apache/spark — pull request #3701 by scwf (2014-12-15 12:30:31+00:00)
Title: [Hot Fix] Fix WriteAheadLogBackedBlockRDDSuite

WriteAheadLogBackedBlockRDDSuite failed due to random string file name
```
/tmp/1418645532799-0/??????????
[info] - Read data available only in write ahead log, and test storing in block manager *** FAILED *** (2 milliseconds)
```
Using another way to produce random file name.