JanusGraph Setup & Testing Instructions for RHEL/CentOS7

Single Node Setup Instructions



Pre-requisites

1.  Ensure you have the syndeia-cloud-3.4_janusgraph_setup.zip (or latest service pack) downloaded to your home directory (or home directory's Downloads folder) from the download/license instructions sent out by our team.  

(info)  Note: the .ZIP will pre-create a separate folder for its contents when extracted so there is no need to pre-create a separate folder for it.  

2.  Ensure you satisfy Janusgraph's pre-requisites, ie: have (Open|Oracle)JDK/JRE + Apache Cassandra (& optionally Elasticsearch) installed.  Re. CPU, memory, HD space, etc. this will depend on how much data you expect to store, query, and graph.  

3.  If using a firewall, and JG will be on a separate server from SC, ensure the following port is accessible (consult your local network admin if required): TCP port 8182 (this is the port to listen to for client connections).  



Downloading & Extracting JanusGraph

1. Ensure you have Janusgraph 0.31 (https://github.com/JanusGraph/janusgraph/releases/tag/v0.3.1) downloaded to your home directory (ie: wget https://github.com/JanusGraph/janusgraph/releases/download/v0.3.1/janusgraph-0.3.1-hadoop2.zip)

(info) Note: JG releases currently seem to be all suffixed with “...-hadoop2...” despite being applicable for all databases, even cassandra, so download the one suffixed with “...-hadoop2.zip

2. Unzip the JanusGraph package to /opt, ie:  sudo unzip janusgraph-0.3.1-hadoop2.zip -d /opt/

(info) Note: if you don't have unzip installed, you may need to first install it via yum install unzip

3. Unzip Syndeia Cloud's JanusGraph setup package in your home directory ~/, ie:  unzip syndeia-cloud-3.4.SP3_2022-07-01_janusgraph_setup.zip -d ~/

4. Create a new user and group named janusgraph , ie:  sudo useradd --system --user-group janusgraph

5. Take ownership of the extracted folder, ie:  sudo chown -R janusgraph:janusgraph /opt/janusgraph-0.3.1-hadoop2

Pre-Janusgraph Setup Health Check

When completed, confirm all of the following are true before proceeding:

(The tools used and the network locations used are site-dependent.)

  • Cassandra service is running:  systemctl status cassandra 
  • Cassandra port is accessible/open:  netstat -tulpn | grep 9042 
  • Cassandra service is accessible via CQLSH:  Linux: clqsh check  
  • JanusGraph files exist at:  /opt/janusgraph-${JG_build-ver} 



JanusGraph Keyspace Setup, Service Setup & Start:

6. In a new terminal session, cd into the bin dir and run the Syndeia Cloud JanusGraph setup script, ie:  cd ~/syndeia-cloud-3.4_janusgraph_setup/bin; ./syndeia-cloud-3.4_janusgraph_setup.bash.  This will:  

- Create/update janusgraph-current symlink to specified version, default = 0.3.1
- Create a new syndeia_admin superuser in Cassandra with a password you specify
- Create a new syndeia_cloud_graph and syndeia_cloud_graph_config keyspaces
GRANT ALL PERMISSIONS ON KEYSPACE syndeia_cloud_graph TO syndeia_admin
GRANT ALL PERMISSIONS ON KEYSPACE syndeia_cloud_graph_config TO syndeia_admin
- Run a Groovy JanusGraph setup script to set storage params for your graph and build indexes
- Create a renamed copy of the file /opt/janusgraph-<release_ver>/conf/janusgraph-cql-configurationgraph.properties as janusgraph-cql-configurationgraph-syndeia.properties with: 

graph.graphname=syndeia_cloud_graph_config
Add storage.username=syndeia_admin
Add storage.password=<password_specified>
storage.hostname=<your_Cassandra_host>

- If you installed Elasticsearch on the same machine, add index.search.backend=elasticsearch and index.search.hostname=localhost to use Elasticsearch for search indexing
- Create a renamed copy of the file /opt/janusgraph-<release_ver>/conf/gremlin-server/gremlin-server-configuration.yaml as gremlin-server-configuration-syndeia.yaml and set ConfigurationManagementGraph to point to janusgraph-cql-configurationgraph-syndeia.properties.  
- Install systemd .service file for JanusGraph service
- Start JanusGraph service

(info)  Note: you may be prompted for sudo authentication.  You will also be prompted for your cassandra account password (default = cassandra), to set your syndeia_admin password and the FQDN of your Cassandra host.  

