Read time out while fetching all edges of a SuperNode

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I have a graph in which a few nodes have many incoming edges(**Supernode**). All the edges are of same type/label. There is a query in which i need to report the total no of incoming edges.
**I'm using cassandarathrift as storage backend**
`g.V().has('vid','qwerty').inE().count().next()`
This fails with

> 14108889 [gremlin-server-session-1] WARN org.apache.tinkerpop.gremlin.server.op.AbstractEvalOpProcessor - Exception processing a script on request [RequestMessage{, requestId=c3d902b7-0fdd-491d-8639-546963212474, op='eval', processor='session', args={gremlin=g.V().has('vid','qwerty').inE().count().next(), session=2831d264-4566-4d15-99c5-d9bbb202b1f8, bindings={}, manageTransaction=false, batchSize=64}}].
> TimedOutException()
> at org.apache.cassandra.thrift.Cassandra$multiget_slice_result$multiget_slice_resultStandardScheme.read(Cassandra.java:14696)
> at org.apache.cassandra.thrift.Cassandra$multiget_slice_result$multiget_slice_resultStandardScheme.read(Cassandra.java:14633)
> at org.apache.cassandra.thrift.Cassandra$multiget_slice_result.read(Cassandra.java:14559)
> at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
> at org.apache.cassandra.thrift.Cassandra$Client.recv_multiget_slice(Cassandra.java:741)
> at org.apache.cassandra.thrift.Cassandra$Client.multiget_slice(Cassandra.java:725)
> at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.getNamesSlice(CassandraThriftKeyColumnValueStore.java:143)
> at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.getSlice(CassandraThriftKeyColumnValueStore.java:100)
> at org.janusgraph.diskstorage.keycolumnvalue.KCVSProxy.getSlice(KCVSProxy.java:82)
> at org.janusgraph.diskstorage.keycolumnvalue.cache.ExpirationKCVSCache.getSlice(ExpirationKCVSCache.java:129)
> at org.janusgraph.diskstorage.BackendTransaction$2.call(BackendTransaction.java:288)
> at org.janusgraph.diskstorage.BackendTransaction$2.call(BackendTransaction.java:285)
> at org.janusgraph.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:69)
> at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:55)
> at org.janusgraph.diskstorage.BackendTransaction.executeRead(BackendTransaction.java:470)
> at org.janusgraph.diskstorage.BackendTransaction.edgeStoreMultiQuery(BackendTransaction.java:285)
> at org.janusgraph.graphdb.database.StandardJanusGraph.edgeMultiQuery(StandardJanusGraph.java:441)
> at org.janusgraph.graphdb.transaction.StandardJanusGraphTx.lambda$executeMultiQuery$3(StandardJanusGraphTx.java:1054)
> at org.janusgraph.graphdb.query.profile.QueryProfiler.profile(QueryProfiler.java:98)
> at org.janusgraph.graphdb.query.profile.QueryProfiler.profile(QueryProfiler.java:90)
> at org.janusgraph.graphdb.transaction.StandardJanusGraphTx.executeMultiQuery(StandardJanusGraphTx.java:1054)
> at org.janusgraph.graphdb.query.vertex.MultiVertexCentricQueryBuilder.execute(MultiVertexCentricQueryBuilder.java:113)
> at org.janusgraph.graphdb.query.vertex.MultiVertexCentricQueryBuilder.edges(MultiVertexCentricQueryBuilder.java:133)
> at org.janusgraph.graphdb.tinkerpop.optimize.JanusGraphVertexStep.initialize(JanusGraphVertexStep.java:95)
> at org.janusgraph.graphdb.tinkerpop.optimize.JanusGraphVertexStep.processNextStart(JanusGraphVertexStep.java:101)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.hasNext(AbstractStep.java:143)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.ExpandableStepIterator.hasNext(ExpandableStepIterator.java:42)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep.processAllStarts(ReducingBarrierStep.java:83)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep.processNextStart(ReducingBarrierStep.java:113)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:128)
> at org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep.next(AbstractStep.java:38)
> at org.apache.tinkerpop.gremlin.process.traversal.util.DefaultTraversal.next(DefaultTraversal.java:200)
> at java_util_Iterator$next.call(Unknown Source)
> at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
> at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
> at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
> at Script13.run(Script13.groovy:1)
> at org.apache.tinkerpop.gremlin.groovy.jsr223.GremlinGroovyScriptEngine.eval(GremlinGroovyScriptEngine.java:843)
> at org.apache.tinkerpop.gremlin.groovy.jsr223.GremlinGroovyScriptEngine.eval(GremlinGroovyScriptEngine.java:548)
> at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:233)
> at org.apache.tinkerpop.gremlin.groovy.engine.ScriptEngines.eval(ScriptEngines.java:120)
> at org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor.lambda$eval$0(GremlinExecutor.java:290)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
> at java.lang.Thread.run(Thread.java:748)

However `g.V().has('vid','qwerty').inE().limit(10000).count().next()` gives
==>10000

Now if i wanted to filter all the edges based on some condition i would have used vertex centric indexes but I simply want all the incoming edges.
The said vertex is expected to have millions of such edges.
Please help

Start by reproducing the failing inE().count() traversal against the Cassandra Thrift backend and compare it with the limited traversal. Trace the request through CassandraThriftKeyColumnValueStore.getNamesSlice, BackendTransaction.edgeStoreMultiQuery, and StandardJanusGraph.edgeMultiQuery. Done requires an agreed fix or documented limitation for counting very high-degree vertices, with evidence that the timeout case is addressed.

Written by the indexing model from the issue text.