InfluxDB學習(一)：基本概念和安裝

一. InfluxDB數據庫介紹

InfluxDB是Influxdata旗下開源的一種時序數據庫(Time Series Database)，根據DB-engine排名，目前在time series數據庫領域排名第一位。

InfluxDB下載地址

https://portal.influxdata.com/downloads/

InfluxDB排名

https://db-engines.com/en/ranking/time+series+dbms

 InfluxDB主要功能

1. 對時序數據(sereis data)使用TSM存儲引擎，提供高性能的數據寫入和壓縮功能。
2. go語言編寫，程序只有一個二進制的可執行文件，沒有其他依關系。
3. 通過http API可提供高性能的便捷的讀寫操作。
4. 插件支持采集Graphite, collectd, and OpenTSDB等數據源。
5. 提供類似SQL語法格式的數據操作。
6. 保留策略(retention policies)功能可以定期清除老舊數據。
7. 不間斷(continuous queries)自動化查詢功能統計聚合數據來使數據查詢更有效率。

缺點：

1. 社區版只支持單機部署，集群功能需要使用收費的企業版。
2. InfluxDB中文學習文檔較少，對於想要了解該數據庫的用戶有一定的不便。

InfluxDB與RDBMS中的概念比較

概念	InfluxDB	RDBMS
數據庫	database	database
表	measurement	table
行	point	row
列	tag(可索引)，field(不可索引)	column

二. InfluxDB數據庫安裝

# mkdir /usr/local/influxdb
# groupadd -r dba
# useradd -r -g dba tnuser
# chown -R tnuser.dba /usr/local/influxdb
# sudo su - tnuser
$ cd /usr/local/influxdb
$ wget https://dl.influxdata.com/influxdb/releases/influxdb-1.8.0-static_linux_amd64.tar.gz
$ tar -zxf influxdb-1.8.0-static_linux_amd64.tar.gz
$ mv influxdb-1.8.0-1/* .
$ rm -rf influxdb-1.8.0*

修改InfluxDB數據庫配置文件,模板文件在數據庫安裝路徑下的etc/influxdb/influxdb.conf

reporting-disabled = true
bind-address = "0.0.0.0:8088"
[meta]
  dir = "/usr/local/influxdb/meta"
  retention-autocreate = true
[data]
  dir = "/usr/local/influxdb/data"
  wal-dir = "/usr/local/influxdb/wal"

使用CentOS7的systemctl管理InfluxDB服務

[Unit]
Description=InfluxDB is time series database
Documentation=https://docs.influxdata.com/influxdb/v1.8/introduction/get-started/
After=syslog.target
After=network.target

[Service]
Type=fork
User=tnuser
Group=dba
Restart=always

# Disable OOM kill on the Redis
OOMScoreAdjust=-1000
Environment=PG_OOM_ADJUST_FILE=/proc/self/oom_score_adj
Environment=PG_OOM_ADJUST_VALUE=0

ExecStart=/usr/local/influxdb/usr/bin/influxd run -config /usr/local/influxdb/etc/influxdb/influxdb.conf
ExecStop=/bin/kill -15 $MAINPID
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

# systemctl daemon-reload
# systemctl enable influxdb
# systemctl start influxdb
# systemctl status influxdb
● influxdb.service - InfluxDB is time series database
   Loaded: loaded (/usr/lib/systemd/system/influxdb.service; disabled; vendor preset: disabled)
   Active: active (running) since Sat 2020-04-18 23:19:03 PDT; 1s ago
     Docs: https://docs.influxdata.com/influxdb/v1.8/introduction/get-started/
 Main PID: 22583 (influxd)
   CGroup: /system.slice/influxdb.service
           └─22583 /usr/local/influxdb/usr/bin/influxd

Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.203421Z lvl=info msg="InfluxDB starting" log...568f5
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.203467Z lvl=info msg="Go runtime" log_id=0MG...ocs=4
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311597Z lvl=info msg="Using data dir" log_id.../data
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311635Z lvl=info msg="Compaction settings" l...31648
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.311647Z lvl=info msg="Open store (start)" lo...start
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.553803Z lvl=info msg="Reading file" log_id=0...87843
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.572851Z lvl=info msg="Opened file" log_id=0M...749ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.594031Z lvl=info msg="Opened file" log_id=0M...915ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.610554Z lvl=info msg="Opened shard" log_id=0...256ms
Apr 18 23:19:04 ec2t-dbaadmin-01.mypna.com influxd[22583]: ts=2020-04-19T06:19:04.612039Z lvl=info msg="Opened shard" log_id=0...741ms
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