Great, thanks for pointing me in the right direction. All of the edge values are strings (in a Text object) and point to and from vertices with Text IDs, but none of the values should be greater than 60 bytes or so during the loading step. The size will increase during computation because I am modifying the values of the edges, but the actual size of the data is not too large.
Given that I am using text based IDs and values, it looks to me like I may have to implement my own edge store-- does that seem right?
Thank you for your help!
On Mon, Sep 8, 2014, at 05:31 PM, Pavan Kumar A wrote:
ByteArrayEdges or any of the other edge stores used array based/ map based stores, all of these will encounter this exception when size of the array approaches Integer.MAX
some things to consider for time being, what do your edges look like?
if they are long ids & null values u can use LongNullArrayEdges to push the boundary a bit i.e, until u get a vertex who has ~2 billion outgoing edges
for long ids & double values u can use LongDoubleArrayEdges etc.
please take a look at classes that implement this interface OutEdges
If none of those work, you can implement one of your own
and use a store backed by datastructures like BigDataOutput instead of plain old ByteArrays

Subject: NegativeArraySizeException with large dataset
Date: Mon, 8 Sep 2014 17:19:17 -0700
I am currently running Giraph on a semi-large dataset of 600 million edges (the edges are directed, so I've used the ReverseEdgeDuplicator for an expected total of 1.2b edges). I am running into an issue during superstep -1 when the edges are being loaded-- I receive a "java.lang.NegativeArraySizeException" exception. This occurs near the end of when the edges should be done loading-- by my estimate, I believe around 1b out of the 1.2b have been loaded.
The exception occurs on one of the workers, and all of the other workers subsequently halt loading before I kill the job.
The issue doesn't occur with half of the dataset (300 million edges, 600 million total with the reverser).
The only reference I've found to this particular exception type is GIRAPH-821 (, which suggests to enable the useBigDataIOForMessages flag. I would be surprised if it helped, because this error occurs during the loading superstep, and there are no "super vertices" in my traversal computation. Enabling this flag had no effect.
Any help on this would be appreciated.
The full stack trace for the exception is as follows:
        at org.apache.giraph.utils.UnsafeByteArrayOutputStream.ensureSize(
        at org.apache.giraph.utils.UnsafeByteArrayOutputStream.write(
        at org.apache.giraph.utils.WritableUtils.writeEdge(
        at org.apache.giraph.edge.ByteArrayEdges.add(
        at org.apache.giraph.edge.AbstractEdgeStore.addPartitionEdges(
        at org.apache.giraph.comm.requests.SendWorkerEdgesRequest.doRequest(
        at org.apache.giraph.comm.netty.handler.WorkerRequestServerHandler.processRequest(
        at org.apache.giraph.comm.netty.handler.WorkerRequestServerHandler.processRequest(
        at org.apache.giraph.comm.netty.handler.RequestServerHandler.channelRead(
        at org.apache.giraph.comm.netty.handler.RequestDecoder.channelRead(
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(
        at io.netty.util.concurrent.SingleThreadEventExecutor$