DSE：查询超时/慢

Question

I am currently running a cluster of 3 nodes with 200 mill of data and the specific vertex I'm querying a total of 25 mill vertex and 30 Mill edges. I am running the following query

gV().hasLabel('people_node').has("age", inside(0,25)).filter(outE('posted_question').count().is(gt(1))).profile()

I have tried this query on a smaller set of ~100 vertex and edges and the profiler showed that indexes have been used for all parts of the query. However, I think the problem might be in my schema which is shown below.

Schema

schema.propertyKey('id').Text().ifNotExists().create()
schema.propertyKey('name').Text().ifNotExists().create()
schema.propertyKey('age').Int().ifNotExists().create()
schema.propertyKey('location').Point().withGeoBounds().ifNotExists().create()
schema.propertyKey('gender').Text().ifNotExists().create()
schema.propertyKey('dob').Timestamp().ifNotExists().create()

schema.propertyKey('tags').Text().ifNotExists().create()
schema.propertyKey('date_posted').Timestamp().ifNotExists().create()

schema.vertexLabel('people_node').properties('id','name','location','gender','dob').create()
schema.vertexLabel('questions_node').properties('id','tags','date_posted').create()
schema.edgeLabel('posted_question').single().connection('people_node','questions_node').create()

Indexes Used

schema.vertexLabel("people_node").index("search").search().by("name").by("age").by("gender").by("location").by("dob").ifNotExists().add()
schema.vertexLabel("people_node").index("people_node_index").materialized().by("id").ifNotExists().add()

schema.vertexLabel("questions_node").index("search").search().by("date_posted").by("tags").ifNotExists().add()
schema.vertexLabel("questions_node").index("questions_node_index").materialized().by("id").ifNotExists().add()

I have also read about "OLAP" queries I believe I have activated it but the query is still way too slow. Any advise or insight on what is slowing it down will be greatly appreciated.

Profile Statement (OLTP)

gremlin> g1.V().has("people_node","age", inside(0,25)).filter(outE('posted_question').count().is(gt(1))).profile()
==>Traversal Metrics
Step                                                               Count  Traversers
     Time (ms)    % Dur
=============================================================================================================
DsegGraphStep(vertex,[],(age < 25 & age > 0 & l...                     1           1
        38.310    25.54
  query-optimizer
         0.219
    \_condition=((age < 25 & age > 0 & label = people_node) & (true))
  query-setup
         0.001
    \_isFitted=true
    \_isSorted=false
    \_isScan=false
  index-query
        26.581
    \_indexType=Search
    \_usesCache=false
    \_statement=SELECT "community_id", "member_id" FROM "MiniGraph"."people_node_p" WHERE "solr_query" = '{"q
                ":"*:*", "fq":["age:{0 TO 25}"]}' LIMIT ?; with params (java.lang.Integer) 50000
    \_options=Options{consistency=Optional[ONE], serialConsistency=Optional.empty, fallbackConsistency=Option
              al.empty, pagingState=null, pageSize=-1, user=Optional[cassandra], waitForSchemaAgreement=true,
               async=true}
TraversalFilterStep([DsegVertexStep(OUT,[posted...
       111.471    74.32
  DsegVertexStep(OUT,[posted_question],edge,(di...                     1           1
        42.814
    query-optimizer
         0.227
    \_condition=((direction = OUT & label = posted_question) & (true))
    query-setup
         0.036
    \_isFitted=true
    \_isSorted=false
    \_isScan=false
    vertex-query
        29.908
    \_usesCache=false
    \_statement=SELECT * FROM "MiniGraph"."people_node_e" WHERE "community_id" = ? AND "member_id" = ? AND "
                 ~~edge_label_id" = ? LIMIT ? ALLOW FILTERING; with params (java.lang.Integer) 1300987392, (j
                 ava.lang.Long) 1026, (java.lang.Integer) 65584, (java.lang.Integer) 2
    \_options=Options{consistency=Optional[ONE], serialConsistency=Optional.empty, fallbackConsistency=Optio
               nal.empty, pagingState=null, pageSize=-1, user=Optional[cassandra], waitForSchemaAgreement=tru
               e, async=true}
    \_usesIndex=false
  RangeGlobalStep(0,2)                                                 1           1
         0.097
  CountGlobalStep                                                      1           1
         0.050
  IsStep(gt(1))
        68.209
DsegPropertyLoadStep
         0.205     0.14
                                            >TOTAL                     -           -
       149.986        -

Next, due to the partial query being much faster I assume the long time consumption is due to the necessary graph traversals. Hence, is it possible to cache or activate the indexes ( _usesIndex=false ) so that OLAP queries to be much faster?

Answer 1

Will you please post the output of the .profile statement?

Semanticaly, it looks like you're trying to find all "people" under the age of 25 that have more than 1 posted question. Is that accurate?