一 ES基础知识介绍
Near Reamtime（NRT）
Elasticsearch 是一个实时的查询平台，从索引数据开始到索引数据结束几乎是1s的时间
Cluster
集群是一个或多个节点的集合，这些节点一起保存数据，并在所有节点上提供联合索引和搜索功能，集群通过唯一的名称（默认为elasticsearch）加以标记，同一个节点只能加入一个集群中。
Node
节点是集群中用来存储数据、参与集群中索引和搜索功能的一台单独的服务器，节点在启动时默认会分配一个随机的UUID作为集群中该节点的身份标识，该名称可以手动在配置文件中指定。
Index
| Elasticsearch | RDBMS |
| Indices（indices1,indices2,indices3...） | Database(database1,database2,database3...) |
| Types | Tables |
| Documents | Rows |
| Fileds | Columns |
Elasticsearch7.4下载
https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.4.2-linux-x86_64.tar.gz
JDK1.8下载
二 安装Elasticsearch
1. 新建用户，并为用户配置环境变量
# groupadd -r elasticsearch # useradd -r -g elasticsearch -G root elasticsearch # cat /home/elasticsearch /.bash_profile # .bash_profile # Get the aliases and functions if [ -f ~/.bashrc ]; then . ~/.bashrc fi # User specific environment and startup programs export JAVA_HOME=/usr/java/jdk1.8.0_111 export ES_HOME=/usr/local/elasticsearch export PATH=$JAVA_HOME/bin:$ES_HOME/bin:$PATH
2. 系统和内核参数优化
# echo "vm.max_map_count=655360" >> /etc/sysctl.conf # sysctl -p # cat /etc/security/limits.conf elasticsearch soft nproc 65536 elasticsearch hard nproc 65536 elasticsearch soft nofile 65536 elasticsearch hard nofile 65536 elasticsearch soft memlock unlimited elasticsearch hard memlock unlimited
注：如果不进行参数优化，启动elasticsearch时候可能会报如下错误
[2018-09-07T09:55:27,564][INFO ][o.e.b.BootstrapChecks ] [sht-sgmhadoopdn-04] bound or publishing to a non-loopback or non-link-local address, enforcing bootstrap checks ERROR: [2] bootstrap checks failed [1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536] [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144] [2018-09-07T09:55:27,572][INFO ][o.e.n.Node ] [sht-sgmhadoopdn-04] stopping ... [2018-09-07T09:55:27,604][INFO ][o.e.n.Node ] [sht-sgmhadoopdn-04] stopped [2018-09-07T09:55:27,604][INFO ][o.e.n.Node ] [sht-sgmhadoopdn-04] closing ... [2018-09-07T09:55:27,613][INFO ][o.e.n.Node ] [sht-sgmhadoopdn-04] closed
注：运行elasticsearch的用户最好为elasticsearch，我曾试着用mysqladmin用户运行elasticsearch，但是会报java版本不匹配的错，实际上我的mysqladmin用户的环境变量里已经配置了java，并且已经生效，但是elasticsearch还是读取系统全局的变量，暂时不清楚原因，可以理解为一个未知的bug吧
$ ./elasticsearch --help Elasticsearch requires at least Java 8 but your Java version from /bin/java does not meet this requirement [mysqladmin@sht-sgmhadoopdn-04 bin]$ java -version java version "1.8.0_111" Java(TM) SE Runtime Environment (build 1.8.0_111-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode) [mysqladmin@sht-sgmhadoopdn-04 bin]$ which java /usr/java/jdk1.8.0_111/bin/java [mysqladmin@sht-sgmhadoopdn-04 bin]$ /bin/java -version java version "1.7.0_40" Java(TM) SE Runtime Environment (build 1.7.0_40-b43) Java HotSpot(TM) 64-Bit Server VM (build 24.0-b56, mixed mode)
3.修改elasticsearch配置文件
$ cat elasticsearch.yml | grep -v "$^" | grep -v "^#" cluster.name: dev-es node.name: sht-sgmhadoopnn-01 node.attr.rack: r1 path.data: /usr/local/elasticsearch/data path.logs: /usr/local/elasticsearch/data/logs bootstrap.memory_lock: false network.host: 0.0.0.0 http.port: 9200 cluster.initial_master_nodes: ["sht-sgmhadoopnn-01"]
4.启动elasticsearch
$ cd /usr/local/elasticsearch/bin/
$ ./elasticsearch
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
[2019-11-29T21:40:49,749][INFO ][o.e.e.NodeEnvironment ] [sht-sgmhadoopnn-01] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [41.5gb], net total_space [76.4gb], types [rootfs]
[2019-11-29T21:40:49,756][INFO ][o.e.e.NodeEnvironment ] [sht-sgmhadoopnn-01] heap size [1007.3mb], compressed ordinary object pointers [true]
[2019-11-29T21:40:49,762][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] node name [sht-sgmhadoopnn-01], node ID [VwFAki8mQjqxSuujq579NA], cluster name [dev-es]
[2019-11-29T21:40:49,763][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] version[7.4.2], pid[15451], build[default/tar/2f90bbf7b93631e52bafb59b3b049cb44ec25e96/2019-10-28T20:40:44.881551Z], OS[Linux/3.10.0-957.12.2.el7.x86_64/amd64], JVM[AdoptOpenJDK/OpenJDK 64-Bit Server VM/13.0.1/13.0.1+9]
[2019-11-29T21:40:49,763][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] JVM home [/usr/local/elasticsearch-7.4.2/jdk]
[2019-11-29T21:40:49,764][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -Des.networkaddress.cache.ttl=60, -Des.networkaddress.cache.negative.ttl=10, -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, -Dio.netty.allocator.numDirectArenas=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch-14884986979711276651, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=data, -XX:ErrorFile=logs/hs_err_pid%p.log, -Xlog:gc*,gc+age=trace,safepoint:file=logs/gc.log:utctime,pid,tags:filecount=32,filesize=64m, -Djava.locale.providers=COMPAT, -Dio.netty.allocator.type=unpooled, -XX:MaxDirectMemorySize=536870912, -Des.path.home=/usr/local/elasticsearch, -Des.path.conf=/usr/local/elasticsearch/config, -Des.distribution.flavor=default, -Des.distribution.type=tar, -Des.bundled_jdk=true]
