homework-jianmu/docs/en/10-deployment/05-helm.md

---
title: Use Helm to deploy TDengine
sidebar_label: Helm
description: This document describes how to deploy TDengine on Kubernetes by using Helm.
---

Helm is a package manager for Kubernetes that can provide more capabilities in deploying on Kubernetes.

## Install Helm

```bash
curl -fsSL -o get_helm.sh \
  https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3
chmod +x get_helm.sh
./get_helm.sh

```

Helm uses the kubectl and kubeconfig configurations to perform Kubernetes operations. For more information, see the Rancher configuration for Kubernetes installation.

## Install TDengine Chart

To use TDengine Chart, download it from GitHub:

```bash
wget https://github.com/taosdata/TDengine-Operator/raw/3.0/helm/tdengine-3.0.2.tgz

```

Query the storageclass of your Kubernetes deployment:

```bash
kubectl get storageclass

```

With minikube, the default value is standard.

Use Helm commands to install TDengine:

```bash
helm install tdengine tdengine-3.0.2.tgz \
  --set storage.className=<your storage class name>

```

You can configure a small storage size in minikube to ensure that your deployment does not exceed your available disk space.

```bash
helm install tdengine tdengine-3.0.2.tgz \
  --set storage.className=standard \
  --set storage.dataSize=2Gi \
  --set storage.logSize=10Mi

```

After TDengine is deployed, TDengine Chart outputs information about how to use TDengine:

```bash
export POD_NAME=$(kubectl get pods --namespace default \
  -l "app.kubernetes.io/name=tdengine,app.kubernetes.io/instance=tdengine" \
  -o jsonpath="{.items[0].metadata.name}")
kubectl --namespace default exec $POD_NAME -- taos -s "show dnodes; show mnodes"
kubectl --namespace default exec -it $POD_NAME -- taos

```

You can test the deployment by creating a table:

```bash
kubectl --namespace default exec $POD_NAME -- \
  taos -s "create database test;
    use test;
    create table t1 (ts timestamp, n int);
    insert into t1 values(now, 1)(now + 1s, 2);
    select * from t1;"

```

## Configuring Values

You can configure custom parameters in TDengine with the `values.yaml` file.

Run the `helm show values` command to see all parameters supported by TDengine Chart.

```bash
helm show values tdengine-3.0.2.tgz

```

Save the output of this command as `values.yaml`. Then you can modify this file with your desired values and use it to deploy a TDengine cluster:

```bash
helm install tdengine tdengine-3.0.2.tgz -f values.yaml

