Deploying MySQL and MongoDB in Kubernetes

Alexander RubinPercona

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About me

● Working with MySQL for 10-15 years○ Started at MySQL AB, Sun Microsystems, Oracle

(MySQL Consulting)○ Joined Percona in 2013

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What is Kubernetes?

Container orchestration system/* Operating system */

* Kubernetes is an open source system for managing containerized applications across multiple hosts

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Container orchestration

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Container Orchestration in Barcelona

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Why ?

Deployment, Deployment, Deployment!○ Challenge: how to deploy massively scaled application○ Or databases: how do you deploy 100 nodes clustering system

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Kubernetes Implementations

●●●●●●●

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Let’s look under the hood

●●●●●

○

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Databases in Containers: Challenges

1. Preserving state2. Setup as cluster/replication

●○○

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Why for databases?

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MySQL In Kubernetes

● A single instance is easy○ https://kubernetes.io/docs/tasks/run-application/run-single-instance-stateful-appli

cation/

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A complex setup is … more complex

● High Availability● Persistent Storage● Backup and recovery● Traffic routing● Monitoring

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Replication

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Replication Options

● Traditional MySQL replication● Group Replication● Percona XtraDB Cluster

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Traditional Replication challenges

● No automatic failover○ New master detection can be quite complicated

● No automatic slave setup

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Group Replication

● Not mature enough● Still no automatic slave setup

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What is Percona XtraDB Cluster (PXC)?

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Why PXC? Auto provisioning...

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PXC: Data transfer

Storage

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Storage options

● Local storage○ Can be fast (SSD, NVMe options)○ Still limited management capabilities in Kubernetes

● Network storage○ Management and Flexibility if supported by your setup

■ Supported by major cloud providers○ On-premise setup may require Ceph or SAN

○ The dynamic provision of persistent volumes is required

Traffic routing

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Traffic routing

● ProxySQL○ High-performance MySQL proxy○ Query Routing○ Supports Failover

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What is ProxySQL?

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ProxySQL read/write split

Query routing is one of the core features of ProxySQL.

Read/write split is perhaps one of the most common query routing use

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ProxySQL read-write split

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PXC + ProxySQL on Kubernetes / Openshift

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Monitoring

● Percona MonitoringAnd Management

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Percona Labs - MySQL for Kubernetes

https://github.com/Percona-Lab/percona-openshift $ git clone git@github.com:Percona-Lab/percona-openshift.git

Deployment options

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Deployment options

● Manual● Helm Charts● Operator

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Manual

● Manual juggling multiple YAML files

● Cumbersome and error-prone● Practically not feasible for a complicated setup● Deployment logic and configuration parameters are mixed together

backup-volume.yamlmysql-configmap.yamlproxysql-pxc.yamlpxc.yamlsecret.yamlxtrabackup-job.yaml

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Helm Charts

Helm - The package manager for Kubernetes● Separate configuration from logic

To continue “Kubernetes is an Operating System” analogy - Helm chart is like RPM/DEB packages

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Operator

● Method of packaging, deploying and managing a Kubernetes application

● The most advanced way of the deployment● Requires software engineering efforts

● A way to think about “Operator” is it’s goal is to replace a human in typical operations

● Assumes a high degree of automation

41* image: RedHat OpenShift documentation

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Demo: Let’s start our PXC cluster

$ helm install --name cluster1 . -f values.yaml

Will start: ● 3 nodes of Percona XtraDB Cluster, each with PMM Client● ProxySQL instance

Configure ProxySQL to route traffic

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$ kubectl get pods NAME READY STATUS RESTARTS AGE cluster1-node-0 2/2 Running 0 5m cluster1-node-1 2/2 Running 0 4m cluster1-node-2 2/2 Running 0 2m cluster1-proxysql-0 2/2 Running 0 5m monitoring-0 1/1 Running 0 16m

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Let’s take a minute here

With a single command we● Started multiple MySQL nodes (and Kubernetes will handle a node

failure)● Started and configured ProxySQL● Added all nodes under PMM Server

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What’s so big deal about it?

● One can do it with reasonably simple Ansible playbooks?

