Janus Graph HBase and Solr Unknown external index backend: jgex

Question

I work with JanusGraph 0.2.0,Hbase 1.2.6 and Solr 7.3.0. I want to run a standalone Janus Graph server with Hbase(storage backend) and Solr (index backend).Then connect with gremlin driver (with Java Client) and use Gremlin Query language to traverse my graph. I locally installed Hbase and Solr. I followed:

https://github.com/JanusGraph/janusgraph/tree/master/janusgraph-examples/example-remotegraph

Updated gremlin-server.yaml with janusgraph-hbase-solr.properties. I successfully started Gremlin server. I created core jgex with

solr create_core -d $JANUSGRAPH_HOME/conf/solr -c jgex

Also gremlin-server.yaml

host: 0.0.0.0
port: 8182
scriptEvaluationTimeout: 30000
channelizer: org.apache.tinkerpop.gremlin.server.channel.WebSocketChannelizer
graphs: {
  graph: conf/gremlin-server/janusgraph-hbase-solr.properties
}
plugins:
  - janusgraph.imports
scriptEngines: {
  gremlin-groovy: {
    imports: [java.lang.Math],
    staticImports: [java.lang.Math.PI],
    scripts: [scripts/empty-sample.groovy]}}
serializers:
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoLiteMessageSerializerV1d0, config: {ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializerV1d0, config: { serializeResultToString: true }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerGremlinV2d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistry] }}
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0, config: { ioRegistries: [org.janusgraph.graphdb.tinkerpop.JanusGraphIoRegistryV1d0] }}
processors:
  - { className: org.apache.tinkerpop.gremlin.server.op.session.SessionOpProcessor, config: { sessionTimeout: 28800000 }}
  - { className: org.apache.tinkerpop.gremlin.server.op.traversal.TraversalOpProcessor, config: { cacheExpirationTime: 600000, cacheMaxSize: 1000 }}
metrics: {
  consoleReporter: {enabled: true, interval: 180000},
  csvReporter: {enabled: true, interval: 180000, fileName: /tmp/gremlin-server-metrics.csv},
  jmxReporter: {enabled: true},
  slf4jReporter: {enabled: true, interval: 180000},
  gangliaReporter: {enabled: false, interval: 180000, addressingMode: MULTICAST},
  graphiteReporter: {enabled: false, interval: 180000}}
maxInitialLineLength: 4096
maxHeaderSize: 8192
maxChunkSize: 8192
maxContentLength: 65536
maxAccumulationBufferComponents: 1024
resultIterationBatchSize: 64
writeBufferLowWaterMark: 32768
writeBufferHighWaterMark: 65536

And janusgraph-hbase-solr.properties like that:(Other fields default-commented lines)

storage.backend=hbase
storage.hostname=127.0.0.1
cache.db-cache = true
cache.db-cache-clean-wait = 20
cache.db-cache-time = 180000
cache.db-cache-size = 0.5
index.search.backend=solr
index.search.solr.mode=http
index.search.solr.http-urls=http://localhost:8983/solr
gremlin.graph=org.janusgraph.core.JanusGraphFactory

When I run

mvn exec:java -pl :example-remotegraph

command it throws

Caused by: org.apache.tinkerpop.gremlin.driver.exception.ResponseException: Unknown external index backend: jgex at org.apache.tinkerpop.gremlin.driver.Handler$GremlinResponseHandler.channelRead0(Handler.java:244) at org.apache.tinkerpop.gremlin.driver.Handler$GremlinResponseHandler.channelRead0(Handler.java:195) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at org.apache.tinkerpop.gremlin.driver.Handler$GremlinSaslAuthenticationHandler.channelRead0(Handler.java:123) at org.apache.tinkerpop.gremlin.driver.Handler$GremlinSaslAuthenticationHandler.channelRead0(Handler.java:67) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at org.apache.tinkerpop.gremlin.driver.handler.WebSocketClientHandler.channelRead0(WebSocketClientHandler.java:91) at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:312) at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:286) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:335) at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1302) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:356) at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:342) at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919) at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131) at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:646) at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:581) at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498) at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:460) at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:131) ... 1 more

Thanks in advance.

Could you edit your question and add the `gremlin-server.yaml` and the graph properties referenced from within it? — Jason Plurad, May 16 '18 at 17:04
Hi @JasonPlurad , I added gremlin-server.yaml and janusgraph-hbase-solr.properties in the question post. — msertacturkel, May 17 '18 at 09:03

score 2 · Answer 1 · edited Jun 20 '20 at 09:12

It sounds like you may used the wrong properties file. This properties file jgex-hbase-solr-http.properties, located in the distribution under $JANUSGRAPH_HOME/examples/example-hbase/conf/ contains the index definition for jgex:

index.jgex.backend=solr
index.jgex.index-name=jgex
index.jgex.hostname=127.0.0.1

index.jgex.solr.mode=http
index.jgex.solr.http-urls=http://127.0.0.1:8983/solr

Use jgex-hbase-solr-cloud.properties from the same directory if you're using Solr Cloud rather than Solr HTTP.

Update: Based on the properties file in your question, note that it defines a Solr index named search (follows pattern index.[X].backend), which is different than what is in the examples directory and shown in my answer, which uses jgex.

JanusGraph’s index options start with the string "index.[X]." where "[X]" is a user-defined name for the backend. This user-defined name must be passed to JanusGraph’s ManagementSystem interface when building a mixed index, as described in Section 9.1.2, “Mixed Index”, so that JanusGraph knows which of potentially multiple configured index backends to use. Configuration snippets in this chapter use the name search, whereas prose discussion of options typically write [X] in the same position. The exact index name is not significant as long as it is used consistently in JanusGraph’s configuration and when administering indices.

Thanks for your comment. I can run example-hbase and I saw hbase tables and indexed data in Solr. By the way i use Solr http. But I tried to run example-remotegraph. Also i did not find any config into example-remotegraph related with hbase and solr. I want to run standalone Janus Graph server(with Hbase and Solr) then send gremlinql commands as string from clients. (It can be send via Java or non-JVM languages) — msertacturkel, May 16 '18 at 09:01
Hi, I edited janusgraph-hbase-solr.properties like you said. I saw Configuring index [jgex] in console output. Everything is OK. But now it looks for a elasticsearch instance and it throws org.janusgraph.diskstorage.es.rest.RestElasticSearchClient - Unable to determine Elasticsearch server version. Default to FIVE. java.net.ConnectException: Connection refused — msertacturkel, May 18 '18 at 07:54
You don't have `storage.hbase.table` set in your properties, so it is using the default table name `janusgraph`. There must be a previous graph instance that was created with the default table name and it was configured with Elasticsearch. Either drop the `janusgraph` table or set a different value for `storage.hbase.table`. — Jason Plurad, May 19 '18 at 13:54

Janus Graph HBase and Solr Unknown external index backend: jgex

1 Answers1