Reputation: 13835
I am using Janusgraph in embedded format with backend as cassandrathrift. Here are my properties for janusgraph and cassandra:
storage.backend=cassandrathrift
storage.cassandra.keyspace=t_graph
storage.cassandra.frame-size-mb=128
storage.hostname=10.XX.XX.XX,20.XX.XX.XX,30.XX.XX.XX
And i have a query which finds out the followers count of a particular vertex. Here is the code for that:
public class FollowCountNormal {
private static JanusGraph graph;
private static GraphTraversalSource traversalSource;
public static void main(String[] args) {
create();
System.exit(0);
}
public static JanusGraph create() {
graph = JanusGraphFactory.open("/resources/jp.properties");
traversalSource = graph.traversal();
getAllEdges();
return graph;
}
static long getAllEdges(){
try{
GraphTraversal<Vertex, Vertex> allV = traversalSource.V();
GraphTraversal<Vertex, Vertex> gt = allV.has("vid", "supernode");
GraphTraversal<Vertex, Long> c = gt.inE()
.count();
long l = c.next();
System.out.println("All edges = "+l);
graph.tx().commit();
return l;
}catch (Exception e) {
System.out.println("Error while fetching the edges for : ");
e.printStackTrace();
}
return -1;
}
}
This code works fine if the vertex have a limited number of incoming Edges (i.e. works fine is follower count is less than 100000). But if the followers count is in millions, i got the following exception:
Caused by: org.janusgraph.diskstorage.PermanentBackendException: Permanent failure in storage backend at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.convertException(CassandraThriftKeyColumnValueStore.java:263) at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.getNamesSlice(CassandraThriftKeyColumnValueStore.java:162) at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.getNamesSlice(CassandraThriftKeyColumnValueStore.java:105) at org.janusgraph.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.getSlice(CassandraThriftKeyColumnValueStore.java:94) at org.janusgraph.diskstorage.keycolumnvalue.KCVSProxy.getSlice(KCVSProxy.java:77) at org.janusgraph.diskstorage.keycolumnvalue.cache.ExpirationKCVSCache$2.call(ExpirationKCVSCache.java:100) at org.janusgraph.diskstorage.keycolumnvalue.cache.ExpirationKCVSCache$2.call(ExpirationKCVSCache.java:96) at com.google.common.cache.LocalCache$LocalManualCache$1.load(LocalCache.java:4742) at com.google.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527) at com.google.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2319) ... 50 common frames omitted Caused by: org.apache.cassandra.thrift.TimedOutException: null at org.apache.cassandra.thrift.Cassandra$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) ... 58 common frames omitted
I looked for many posts online like this:
but no solution worked for me. Any suggestion on how to solve this?
Upvotes: 1
Views: 363
Reputation: 13835
Changing the storage backend to cql and other properties relevant to cql solved the issue for me. Here are the properties which i used:
storage.backend=cql
storage.cql.keyspace=t_graph
storage.cql.read-consistency-level=ONE
Upvotes: 1