Kubernetes is Cloud-agnostic; provides an uniform API; “write once - run anywhere” approach

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Demo / Howto - pods

$ kubectl get pods

NAME READY STATUS RESTARTS cluster1-proxysql-0 2/2 Running 0

cluster1-node-0 2/2 Running 0

cluster1-node-1 2/2 Running 0

cluster1-node-2 2/2 Running 0

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Demo / Howto

$ kubectl get services

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S)

cluster1-proxysql ClusterIP 10.11.251.66 <none> 3306/TCP,6032/TCP

MySQL Port(for app) Proxy Admin Port

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ProxySQL Admin Configuration

kubectl exec cluster1-proxysql-0 -it -- mysql -uadmin -padmin -h127.0.0.1 -P6032

mysql> select * from mysql_servers;+--------------+-----------+------+--------+---------+-------------+-----------------+----+---------+| hostgroup_id | hostname | port | status | weight | compression | max_connections | .. | comment |+--------------+-----------+------+--------+---------+-------------+-----------------+----+---------+| 10 | 10.8.2.10 | 3306 | ONLINE | 1000000 | 0 | 1000 | .. | WRITE || 11 | 10.8.1.6 | 3306 | ONLINE | 1000 | 0 | 1000 | .. | READ || 11 | 10.8.0.10 | 3306 | ONLINE | 1000 | 0 | 1000 | .. | READ |+--------------+-----------+------+--------+---------+-------------+-----------------+----+---------+

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Let’s kill one pod…

NAME READY STATUS RESTARTS AGE

cluster1-node-0 0/2 Terminating 0 41m

cluster1-node-1 2/2 Running 0 41m

cluster1-node-2 2/2 Running 0 40m

cluster1-proxysql-0 2/2 Running 0 41m

monitoring-0 1/1 Running 0 35m

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Kubernetes will restart it

mysql> select * from mysql_servers;+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+| hostgroup_id | hostname | port | status | weight | compression | max_connections | comment |+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+| 11 | 10.8.2.10 | 3306 | OFFLINE_HARD | 1000 | 0 | 1000 | READ || 11 | 10.8.1.6 | 3306 | ONLINE | 1000 | 0 | 1000 | READ || 10 | 10.8.0.10 | 3306 | ONLINE | 1000000 | 0 | 1000 | WRITE || 11 | 10.8.2.12 | 3306 | ONLINE | 1000 | 0 | 1000 | READ |+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+

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Let’s scale it up

kubectl scale --replicas=4 statefulset/cluster1-node

statefulset "cluster1-node" scaled

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mysql> select * from mysql_servers;+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+| hostgroup_id | hostname | port | status | weight | compression | max_connections | comment |+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+| 11 | 10.8.2.10 | 3306 | OFFLINE_HARD | 1000 | 0 | 1000 | READ || 11 | 10.8.1.6 | 3306 | ONLINE | 1000 | 0 | 1000 | READ || 10 | 10.8.0.10 | 3306 | ONLINE | 1000000 | 0 | 1000 | WRITE || 11 | 10.8.2.12 | 3306 | ONLINE | 1000 | 0 | 1000 | READ || 11 | 10.8.1.7 | 3306 | ONLINE | 1000 | 0 | 1000 | READ |+--------------+-----------+------+--------------+---------+-------------+-----------------+---------+

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DemoFailover

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The Road Ahead

● Operators● Encryptions

○ At Rest○ End-to-end

● Key Management

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Additional resources

● Oracle’s MySQL Operator (Alpha quality) https://github.com/oracle/mysql-operator

● Presslab’s Operatorhttps://github.com/presslabs/mysql-operator

● MariaDB Helm https://github.com/mariadb-corporation/mariadb-kubernetes

● GRTL MySQL Operator https://github.com/grtl/mysql-operator

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Helm for MongoDB

https://github.com/Percona-Lab/percona-server-mongodb-openshift/tree/master/helm/mongodb-replicaset

Install Helm in OpenShiftFor the details see https://blog.openshift.com/getting-started-helm-openshift/

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Operator

MongoDB server: Operator

https://github.com/Percona-Lab/percona-server-mongodb-operator

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Conclusion

● Openshift provides easy deployment for MySQL (Percona XtraDB Cluster)○ Great for deployment and testing

● ProxySQL provides the cluster endpoint○ Implements read-write split

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Thank you!

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Thank You Sponsors!!