(warning)  Avoid all of the following special characters: \?*[]+#&.{}$ when setting your syndeia_admin password.

Configuration Health Check

When completed, confirm all of the following are true before proceeding or when trying to determine if the JanusGraph service is properly configured and operating.

(The tools used and the network locations used are site-dependent.)

  • SC's .groovy script for JG ran successfully, ie:  you should have only received a WARN  org.apache.hadoop.util.NativeCodeLoader  - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable WARN-ing 
  • JanusGraph service is now running:  systemctl status janusgraph 
  • JanusGraph port is accessible:  netstat -tulpn | grep 8182
  • Cassandra syndeia_cloud_graph and syndeia_cloud_graph_config keyspaces exist, ie:  if you type SELECT * FROM syndeia_cloud_ in CQLSH and hit tab, you should see syndeia_cloud_graph. syndeia_cloud_graph_config. 
  • Following files exist as described below:  
    • /opt/janusgraph-current symlink exists, and points to the latest Intercax-approved version of JanusGraph
    • /opt/janusgraph-current/conf/gremlin-server/gremlin-server-configuration-syndeia.yaml exists.

      • When completed with the defaults, the beginning of the file should resemble this content:

        sample: gremlin-server-configuration-syndeia.yaml
        host: localhost
        port: 8182
        scriptEvaluationTimeout: 60000
        channelizer: org.janusgraph.channelizers.JanusGraphWebSocketChannelizer
        graphManager: org.janusgraph.graphdb.management.JanusGraphManager
        graphs: {
          ConfigurationManagementGraph: conf/janusgraph-cql-configurationgraph-syndeia.properties
        }
        ...
    • /opt/janusgraph-current/conf/janusgraph-cql-configurationgraph-syndeia.properties exists

      • storage.hostname entry should be set to the hostname/IP address for the Cassandra host

    • /opt/janusgraph-current/log/gremlin-server.log exists (may only apply for Linux)

  • A message similar to INFO org.apache.tinkerpop.gremlin.server.GremlinServer - Channel started at port 8182. appears near the recent end of the gremlin-server.log file

Managing JanusGraph:

7. To check the status of JanusGraph services, use systemctl status janusgraph.  You can verify that it started by verifying "Active: active (running)" shows up in the output: 

$ systemctl status janusgraph
ā— janusgraph.service
   Loaded: loaded (/etc/systemd/system/janusgraph.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2019-04-17 10:21:59 EDT; 7s ago
  Process: 22486 ExecStop=/bin/bash -c /opt/janusgraph-0.3.1-hadoop2/bin/janusgraph.sh stop (code=exited, status=0/SUCCESS)
 Main PID: 23677 (java)
   CGroup: /system.slice/janusgraph.service
           ā””ā”€23677 java -server -Djanusgraph.logdir=/opt/janusgraph-0.3.1-hadoop2/bin/../log -Dlog4j.configuration=conf/gremlin-server/log4j-server.properties -Xms32m -Xmx512m -javaagent:

8. To stop/start the JanusGraph services, use sudo systemctl <action> janusgraph; where <action> = one of start|stop.  If the service successfully starts you should get the command prompt again. 

(info)  Note: If you wish to ensure the services run on startup, run sudo systemctl enable janusgraph.  For more information on installing the .service files manually and configuring them to start after Cassandra, see Setting up Services to Start on Boot.  

