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I set up Titan with HBase.

I remove all vertex in the graph

It shows null after delete all. 

gremlin> g.V.count()
==>0

But if I re-login titan, then there are bunch of empty vertex in the graph

gremlin> g.V.count()
==>85267

I check the value of one vertex, it is empty gremlin> g.v(840012).map()

What is the reason for empty vertex? How can I clean them completely?

guerda
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yzhang
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  • I've seen phantom vertices in cassandra (long since fixed), but hadn't heard of that behavior in hbase. What version of Titan are you using? 0.3.2? – stephen mallette Sep 19 '13 at 11:13
  • yes, i am using titan 0.3.2, hbase 0.94.6-cdh4.3.0 – yzhang Sep 19 '13 at 14:16
  • i tried g.V.remove(); g.commit(); then I got following error 13/09/19 00:51:24 ERROR consistentkey.ConsistentKeyLockTransaction: Lock expired: LockClaim [backer=com.thinkaurelius.titan.diskstorage.locking.consistentkey.ConsistentKeyLockStore@762f6f82, key=0x0-0-0-0-0-7-182-136, col=0x0-135, expectedValue=0x128-61-16-195] (txn=com.thinkaurelius.titan.diskstorage.locking.consistentkey.ConsistentKeyLockTransaction@21811d3) – yzhang Sep 19 '13 at 14:16
  • do you have a HBase cluster or is there just one instance? – Martin Seeler Dec 16 '13 at 17:11

1 Answers1

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Hi I had the same issue in Titan with cassendra DB.

It was due to closing graph without committing.

g = TitanFactory.open('../conf/titan-cassandra-es.properties');

// Delete Nodes 

g.commit();

execute "g.commit();" before closing the graph.

Mahesh Madushanka
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