How to report a bug in apache hadoop -and when not to

1. Help! My Hadoop doesn't work!
Steve Loughran– Hortonworks
stevel at apache.org
@steveloughran
January 2014
© Hortonworks Inc. 2014

2. Reporting bugs in
Apache Hadoop
TM
© Hortonworks Inc. 2014
TM
Page 2

3. Terminology
JIRA
An issue (bug or feature request) in the JIRA
database, referenced by its ID, i.e. HADOOP-8545
Feature Request
A proposal for adding something new to the codebase.
Implicit promise to implement the feature.
Bug
A flaw in the Hadoop codebase which causes it to not
behave as planned –in a well configured cluster.
© Hortonworks Inc.
Page 3

4. Is it a Bug? Probably Not
• Look at your own code
• Look at the logs and any stack traces
• Follow any URLs in the exception messages
• Search for the exception messages
• Commercial Big Data Stacks:
use their tools, forums, support services
• Before filing: ask on user@hadoop.apache.org
Invalid issues will be closed:
http://wiki.apache.org/hadoop/InvalidJiraIssues
© Hortonworks Inc.
Page 4

5. Tools
• Hadoop Documentation, Javadocs, Wiki
• Books
• Network tools: ping, telnet, nslookup, ifconfig
• Browsers & search engines
• Stack traces
• kill -QUIT
• Hadoop source code
• Dev tool chain: svn, mvn, git, patch, JDK
© Hortonworks Inc.
Page 5

6. Be able to start a Minecraft
server before trying to bring
up a Hadoop cluster
© Hortonworks Inc. 2014
Page 6

7. Apache JIRA
https://issues.apache.org/jira
© Hortonworks Inc.
Page 7

8. DEMO 1: Bad JIRA
HADOOP-10226
© Hortonworks Inc. 2014
Page 8

9. Don't
• File “critical” issue when it is just your server not working.
• File the same issue repeatedly.
• File issues against non ASF-releases
• File bug reports against old releases
• Include confidential information in emails or bug reports
(including stack traces).
• Send “help!” emails to development lists or developers
• Send those “help!” emails every 15 minutes
© Hortonworks Inc.
Page 9

10. DEMO 2: Good JIRA
HADOOP-10227
© Hortonworks Inc. 2014
Page 10

11. Special Case: Security Bugs
Report security bugs to security@hadoop.apache.org
These get fixed before being announced
Kerberos not liking you is not a bug
© Hortonworks Inc.
Page 11

12. What happens to an issue?
• People who care about it will fix it when they have time.
• You are probably the person who cares the most.
• You may be the only person who can replicate it
• You are the best placed person to fix it.
• No fix will ship until a new major/minor Hadoop release.
• So come up with a workaround!
© Hortonworks Inc.
Page 12

13. Summary
• Apache JIRA is for reporting bugs in ASF code
• Search for the problem on the web & in JIRA first.
• Ask for help via user@hadoop or support channels
• Replicate in most recent release
• Create an informative JIRA
Then one of
1. Wait
2. Provide a fix with tests
Either way: a workaround is the only timely solution
© Hortonworks Inc.
Page 14

14. How do I fix a bug?
To follow…
© Hortonworks Inc. 2014
Page 15