[CASSANDRA-3639] Move streams too many data

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Assignee: Fabien Rousseau
• Reporter: Fabien Rousseau

Authors

Fabien Rousseau

Reviewers

paul cannon

• Created: 15/Dec/11 15:51
• Updated: 16/Apr/19 09:32
• Resolved: 07/Feb/12 23:01

Description

During a move operation, we observed that the node streamed most of its data and received all its data.

We are running Cassandra 0.8.7 (plus a few patches)

After reading the code related to "move", we found out that :

• in StorageService.java, line 2002 and line 2004 => ranges are returned in a non ordered collection, but calculateStreamAndFetchRanges() method (line 2011) assume ranges are sorted, thus, resulting in wider ranges to be fetched/streamed

We managed to isolate and reproduce this in a unit test.
We also propose a patch which :

• does not rely on any sort
• adds a few unit tests (may not be exhaustive...)

Unit tests are done only for RF=2 and for the "OldNetworkStrategyTopology". For the sake of simplicity, we've put them in OldNetworkStrategyTopologyTest, but they probably should be moved.