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InfluxDB

Configuration

/etc/influxdb/influxdb.conf

[http]
  auth-enabled = true
Schema Design

official tutorial: InfluxDB schema design

Data Elements

    timstamp measurement tag key tag value field key field value

    Where to store data (tag or field)

    tag value

      資料型式只能是 string 資料長度不宜過長 資料唯一性的筆數不宜過多

      field value

        資料型式可以是 strings, floats, integers, or booleans。  

         

        Management

        Create a new user and database

        influx
> CREATE USER admin WITH PASSWORD 'adminpass' WITH ALL PRIVILEGES
> exit

influx -username admin -password adminpass
> set password for admin = 'newpass'
>
> create database mmap_nmon with duration 180d
> create user mon with password 'thisispassword'
> grant ALL on mmap_nmon to mon
> show GRANTS for mon

        Login to InfluxDB

        # In the shell
influx -username admin -password thisispass

# In the InfluxDB CLI
> auth
username:
password
        InfluxQL
        > show databases
name: databases
name
----
_internal
nmon_reports
nmon2influxdb_log

> show users
user  admin
----  -----
admin true
mon   false

> use nmon_reports
Using database nmon_reports
> show measurements
name: measurements
name
----
CPU_ALL
DISKAVGRIO
DISKAVGWIO
DISKBSIZE
DISKBUSY
DISKREAD
DISKREADSERV
DISKRIO
DISKRXFER
DISKSERV
...

        Retention Policy

        # for current database
> show retention policies
name    duration  shardGroupDuration replicaN default
----    --------  ------------------ -------- -------
autogen 8760h0m0s 168h0m0s           1        true

# for specified database
> show retention policies on nmon2influxdb_log
name          duration shardGroupDuration replicaN default
----          -------- ------------------ -------- -------
autogen       0s       168h0m0s           1        false
log_retention 48h0m0s  24h0m0s            1        true

# Create a policy
> CREATE RETENTION POLICY "one_day_only" ON "NOAA_water_database" DURATION 1d REPLICATION 1

# Alter the policy
> ALTER RETENTION POLICY "what_is_time" ON "NOAA_water_database" DURATION 3w SHARD DURATION 2h DEFAULT

# Delete a policy
> DROP RETENTION POLICY "what_is_time" ON "NOAA_water_database"

        Verify the account

        curl -G http://localhost:8086/query -u mon:thisispassword --data-urlencode "q=SHOW DATABASES"
{"results":[{"statement_id":0,"series":[{"name":"databases","columns":["name"],"values":[["mmap_nmon"]]}]}]}

        查詢表資訊

        SHOW MEASUREMENTS  --查詢當前資料庫中含有的表
SHOW FIELD KEYS --查看當前資料庫所有表的欄位
SHOW series from pay --查看key數據
SHOW TAG KEYS FROM "pay" --查看key中tag key值
SHOW TAG VALUES FROM "pay" WITH KEY = "merId" --查看key中tag 指定key值對應的值
SHOW TAG VALUES FROM cpu WITH KEY IN ("region", "host") WHERE service = 'redis'
DROP SERIES FROM  WHERE ='' --刪除key
SHOW CONTINUOUS QUERIES   --查看連續執行命令
SHOW QUERIES  --查看最後執行命令
KILL QUERY  --結束命令
SHOW RETENTION POLICIES ON mydb  --查看保留數據

        查詢資料

        SELECT * FROM /.*/ LIMIT 1  --查詢當前資料庫下所有表的第一行記錄
select * from pay  order by time desc limit 2
select * from  db_name."POLICIES name".measurement_name --指定查詢資料庫下資料保留中的表資料 POLICIES name資料保留

        刪除資料

        delete from "query" --刪除表所有資料，則表就不存在了
drop MEASUREMENT "query"   --刪除表（注意會把資料保留刪除使用delete不會）
DELETE FROM cpu
DELETE FROM cpu WHERE time < '2000-01-01T00:00:00Z'
DELETE WHERE time < '2000-01-01T00:00:00Z'
DROP DATABASE “testDB” --刪除資料庫
DROP RETENTION POLICY "dbbak" ON mydb --刪除保留資料為dbbak資料
DROP SERIES from pay where tag_key='' --刪除key中的tag

        函數使用

        • mean: 平均值
        • sum: 總和
        • min: 最小值
        • max: 最大值
        • count: 總個數
        • difference: 差異數 (前後筆資料的比較)
        • non_negative_difference: 正差異數 (前後筆資料的比較)
        select * from pay   order by time desc limit 2
select mean(allTime) from pay where time >= today() group by time(10m) time_zone(+8)
select * from pay time_zone(+8) limit 2
SELECT sum(allTime) FROM "pay" WHERE time > now() - 10s
select count(allTime) from pay  where time > now() - 10m  group by time(1s)

select difference("commit_sql") from "snapdb2" where time > now() - 1h limit 10
select non_negative_difference(*) from "snapdb2" where time > now() - 1h limit 10
select non_negative_difference(/commit_sql|rollback_sql/) from "snapdb2" where time > now() - 1h limit 10

        User and Privileges

        > CREATE USER "todd" WITH PASSWORD '123456'

> SHOW GRANTS for "todd"

> SET PASSWORD FOR "todd" = 'newpassword'

> GRANT READ ON "NOAA_water_database" TO "todd"
> GRANT ALL ON "NOAA_water_database" TO "todd"

> REVOKE ALL PRIVILEGES FROM "todd"
> REVOKE ALL ON "NOAA_water_database" FROM "todd"
> REVOKE WRITE ON "NOAA_water_database" FROM "todd"

> DROP USER "todd"

        Covert timestamp to normal datetime

        influx -precision rfc3339
# Or, in CLI
> precision rfc3339

        Convert InfluxData to csv format

        # With CLI
# There is also useful -precision option to set format of timestamp.
influx -database 'database_name' -execute "SELECT * FROM table_name" -format csv > test.csv

influx -username your_user_if_any -password "secret!" -database 'db_name' -host 'localhost' -execute 'SELECT * FROM "db_name"."your_retention_policy_or_nothing"."your_measurement_name" WHERE time > '\''2017-09-05'\'' and time < '\''2017-09-05T23:59:59Z'\'' AND other_conditions_if_required' -format 'csv' > /tmp/your_measurement_name_20170905.csv

# With HTTP-API
# Samples:
# "q=SELECT * FROM \"mymeasurement\" where time > now() - 130d"
# "q=SELECT * FROM \"mymeasurement\" where (time < now() - 130d) and  (time > now() - 260d)"
curl -G 'http://localhost:8086/query' --data-urlencode "db=mydb" --data-urlencode "epoch=#timeunit" --data-urlencode "q=SELECT * FROM \"mymeasurement\" " -H "Accept: application/csv" >  mytargetcsv.csv

         

        Services
        systemctl start influxdb
systemctl enable influxdb
        Learning

         

         

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