Hibernate Oracle sessions not be closed correctly
We got escalation today, a lot of services are very slow or stop working. Our Oracle database(10g) admin has found that there are a huge number of unclosed sessions in the Oracle database. In...
Category: Java Architecture
Liveness and Readiness Probes with Spring Boot – for k8s
In Kubernetes, the Liveness and Readiness Kubernetes concepts represent facets of the application state. The Liveness state of an application tells whether the internal state is valid. If Liveness is broken, this means that the application...
How to do JVM performance analysis in docker container?
1. Prerequisite Java application with docker based on JDK 8 and alpine. This app is a Jhipster application. Dockerfile:
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FROM openjdk:8-jre-alpine ENV SPRING_OUTPUT_ANSI_ENABLED=ALWAYS \ JHIPSTER_SLEEP=0 \ JAVA_OPTS="" # Add a jhipster user to run our application so that it doesn't need to run as root RUN adduser -D -s /bin/sh jhipster WORKDIR /home/jhipster ADD entrypoint.sh entrypoint.sh RUN chmod 755 entrypoint.sh && chown jhipster:jhipster entrypoint.sh USER jhipster ENTRYPOINT ["./entrypoint.sh"] EXPOSE 18082 5701/udp ADD *.jar app.jar |
entrypoint.sh
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#!/bin/sh echo "The application will start in ${JHIPSTER_SLEEP}s..." && sleep ${JHIPSTER_SLEEP} exec java ${JAVA_OPTS} -Djava.security.egd=file:/dev/./urandom -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=5005,suspend=n -jar "${HOME}/app.jar" "$@" |
2. Precheck Enter container to check the process. Of course, we...
Hibernate second-level cache stops all database operation
The customer reported today that one of our services stopped working, the new coming data can not be saved into the database. After checking the logs, there are a lot of “Hazelcast instance is...
Disable Logback log files in containers
We found the spring boot project running containers will keep restarting after some time, maybe 10 days, maybe 5 days. The root cause is spring logback is writing log files into /tmp/ directory as...
Be careful, when you are using CrudReporsitory.save() in JPA
in some JPA project, CrudReporsitory.save() is used this way:
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repository.save(oldtEntity) |
sometime the oldEntity will be set with new properties, but sometimes you will find that the new assigned ID has not been set to...
The message is xxx bytes when serialized which is larger than the maximum request size you have configured with the max.request.size configuration.
org.apache.kafka.common.errors.RecordTooLargeException: The message is xxxx bytes when serialized which is larger than the maximum request size you have configured with the max.request.size configuration. How to fix this when you are using confluent Kafka docker....
OAuth 2 Password Credentials&Client Credentials
In microservices, the front service should use the Authorization Code(Grant Type) to let users log in with the web browser, and other services in the background should use Client Credentials(Grant Type).
Nested Transaction Implementation
There are two classes OrderService and OrderRepository, OrderRepository will be called inside of OrderService. OrderRepository inserts one record of order into the database. My Purpose: When an exception happens in OrderRepository or OrderService, the transaction will rollback and...
