[SPARK-5380][GraphX] Solve an ArrayIndexOutOfBoundsException when build graph with a file format error

[Leolh]

When I build a graph with a file format error, there will be an ArrayIndexOutOfBoundsException

[AmplabJenkins]

Can one of the admins verify this patch?

[srowen]

The argument I can see against it is simply that you want to fail fast on bad input, not sort of continue. If all of the file is like this you'll just log a zillion warnings instead of just stopping. How about changing the warning to throw a standard exception like IllegalArgumentException using require?

[maropu]

I wonder if stopping the process is the best solution.
If there is only one illegal entry in a last line, we need to re-try loading a whole file,
which is time-consuming.

An other idea is that illegal entries are silently re-directed into a file or something.
Finally, # of the re-directed entries is only output in the last phase of bulk-loading.
Moreover, I think that it'd be better to add a new API to append these entries into existing Graph
such as GraphOps.addEdges(val edges: RDD[Edge[ED]]).

[srowen]

Since this was a very simple change, I went ahead and merged it as my first test-drive of the commit bit. Looks like it worked!

[JoshRosen]

I've also merged this into branch-1.3 (1.3.0).

[srowen]

Ah sounds like I should have done more back-porting. I was conservative and only put these several small fixes in master. Go ahead and I'll recalibrate a little accordingly.

[JoshRosen]

@srowen From now until we cut a 1.3.0 preview, I'd merge all bug fixes into at least master and branch-1.3. We'll raise the bar for getting fixes into branch-1.3 as we get closer to the RC voting period.