9. To view the logs for JanusGraph, use sudo journalctl -eu janusgraph & less /opt/janusgraph-0.3.1-hadoop2/log/gremlin-server.log.  To follow the log files, you can use sudo journalctl -feu janusgraph & tail -f /opt/janusgraph-0.3.1-hadoop2/log/gremlin-server.log.  You should see output similar to the following (abridged) text:

(info) Note, for your convenience you may wish to create a symlink to /opt/janusgraph-0.3.1-hadoop2/log/ from /var/log, ie: sudo ln -nfs /opt/janusgraph-0.3.1-hadoop2/log/ /var/log/janusgraph

$ less /var/log/janusgraph/gremlin-server.log
[...]
2987 [main] INFO  com.datastax.driver.core.NettyUtil  - Found Netty's native epoll transport in the classpath, using it
4827 [main] INFO  com.datastax.driver.core.policies.DCAwareRoundRobinPolicy  - Using data-center name 'datacenter1' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the c
orrect datacenter name with DCAwareRoundRobinPolicy constructor)
4835 [main] INFO  com.datastax.driver.core.Cluster  - New Cassandra host janusgraph.domain.com/localhost:9042 added
9043 [main] INFO  org.janusgraph.graphdb.configuration.GraphDatabaseConfiguration  - Set default timestamp provider MICRO
11325 [main] INFO  org.janusgraph.graphdb.configuration.GraphDatabaseConfiguration  - Generated unique-instance-id=2d3877742385-janusgraph-domain-com1
11341 [main] INFO  com.datastax.driver.core.ClockFactory  - Using java.lang.System clock to generate timestamps.
11902 [main] INFO  com.datastax.driver.core.policies.DCAwareRoundRobinPolicy  - Using data-center name 'datacenter1' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the
correct datacenter name with DCAwareRoundRobinPolicy constructor)
11902 [main] INFO  com.datastax.driver.core.Cluster  - New Cassandra host janusgraph.domain.com/localhost:9042 added
12251 [main] INFO  org.janusgraph.diskstorage.Backend  - Initiated backend operations thread pool of size 8
27969 [main] INFO  org.janusgraph.diskstorage.Backend  - Configuring total store cache size: 208138508
33098 [main] INFO  org.janusgraph.diskstorage.log.kcvs.KCVSLog  - Loaded unidentified ReadMarker start time 2019-03-18T01:55:02.918Z into org.janusgraph.diskstorage.log.kcvs.KCVSLog$Messa
gePuller@28d6290
35668 [main] INFO  org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor  - Initialized Gremlin thread pool.  Threads in pool named with pattern gremlin-*
36019 [main] INFO  org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor  - Initialized GremlinExecutor and preparing GremlinScriptEngines instances.
40510 [main] INFO  org.apache.tinkerpop.gremlin.server.util.ServerGremlinExecutor  - Initialized gremlin-groovy GremlinScriptEngine and registered metrics
40532 [main] INFO  org.apache.tinkerpop.gremlin.server.op.OpLoader  - Adding the standard OpProcessor.
40540 [main] INFO  org.apache.tinkerpop.gremlin.server.op.OpLoader  - Adding the session OpProcessor.
41030 [main] INFO  org.apache.tinkerpop.gremlin.server.op.OpLoader  - Adding the traversal OpProcessor.
41076 [main] INFO  org.apache.tinkerpop.gremlin.server.op.traversal.TraversalOpProcessor  - Initialized cache for TraversalOpProcessor with size 1000 and expiration time of 600000 ms
41097 [main] INFO  org.apache.tinkerpop.gremlin.server.GremlinServer  - idleConnectionTimeout was set to 0 which resolves to 0 seconds when configuring this value - this feature will be d
isabled
41098 [main] INFO  org.apache.tinkerpop.gremlin.server.GremlinServer  - keepAliveInterval was set to 0 which resolves to 0 seconds when configuring this value - this feature will be disab
led
41247 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v3.0+gryo with org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializ
erV3d0
41248 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v3.0+gryo-stringd with org.apache.tinkerpop.gremlin.driver.ser.GryoMessage
SerializerV3d0
41298 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v3.0+json with org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSeri
alizerV3d0
41299 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/json with org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0
41306 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v1.0+gryo with org.apache.tinkerpop.gremlin.driver.ser.GryoMessageSerializ
erV1d0
41311 [main] WARN  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - The org.apache.tinkerpop.gremlin.driver.ser.GryoLiteMessageSerializerV1d0 serialization class is deprecated.
41314 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v1.0+gryo-lite with org.apache.tinkerpop.gremlin.driver.ser.GryoLiteMessag
eSerializerV1d0
41315 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v1.0+gryo-stringd with org.apache.tinkerpop.gremlin.driver.ser.GryoMessage
SerializerV1d0
41325 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v2.0+json with org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSeri
alizerGremlinV2d0
41347 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - Configured application/vnd.gremlin-v1.0+json with org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSeri
alizerGremlinV1d0
41350 [main] INFO  org.apache.tinkerpop.gremlin.server.AbstractChannelizer  - application/json already has org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0 configured
 - it will not be replaced by org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0.
41437 [gremlin-server-boss-1] INFO  org.apache.tinkerpop.gremlin.server.GremlinServer  - Gremlin Server configured with worker thread pool of 1, gremlin pool of 4 and boss thread pool of
1.
41438 [gremlin-server-boss-1] INFO  org.apache.tinkerpop.gremlin.server.GremlinServer  - Channel started at port 8182.
181192 [metrics-logger-reporter-thread-1] INFO  org.apache.tinkerpop.gremlin.server.Settings$Slf4jReporterMetrics  - type=GAUGE, name=org.apache.tinkerpop.gremlin.server.GremlinServer.gre
mlin-groovy.sessionless.class-cache.average-load-penalty, value=2.450843818E9

