Deploying TDengine with Docker

This chapter describes how to start the TDengine service in a container and access it. Users can control the behavior of the service in the container by using environment variables on the docker run command-line or in the docker-compose file.

Starting TDengine

The TDengine image starts with the HTTP service activated by default, using the following command:

docker run -d --name tdengine -p 6041:6041 tdengine/tdengine

The above command starts a container named “tdengine” and maps the HTTP service port 6041 to the host port 6041. You can verify that the HTTP service provided in this container is available using the following command.

curl -u root:taosdata -d "show databases" localhost:6041/rest/sql

The TDengine client taos can be executed in this container to access TDengine using the following command.

$ docker exec -it tdengine taos
Welcome to the TDengine shell from Linux, Client Version:2.4.0.0
Copyright (c) 2020 by TAOS Data, Inc.
taos> show databases;
              name | created_time | ntables | vgroups | replica | quorum | days | keep | cache(MB) | blocks | minrows | maxrows | wallevel | fsync | comp | cachelast | precision | update | status | status precision | update | status |
================================================================================================================================== ================================================================================================================================== ================
 log | 2022-01-17 13:57:22.270 | 10 | 1 | 1 | 1 | 10 | 30 | 1 | 3 | 100 | 4096 | 1 | 3000 | 2 | 0 | us | 0 | ready |
Query OK, 1 row(s) in set (0.002843s)

The TDengine server running in the container uses the container’s hostname to establish a connection. Using TDengine CLI or various connectors (such as JDBC-JNI) to access the TDengine inside the container from outside the container is more complicated. So the above is the simplest way to access the TDengine service in the container and is suitable for some simple scenarios. Please refer to the next section if you want to access the TDengine service in the container from outside the container using TDengine CLI or various connectors for complex scenarios.

Start TDengine on the host network

docker run -d --name tdengine --network host tdengine/tdengine

The above command starts TDengine on the host network and uses the host’s FQDN to establish a connection instead of the container’s hostname. It is the equivalent of using systemctl to start TDengine on the host. If the TDengine client is already installed on the host, you can access it directly with the following command.

$ taos
Welcome to the TDengine shell from Linux, Client Version:2.4.0.0
Copyright (c) 2020 by TAOS Data, Inc.
taos> show dnodes;
   id | end_point | vnodes | cores | status | role | create_time | offline reason |
================================================================================================================================== ====
      1 | myhost:6030 | 1 | 8 | ready | any | 2022-01-17 22:10:32.619 | |
Query OK, 1 row(s) in set (0.003233s)

Start TDengine with the specified hostname and port

The TAOS_FQDN environment variable or the fqdn configuration item in taos.cfg allows TDengine to establish a connection at the specified hostname. This approach provides greater flexibility for deployment.

docker run -d \
   --name tdengine \
   -e TAOS_FQDN=tdengine \
   -p 6030-6049:6030-6049 \
   -p 6030-6049:6030-6049/udp \
   tdengine/tdengine

The above command starts a TDengine service in the container, which listens to the hostname tdengine, and maps the container’s port segment 6030 to 6049 to the host’s port segment 6030 to 6049 (both TCP and UDP ports need to be mapped). If the port segment is already occupied on the host, you can modify the above command to specify a free port segment on the host. If rpcForceTcp is set to 1, you can map only the TCP protocol.

Next, ensure the hostname “tdengine” is resolvable in /etc/hosts.

echo 127.0.0.1 tdengine |sudo tee -a /etc/hosts

Finally, the TDengine service can be accessed from the taos shell or any connector with “tdengine” as the server address.

taos -h tdengine -P 6030

If set TAOS_FQDN to the same hostname, the effect is the same as “Start TDengine on host network”.

Start TDengine on the specified network

You can also start TDengine on a specific network.

