> On Aug. 16, 2012, 12:42 p.m., Maja Kabiljo wrote: > > I'll take a deeper look into this once you have a final version, for now > > one comment: When we do checkpointing, there is no need to deserialize all > > the partitions and then write them again to checkpoint file, instead you > > could just copy the bytes from out-of-core files (I did something similar > > with message stores if you want to take a look). > > > > Another thing, would it be possible to make some kind of optimization for > > non-mutating graphs - to keep the edges on disk all the time and just > > rewrite vertex values?
Having thought about it more, I don't think it's a good idea to separate vertex storage from edge storage within the current API: the user can redefine readFields/write to do something non-standard. Either we disallow that (making the Writable methods of Vertex final) or we can't make any assumption when storing the graph out of core. With messages it's different because we have taken those away from user code. Regarding the other idea on checkpointing, that's a bit messy too because out-of-core partitions don't necessarily have the same representation as normally serialized partitions. I'd be for evaluating the benefits before introducing even more clutter. By the way, for this iteration I'm trying not to change the standard behavior a lot, much in the same vein as out-of-core messages. For the future, I'm fine with disrupting even the basic building blocks (think Vertex, Partition) but we need to have some sort of new design in mind, otherwise we end up with an inconsistent codebase and lots of hacks to glue things together. A discussion about this in the dev list is just getting started. - Alessandro ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/5987/#review10400 ----------------------------------------------------------- On Aug. 17, 2012, 11:12 a.m., Alessandro Presta wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/5987/ > ----------------------------------------------------------- > > (Updated Aug. 17, 2012, 11:12 a.m.) > > > Review request for giraph and Avery Ching. > > > Description > ------- > > I gave this another shot. This time it plays nicely with input superstep: I > replaced both the temporary partitions and the worker partition map with a > common data structure, PartitionStore, held in ServerData. This is similar to > what we now have for messages. > > Partition is now thread-safe so that we can have concurrent calls to > putVertex(). > > SimplePartitionStore is backed by a concurrent hash map (nothing new here, > except that we skip copying partitions to the worker). > > DiskBackedPartitionStore can hold up to a user-defined number of partitions > in memory, and spill the remaining ones to disk. Each partition is stored in > a separate file. > Adding vertices to an out-of-core partition consists in appending them to the > file, which makes processing vertex requests relatively fast. > We use a ReadWriteLock for each partition: performing operations on a > partition held in memory only requires a read-lock (since Partition is > thread-safe), while creating a new partition, moving it in and out of core or > appending vertices requires a write-lock (we can't have concurrent writes). > > Also note that this breaks Hadoop RPC: I preferred to keep it clean (this > also shows what code we get rid of) instead of working around it. I suppose > the Netty security patch will be completed soon. If not, I will restore RPC > compatibility. > > More here: > https://issues.apache.org/jira/browse/GIRAPH-249?focusedCommentId=13435280&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13435280 > > > This addresses bug GIRAPH-249. > https://issues.apache.org/jira/browse/GIRAPH-249 > > > Diffs > ----- > > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/bsp/CentralizedServiceWorker.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/BasicRPCCommunications.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/NettyWorkerClientServer.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/NettyWorkerServer.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/SendVertexRequest.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/ServerData.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/comm/WorkerServer.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/BspServiceWorker.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/GiraphJob.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/GraphMapper.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/DiskBackedPartitionStore.java > PRE-CREATION > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/HashWorkerPartitioner.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/Partition.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/PartitionStore.java > PRE-CREATION > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/SimplePartitionStore.java > PRE-CREATION > > http://svn.apache.org/repos/asf/giraph/trunk/src/main/java/org/apache/giraph/graph/partition/WorkerGraphPartitioner.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/test/java/org/apache/giraph/TestMutateGraphVertex.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/test/java/org/apache/giraph/comm/ConnectionTest.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/test/java/org/apache/giraph/comm/RequestTest.java > 1374194 > > http://svn.apache.org/repos/asf/giraph/trunk/src/test/java/org/apache/giraph/graph/partition/TestPartitionStores.java > PRE-CREATION > > Diff: https://reviews.apache.org/r/5987/diff/ > > > Testing > ------- > > mvn verify and pseudo-distributed mode tests with both SimplePartitionStore > and DiskBackedPartitionStore > > > Thanks, > > Alessandro Presta > >
