apache iotdb_Apache-IoTDB

Overview

IoTDB (Internet of Things Database) is an integrated data management engine designed for time series data, which can provide users specific services for data collection, storage and analysis. Due to its light weight structure, high performance and usable features together with its intense integration with Hadoop and Spark ecology, IoTDB meets the requirements of massive dataset storage, high-speed data input and complex data analysis in the IoT industrial field.

Main Features

IoTDB's features are as following:

Flexible deployment. IoTDB provides users one-click installation tool on the cloud, once-decompressed-used terminal tool and the bridge tool between cloud platform and terminal tool (Data Synchronization Tool).

Low cost on hardware. IoTDB can reach a high compression ratio of disk storage

Efficient directory structure. IoTDB supports efficient organization for complex time series data structure from intelligent networking devices, organization for time series data from devices of the same type, fuzzy searching strategy for massive and complex directory of time series data.

High-throughput read and write. IoTDB supports millions of low-power devices' strong connection data access, high-speed data read and write for intelligent networking devices and mixed devices mentioned above.

Rich query semantics. IoTDB supports time alignment for time series data across devices and sensors, computation in time series field (frequency domain transformation) and rich aggregation function support in time dimension.

Easy to get start. IoTDB supports SQL-Like language, JDBC standard API and import/export tools which is easy to use.

Intense integration with Open Source Ecosystem. IoTDB supports Hadoop, Spark, etc. analysis ecosystems and Grafana visualization tool.

For the latest information about IoTDB, please visit our IoTDB official website.

Outline

Quick Start

Prerequisites

Installation

Build from source

Configurations

Start

Start IoTDB

Use IoTDB

Use Cli

Basic commands for IoTDB

Stop IoTDB

Only build server

Only build client

Usage of import-csv.sh

Create metadata

An Example of import csv file

Run import shell

Error data file

Usage of export-csv.sh

Run export shell

Input query

Quick Start

This short guide will walk you through the basic process of using IoTDB. For a more-complete guide, please visit our website's User Guide.

Prerequisites

To use IoTDB, you need to have:

Java >= 1.8 (1.8, 11, and 13 are verified. Please make sure the environment path has been set)

Maven >= 3.1 (If you want to compile and install IoTDB from source code)

Set the max open files num as 65535 to avoid "too many open files" problem.

Installation

IoTDB provides you three installation methods, you can refer to the following suggestions, choose one of them:

Installation from source code. If you need to modify the code yourself, you can use this method.

Installation from binary files. Download the binary files from the official website. This is the recommended method, in which you will get a binary released package which is out-of-the-box.(Comming Soon...)

Here in the Quick Start, we give a brief introduction of using source code to install IoTDB. For further information, please refer to Chapter 4 of the User Guide.

Build from source

You can download the source code from:

git clone https://github.com/apache/incubator-iotdb.git

Under the root path of incubator-iotdb:

> mvn clean package -DskipTests

Then the binary version (including both server and client) can be found at distribution/target/apache-iotdb-{project.version}-incubating-bin.zip

NOTE: Directories "service-rpc/target/generated-sources/thrift" and "server/target/generated-sources/antlr3" need to be added to sources roots to avoid compilation errors in IDE.

Configurations

configuration files are under "conf" folder

environment config module (iotdb-env.bat, iotdb-env.sh),

system config module (tsfile-format.properties, iotdb-engine.properties)

log config module (logback.xml).

Start

You can go through the following step to test the installation, if there is no error after execution, the installation is completed.

Start IoTDB

Users can start IoTDB by the start-server script under the sbin folder.

# Unix/OS X

> sbin/start-server.sh

# Windows

> sbin\start-server.bat

Use IoTDB

Use Cli

IoTDB offers different ways to interact with server, here we introduce basic steps of using Cli tool to insrert and query data.

After installing IoTDB, there is a default user 'root', its default password is also 'root'. Users can use this

default user to login Cli to use IoTDB. The startup script of Cli is the start-client script in the folder sbin. When executing the script, user should assign

IP, PORT, USER_NAME and PASSWORD. The default parameters are "-h 127.0.0.1 -p 6667 -u root -pw -root".

Here is the command for starting the Cli:

# Unix/OS X

> sbin/start-client.sh -h 127.0.0.1 -p 6667 -u root -pw root

# Windows

> sbin\start-client.bat -h 127.0.0.1 -p 6667 -u root -pw root

The command line client is interactive so if everything is ready you should see the welcome logo and statements:

_____ _________ ______ ______

|_ _| | _ _ ||_ _ `.|_ _ \

| | .--.|_/ | | \_| | | `. \ | |_) |

| | / .'`\ \ | | | | | | | __'.

_| |_| \__. | _| |_ _| |_.' /_| |__) |

|_____|'.__.' |_____| |______.'|_______/ version x.x.x

IoTDB> login successfully

IoTDB>

Basic commands for IoTDB

Now, let us introduce the way of creating timeseries, inserting data and querying data.