[2019-11-29T21:40:54,923][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [aggs-matrix-stats]
[2019-11-29T21:40:54,923][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [analysis-common]
[2019-11-29T21:40:54,924][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [data-frame]
[2019-11-29T21:40:54,924][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [flattened]
[2019-11-29T21:40:54,929][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [frozen-indices]
[2019-11-29T21:40:54,930][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [ingest-common]
[2019-11-29T21:40:54,930][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [ingest-geoip]
[2019-11-29T21:40:54,931][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [ingest-user-agent]
[2019-11-29T21:40:54,931][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [lang-expression]
[2019-11-29T21:40:54,931][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [lang-mustache]
[2019-11-29T21:40:54,934][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [lang-painless]
[2019-11-29T21:40:54,934][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [mapper-extras]
[2019-11-29T21:40:54,935][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [parent-join]
[2019-11-29T21:40:54,935][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [percolator]
[2019-11-29T21:40:54,935][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [rank-eval]
[2019-11-29T21:40:54,939][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [reindex]
[2019-11-29T21:40:54,939][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [repository-url]
[2019-11-29T21:40:54,940][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [search-business-rules]
[2019-11-29T21:40:54,940][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [spatial]
[2019-11-29T21:40:54,940][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [transport-netty4]
[2019-11-29T21:40:54,944][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [vectors]
[2019-11-29T21:40:54,945][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-analytics]
[2019-11-29T21:40:54,945][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-ccr]
[2019-11-29T21:40:54,946][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-core]
[2019-11-29T21:40:54,946][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-deprecation]
[2019-11-29T21:40:54,946][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-graph]
[2019-11-29T21:40:54,953][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-ilm]
[2019-11-29T21:40:54,954][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-logstash]
[2019-11-29T21:40:54,954][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-ml]
[2019-11-29T21:40:54,954][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-monitoring]
[2019-11-29T21:40:54,955][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-rollup]
[2019-11-29T21:40:54,955][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-security]
[2019-11-29T21:40:54,959][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-sql]
[2019-11-29T21:40:54,959][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-voting-only-node]
[2019-11-29T21:40:54,960][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] loaded module [x-pack-watcher]
[2019-11-29T21:40:54,961][INFO ][o.e.p.PluginsService ] [sht-sgmhadoopnn-01] no plugins loaded
[2019-11-29T21:41:04,226][INFO ][o.e.x.s.a.s.FileRolesStore] [sht-sgmhadoopnn-01] parsed [0] roles from file [/usr/local/elasticsearch/config/roles.yml]
[2019-11-29T21:41:06,319][INFO ][o.e.x.m.p.l.CppLogMessageHandler] [sht-sgmhadoopnn-01] [controller/15548] [Main.cc@110] controller (64 bit): Version 7.4.2 (Build 473f61b8a5238b) Copyright (c) 2019 Elasticsearch BV
[2019-11-29T21:41:07,855][DEBUG][o.e.a.ActionModule ] [sht-sgmhadoopnn-01] Using REST wrapper from plugin org.elasticsearch.xpack.security.Security
[2019-11-29T21:41:08,615][INFO ][o.e.d.DiscoveryModule ] [sht-sgmhadoopnn-01] using discovery type [zen] and seed hosts providers [settings]
[2019-11-29T21:41:10,403][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] initialized
[2019-11-29T21:41:10,404][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] starting ...