10.  Validate correct operation and create/update an archive image to use as a new base image if the node needs to be rebuilt or if you wish to create a cluster. 

(info)  Before making the image you may wish to first stop and optionally disable the service temporarily to prevent auto-start on boot, ie:  sudo systemctl disable janusgraph.  



Multi-Node (Cluster) Setup Instructions

Enabling your single-node deployment for cluster operation

11. If Cassandra will be on a separate server from JG, ensure you first enable Cassandra for cluster operation.   

12. Update the Janusgraph syndeia_cloud_graph configuration by running /opt/janusgraph-current/bin/gremlin.sh and running the following Groovy code ; where cassandra.mydomain.com = the FQDN of the Casandra server that you have now exposed :  

:remote connect tinkerpop.server conf/remote.yaml session
:remote console
map = new HashMap();
map.put('storage.backend', 'cql');  // should return: ==>null
map.put('storage.hostname', 'cassandra.mydomain.com');
ConfiguredGraphFactory.updateConfiguration('syndeia_cloud_graph', map);

13.  If Janusgraph will be on a different server than SC, please also:

13A.  Update the host: localhost entry on L1 in /opt/janusgraph-current/conf/gremlin-server/gremlin-server-configuration-syndeia.yaml, ex:  

host: jg-server.domain.tld
port: 8182

[...]

where jg-server.domain.tld = the FQDN of your JG server

13B.  Ensure port 8182 is accessible on the JG server. 


Adding new nodes to an existing single-node

14. Deploy another instance of your Janusgraph base image (which depending on your topology could be the same as your Cassandra base image).

15. Make any appropriate changes for the MAC address (ex: in the VM settings and/or udev, if used).

16. Setup forward & reverse DNS records on your DNS server (consult your IT admin/sysadmin if required) and set the hostname and primary DNS suffix on the machine itself (sudo hostnamectl set-hostname <new_JanusGraph_node_FQDN> where FQDN = Fully Qualified Domain Name, ex: janusgraph2.mycompany.com )

17. SSH to the IP (or the FQDN of the new node if DNS has already propagated).

(info) Note: If using Fail2Ban, update the sender line in /etc/fail2ban/jail.local to root@<new_JanusGraph_node_FQDN>. Restart the fail2ban service (sudo systemctl restart fail2ban)

18. Three things need to occur:  you will need to change the Snitch (if not already done for Cassandra), alter the keyspace Replication Factor (RF), and run nodetool repair on each node (see https://docs.datastax.com/en/archived/cassandra/3.x/cassandra/operations/opsChangeKSStrategy.html for a summary of the process).