1. First, create a docker network named td-net

   docker network create td-net
   ``` Create td-net

2. Start TDengine

   Start the TDengine service on the td-net network with the following command:

   docker run -d --name tdengine --network td-net \
      -e TAOS_FQDN=tdengine \
      tdengine/tdengine

3. Start the TDengine client in another container on the same network

   docker run --rm -it --network td-net -e TAOS_FIRST_EP=tdengine tdengine/tdengine taos
   # or
   # docker run --rm -it --network td-net -e tdengine/tdengine taos -h tdengine

Launching a client application in a container

If you want to start your application in a container, you need to add the corresponding dependencies on TDengine to the image as well, e.g.

FROM ubuntu:20.04
RUN apt-get update && apt-get install -y wget
ENV TDENGINE_VERSION=2.4.0.0
RUN wget -c https://www.taosdata.com/assets-download/TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && tar xvf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && cd TDengine-client-${TDENGINE_VERSION} \
   && ./install_client.sh \
   && cd ../ \
   && rm -rf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz TDengine-client-${TDENGINE_VERSION}
## add your application next, eg. go, build it in builder stage, copy the binary to the runtime
#COPY --from=builder /path/to/build/app /usr/bin/
#CMD ["app"]

Here is an example GO program:

/*
 * In this test program, we'll create a database and insert 4 records then select out.
 */
package main
import (
    "database/sql"
    "flag"
    "fmt"
    "time"
    _ "github.com/taosdata/driver-go/v2/taosSql"
)
type config struct {
    hostName   string
    serverPort string
    user       string
    password   string
}
var configPara config
var taosDriverName = "taosSql"
var url string
func init() {
    flag.StringVar(&configPara.hostName, "h", "", "The host to connect to TDengine server.")
    flag.StringVar(&configPara.serverPort, "p", "", "The TCP/IP port number to use for the connection to TDengine server.")
    flag.StringVar(&configPara.user, "u", "root", "The TDengine user name to use when connecting to the server.")
    flag.StringVar(&configPara.password, "P", "taosdata", "The password to use when connecting to the server.")
    flag.Parse()
}
func printAllArgs() {
    fmt.Printf("============= args parse result: =============\n")
    fmt.Printf("hostName:             %v\n", configPara.hostName)
    fmt.Printf("serverPort:           %v\n", configPara.serverPort)
    fmt.Printf("usr:                  %v\n", configPara.user)
    fmt.Printf("password:             %v\n", configPara.password)
    fmt.Printf("================================================\n")
}
func main() {
    printAllArgs()
    url = "root:taosdata@/tcp(" + configPara.hostName + ":" + configPara.serverPort + ")/"
    taos, err := sql.Open(taosDriverName, url)
    checkErr(err, "open database error")
    defer taos.Close()
    taos.Exec("create database if not exists test")
    taos.Exec("use test")
    taos.Exec("create table if not exists tb1 (ts timestamp, a int)")
    _, err = taos.Exec("insert into tb1 values(now, 0)(now+1s,1)(now+2s,2)(now+3s,3)")
    checkErr(err, "failed to insert")
    rows, err := taos.Query("select * from tb1")
    checkErr(err, "failed to select")
    defer rows.Close()
    for rows.Next() {
        var r struct {
            ts time.Time
            a  int
        }
        err := rows.Scan(&r.ts, &r.a)
        if err != nil {
            fmt.Println("scan error:\n", err)
            return
        }
        fmt.Println(r.ts, r.a)
    }
}
func checkErr(err error, prompt string) {
    if err != nil {
        fmt.Println("ERROR: %s\n", prompt)
        panic(err)
    }
}

Here is the full Dockerfile:

FROM golang:1.17.6-buster as builder
ENV TDENGINE_VERSION=2.4.0.0