The data in IoTDB is organized as timeseries, in each timeseries there are some data-time pairs, and every timeseries is owned by a storage group. Before defining a timeseries, we should difine a storage group using SET STORAGE GROUP, and here is an example:

IoTDB> SET STORAGE GROUP TO root.ln

We can also use SHOW STORAGE GROUP to check created storage group:

IoTDB> SHOW STORAGE GROUP

+-----------------------------------+

| Storage Group|

+-----------------------------------+

| root.ln|

+-----------------------------------+

storage group number = 1

After the storage group is set, we can use CREATE TIMESERIES to create new timeseries. When we create a timeseries, we should define its data type and the encoding scheme. We create two timeseries as follow:

IoTDB> CREATE TIMESERIES root.ln.wf01.wt01.status WITH DATATYPE=BOOLEAN, ENCODING=PLAIN

IoTDB> CREATE TIMESERIES root.ln.wf01.wt01.temperature WITH DATATYPE=FLOAT, ENCODING=RLE

Inorder to query the specific timeseries, we can use SHOW TIMESERIES . represent the path of the timeseries. Its default value is null, which means quering all the timeseries in the system(the same as using "SHOW TIMESERIES root"). Here are the examples:

Querying all timeseries in the system:

IoTDB> SHOW TIMESERIES

+-------------------------------+---------------+--------+--------+

| Timeseries| Storage Group|DataType|Encoding|

+-------------------------------+---------------+--------+--------+

| root.ln.wf01.wt01.status| root.ln| BOOLEAN| PLAIN|

| root.ln.wf01.wt01.temperature| root.ln| FLOAT| RLE|

+-------------------------------+---------------+--------+--------+

Total timeseries number = 2

Querying a specific timeseries(root.ln.wf01.wt01.status):

IoTDB> SHOW TIMESERIES root.ln.wf01.wt01.status

+------------------------------+--------------+--------+--------+

| Timeseries| Storage Group|DataType|Encoding|

+------------------------------+--------------+--------+--------+

| root.ln.wf01.wt01.status| root.ln| BOOLEAN| PLAIN|

+------------------------------+--------------+--------+--------+

Total timeseries number = 1

Insert timeseries data is the basic operation of IoTDB, you can use ‘INSERT’ command to finish this. Before inserting you should assign the timestamp and the suffix path name:

IoTDB> INSERT INTO root.ln.wf01.wt01(timestamp,status) values(100,true);

IoTDB> INSERT INTO root.ln.wf01.wt01(timestamp,status,temperature) values(200,false,20.71)

The data we’ve just inserted displays like this:

IoTDB> SELECT status FROM root.ln.wf01.wt01

+-----------------------+------------------------+

| Time|root.ln.wf01.wt01.status|

+-----------------------+------------------------+

|1970-01-01T08:00:00.100| true|

|1970-01-01T08:00:00.200| false|

+-----------------------+------------------------+

Total line number = 2

We can also query several timeseries data at once like this:

IoTDB> SELECT * FROM root.ln.wf01.wt01

+-----------------------+--------------------------+-----------------------------+

| Time| root.ln.wf01.wt01.status|root.ln.wf01.wt01.temperature|

+-----------------------+--------------------------+-----------------------------+

|1970-01-01T08:00:00.100| true| null|

|1970-01-01T08:00:00.200| false| 20.71|

+-----------------------+--------------------------+-----------------------------+

Total line number = 2

The commands to exit the Cli is:

IoTDB> quit

or

IoTDB> exit

For more on what commands are supported by IoTDB SQL, see Chapter 5: IoTDB SQL Documentation.

Stop IoTDB

The server can be stopped with ctrl-C or the following script:

# Unix/OS X

> sbin/stop-server.sh

# Windows

> sbin\stop-server.bat

Only build server

Under the root path of incubator-iotdb:

> mvn clean package -pl server -am -DskipTests

After build, the IoTDB server will be at the folder "server/target/iotdb-server-{project.version}".

Only build client

Under the root path of incubator-iotdb:

> mvn clean package -pl client -am -DskipTests

After build, the IoTDB client will be at the folder "client/target/iotdb-client-{project.version}".

Usage of import-csv.sh

Create metadata

SET STORAGE GROUP TO root.fit.d1;

SET STORAGE GROUP TO root.fit.d2;

SET STORAGE GROUP TO root.fit.p;

CREATE TIMESERIES root.fit.d1.s1 WITH DATATYPE=INT32,ENCODING=RLE;

CREATE TIMESERIES root.fit.d1.s2 WITH DATATYPE=TEXT,ENCODING=PLAIN;

CREATE TIMESERIES root.fit.d2.s1 WITH DATATYPE=INT32,ENCODING=RLE;

CREATE TIMESERIES root.fit.d2.s3 WITH DATATYPE=INT32,ENCODING=RLE;

CREATE TIMESERIES root.fit.p.s1 WITH DATATYPE=INT32,ENCODING=RLE;

An example of import csv file

Time,root.fit.d1.s1,root.fit.d1.s2,root.fit.d2.s1,root.fit.d2.s3,root.fit.p.s1

1,100,'hello',200,300,400

2,500,'world',600,700,800

3,900,'IoTDB',1000,1100,1200

Run import shell

# Unix/OS X

> tools/import-csv.sh -h -p -u -pw -f

# Windows

> tools\import-csv.bat -h -p -u -pw -f

Error data file

csvInsertError.error

Usage of export-csv.sh

Run export shell

# Unix/OS X

> tools/export-csv.sh -h -p -u -pw -td [-tf ]

# Windows

> tools\export-csv.bat -h -p -u -pw -td [-tf ]

Input query

select * from root.fit.d1
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原文链接：https://blog.csdn.net/weixin_42237925/article/details/113373810