[2019-11-29T21:41:10,642][INFO ][o.e.t.TransportService ] [sht-sgmhadoopnn-01] publish_address {172.16.101.55:9300}, bound_addresses {[::]:9300}
[2019-11-29T21:41:10,657][INFO ][o.e.b.BootstrapChecks ] [sht-sgmhadoopnn-01] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2019-11-29T21:41:10,688][INFO ][o.e.c.c.Coordinator ] [sht-sgmhadoopnn-01] setting initial configuration to VotingConfiguration{VwFAki8mQjqxSuujq579NA}
[2019-11-29T21:41:11,063][INFO ][o.e.c.s.MasterService ] [sht-sgmhadoopnn-01] elected-as-master ([1] nodes joined)[{sht-sgmhadoopnn-01}{VwFAki8mQjqxSuujq579NA}{vo1YU6yIR5y3eevPfr-PvQ}{172.16.101.55}{172.16.101.55:9300}{dilm}{ml.machine_memory=6087860224, rack=r1, xpack.installed=true, ml.max_open_jobs=20} elect leader, _BECOME_MASTER_TASK_, _FINISH_ELECTION_], term: 1, version: 1, reason: master node changed {previous [], current [{sht-sgmhadoopnn-01}{VwFAki8mQjqxSuujq579NA}{vo1YU6yIR5y3eevPfr-PvQ}{172.16.101.55}{172.16.101.55:9300}{dilm}{ml.machine_memory=6087860224, rack=r1, xpack.installed=true, ml.max_open_jobs=20}]}
[2019-11-29T21:41:11,180][INFO ][o.e.c.c.CoordinationState] [sht-sgmhadoopnn-01] cluster UUID set to [kfD_MSD4SOSuF0gPlKBWVQ]
[2019-11-29T21:41:11,257][INFO ][o.e.c.s.ClusterApplierService] [sht-sgmhadoopnn-01] master node changed {previous [], current [{sht-sgmhadoopnn-01}{VwFAki8mQjqxSuujq579NA}{vo1YU6yIR5y3eevPfr-PvQ}{172.16.101.55}{172.16.101.55:9300}{dilm}{ml.machine_memory=6087860224, rack=r1, xpack.installed=true, ml.max_open_jobs=20}]}, term: 1, version: 1, reason: Publication{term=1, version=1}
[2019-11-29T21:41:11,428][INFO ][o.e.h.AbstractHttpServerTransport] [sht-sgmhadoopnn-01] publish_address {172.16.101.55:9200}, bound_addresses {[::]:9200}
[2019-11-29T21:41:11,429][INFO ][o.e.n.Node ] [sht-sgmhadoopnn-01] started
[2019-11-29T21:41:11,669][INFO ][o.e.g.GatewayService ] [sht-sgmhadoopnn-01] recovered [0] indices into cluster_state
[2019-11-29T21:41:12,228][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.triggered_watches] for index patterns [.triggered_watches*]
[2019-11-29T21:41:12,370][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.watches] for index patterns [.watches*]
[2019-11-29T21:41:12,517][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.watch-history-10] for index patterns [.watcher-history-10*]
[2019-11-29T21:41:12,637][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.slm-history] for index patterns [.slm-history-1*]
[2019-11-29T21:41:12,741][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.monitoring-logstash] for index patterns [.monitoring-logstash-7-*]
[2019-11-29T21:41:12,916][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.monitoring-es] for index patterns [.monitoring-es-7-*]
[2019-11-29T21:41:13,079][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.monitoring-beats] for index patterns [.monitoring-beats-7-*]
[2019-11-29T21:41:13,195][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.monitoring-alerts-7] for index patterns [.monitoring-alerts-7]
[2019-11-29T21:41:13,291][INFO ][o.e.c.m.MetaDataIndexTemplateService] [sht-sgmhadoopnn-01] adding template [.monitoring-kibana] for index patterns [.monitoring-kibana-7-*]
[2019-11-29T21:41:13,385][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [sht-sgmhadoopnn-01] adding index lifecycle policy [watch-history-ilm-policy]
[2019-11-29T21:41:13,503][INFO ][o.e.x.i.a.TransportPutLifecycleAction] [sht-sgmhadoopnn-01] adding index lifecycle policy [slm-history-ilm-policy]
[2019-11-29T21:41:13,934][INFO ][o.e.l.LicenseService ] [sht-sgmhadoopnn-01] license [c6634b36-15ab-4c2f-a1d1-01dfc4dafe4e] mode [basic] - valid
[2019-11-29T21:41:13,935][INFO ][o.e.x.s.s.SecurityStatusChangeListener] [sht-sgmhadoopnn-01] Active license is now [BASIC]; Security is disabled
注:我在CentOS6启动时会报错
