🍛 Discovering Orientdb

OrientDB get into the GraphDB category. It’s a lightweight DB writen in java which can be embedded in applications. One project which have a strong dependencies on Orientdb is the Nexus Repository which carry an embedded OrientDB.

A bit of History

OrientDB was created in 2010 by Luca Garulli, a pionneer in the multi-model databases. Nonetheless, even if OrientDB is a recognized opensource project, since the acquisition by SAP and the leaving of the foundator in 2021, OrientDB looks hardly supproted. The foundator forked the project to ArkadeDB.

For ArcadeDB the vision stay clearly opensource and it’s visible that it’s much more dynamic even though the project is only two years old.

All things open source moves faster compared to the proprietary world.
– Luca Garulli – Blog

OrientDB Install

I will not repeat what other blog or official documentation already described properly. General idea is to download the latest bundle, put in a directory, launch the server to setup, and you are good to start.

Another install method would be with container:

podman run -d --name orientdb --restart=unless-stopped \
-v /opt/orientdb/data:/orientdb/databases \
-v /opt/orientdb/config:/orientdb/config \
-v /opt/orientdb/backup:/orientdb/backup \
-e ORIENTDB_ROOT_PASSWORD=password \
-p 2424:2424 -p 2480:2480 \
orientdb:latest

# When you will need to retrieve info
docker inspect -f "{{ .Config.ExposedPorts }}" orientdb
docker inspect -f "{{ .Config.Volumes }}" orientdb
docker inspect -f "{{ .Config.Env }}" orientdb

Connect with

# Normal install
${ORIENTDB_HOME}/bin/console.sh "connect remote:localhost/demodb root"

# Connect to container
podman exec -it orientdb /bin/sh

Fine Tuning:

Xmx + diskCache.buffersize < Memory
diskCache.buffersize > Xmx Usually better assigning small heap and large disk cache buffer (off-heap memory) Source
If the sum of maximum heap and disk cache buffer is too high, it could cause the OS to swap with huge slowdown. (Get back to the first point)
Setting MaxDirectMemorySize to a very high value should not concern you as it does not mean that OrientDB will consume all 512GB of memory. The size of direct memory consumed by OrientDB is limited by the size of the disk cache (variable storage.diskCache.bufferSize). Source
xms = xmx Generally a good pratice.
-Dmemory.useUnsafe=false This one, I do not know what it’s for, but does not inspire me confidence… so should we pass it to true ?

To resume, for a server with 24GB memory, this should give a config like this in your ${ORIENTDB_HOME}/bin/server.sh like the one below:

ORIENTDB_OPTS_MEMORY="-Xms8G -Xmx8G -XX:MaxDirectMemorySize=512G -Dstorage.diskCache.bufferSize=12400"

Monitoring

After config below, you should be able to see metrics in your dashboard in the server management part.

Push agent.jar corresponding to your orientdb version inside ${ORIENTDB_HOME}/plugins directory
inside ${ORIENTDB_HOME}/bin/server.sh

if [ -z "$JAVA_OPTS_SCRIPT" ] ; then
    JAVA_OPTS_SCRIPT="-Djna.nosys=true -XX:+HeapDumpOnOutOfMemoryError -Djava.awt.headless=true -Dfile.encoding=UTF8 -Drhino.opt.level=9 -Dprofiler.autoDump.reset=true -Dprofiler.autoDump.interval=60 -Dprofiler.enabled=true"
fi

So you can get in ${ORIENTDB_HOME}/logs/orient-server.log.0 :

*******************************************************************************************************************************************
PROFILER AUTO DUMP 'full' OUTPUT (to disabled it set 'profiler.autoDump.interval' = 0):
OrientDB Memory profiler: HEAP=674.70MB of 7.67GB - DISKCACHE (1 dbs)=2.88MB of 12.11GB - OS=5.43GB of 23.28GB - FS=48.91GB of 49.98GB
*******************************************************************************************************************************************

Activate JMX inside ${ORIENTDB_HOME}/config/orientdb-server-config.xml make the metrics available in the dashboard.

        <!-- JMX SERVER, TO TURN ON SET THE 'ENABLED' PARAMETER TO 'true' -->
        <handler class="com.orientechnologies.orient.server.handler.OJMXPlugin">
            <parameters>
                <parameter name="enabled" value="true"/>
                <parameter name="profilerManaged" value="true"/>
            </parameters>
        </handler>

inside ${ORIENTDB_HOME}/config/profiler.json

{
  "enabled": true,
  "server": {
    "enabled": true
  },
  "database": {
    "enabled": true
  },
  "cluster": {
    "enabled": false
  },
  "reporters": {
    "jmx": {
      "enabled": false,
      "domain": "Test"
    },
    "console": {
      "enabled": true,
      "interval": 60
    },
    "csv": {
      "enabled": true,
      "directory": "/tmp/metrics",
      "interval": 5000
    },
    "prometheus": {
      "enabled": false
    }
  }
}