ubuntu 20.04搭建elasticsearch-7.6.2

目錄

ubuntu安裝 es7.6.2

安裝步驟

上傳至Ubuntu 服務器 這里我存放在 /usr/

解壓elasticsearch-7.6.2-linux-x86_64.tar.gz

出現問題及解決方法

1.如啟動時出現如下內容

2.最大虛擬記憶體區域 vm.max_map_count [65530] 太低警告

3.啟動例外：failed to obtain node locks

4.啟動后外網無法訪問問題

ubuntu安裝 es7.6.2

• Ubuntu 18.04.4
• jdk （Ubuntu 18.04.4搭建開發環境之 JDK1.8安裝，原先安裝jdk8，后直接升級為jdk11版本，關于linux配置jdk1.8或者jdk11這里不再細說）
• elasticsearch-7.6.2

安裝步驟

下載 ES （官網）

在visit our downloads page中找到elasticsearch7.6.2版本，點擊下載即可

上傳至Ubuntu 服務器 這里我存放在 /usr/

解壓elasticsearch-7.6.2-linux-x86_64.tar.gz

解壓后看下目錄結構

bin 存放可執行的腳本檔案目錄
config 存放組態檔目錄
data 存放node資料
jdk 版本自帶jdk
logs 存放日志目錄
plugins 用來擴展ES的插件目錄

這樣就算基本完成了，先啟動（一步一步踩坑開始）

root@daryl:/usr/elasticsearch-7.6.2# ./bin/elasticsearch &

出現問題及解決方法

1.如啟動時出現如下內容

java.lang.RuntimeException: can not run elasticsearch as root

解決方法：此錯誤，是因為ES不能直接使用 Root 用戶來啟動，需要創建es用戶，我這里直接創建的是esroot用戶，

root@VM-0-2-ubuntu:/usr/local/elasticsearch-7.6.2# adduser esroot
Enter new UNIX password: *****   '輸入你的密碼'
Retype new UNIX password:*****   '再次輸入你的密碼'

enter 走下去，確認選 y 就 ok 了，然后再root用戶下授權檔案夾elasticsearch-7.6.2 權限給esroot用戶，

root@daryl:/usr# chown -R esroot elasticsearch-7.6.2

再切換到這個 esroot 用戶 再次運行 ./bin/elasticsearch，后臺啟動則在啟動命令后加 &

root@daryl:/usr# su esroot
esroot@daryl:/usr$ ./elasticsearch-7.6.2/bin/elasticsearch &

看到started之后，再使用curl命令查看，出現如下則為啟動成功

2.最大虛擬記憶體區域 vm.max_map_count [65530] 太低警告

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

解決方法：修改/etc/sysctl.conf檔案，添加如下代碼

vm.max_map_count=262144

退出保存后執行如下命令: sysctl -p

root@daryl:~# sysctl -p
vm.max_map_count = 655360
root@daryl:~#

3.啟動例外：failed to obtain node locks

[ERROR][o.e.b.Bootstrap          ] [daryl] Exception
java.lang.IllegalStateException: failed to obtain node locks, tried [[/usr/elasticsearch-7.6.2/data]] with lock id [0]; maybe these locations are not writable or multiple nodes were started without increasing [node.max_local_storage_nodes] (was [1])?
	at org.elasticsearch.env.NodeEnvironment.<init>(NodeEnvironment.java:301) ~[elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.node.Node.<init>(Node.java:277) ~[elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.node.Node.<init>(Node.java:257) ~[elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:221) ~[elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:221) ~[elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:349) [elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:170) [elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:161) [elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) [elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:125) [elasticsearch-cli-7.6.2.jar:7.6.2]
	at org.elasticsearch.cli.Command.main(Command.java:90) [elasticsearch-cli-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:126) [elasticsearch-7.6.2.jar:7.6.2]
	at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) [elasticsearch-7.6.2.jar:7.6.2]

解決方法：這類錯誤網上有很多解決方案，我們這邊問題的原因則是第一次啟動es是用root用戶啟動造成的，這時，只要洗掉/重命名data下的node目錄，再次運行ES就可以解決

4.啟動后外網無法訪問問題

netstat查看行程在運行狀態，使用curl命令出現如下提示

esroot@daryl:/usr/elasticsearch-7.6.2$ curl 192.168.29.131:9200
curl: (7) Failed to connect to 192.168.29.131 port 9200: Connection refused

解決方法：修改組態檔elasticsearch.yml，在network模塊添加 network.host: 0.0.0.0

# ---------------------------------- Network -----------------------------------
#
# Set the bind address to a specific IP (IPv4 or IPv6):
#
#network.host: 192.168.0.1
network.host: 0.0.0.0
#
# Set a custom port for HTTP:
#
#http.port: 9200
#
# For more information, consult the network module documentation.

然后在Discovery模塊添加 discovery.seed_hosts: ["127.0.0.1", "[::1]"]

# --------------------------------- Discovery ----------------------------------
#
# Pass an initial list of hosts to perform discovery when this node is started:
# The default list of hosts is ["127.0.0.1", "[::1]"]
#
#discovery.seed_hosts: ["host1", "host2"]
discovery.seed_hosts: ["127.0.0.1", "[::1]"]
#
# Bootstrap the cluster using an initial set of master-eligible nodes:
#
#cluster.initial_master_nodes: ["node-1", "node-2"]
#
# For more information, consult the discovery and cluster formation module documentation.

如果不添加的話啟動會提示需要在discovery.seed_hosts,discovery.seed_providers, cluster.initial_master_nodes中至少設定一項的例外

[ERROR][o.e.b.Bootstrap          ] [daryl] node validation exception
[1] bootstrap checks failed
[1]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured

配置好之后，esroot用戶下啟動es用瀏覽器訪問 http://192.168.29.131:9200/，ok