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timescaledb-multinode

README.md

TimescaleDB Multinode

This directory contains a Helm chart to deploy a multinode TimescaleDB cluster. This chart will do the following:

  • Creates a single TimescaleDB Access Node using a Kubernetes StatefulSet.
  • Creates multiple pods (by default 3) containing Data Nodes using another Kubernetes StatefulSet
  • Each pod has a container created using a Docker image which includes the TimescaleDB multinode sources

When deploying on AWS EKS:

  • An AWS Elastic Load Balancer (ELB) is configured to handle routing incoming traffic to the Access Node.

Installing

To install the chart as a release and name it my-release:

helm upgrade --install my-release .

You can override parameters using the --set key=value[,key=value] argument to helm upgrade --install, e.g., to install the chart with randomly generated passwords:

random_password () { < /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c32; }
helm upgrade --install my-release . \
    --set credentials.accessNode.superuser="$(random_password)"

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

helm upgrade --install my-release -f myvalues.yaml .

For details about what parameters you can set, have a look at the Administrator Guide

Using a local image

During development, it is practical to be able to use a locally built image of TimescaleDB multinode without having to push it to a registry. This can be done as follows:

# Setup the environment to use Minikube's Docker daemon
eval $(minikube docker-env)

# Build a new image (this requires being in the TimescaleDB source directory):
IMAGE_NAME=mytsdb TAG_NAME=build-1 ../scripts/docker-build.sh

If you don't specify an image name and tag name, like above, make note of the name and the tag of the new image that gets built. Then launch multinode TimescaleDB using the new image:

helm upgrade --install my-release --set image.repository=mytsdb --set image.tag=build-1 .

Connecting to TimescaleDBs

Once the multinode deployment of TimescaleDB is running, you can connect to the access node:

kubectl exec -it my-release-timescaledb-access-0 -- psql -U postgres

Connecting from outside Kubernetes

If you want to connect directly to the access node, without going through Kubernetes, you need to know the host (and port) to connect to. Use kubectl to get that information:

kubectl get service/my-release-timescaledb
NAME                             TYPE           CLUSTER-IP      EXTERNAL-IP                PORT(S)          AGE
service/my-release-timescaledb   LoadBalancer   10.100.157.80   verylongname.example.com   5432:32641/TCP   79s

Using the External IP for the service (which will route through the LoadBalancer to the Access Node), you can connect via psql using the following (default example superuser password is tea)

psql -h verylongname.example.com -U postgres
Password for user postgres:
postgres=#

From here, you can start creating users and databases, for example, using the above psql session:

CREATE USER example WITH PASSWORD 'thisIsInsecure';
CREATE DATABASE example OWNER example;

Connect to the example database with the example user:

psql -h verylongname.example.com -U example -d example

This should get you into the example database, from here on you can follow our TimescaleDB > Tutorial: Scaling out TimescaleDB to create distributed hypertables and start using multinode TimescaleDB.

Connecting from another pod

From inside a pod in the Kubernetes cluster, you need to use the internal DNS address, e.g., my-release-timescaledb.default.svc.cluster.local. For instance, let's run a new pod where we can run the PostgreSQL client:

kubectl run -i --tty --rm psql --image=postgres --restart=Never -- bash -il

Then from within the Pod, connect to the access node:

$ psql -U postgres -h my-release-timescaledb.default.svc.cluster.local postgres

provide the password tea followed by "Enter".

Cleanup

To remove the spawned pods you can run a simple

helm delete my-release --purge

Some items, (pvc's for example) are not immediately removed. To also purge these items, have a look at the Administrator Guide

Further reading