How to setup embedded master/master replication with OrientDB? - orientdb

Question

My goal is to have two nodes. Node A should write some vertices and node B should be able to read those vertices.
So far my hazelcast discovery works just fine. OrientDB will also hot deploy any found database from nodeA to nodeB. Unfortunately any write on Node A will not be replicated to nodeB.
My setup:
orientdb-server-config.xml:
Simplified version (copied from orientdb-community tar.gz)
%NODENAME% will be replaced with nodeA or nodeB.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<orient-server>
<handlers>
<handler
class="com.orientechnologies.orient.graph.handler.OGraphServerHandler">
<parameters>
<parameter name="enabled" value="true" />
<parameter name="graph.pool.max" value="50" />
</parameters>
</handler>
<!-- CLUSTER PLUGIN, TO TURN ON SET THE 'ENABLED' PARAMETER TO 'true' -->
<handler
class="com.orientechnologies.orient.server.hazelcast.OHazelcastPlugin">
<parameters>
<parameter name="nodeName" value="%NODENAME%" />
<parameter name="enabled" value="true" />
<parameter name="configuration.db.default"
value="config/default-distributed-db-config.json" />
<parameter name="configuration.hazelcast" value="config/hazelcast.xml" />
</parameters>
</handler>
</handlers>
<network>
<sockets>
<socket
implementation="com.orientechnologies.orient.server.network.OServerSSLSocketFactory"
name="ssl">
<parameters>
<parameter value="false" name="network.ssl.clientAuth" />
<parameter value="config/cert/orientdb.ks" name="network.ssl.keyStore" />
<parameter value="password" name="network.ssl.keyStorePassword" />
<parameter value="config/cert/orientdb.ks" name="network.ssl.trustStore" />
<parameter value="password" name="network.ssl.trustStorePassword" />
</parameters>
</socket>
<socket
implementation="com.orientechnologies.orient.server.network.OServerSSLSocketFactory"
name="https">
<parameters>
<parameter value="false" name="network.ssl.clientAuth" />
<parameter value="config/cert/orientdb.ks" name="network.ssl.keyStore" />
<parameter value="password" name="network.ssl.keyStorePassword" />
<parameter value="config/cert/orientdb.ks" name="network.ssl.trustStore" />
<parameter value="password" name="network.ssl.trustStorePassword" />
</parameters>
</socket>
</sockets>
<protocols>
<!-- Default registered protocol. It reads commands using the HTTP protocol
and write data locally -->
<protocol name="binary"
implementation="com.orientechnologies.orient.server.network.protocol.binary.ONetworkProtocolBinary" />
<protocol name="http"
implementation="com.orientechnologies.orient.server.network.protocol.http.ONetworkProtocolHttpDb" />
</protocols>
<listeners>
<listener protocol="binary" ip-address="0.0.0.0" port-range="2424-2430"
socket="default" />
<!-- <listener protocol="binary" ip-address="0.0.0.0" port-range="2434-2440"
socket="ssl"/> -->
<listener protocol="http" ip-address="0.0.0.0" port-range="2480-2490"
socket="default">
<parameters>
<!-- Connection's custom parameters. If not specified the global configuration
will be taken -->
<parameter name="network.http.charset" value="utf-8" />
<parameter value="true" name="network.http.jsonResponseError" />
<!-- Define additional HTTP headers to always send as response -->
<!-- Allow cross-site scripting -->
<!-- parameter name="network.http.additionalResponseHeaders" value="Access-Control-Allow-Origin:
*;Access-Control-Allow-Credentials: true" / -->
</parameters>
<commands>
<command
pattern="GET|www GET|studio/ GET| GET|*.htm GET|*.html GET|*.xml GET|*.jpeg GET|*.jpg GET|*.png GET|*.gif GET|*.js GET|*.css GET|*.swf GET|*.ico GET|*.txt GET|*.otf GET|*.pjs GET|*.svg GET|*.json GET|*.woff GET|*.woff2 GET|*.ttf GET|*.svgz"
implementation="com.orientechnologies.orient.server.network.protocol.http.command.get.OServerCommandGetStaticContent">
<parameters>
<!-- Don't cache html resources in development mode -->
<entry name="http.cache:*.htm *.html"
value="Cache-Control: no-cache, no-store, max-age=0, must-revalidate\r\nPragma: no-cache" />
<!-- Default caching -->
<entry name="http.cache:default" value="Cache-Control: max-age=120" />
</parameters>
</command>
<command pattern="GET|gephi/*"
implementation="com.orientechnologies.orient.graph.server.command.OServerCommandGetGephi" />
</commands>
</listener>
</listeners>
<cluster>
</cluster>
</network>
<!-- <storages> <storage name="db_%NODENAME%" path="%DB_PATH%" userName="admin"
userPassword="admin" loaded-at-startup="true" /> </storages> -->
<users>
<user name="root" password="finger" resources="*" />
<user name="admin" password="finger" resources="*" />
</users>
<properties>
<!-- DATABASE POOL: size min/max -->
<entry name="db.pool.min" value="1" />
<entry name="db.pool.max" value="50" />
<!-- PROFILER: configures the profiler as <seconds-for-snapshot>,<archive-snapshot-size>,<summary-size> -->
<entry name="profiler.enabled" value="true" />
<!-- <entry name="profiler.config" value="30,10,10" /> -->
<entry name="plugin.directory" value="%PLUGIN_DIRECTORY%" />
<!-- LOG: enable/Disable logging. Levels are: finer, fine, finest, info,
warning -->
<entry name="log.console.level" value="%CONSOLE_LOG_LEVEL%" />
<entry name="log.file.level" value="%FILE_LOG_LEVEL%" />
</properties>
</orient-server>
default-distributed-db-config.json:
{
"autoDeploy": true,
"hotAlignment": true,
"executionMode": "synchronous",
"readQuorum": 1,
"writeQuorum": 1,
"failureAvailableNodesLessQuorum": false,
"readYourWrites": true,
"servers": {
"*": "master"
},
"clusters": {
"internal": {
},
"index": {
},
"*": {
"servers": ["<NEW_NODE>"]
}
}
}
Start OServer:
OServer server = OServerMain.create();
server.startup(getOrientServerConfig());
server.activate();
Wait until both nodes have been started.
Each node connects to the graph database.
OrientGraphFactory factory = new OrientGraphFactory("plocal:" + new File("databases/db_testdb").getAbsolutePath());
NodeA will add new vertices using getNoTx.
NodeB will just read the graph and count the found vertices using getNoTx.
I created a very basic maven project which contains two tests that will start nodeA and nodeB.

Answer 1

It is mandatory to set the ORIENTDB_HOME property for each node. The property must be set that way so that the $ORIENTDB_HOME/databases folder can be located. I have updated the maven project.
Each node can set the property for example this way:
String orientdbHome = new File("").getAbsolutePath();
System.setProperty("ORIENTDB_HOME", orientdbHome);