RUN wget -c https://www.taosdata.com/assets-download/TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && tar xvf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && cd TDengine-client-${TDENGINE_VERSION} \
   && ./install_client.sh \
   && cd ../ \
   && rm -rf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz TDengine-client-${TDENGINE_VERSION}
WORKDIR /usr/src/app/
ENV GOPROXY="https://goproxy.io,direct"
COPY ./main.go ./go.mod ./go.sum /usr/src/app/
RUN go env
RUN go mod tidy
RUN go build
FROM ubuntu:20.04
RUN apt-get update && apt-get install -y wget
ENV TDENGINE_VERSION=2.4.0.0
RUN wget -c https://www.taosdata.com/assets-download/TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && tar xvf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz \
   && cd TDengine-client-${TDENGINE_VERSION} \
   && ./install_client.sh \
   && cd ../ \
   && rm -rf TDengine-client-${TDENGINE_VERSION}-Linux-x64.tar.gz TDengine-client-${TDENGINE_VERSION}
## add your application next, eg. go, build it in builder stage, copy the binary to the runtime
COPY --from=builder /usr/src/app/app /usr/bin/
CMD ["app"]

Now that we have main.go, go.mod, go.sum, app.dockerfile, we can build the application and start it on the td-net network.

$ docker build -t app -f app.dockerfile
$ docker run --rm --network td-net app -h tdengine -p 6030
============= args parse result: =============
hostName:             tdengine
serverPort:           6030
usr:                  root
password:             taosdata
================================================
2022-01-17 15:56:55.48 +0000 UTC 0
2022-01-17 15:56:56.48 +0000 UTC 1
2022-01-17 15:56:57.48 +0000 UTC 2
2022-01-17 15:56:58.48 +0000 UTC 3
2022-01-17 15:58:01.842 +0000 UTC 0
2022-01-17 15:58:02.842 +0000 UTC 1
2022-01-17 15:58:03.842 +0000 UTC 2
2022-01-17 15:58:04.842 +0000 UTC 3
2022-01-18 01:43:48.029 +0000 UTC 0
2022-01-18 01:43:49.029 +0000 UTC 1
2022-01-18 01:43:50.029 +0000 UTC 2
2022-01-18 01:43:51.029 +0000 UTC 3

Start the TDengine cluster with docker-compose

1. The following docker-compose file starts a TDengine cluster with two replicas, two management nodes, two data nodes, and one arbitrator.

   version: "3"
   services:
     arbitrator:
       image: tdengine/tdengine:$VERSION
       command: tarbitrator
     td-1:
       image: tdengine/tdengine:$VERSION
       environment:
         TAOS_FQDN: "td-1"
         TAOS_FIRST_EP: "td-1"
         TAOS_NUM_OF_MNODES: "2"
         TAOS_REPLICA: "2"
         TAOS_ARBITRATOR: arbitrator:6042
       volumes:
         - taosdata-td1:/var/lib/taos/
         - taoslog-td1:/var/log/taos/
     td-2:
       image: tdengine/tdengine:$VERSION
       environment:
         TAOS_FQDN: "td-2"
         TAOS_FIRST_EP: "td-1"
         TAOS_NUM_OF_MNODES: "2"
         TAOS_REPLICA: "2"
         TAOS_ARBITRATOR: arbitrator:6042
       volumes:
         - taosdata-td2:/var/lib/taos/
         - taoslog-td2:/var/log/taos/
   volumes:
     taosdata-td1:
     taoslog-td1:
     taosdata-td2:
     taoslog-td2:

note

• The VERSION environment variable is used to set the tdengine image tag

  • TAOS_FIRST_EP must be set on the newly created instance so that it can join the TDengine cluster; if there is a high availability requirement, TAOS_SECOND_EP needs to be used at the same time
  • TAOS_REPLICA is used to set the default number of database replicas. Its value range is [1,3] We recommend setting it with TAOS_ARBITRATOR to use arbitrator in a two-nodes environment.

  :::

1. Start the cluster

   $ VERSION=2.4.0.0 docker-compose up -d
   Creating network "test_default" with the default driver
   Creating volume "test_taosdata-td1" with default driver
   Creating volume "test_taoslog-td1" with default driver
   Creating volume "test_taosdata-td2" with default driver