  1. Change the Snitch:  see "Switching Snitches":  https://docs.datastax.com/en/archived/cassandra/3.x/cassandra/operations/opsChangeKSStrategy.html
  2. Alter the RF:  verify the Cassandra “datacenter” name (default = dc1) from the CLI by running nodetool status and then from Cassandra CQLSH increment the RF for your JanusGraph keyspace(s):

    ALTER KEYSPACE syndeia_cloud_auth WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', '<datacenter_name>' : <total_number_of_nodes> };
    -- where <datacenter_name> = the name of the datacenter as shown via nodetool status, and <total_number_of_nodes> = total # of nodes (in the cluster)
    ALTER KEYSPACE syndeia_cloud_store WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', '<datacenter_name>' : <total_number_of_nodes> };
    -- where <datacenter_name> = the name of the datacenter as shown via nodetool status, and <total_number_of_nodes> = total # of nodes (in the cluster)
    ALTER KEYSPACE syndeia_cloud_confluence WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', '<datacenter_name>' : <total_number_of_nodes> };
    -- where <datacenter_name> = the name of the datacenter as shown via nodetool status, and <total_number_of_nodes> = total # of nodes (in the cluster)
    ALTER KEYSPACE syndeia_cloud_graph WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', '<datacenter_name>' : <total_number_of_nodes> };
    -- where <datacenter_name> = the name of the datacenter as shown via nodetool status, and <total_number_of_nodes> = total # of nodes (in the cluster)
    ALTER KEYSPACE syndeia_cloud_graph_config WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', '<datacenter_name>' : <total_number_of_nodes> };
    -- where <datacenter_name> = the name of the datacenter as shown via nodetool status, and <total_number_of_nodes> = total # of nodes (in the cluster)
    
  3. Run nodetool repair:  Run nodetool repair --full <keyspace_name> on each node (for more details see https://docs.datastax.com/en/dse/5.1/cql/cql/cql_using/cqlUpdateKeyspaceRF.html)

19. Follow  "Things to Consider in a Multi-Node JanusGraph Cluster" https://docs.janusgraph.org/0.3.1/things-to-consider-in-a-multi-node-janusgraph-cluster.html

20. Repeat steps 14 ~ 19 for each additional cluster node.

(info) Note, this is a simplified view of adding nodes to a single-datacenter (DC) scenario.  As your data usage increase and your cluster grows, you may wish to consider more sophisticated multi-DC topologies.  For further information on this please consult the Cassandra documentation.  



Validating JanusGraph Operation for 1-node (or multiple nodes)

21. To validate JanusGraph operation, we start a Gremlin client and issue commands to check the edges and vertices in our graph  To do this, perform the following steps:  

21.1.  Open a new terminal window

21.2.  Go to the bin folder in JanusGraph installation and type the following command:  ./gremlin.sh.  You should see output similar to the below:    

$ ./gremlin.sh 

         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/janusgraph-0.3.1-hadoop2/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/opt/janusgraph-0.3.1-hadoop2/lib/logback-classic-1.1.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
plugin activated: janusgraph.imports
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
20:19:16 WARN  org.apache.hadoop.util.NativeCodeLoader  - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
plugin activated: tinkerpop.hadoop
plugin activated: tinkerpop.spark
plugin activated: tinkerpop.tinkergraph
gremlin> 

21.3.  Type the following commands, substituting your appropriate values as required:  

:remote connect tinkerpop.server conf/remote.yaml session
:remote console
graph = ConfiguredGraphFactory.open('syndeia_cloud_graph');
// should return: ==>standardjanusgraph[cql:[cassandra.mydomain.com]]
g = graph.traversal();
g.V();
g.E();

(info) The last 2 commands above should not return any results since the graph (syndeia_cloud_graph) is empty - no vertices or edges.

21.4.  Type :quit   


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