Mariadb on kubernetes Got an error reading communication packets - spring-boot

Question

I try to deploy an application with a mariadb database on my k8s cluster. This is the deployment i use:
apiVersion: v1
kind: Service
metadata:
name: app-back
labels:
app: app-back
namespace: dev
spec:
type: ClusterIP
ports:
- port: 8080
name: app-back
selector:
app: app-back
---
apiVersion: v1
kind: Service
metadata:
name: app-db
labels:
app: app-db
namespace: dev
spec:
type: ClusterIP
clusterIP: None
ports:
- port: 3306
name: app-db
selector:
app: app-db
---
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
labels:
app: mysql
data:
60-server.cnf: |
[mysqld]
bind-address = 0.0.0.0
skip-name-resolve
connect_timeout = 600
net_read_timeout = 600
net_write_timeout = 600
max_allowed_packet = 256M
default-time-zone = +00:00
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: app-db
namespace: dev
spec:
replicas: 1
strategy:
type: Recreate
selector:
matchLabels:
app: app-db
template:
metadata:
labels:
app: app-db
spec:
containers:
- name: app-db
image: mariadb:10.5.8
env:
- name: MYSQL_DATABASE
value: app
- name: MYSQL_USER
value: app
- name: MYSQL_PASSWORD
value: app
- name: MYSQL_RANDOM_ROOT_PASSWORD
value: "true"
ports:
- containerPort: 3306
name: app-db
resources:
requests:
memory: "200Mi"
cpu: "100m"
limits:
memory: "400Mi"
cpu: "200m"
volumeMounts:
- name: config-volume
mountPath: /etc/mysql/conf.d
volumes:
- name: config-volume
configMap:
name: mysql
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: app-back
namespace: dev
spec:
replicas: 1
strategy:
type: Recreate
selector:
matchLabels:
app: app-back
template:
metadata:
labels:
app: app-back
spec:
containers:
- name: app-back
image: private-repository/app/app-back:latest
env:
- name: spring.profiles.active
value: dev
- name: DB_HOST
value: app-db
- name: DB_PORT
value: "3306"
- name: DB_NAME
value: app
- name: DB_USER
value: app
- name: DB_PASSWORD
value: app
ports:
- containerPort: 8080
name: app-back
resources:
requests:
memory: "200Mi"
cpu: "100m"
limits:
memory: "200Mi"
cpu: "400m"
imagePullSecrets:
- name: docker-private-credentials
When i run this, the mariadb container log the following warning :
2020-12-03 8:23:41 28 [Warning] Aborted connection 28 to db: 'app' user: 'app' host: 'xxx.xxx.xxx.xxx' (Got an error reading communication packets)
2020-12-03 8:23:41 25 [Warning] Aborted connection 25 to db: 'app' user: 'app' host: 'xxx.xxx.xxx.xxx' (Got an error reading communication packets)
2020-12-03 8:23:41 31 [Warning] Aborted connection 31 to db: 'app' user: 'app' host: 'xxx.xxx.xxx.xxx' (Got an error reading communication packets)
2020-12-03 8:23:41 29 [Warning] Aborted connection 29 to db: 'app' user: 'app' host: 'xxx.xxx.xxx.xxx' (Got an error reading communication packets)
...
My app is stuck on trying to connect to the database. The application is a Sprinbboot application build with this dockerfile:
FROM maven:3-adoptopenjdk-8 AS builder
WORKDIR /usr/src/mymaven/
COPY . .
RUN mvn clean package -e -s settings.xml -DskipTests
FROM tomcat:9-jdk8-adoptopenjdk-hotspot
ENV spring.profiles.active=dev
ENV DB_HOST=localhost
ENV DB_PORT=3306
ENV DB_NAME=app
ENV DB_USER=app
ENV DB_PASSWORD=app
COPY --from=builder /usr/src/mymaven/target/app.war /usr/local/tomcat/webapps/
Any idea?

Answer 1

Ok, i found the solution. This was not an error of mariadb. This is due to apache that break the connection if running inside a container with to low memory. Set memory limit to 1500Mi solved the problem.