[2018-09-10T10:35:24,090][WARN ][o.e.b.JNANatives ] unable to install syscall filter: java.lang.UnsupportedOperationException: seccomp unavailable: requires kernel 3.5+ with CONFIG_SECCOMP and CONFIG_SECCOMP_FILTER compiled in at org.elasticsearch.bootstrap.SystemCallFilter.linuxImpl(SystemCallFilter.java:350) ~[elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.SystemCallFilter.init(SystemCallFilter.java:638) ~[elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.JNANatives.tryInstallSystemCallFilter(JNANatives.java:245) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Natives.tryInstallSystemCallFilter(Natives.java:113) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:111) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:194) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:351) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:123) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:114) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:67) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:122) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.cli.Command.main(Command.java:88) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:91) [elasticsearch-5.5.3.jar:5.5.3] at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:84) [elasticsearch-5.5.3.jar:5.5.3]
https://github.com/elastic/elasticsearch/issues/22899
解决办法:在elasticsearch.yml配置文件添加
bootstrap.memory_lock: false
bootstrap.system_call_filter: false
注：不加任何参数为前台启动，以后台进程启动的话需执行下面的命令
[elsearch@sht-sgmhadoopdn-04 bin]$ ./elasticsearch &
[elsearch@sht-sgmhadoopdn-04 bin]$ ./elasticsearch -d
5.将elasticsearch添加为系统服务
# cat /usr/lib/systemd/system/elasticsearch.service
[Unit] Description=Elasticsearch Documentation=http://www.elastic.co Wants=network-online.target After=network-online.target [Service] Type=notify RuntimeDirectory=elasticsearch PrivateTmp=true Environment=ES_HOME=/usr/local/elasticsearch Environment=ES_PATH_CONF=/usr/local/elasticsearch/config Environment=PID_DIR=/var/run/elasticsearch Environment=ES_SD_NOTIFY=true EnvironmentFile=-/etc/sysconfig/elasticsearch WorkingDirectory=/usr/local/elasticsearch User=elasticsearch Group=elasticsearch Type=forking Restart=always ExecStart=/usr/local/elasticsearch/bin/elasticsearch -d -p ${PID_DIR}/elasticsearch.pid # StandardOutput is configured to redirect to journalctl since # some error messages may be logged in standard output before # elasticsearch logging system is initialized. Elasticsearch # stores its logs in /var/log/elasticsearch and does not use # journalctl by default. If you also want to enable journalctl # logging, you can simply remove the "quiet" option from ExecStart. StandardOutput=journal StandardError=inherit # Specifies the maximum file descriptor number that can be opened by this process LimitNOFILE=65535 # Specifies the maximum number of processes LimitNPROC=4096 # Specifies the maximum size of virtual memory LimitAS=infinity # Specifies the maximum file size LimitFSIZE=infinity # Disable timeout logic and wait until process is stopped TimeoutStopSec=0 # SIGTERM signal is used to stop the Java process KillSignal=SIGTERM # Send the signal only to the JVM rather than its control group KillMode=process # Java process is never killed SendSIGKILL=no # When a JVM receives a SIGTERM signal it exits with code 143 SuccessExitStatus=143 [Install] WantedBy=multi-user.target # Built for ${project.name}-${project.version} (${project.name})
# systemctl daemon-reload # systemctl enable elasticsearch # systemctl start elasticsearch # systemctl status elasticsearch ● elasticsearch.service - Elasticsearch Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: disabled) Active: active (running) since Fri 2019-12-06 21:29:41 CST; 34s ago Docs: http://www.elastic.co Process: 8675 ExecStart=/usr/local/elasticsearch/bin/elasticsearch -d -p ${PID_DIR}/elasticsearch.pid (code=exited, status=0/SUCCESS) Main PID: 8756 (java) Tasks: 66 Memory: 1.2G CGroup: /system.slice/elasticsearch.service ├─8756 /usr/local/elasticsearch/jdk/bin/java -Xms1g -Xmx1g -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -Des.networkaddress.cache.ttl=60 -Des.networkaddress.cache.negative.ttl=10 -XX:+Alw... └─8774 /usr/local/elasticsearch/modules/x-pack-ml/platform/linux-x86_64/bin/controller Dec 06 21:29:39 sht-sgmhadoopnn-01 systemd[1]: Starting Elasticsearch... Dec 06 21:29:41 sht-sgmhadoopnn-01 systemd[1]: Started Elasticsearch.