Distributing PostgreSQL on Amazon Elastic Kubernetes

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After attending the Global AWS Heroes Summit in Seattle, I’m traveling though US and going to present and demonstrate YugabyteDB to the following locations:

I would be glad to meet you in those locations, and I can share the slides with you afterward. I will also do a live demonstration of YugabyteDB’s elasticity and resilience using a great platform for a cloud-native database: Amazon Elastic Kubernetes Service (Amazon EKS). Here is what I will most likely present during the demonstration.

I’ll create an Amazon EKS cluster using the eksctl command-line tool. I’ll configure the cluster with specific node types, sizes, and regions, and then update my .kube/config to manage the cluster using kubectl.

eksctl create cluster --name yb-demo1 --tags eks=yb-demo1 \ --version 1.27 \ --node-type c5.2xlarge --nodes 4 --nodes-min 0 --nodes-max 4 \ --region eu-west-1 --zones eu-west-1a,eu-west-1b,eu-west-1c \ --nodegroup-name standard-workers --managed --dumpLogs aws eks update-kubeconfig --region eu-west-1 --name yb-demo1
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I’ll set up a single-region highly available YugabyteDB cluster on Amazon EKS. I’ll automate the creation of storage classes and StatefulSets for each availability zone within a specified region, eu-west-1, ensuring the proper configuration of multi-AZ deployments. This process involves generating necessary Kubernetes manifests, applying them, and using Helm to deploy the YugabyteDB database.

cd
region=eu-west-1
masters=$(for az in {a..c} ; do echo "yb-master-0.yb-masters.yb-demo-${region}${az}.svc.cluster.local:7100" ; done | paste -sd,)
placement=$(for az in {a..c} ; do echo "aws.${region}.${region}${az}" ; done | paste -sd,)
echo
echo "$masters"
echo "$region"
echo "$placement" # create per-AZ StorageClass and StatefulSet
{
for az in {a..c} ; do { cat <<CAT
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata: name: standard-${region}${az}
provisioner: kubernetes.io/aws-ebs
parameters: type: gp2 zone: ${region}${az}
CAT
} > ${region}${az}.storageclass.yaml
echo "kubectl apply -f ${region}${az}.storageclass.yaml" { cat <<CAT
isMultiAz: True
AZ: ${region}${az}
masterAddresses: "$masters"
storage: ephemeral: true master: storageClass: "standard-${region}${az}" tserver: storageClass: "standard-${region}${az}"
replicas: master: 1 tserver: 2 totalMasters: 3
resource: master: requests: cpu: 0.5 memory: 1Gi tserver: requests: cpu: 1 memory: 2Gi
gflags: master: placement_cloud: "aws" placement_region: "${region}" placement_zone: "${region}${az}" ysql_num_shards_per_tserver: 2 tserver_unresponsive_timeout_ms: 10000 hide_dead_node_threshold_mins: 900 tserver: placement_cloud: "aws" placement_region: "${region}" placement_zone: "${region}${az}" ysql_num_shards_per_tserver: 2 ysql_enable_auth: true yb_enable_read_committed_isolation: true ysql_suppress_unsafe_alter_notice: true ysql_beta_features: true allowed_preview_flags_csv: ysql_yb_ash_enable_infra,ysql_yb_enable_ash ysql_yb_ash_enable_infra: true ysql_yb_enable_ash: true
CAT
} > ${region}${az}.overrides.yaml
echo "kubectl create namespace yb-demo-${region}${az}" echo "helm install yb-demo yugabytedb/yugabyte --namespace yb-demo-${region}${az} -f ${region}${az}.overrides.yaml --wait \$* ; sleep 5" done echo "kubectl exec -it -n yb-demo-${region}a yb-master-0 -- yb-admin --master_addresses $masters modify_placement_info $placement 3" } | tee yb-demo-install.sh
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This has generated the install script. I’ll start by adding the YugabyteDB Helm repository and updating it, then proceed to deploy YugabyteDB using the script.

