如何使用 mogwai 执行 gremlin 查询

How to execute gremlin query with mogwai

我正在尝试通过 mogwai 查询 titan db 0.5.4,但是当我 运行 以下脚本时出现错误:rexpro.exceptions.RexProScriptException:事务未打开

我发现了同样的问题here

P.S没有mogwai的标签

脚本:

#!/usr/bin/env python3
from mogwai.connection import execute_query, setup


con = setup('127.0.0.1', graph_name="bio4j", username="re", password="re")

results = execute_query("2 * a",params={"a":2}, connection= con)
print(results)


results = execute_query("bio4j.E",params={}, connection= con)
print(results)

日志:

$ ./bin/rexster.sh --start
0    [main] INFO  com.tinkerpop.rexster.Application  - .:Welcome to Rexster:.
93   [main] INFO  com.tinkerpop.rexster.server.RexsterProperties  - Using [/Users/Phoenix/Dropbox/Graph4Bio/Titan/rexhome/config/rexster.xml] as configuration source.
102  [main] INFO  com.tinkerpop.rexster.Application  - Rexster is watching [/Users/Phoenix/Dropbox/Graph4Bio/Titan/rexhome/config/rexster.xml] for change.
730  [main] INFO  com.thinkaurelius.titan.graphdb.configuration.GraphDatabaseConfiguration  - Generated unique-instance-id=0a69045d1736-AngryMac-local1
804  [main] INFO  com.thinkaurelius.titan.diskstorage.Backend  - Initiated backend operations thread pool of size 8
905  [main] INFO  com.thinkaurelius.titan.diskstorage.log.kcvs.KCVSLog  - Loaded unidentified ReadMarker start time Timepoint[1455128079919000 μs] into com.thinkaurelius.titan.diskstorage.log.kcvs.KCVSLog$MessagePuller@302c971f
908  [main] INFO  com.tinkerpop.rexster.RexsterApplicationGraph  - Graph [bio4j] - configured with allowable namespace [tp:gremlin]
932  [main] INFO  com.tinkerpop.rexster.config.GraphConfigurationContainer  - Graph bio4j - titangraph[berkeleyje:/Users/Phoenix/Dropbox/Graph4Bio/Bio4j/bio4j] loaded
939  [main] INFO  com.tinkerpop.rexster.server.metrics.HttpReporterConfig  - Configured HTTP Metric Reporter.
941  [main] INFO  com.tinkerpop.rexster.server.metrics.ConsoleReporterConfig  - Configured Console Metric Reporter.
2058 [main] INFO  com.tinkerpop.rexster.server.HttpRexsterServer  - HTTP/REST thread pool configuration: kernal[4 / 4] worker[8 / 8] 
2060 [main] INFO  com.tinkerpop.rexster.server.HttpRexsterServer  - Using org.glassfish.grizzly.strategies.LeaderFollowerNIOStrategy IOStrategy for HTTP/REST.
2160 [main] INFO  com.tinkerpop.rexster.server.HttpRexsterServer  - Rexster Server running on: [http://localhost:8182]
2160 [main] INFO  com.tinkerpop.rexster.server.RexProRexsterServer  - Using org.glassfish.grizzly.strategies.LeaderFollowerNIOStrategy IOStrategy for RexPro.
2160 [main] INFO  com.tinkerpop.rexster.server.RexProRexsterServer  - RexPro thread pool configuration: kernal[4 / 4] worker[8 / 8] 
2162 [main] INFO  com.tinkerpop.rexster.server.RexProRexsterServer  - Rexster configured with [DefaultSecurity].
2163 [main] INFO  com.tinkerpop.rexster.server.RexProRexsterServer  - RexPro Server bound to [0.0.0.0:8184]
2177 [main] INFO  com.tinkerpop.rexster.server.ShutdownManager  - Bound shutdown socket to /127.0.0.1:8183. Starting listener thread for shutdown requests.
152568 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineController  - ScriptEngineManager has factory for: ECMAScript
152568 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineController  - ScriptEngineManager has factory for: gremlin-groovy
152568 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineController  - Registered ScriptEngine for: gremlin-groovy
152569 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineHolder  - Initializing gremlin-groovy engine with additional imports.
153259 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineHolder  - ScriptEngine initializing with a custom script
154074 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.EngineController  - ScriptEngineManager has factory for: Groovy
154076 [Grizzly(2) SelectorRunner] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - RexPro Session created: a2b416ce-75ea-4ecb-9835-b287162c90cb
154354 [Grizzly(4)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - Try to destroy RexPro Session: a2b416ce-75ea-4ecb-9835-b287162c90cb
154355 [Grizzly(4)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - RexPro Session destroyed or doesn't otherwise exist: a2b416ce-75ea-4ecb-9835-b287162c90cb
154356 [Grizzly(5)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - RexPro Session created: 5b8a669f-615d-4f84-9d1e-2d10624347f0
154525 [Grizzly(7)] WARN  com.tinkerpop.rexster.protocol.server.ScriptServer  - Could not process script [bio4j.E] for language [groovy] on session [[B@6634722f] and request [[B@68f38099]
154527 [Grizzly(8)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - Try to destroy RexPro Session: 5b8a669f-615d-4f84-9d1e-2d10624347f0
154527 [Grizzly(8)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - RexPro Session destroyed or doesn't otherwise exist: 5b8a669f-615d-4f84-9d1e-2d10624347f0
154529 [Grizzly(1)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - Try to destroy RexPro Session: 00000000-0000-0000-0000-000000000000
154529 [Grizzly(1)] INFO  com.tinkerpop.rexster.protocol.session.RexProSessions  - RexPro Session destroyed or doesn't otherwise exist: 00000000-0000-0000-0000-000000000000

这里是 mogwai 的维护者。

您使用的是什么版本的 mogwai?在 0.7.7 中,设置方法没有 return 值,连接对象不应传递。事实上,当您调用 setup 时,它会创建一个连接池(一个同步 rexpro 连接池,因为没有指定并发选项)。所以一般来说,在你的应用程序的生命周期中只需调用一次设置,你就可以在没有任何引用的情况下使用执行查询。

这条消息也特别引人注目:

154525 [Grizzly(7)] WARN  com.tinkerpop.rexster.protocol.server.ScriptServer  - Could not process script [bio4j.E] for language [groovy] on session [[B@6634722f] and request [[B@68f38099]

您的图表是否配置了图表名称 "bio4j"?默认的 Titan 图名称是 "graph",mogwai 使用的默认图对象名称是 "g"。如果您的图形名称为 "bio4j",则您不会直接引用它,而是使用与交易关联的图形对象名称。您可以将图形名称视为 SQL 数据库中的数据库名称,而图形对象是对所述数据库的事务引用。这是在启动 titan 时在 xml 配置文件中配置的。特别是:

<graphs>
    <graph>
        <graph-name>graph</graph-name>
        ....
    </graph>
</graphs>

因此假设您将其从 "graph" 更改为 "bio4j" 并将设置函数中的默认值 graph_obj_name 保留为 "g",那么您的查询应显示为 "g.E".