[2018-07-27T10:52:20,992][INFO ][o.e.n.Node ] [] initializing ...
[2018-07-27T10:52:21,327][INFO ][o.e.e.NodeEnvironment ] [P0sZjuJ] using [1] data paths, mounts [[/ (/dev/sda7)]], net usable_space [12.5gb], net total_space [23.3gb], types [ext4]
[2018-07-27T10:52:21,327][INFO ][o.e.e.NodeEnvironment ] [P0sZjuJ] heap size [990.7mb], compressed ordinary object pointers [true]
[2018-07-27T10:52:21,473][INFO ][o.e.n.Node ] [P0sZjuJ] node name derived from node ID [P0sZjuJjSQm_IOslBJ-moQ]; set [node.name] to override
[2018-07-27T10:52:21,473][INFO ][o.e.n.Node ] [P0sZjuJ] version[6.3.1], pid[1220], build[default/deb/eb782d0/2018-06-29T21:59:26.107521Z], OS[Linux/4.4.0-130-generic/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_171/25.171-b11]
[2018-07-27T10:52:21,473][INFO ][o.e.n.Node ] [P0sZjuJ] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -XX:-OmitStackTraceInFastThrow, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch.MlP4iHem, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=/var/lib/elasticsearch, -XX:ErrorFile=/var/log/elasticsearch/hs_err_pid%p.log, -XX:+PrintGCDetails, -XX:+PrintGCDateStamps, -XX:+PrintTenuringDistribution, -XX:+PrintGCApplicationStoppedTime, -Xloggc:/var/log/elasticsearch/gc.log, -XX:+UseGCLogFileRotation, -XX:NumberOfGCLogFiles=32, -XX:GCLogFileSize=64m, -Des.path.home=/usr/share/elasticsearch, -Des.path.conf=/etc/elasticsearch, -Des.distribution.flavor=default, -Des.distribution.type=deb]
[2018-07-27T10:52:25,950][ERROR][o.e.b.Bootstrap ] Exception
java.lang.IllegalArgumentException: Plugin [ingest-geoip] was built for Elasticsearch version 6.3.0 but version 6.3.1 is running
at org.elasticsearch.plugins.PluginsService.verifyCompatibility(PluginsService.java:421) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.loadBundle(PluginsService.java:618) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.loadBundles(PluginsService.java:557) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.<init>(PluginsService.java:162) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.node.Node.<init>(Node.java:311) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.node.Node.<init>(Node.java:252) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:213) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:213) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:326) [elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:136) [elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:127) [elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) [elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) [elasticsearch-cli-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.Command.main(Command.java:90) [elasticsearch-cli-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:93) [elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:86) [elasticsearch-6.3.1.jar:6.3.1]
[2018-07-27T10:52:25,956][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: Plugin [ingest-geoip] was built for Elasticsearch version 6.3.0 but version 6.3.1 is running
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:140) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:127) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.3.1.jar:6.3.1]
at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:93) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:86) ~[elasticsearch-6.3.1.jar:6.3.1]
Caused by: java.lang.IllegalArgumentException: Plugin [ingest-geoip] was built for Elasticsearch version 6.3.0 but version 6.3.1 is running
at org.elasticsearch.plugins.PluginsService.verifyCompatibility(PluginsService.java:421) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.loadBundle(PluginsService.java:618) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.loadBundles(PluginsService.java:557) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.plugins.PluginsService.<init>(PluginsService.java:162) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.node.Node.<init>(Node.java:311) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.node.Node.<init>(Node.java:252) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:213) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:213) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:326) ~[elasticsearch-6.3.1.jar:6.3.1]
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:136) ~[elasticsearch-6.3.1.jar:6.3.1]
... 6 more
Here are some of the logs. I hope you can make something out of it