with the “properties” parameter. Change the code to only generate a warning
for a final property if the value of the property with the same name in the “properties”
field is not equal to the new value, and the property name is in the finalParameters field.

I’ve made a patch containing this tiny change.

Note that I have done very minimal testing of this fix

h3. Example warning:

2017-07-25 12:14:24,639 WARN  org.apache.hadoop.conf.Configuration: [HiveServer2-Background-Pool:
Thread-77]: hdfs://asherman-cdh6-subset-parcel-1.gce.cloudera.com:8020/user/hive/.staging/job_1501008923167_0001/job.xml:an
attempt to override final parameter: mapreduce.job.end-notification.max.retry.interval;  Ignoring.




--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: common-issues-help@hadoop.apache.org


Mime
View raw message