# install yugabyte Helm chart
helm repo add yugabytedb https://charts.yugabyte.com
helm repo update
helm search repo yugabytedb/yugabyte | cut -c-75 export PATH="$HOME/cloud/aws-cli:$PATH" . yb-demo-install.sh
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I’ll share the internal web console, which is open to the public web, with the attendees. This will allow them to view the deployment, tables, and perform read/write operations on their own. Here’s how I generate a QR code for the URL of this UI service:

for i in 0 ; do echo $(kubectl get svc -n yb-demo-eu-west-1a --field-selector "metadata.name=yb-master-ui" -o jsonpath='http://{.items['$i'].status.loadBalancer.ingress[0].hostname}:{.items[0].spec.ports[?(@.name=="http-ui")].port}') ; done | while read url ; do echo "yb-master-ui $i" ; qrencode -t ANSIUTF8 -s 1 -m 0 "$url" ; echo "$url" ; done
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PgBench

I’ll use kubectl to start a PostgreSQL pod in eu-west-1a, set the necessary environment variables to connect to the load balancer in this availability zone, and execute the pgbench tool to create the tables with primary and foreign keys. Then I fill the table with scale 150 and YugabyteDB non-transactional writes for faster bulk load.

kubectl -n yb-demo-eu-west-1a run -it eu-west-1a --image=postgres:17beta2 --rm=true bash export PGPASSWORD=yugabyte PGUSER=yugabyte PGDATABASE=yugabyte PGPORT=5433 PGHOST=yb-tservers pgbench -iIdtpf PGOPTIONS="-c yb_disable_transactional_writes=on -c yb_default_copy_from_rows_per_transaction=0" pgbench -iIg --scale 150
psql -c "select tablename, pg_size_pretty(pg_table_size(tablename::regclass)) from pg_tables where schemaname='public'"
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I’ll run the Simple Update benchmark from 20 clients.


pgbench --client 20 -nN --progress 5 --max-tries 10 -T 3600
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Elasticity

To demonstrate how we can scale without downtime, I’ll double the number of tablet servers in each availability zone by simply scaling the StatefulSets:

kubectl scale -n yb-demo-eu-west-1a statefulset yb-tserver --replicas=4
kubectl scale -n yb-demo-eu-west-1b statefulset yb-tserver --replicas=4
kubectl scale -n yb-demo-eu-west-1c statefulset yb-tserver --replicas=4
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The PgBench application will continue to run, and the throughput will increase. However, because PgBench runs with a static set of connections initiated when starting it, it will not fully benefit from all nodes and only the reads and writes will be rebalanced. Restarting PgBench will also balance the connections to the new nodes and the throughput will double. Of course, with a connection pool, you wouldn’t need to restart it.

Resilience

To demonstrate resilience to failure, one node can be removed by scaling down one StatefulSet. I will even scale down an AZ to zero to simulate a zone failure:

kubectl scale -n yb-demo-eu-west-1c statefulset yb-tserver --replicas=3
kubectl scale -n yb-demo-eu-west-1c statefulset yb-tserver --replicas=0
kubectl scale -n yb-demo-eu-west-1c statefulset yb-tserver --replicas=4
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The PgBench application should continue without any errors. The only consequence of the failure is a few seconds of decreased throughput due to various TCP/IP timeouts for connections to the failed nodes.

Cleanup

You can play as you want with such lab. Don’t forget to terminate the EKS cluster:

aws cloudformation delete-stack --stack-name eksctl-yb-demo1 aws cloudformation delete-stack --stack-name eksctl-yb-demo1-cluster
aws cloudformation delete-stack --stack-name eksctl-yb-demo1-nodegroup-standard-workers
eksctl delete cluster --region=eu-west-1 --name=yb-demo1
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At those locations, I won’t be presenting alone. Colleagues from YugabyteDB, AWS partners, and Snowflake and Striim speakers will also be presenting. It will be an excellent opportunity to network, learn, and share.

Join us at a city near you for an evening of tech talks, show-and-tell sessions, and demos accompanied by food, drinks, prizes, and giveaways

info.yugabyte.com

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