[Reservation program] Solving issues that arose while creating

I wrote this because I thought I should organize the issues I wanted to remember among the issues that arose while creating a reservation program.

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1. action 'action-8-builtin:omfile' suspended (module 'builtin:omfile'), retry 0. there should be messages before this one giving the reason for suspension. [v8.2001.0 try https://www.rsyslog.com/e/2007 ]

A yellow warning message with action-numbers appeared and the distribution site did not open properly. I checked the text with journal -r in Putty, and the problem occurred when I entered the url. Thinking that there was a problem with the execution itself, I searched and found out that it was caused by differences in the installation and version of rsyslog.

Since I am using Ubuntu in this project, I installed rsyslog by entering the command below and the warning message did not occur again!

sudo add-apt-repository ppa:adiscon/v8-stable
sudo apt-get update
sudo apt-get install rsyslog

Helpful Site https://ubuntuforums.org/showthread.php?t=2395258

https://www.rsyslog.com/ubuntu-repository/

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2. HibernateException : Access to DialectResolutionInfo cannot be nulll when 'hibernate.dialect' not set

This error occurred due to failure to connect to MariaDB. This occurred when application.properties settings were incorrect. In this case, it occurred because spring.datasource.url was deployed using localhost, the development environment, during deployment.

Please note that when deploying, the DB url setting must be connected to the RDS endpoint of the deployment environment. (Because this project used AWS RDS MariaDB)

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3. Unhealthy Issues in Target Groups

The https connection deployment with ALB was completed and running well, but in AWS Target Group, it was displayed as unhealty.

AWS defines ALB's role as a load balancer as providing advanced routing and visibility capabilities targeting application architectures, including microservices and containers, at the request level. In other words, it is in a position to check Internet requests and communication with the server.

Because traffic is sent to the target group regardless of whether or not the health is checked, the project can be seen running well even if it is unhealed.

Still, I felt uncomfortable, so I re-issued ACM and re-configured the hosting zone in Route53, and the problem was resolved. Perhaps there was a problem with the record settings used by ACM for verification purposes.

Sites that helped

https://kim-dragon.tistory.com/121

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4. error: kex_exchange_identification: banner line contains invalid characters error: kex_exchange_identification: Connection closed by remote host

This is an error encountered in Putty after confirming that the RDS connection is established in intelliJ. Here, key_exchange_identification is an error that occurred due to interruption of the socket connection between the client and the server.

According to stackoverflow, I found out that an ssh error occurred when connecting to https instead of sshd, and I solved it by changing the port settings.

Helpful Site https://stackoverflow.com/questions/66685456/cannot-ssh-my-ubuntu-server-kex-exchange-identification-banner-line-contains

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5. java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException

This was a problem I also saw during previous projects.

In IntelliJ, I ran the first option, Clear file system cache and Local History, in File > Invalidate Cashes. A new distribution was carried out, but the problem was the same. As it turned out, the problem was caused by the directory previously deployed in the webapps file not being properly deleted. It was not deleted even when using Filezila, so I deleted it myself using putty.

rm -r ./디렉토리명

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