   Creating volume "test_taoslog-td2" with default driver
   Creating test_td-1_1       ... done
   Creating test_arbitrator_1 ... done
   Creating test_td-2_1       ... done

2. Check the status of each node

   $ docker-compose ps
         Name                     Command               State                                                                Ports
   ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
   test_arbitrator_1   /usr/bin/entrypoint.sh tar ...   Up      6030/tcp, 6031/tcp, 6032/tcp, 6033/tcp, 6034/tcp, 6035/tcp, 6036/tcp, 6037/tcp, 6038/tcp, 6039/tcp, 6040/tcp, 6041/tcp, 6042/tcp
   test_td-1_1         /usr/bin/entrypoint.sh taosd     Up      6030/tcp, 6031/tcp, 6032/tcp, 6033/tcp, 6034/tcp, 6035/tcp, 6036/tcp, 6037/tcp, 6038/tcp, 6039/tcp, 6040/tcp, 6041/tcp, 6042/tcp
   test_td-2_1         /usr/bin/entrypoint.sh taosd     Up      6030/tcp, 6031/tcp, 6032/tcp, 6033/tcp, 6034/tcp, 6035/tcp, 6036/tcp, 6037/tcp, 6038/tcp, 6039/tcp, 6040/tcp, 6041/tcp, 6042/tcp

3. Show dnodes via TDengine CLI

   $ docker-compose exec td-1 taos -s "show dnodes"
   Welcome to the TDengine shell from Linux, Client Version:2.4.0.0
   Copyright (c) 2020 by TAOS Data, Inc. All rights reserved.
   taos> show dnodes
      id   |           end_point            | vnodes | cores  |   status   | role  |       create_time       |      offline reason      |
   ======================================================================================================================================
         1 | td-1:6030                      |      1 |      8 | ready      | any   | 2022-01-18 02:47:42.871 |                          |
         2 | td-2:6030                      |      0 |      8 | ready      | any   | 2022-01-18 02:47:43.518 |                          |
         0 | arbitrator:6042                |      0 |      0 | ready      | arb   | 2022-01-18 02:47:43.633 | -                        |
   Query OK, 3 row(s) in set (0.000811s)

taosAdapter

1. taosAdapter is enabled by default in the TDengine container. If you want to disable it, specify the environment variable TAOS_DISABLE_ADAPTER=true at startup

2. At the same time, for flexible deployment, taosAdapter can be started in a separate container

   services:
     # ...
     adapter:
       image: tdengine/tdengine:$VERSION
       command: taosadapter

   Suppose you want to deploy multiple taosAdapters to improve throughput and provide high availability. In that case, the recommended configuration method uses a reverse proxy such as Nginx to offer a unified access entry. For specific configuration methods, please refer to the official documentation of Nginx. Here is an example:

   version: "3"
   networks:
     inter:
     api:
   services:
     arbitrator:
       image: tdengine/tdengine:$VERSION
       command: tarbitrator
       networks:
         - inter
     td-1:
       image: tdengine/tdengine:$VERSION
       networks:
         - inter
       environment:
         TAOS_FQDN: "td-1"
         TAOS_FIRST_EP: "td-1"
         TAOS_NUM_OF_MNODES: "2"
         TAOS_REPLICA: "2"
         TAOS_ARBITRATOR: arbitrator:6042
       volumes:
         - taosdata-td1:/var/lib/taos/
         - taoslog-td1:/var/log/taos/
     td-2:
       image: tdengine/tdengine:$VERSION
       networks:
         - inter
       environment:
         TAOS_FQDN: "td-2"
         TAOS_FIRST_EP: "td-1"
         TAOS_NUM_OF_MNODES: "2"
         TAOS_REPLICA: "2"
         TAOS_ARBITRATOR: arbitrator:6042
       volumes:
         - taosdata-td2:/var/lib/taos/
         - taoslog-td2:/var/log/taos/
     adapter:
       image: tdengine/tdengine:$VERSION
       command: taosadapter
       networks:
         - inter
       environment:
         TAOS_FIRST_EP: "td-1"
         TAOS_SECOND_EP: "td-2"
       deploy:
