[HADOOP-8056] Configuration doesn't pass empty string values to tasks

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 0.20.2, 1.0.0
• Component/s: conf
• Assignee: Unassigned
• Reporter: Luca Pireddu
• Created: 10/Feb/12 17:26
• Updated: 09/Mar/15 15:45
• Resolved: 09/Mar/15 15:45

Description

If I assign an empty string as a value to a property in a JobConf 'job' while I'm preparing it to run, the Configuration does store that value. I can retrieve it later while in the same process and the value is maintained.

However, if then call JobClient.runJob(job), the Configuration that is received by the Map and Reduce tasks doesn't contain the property, and calling JobConf.get with that property name returns null (instead of an empty string). Futher, if I inspect the job's configuration via Hadoop's web interface, the property isn't present.

It seems as if whatever serialization mechanism that is used to transmit the Configuration from the job client to the tasks discards properties with "" value.

Issue Links

• is duplicated by: HADOOP-6228 Configuration should allow storage of null values.
• relates to: HIVE-3779 An empty value to hive.logquery.location can't disable the creation of hive history log files