[HDFS-1380] The append pipeline does not followed TSP principal

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: 0.20-append
• Component/s: hdfs-client
• Assignee: Unassigned
• Reporter: Thanh Do
• Created: 07/Sep/10 21:36
• Updated: 30/Jul/14 23:49
• Resolved: 30/Jul/14 23:49

Description

1. Say we have 2 racks: rack-0 and rack-1.
Rack-0 has dn1, dn2, dn3. Rack-0 has dn4, dn5, dn6.

2. Suppose client is in rack-0, and the write pipeline is:
client --> localnode --> other rack --> other rack
In this example we have the pipeline client-dn1-dn4-dn6.
That is rack0-rack0-rack1-rack1. So far so good.

3. Now other client comes, and append to file.
This client is also in rack-0. Interestingly,
the append pipeline is client-dn6-dn4-dn1.
That is the new client (from rack0) sends packet
to the first node in pipeline (dn6) which belongs to rack1.

This bug was found by our Failure Testing Service framework:
http://www.eecs.berkeley.edu/Pubs/TechRpts/2010/EECS-2010-98.html
For questions, please email us: Thanh Do ([e-mail]) and
Haryadi Gunawi ([e-mail])