ElasticSearch學習（1）-Centos下安裝ElasticSearch

1.獲取ElasticSearch安裝包

wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.1.2.tar.gz

2.解壓後運行

tar xf elasticsearch-6.1.2.tar.gz

sh elasticsearch-6.1.2/bin/elasticsearch

會報以下錯誤：

[2018-01-24T13:59:16,633][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
	at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~[elasticsearch-6.1.2.jar:6.1.2]
	at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) ~[elasticsearch-6.1.2.jar:6.1.2]
	at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.1.2.jar:6.1.2]
	at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.1.2.jar:6.1.2]
	at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.1.2.jar:6.1.2]
	at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-6.1.2.jar:6.1.2]
	at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:85) ~[elasticsearch-6.1.2.jar:6.1.2]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root

該問題是由於運行es不能使用root用戶，所以要新建用戶es

useradd es
passwd es

修改文件所屬爲es

chown -R es:es /usr/local/es

修改elasticsearch.yml

network.host: 192.168.15.38
http.port: 9200

再次啓動： 報以下問題：

[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]

解決：
vim /etc/security/limits.conf

在最後面追加下面內容
es hard nofile 65536
es soft nofile 65536


[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

解決：
切換到root用戶
vi /etc/sysctl.conf 
添加
vm.max_map_count=655360
執行命令：
sysctl -p

再次執行./elasticsearch

[2018-01-24T15:36:35,412][INFO ][o.e.n.Node               ] [] initializing ...
[2018-01-24T15:36:35,508][INFO ][o.e.e.NodeEnvironment    ] [KMyyO-3] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [46.8gb], net total_space [49.9gb], types [rootfs]
[2018-01-24T15:36:35,509][INFO ][o.e.e.NodeEnvironment    ] [KMyyO-3] heap size [990.7mb], compressed ordinary object pointers [true]
[2018-01-24T15:36:35,510][INFO ][o.e.n.Node               ] node name [KMyyO-3] derived from node ID [KMyyO-3KRPy_Q3Eb0mYDaw]; set [node.name] to override
[2018-01-24T15:36:35,511][INFO ][o.e.n.Node               ] version[6.1.2], pid[3404], build[5b1fea5/2018-01-10T02:35:59.208Z], OS[Linux/3.10.0-514.el7.x86_64/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_144/25.144-b01]
[2018-01-24T15:36:35,511][INFO ][o.e.n.Node               ] 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, -XX:+HeapDumpOnOutOfMemoryError, -Des.path.home=/usr/local/es/elasticsearch-6.1.2, -Des.path.conf=/usr/local/es/elasticsearch-6.1.2/config]
[2018-01-24T15:36:36,449][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [aggs-matrix-stats]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [analysis-common]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [ingest-common]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [lang-expression]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [lang-mustache]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [lang-painless]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [mapper-extras]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [parent-join]
[2018-01-24T15:36:36,450][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [percolator]
[2018-01-24T15:36:36,451][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [reindex]
[2018-01-24T15:36:36,451][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [repository-url]
[2018-01-24T15:36:36,451][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [transport-netty4]
[2018-01-24T15:36:36,451][INFO ][o.e.p.PluginsService     ] [KMyyO-3] loaded module [tribe]
[2018-01-24T15:36:36,451][INFO ][o.e.p.PluginsService     ] [KMyyO-3] no plugins loaded
[2018-01-24T15:36:37,956][INFO ][o.e.d.DiscoveryModule    ] [KMyyO-3] using discovery type [zen]
[2018-01-24T15:36:38,643][INFO ][o.e.n.Node               ] initialized
[2018-01-24T15:36:38,643][INFO ][o.e.n.Node               ] [KMyyO-3] starting ...
[2018-01-24T15:36:38,880][INFO ][o.e.t.TransportService   ] [KMyyO-3] publish_address {192.168.15.38:9300}, bound_addresses {192.168.15.38:9300}
[2018-01-24T15:36:38,890][INFO ][o.e.b.BootstrapChecks    ] [KMyyO-3] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2018-01-24T15:36:41,955][INFO ][o.e.c.s.MasterService    ] [KMyyO-3] zen-disco-elected-as-master ([0] nodes joined), reason: new_master {KMyyO-3}{KMyyO-3KRPy_Q3Eb0mYDaw}{RY8JlkNjT3iTPoO_VT1isw}{192.168.15.38}{192.168.15.38:9300}
[2018-01-24T15:36:41,961][INFO ][o.e.c.s.ClusterApplierService] [KMyyO-3] new_master {KMyyO-3}{KMyyO-3KRPy_Q3Eb0mYDaw}{RY8JlkNjT3iTPoO_VT1isw}{192.168.15.38}{192.168.15.38:9300}, reason: apply cluster state (from master [master {KMyyO-3}{KMyyO-3KRPy_Q3Eb0mYDaw}{RY8JlkNjT3iTPoO_VT1isw}{192.168.15.38}{192.168.15.38:9300} committed version [1] source [zen-disco-elected-as-master ([0] nodes joined)]])
[2018-01-24T15:36:41,990][INFO ][o.e.h.n.Netty4HttpServerTransport] [KMyyO-3] publish_address {192.168.15.38:9200}, bound_addresses {192.168.15.38:9200}
[2018-01-24T15:36:41,990][INFO ][o.e.n.Node               ] [KMyyO-3] started
[2018-01-24T15:36:41,997][INFO ][o.e.g.GatewayService     ] [KMyyO-3] recovered [0] indices into cluster_state

啓動成功

瀏覽器中輸入：http://192.168.15.38:9200/

{
  "name" : "KMyyO-3",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "Z2ReGjxgTx28uA3wHT-gZg",
  "version" : {
    "number" : "6.1.2",
    "build_hash" : "5b1fea5",
    "build_date" : "2018-01-10T02:35:59.208Z",
    "build_snapshot" : false,
    "lucene_version" : "7.1.0",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}