JanusGraph summary of use

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1. What is JanusGraph?
   JanusGraph is designed to support large graphics processing, storage and computing power required beyond a single machine. Data processing extension graph traversal and analyze real-time query is JanusGraph essential interests.

2. JanusGraph installation and use
   . A Download: https://github.com/JanusGraph/janusgraph/releases/
   B janusgraph-0.3.1-hadoop2.zip the unzip.
   Archive: janusgraph-0.3.1-hadoop2.zip
   Creating: janusgraph hadoop2--0.3.1 /
   C. to the bin under decompressed packet, to run into the console ./gremlin.sh
   d. FIG loaded (initialization), graph = JanusGraphFactory.open('conf/janusgraph-berkeleyje-es.properties')the profile itself can be modified
   E. GraphOfTheGodsFactory.load(graph), performed this command, loadable FIG gods
   F. g = graph.traversal(), to obtain a full image of the object is similar to
   g in FIG operable to initialize: saturn = g.V().has('name', 'saturn').next()
   results: ==> v [256]

     g.V(saturn).valueMap()
    	==>[name:[saturn], age:[10000]]
   

3. JanusGraph the storage configuration and
   each side has JanusGraph FIG pattern composed of a tag, attribute key, using the vertex tags.
   type of data:
   

Property management statement:

mgmt = graph.openManagement()
person = mgmt.makeVertexLabel('person').make()
name = mgmt.makePropertyKey('name').dataType(String.class).cardinality(Cardinality.SET).make()
birthDate = mgmt.makePropertyKey('birthDate').dataType(Long.class).cardinality(Cardinality.SINGLE).make()
mgmt.addProperties(person, name, birthDate)
mgmt.commit()

4. How JAVA connected JanusGraph

5. How JAVA operating JanusGraph

6. JanusGraph advantages and disadvantages
   basic advantages:
   A support very large in FIG. JanusGraph map size and number of machines in the cluster. 　　
   b. support many simultaneous transactions and the operation of FIG. The number and scale cluster JanusGraph servicing capacity of the machine and answers in a huge complex query graph traversal, in milliseconds. 　　
   c. support the global graphical analysis and batch image processing by the Hadoop framework. 　　
   D. geographic support, the numerical ranges and very large full-text search of FIG vertices and edges. 　　
   e. native support for popular data model attributes FIG exposed by the Apache TinkerPop. 　　
   F. FIG traversal native support language imp. 　　
   g. easily integrated connectivity server regardless of the programming language imp. 　　
   H. graph-level configuration provides many performance tuning knob. 　　
   i.Vertex-centric index provides vertex-level query alleviate the problem of super-node problem notorious. 　　
   j. provides an optimized, in order to effectively use the disk represents a storage and access speed. 　　
   k. a free open source under the Apache 2 license.
   Apache Cassandra advantage with
   a. Continuously available, there is no single point of failure. 　　
   b. no read / write bottlenecks no master / slave architecture diagram. 　　
   C. resilient extensions allows introduction and deletion of the machine. 　　
   d. Data in the buffer layer ensures continuous access is available in memory. 　　
   e. increase the cache size by adding more machines in the cluster. 　　
   f. Integration with Apache Hadoop. 　　
   g. free under the Apache 2 open source license.

The advantage with HBase JanusGraph 　　 　　
a. Tightly integrated with the Apache Hadoop ecosystem. 　　
b. The machine supports a strong consistency. 　　
C. linear scalability and adding more machines. 　　
d. strictly consistent reads and writes. 　　
E. convenience base class support Hadoop MapReduce HBase work table. 　　
f. by JMX support export targets. 　　
g. free under the Apache 2 open source license.

Drawback:
. A new graphical database
b visualization tools lack.

注意:JanusGraph对JDK要求在8.0以上。