Unable to determine cause of DB crash - orientdb

Question

I have hosted an instance of OreintDB on azure VM. This instance crashes or stops on its own after sometime. And I am unable to find the reason for that.
To find the reason I have enabled logs. But to no avail. The logs printed are insufficient to point to any problem. Following the is the orient-server-log.properties
# Specify the handlers to create in the root logger
# (all loggers are children of the root logger)
# The following creates two handlers
handlers = java.util.logging.ConsoleHandler, java.util.logging.FileHandler
# Set the default logging level for the root logger
.level = INFO
com.orientechnologies.level = INFO
com.orientechnologies.orient.server.distributed.level = INFO
# Set the default logging level for new ConsoleHandler instances
java.util.logging.ConsoleHandler.level = INFO
# Set the default formatter for new ConsoleHandler instances
java.util.logging.ConsoleHandler.formatter = com.orientechnologies.common.log.OAnsiLogFormatter
# Set the default logging level for new FileHandler instances
java.util.logging.FileHandler.level = INFO
# Naming style for the output file
java.util.logging.FileHandler.pattern=../log/orient-server.log
# Set the default formatter for new FileHandler instances
java.util.logging.FileHandler.formatter = com.orientechnologies.common.log.OLogFormatter
# Limiting size of output file in bytes:
java.util.logging.FileHandler.limit=10000000
# Number of output files to cycle through, by appending an
# integer to the base file name:
java.util.logging.FileHandler.count=10
Following is the contents of one of the log file generated named orient-server.log.0:
XXXX-XX-XX 05:10:06:517 INFO Loading configuration from: /opt/orientdb/config/orientdb-server-config.xml... [OServerConfigurationLoaderXml]
XXXX-XX-XX 05:10:06:917 INFO OrientDB Server v2.2.13 (build 2.2.x#r90d7caa1e4af3fad86594e592c64dc1202558ab1; 2016-11-15 12:04:05+0000) is starting up... [OServer]
XXXX-XX-XX 05:10:06:921 INFO Databases directory: /opt/orientdb/databases [OServer]
XXXX-XX-XX 05:10:07:010 INFO OrientDB auto-config DISKCACHE=4,428MB (heap=491MB direct=524,288MB os=6,967MB) [orientechnologies]
XXXX-XX-XX 05:10:07:719 INFO Listening binary connections on 0.0.0.0:2424 (protocol v.36, socket=default) [OServerNetworkListener]
XXXX-XX-XX 05:10:07:730 INFO Listening http connections on 0.0.0.0:2480 (protocol v.10, socket=default) [OServerNetworkListener]
XXXX-XX-XX 05:10:07:761 INFO Installing dynamic plugin 'studio-2.2.zip'... [OServerPluginManager]
XXXX-XX-XX 05:10:07:765 INFO ODefaultPasswordAuthenticator is active [ODefaultPasswordAuthenticator]
XXXX-XX-XX 05:10:07:766 INFO OServerConfigAuthenticator is active [OServerConfigAuthenticator]
XXXX-XX-XX 05:10:07:766 INFO OSystemUserAuthenticator is active [OSystemUserAuthenticator]
XXXX-XX-XX 05:10:07:805 INFO Installed GREMLIN language v.2.6.0 - graph.pool.max=50 [OGraphServerHandler]
XXXX-XX-XX 05:10:07:805 INFO [OVariableParser.resolveVariables] Error on resolving property: distributed [orientechnologies]
XXXX-XX-XX 05:10:07:808 WARNI Authenticated clients can execute any kind of code into the server by using the following allowed languages: [sql] [OServerSideScriptInterpreter]
XXXX-XX-XX 05:10:07:810 INFO OrientDB Studio available at http://XXX.XXX.XXX.XXX:2480/studio/index.html [OServer]
XXXX-XX-XX 05:10:07:810 INFO OrientDB Server is active v2.2.13 (build 2.2.x#r90d7caa1e4af3fad86594e592c64dc1202558ab1; 2016-11-15 12:04:05+0000).
Other log files have similar content.
I want some pointer of what could be the issue or some other debugging method. Crash report, DB connection reports, etc. which can help me determine the underlying problem.
I am using OrientDB v2.2.13