         replicas: 4
     nginx:
       image: nginx
       depends_on:
         - adapter
       networks:
         - inter
         - api
       ports:
         - 6041:6041
         - 6044:6044/udp
       command: [
           "sh",
           "-c",
           "while true;
           do curl -s http://adapter:6041/-/ping >/dev/null && break;
           done;
           printf 'server{listen 6041;location /{proxy_pass http://adapter:6041;}}'
           > /etc/nginx/conf.d/rest.conf;
           printf 'stream{server{listen 6044 udp;proxy_pass adapter:6044;}}'
           >> /etc/nginx/nginx.conf;cat /etc/nginx/nginx.conf;
           nginx -g 'daemon off;'",
         ]
   volumes:
     taosdata-td1:
     taoslog-td1:
     taosdata-td2:
     taoslog-td2:

Deploy with docker swarm

If you want to deploy a container-based TDengine cluster on multiple hosts, you can use docker swarm. First, to establish a docker swarm cluster on these hosts, please refer to the official docker documentation.

The docker-compose file can refer to the previous section. Here is the command to start TDengine with docker swarm:

$ VERSION=2.4.0 docker stack deploy -c docker-compose.yml taos
Creating network taos_inter
Creating network taos_api
Creating service taos_arbitrator
Creating service taos_td-1
Creating service taos_td-2
Creating service taos_adapter
Creating service taos_nginx

Checking status:

$ docker stack ps taos
ID                  NAME                IMAGE                     NODE                DESIRED STATE       CURRENT STATE                ERROR               PORTS
79ni8temw59n        taos_nginx.1        nginx:latest              TM1701     Running             Running about a minute ago
3e94u72msiyg        taos_adapter.1      tdengine/tdengine:2.4.0   TM1702     Running             Running 56 seconds ago
100amjkwzsc6        taos_td-2.1         tdengine/tdengine:2.4.0   TM1703     Running             Running about a minute ago
pkjehr2vvaaa        taos_td-1.1         tdengine/tdengine:2.4.0   TM1704     Running             Running 2 minutes ago
tpzvgpsr1qkt        taos_arbitrator.1   tdengine/tdengine:2.4.0   TM1705     Running             Running 2 minutes ago
rvss3g5yg6fa        taos_adapter.2      tdengine/tdengine:2.4.0   TM1706     Running             Running 56 seconds ago
i2augxamfllf        taos_adapter.3      tdengine/tdengine:2.4.0   TM1707     Running             Running 56 seconds ago
lmjyhzccpvpg        taos_adapter.4      tdengine/tdengine:2.4.0   TM1708     Running             Running 56 seconds ago
$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE                     PORTS
561t4lu6nfw6        taos_adapter        replicated          4/4                 tdengine/tdengine:2.4.0
3hk5ct3q90sm        taos_arbitrator     replicated          1/1                 tdengine/tdengine:2.4.0
d8qr52envqzu        taos_nginx          replicated          1/1                 nginx:latest              *:6041->6041/tcp, *:6044->6044/udp
2isssfvjk747        taos_td-1           replicated          1/1                 tdengine/tdengine:2.4.0
9pzw7u02ichv        taos_td-2           replicated          1/1                 tdengine/tdengine:2.4.0

From the above output, you can see two dnodes, two taosAdapters, and one Nginx reverse proxy service.

Next, we can reduce the number of taosAdapter services.

$ docker service scale taos_adapter=1
taos_adapter scaled to 1
overall progress: 1 out of 1 tasks
1/1: running   [==================================================>]
verify: Service converged
$ docker service ls -f name=taos_adapter
ID                  NAME                MODE                REPLICAS            IMAGE                     PORTS
561t4lu6nfw6        taos_adapter        replicated          1/1                 tdengine/tdengine:2.4.0