```

The parameters are described as follows:

```yaml
# Default values for tdengine.
# This is a YAML-formatted file.
# Declare variables to be passed into helm templates.

replicaCount: 1

image:
  prefix: tdengine/tdengine
  #pullPolicy: Always
  # Overrides the image tag whose default is the chart appVersion.
#  tag: "3.0.2.0"

service:
  # ClusterIP is the default service type, use NodeIP only if you know what you are doing.
  type: ClusterIP
  ports:
    # TCP range required
    tcp: [6030, 6041, 6042, 6043, 6044, 6046, 6047, 6048, 6049, 6060]
    # UDP range
    udp: [6044, 6045]


# Set timezone here, not in taoscfg
timezone: "Asia/Shanghai"

resources:
  # We usually recommend not to specify default resources and to leave this as a conscious
  # choice for the user. This also increases chances charts run on environments with little
  # resources, such as Minikube. If you do want to specify resources, uncomment the following
  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
  # limits:
  #   cpu: 100m
  #   memory: 128Mi
  # requests:
  #   cpu: 100m
  #   memory: 128Mi

storage:
  # Set storageClassName for pvc. K8s use default storage class if not set.
  #
  className: ""
  dataSize: "100Gi"
  logSize: "10Gi"

nodeSelectors:
  taosd:
    # node selectors

clusterDomainSuffix: ""
# Config settings in taos.cfg file.
#
# The helm/k8s support will use environment variables for taos.cfg,
# converting an upper-snake-cased variable like `TAOS_DEBUG_FLAG`,
# to a camelCase taos config variable `debugFlag`.
#
# See the [Configuration Variables](../../reference/config)
#
# Note:
# 1. firstEp/secondEp: should not be set here, it's auto generated at scale-up.
# 2. serverPort: should not be set, we'll use the default 6030 in many places.
# 3. fqdn: will be auto generated in kubernetes, user should not care about it.
# 4. role: currently role is not supported - every node is able to be mnode and vnode.
#
# Btw, keep quotes "" around the value like below, even the value will be number or not.
taoscfg:
  # Starts as cluster or not, must be 0 or 1.
  #   0: all pods will start as a separate TDengine server
  #   1: pods will start as TDengine server cluster. [default]
  CLUSTER: "1"

  # number of replications, for cluster only
  TAOS_REPLICA: "1"

  #
  # TAOS_NUM_OF_RPC_THREADS: number of threads for RPC
  #TAOS_NUM_OF_RPC_THREADS: "2"


  #
  # TAOS_NUM_OF_COMMIT_THREADS: number of threads to commit cache data
  #TAOS_NUM_OF_COMMIT_THREADS: "4"

  # enable/disable installation / usage report
  #TAOS_TELEMETRY_REPORTING: "1"

  # time interval of system monitor, seconds
  #TAOS_MONITOR_INTERVAL: "30"

  # time interval of dnode status reporting to mnode, seconds, for cluster only
  #TAOS_STATUS_INTERVAL: "1"

  # time interval of heart beat from shell to dnode, seconds
  #TAOS_SHELL_ACTIVITY_TIMER: "3"

  # minimum sliding window time, milli-second
  #TAOS_MIN_SLIDING_TIME: "10"

  # minimum time window, milli-second
  #TAOS_MIN_INTERVAL_TIME: "1"

  # the compressed rpc message, option:
  #  -1 (no compression)
  #   0 (all message compressed),
  # > 0 (rpc message body which larger than this value will be compressed)
  #TAOS_COMPRESS_MSG_SIZE: "-1"

  # max number of connections allowed in dnode
  #TAOS_MAX_SHELL_CONNS: "50000"

  # stop writing logs when the disk size of the log folder is less than this value
  #TAOS_MINIMAL_LOG_DIR_G_B: "0.1"

  # stop writing temporary files when the disk size of the tmp folder is less than this value
  #TAOS_MINIMAL_TMP_DIR_G_B: "0.1"

  # if disk free space is less than this value, taosd service exit directly within startup process
  #TAOS_MINIMAL_DATA_DIR_G_B: "0.1"

  # One mnode is equal to the number of vnode consumed
  #TAOS_MNODE_EQUAL_VNODE_NUM: "4"

  # enbale/disable http service
  #TAOS_HTTP: "1"

  # enable/disable system monitor
  #TAOS_MONITOR: "1"

  # enable/disable async log
  #TAOS_ASYNC_LOG: "1"

  #
  # time of keeping log files, days
  #TAOS_LOG_KEEP_DAYS: "0"

  # The following parameters are used for debug purpose only.
  # debugFlag 8 bits mask: FILE-SCREEN-UNUSED-HeartBeat-DUMP-TRACE_WARN-ERROR
  # 131: output warning and error
  # 135: output debug, warning and error
  # 143: output trace, debug, warning and error to log
  # 199: output debug, warning and error to both screen and file
  # 207: output trace, debug, warning and error to both screen and file
  #
  # debug flag for all log type, take effect when non-zero value\
  #TAOS_DEBUG_FLAG: "143"

  # generate core file when service crash
  #TAOS_ENABLE_CORE_FILE: "1"
```

## Scaling Out

For information about scaling out your deployment, see Kubernetes. Additional Helm-specific is described as follows.

First, obtain the name of the StatefulSet service for your deployment.

```bash
export STS_NAME=$(kubectl get statefulset \
  -l "app.kubernetes.io/name=tdengine" \
  -o jsonpath="{.items[0].metadata.name}")

```

You can scale out your deployment by adding replicas. The following command scales a deployment to three nodes:

```bash
kubectl scale --replicas 3 statefulset/$STS_NAME

```

Run the `show dnodes` and `show mnodes` commands to check whether the scale-out was successful.

## Scaling In

:::warning
Exercise caution when scaling in a cluster.

:::

Determine which dnodes you want to remove and drop them manually.

```bash
kubectl --namespace default exec $POD_NAME -- \
  cat /var/lib/taos/dnode/dnodeEps.json \
  | jq '.dnodeInfos[1:] |map(.dnodeFqdn + ":" + (.dnodePort|tostring)) | .[]' -r
kubectl --namespace default exec $POD_NAME -- taos -s "show dnodes"
kubectl --namespace default exec $POD_NAME -- taos -s 'drop dnode "<you dnode in list>"'

```

## Remove a TDengine Cluster

You can use Helm to remove your cluster:

```bash
helm uninstall tdengine

```

However, Helm does not remove PVCs automatically. After you remove your cluster, manually remove all PVCs.