HikariPool-1 - Failed to validate connection com.mysql.cj.jdbc.ConnectionImpl - mariadb

Using azure db server but getting this error continuously in spring boot application running in a pod in Azure Kuberenetes Service. Not able to solve it.

It is happen long time inactive of database server. Restart the DB server.

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Why is EF losing it's connection details on aws lambda startup

We have an API using entity framework, this is running in AWS lambda on the public.ecr.aws/lambda/dotnet:5.0 image. We are having an issue with it making a connection to a remote server on an internal network. If I test the setup on an EC2 windows server then it runs fine, but on the lambda function it is returning the following errors:
[Debug] Microsoft.EntityFrameworkCore.Database.Connection: Opening connection to database 'DatabaseXYZ' on server '10.0.10.30'.
[Debug] Microsoft.EntityFrameworkCore.Infrastructure: 'EFDbContext' disposed.
[Error] Microsoft.EntityFrameworkCore.Database.Connection: An error occurred using the connection to database '' on server ''.
We can't work out why we are getting this error. It is a very similar setup to our other dotnet apps running on lambda which use RDS databases, the only difference is that this DB is running on-prem via a VPN - as mentioned above the API works if we load it on a EC2 instance but we want to use this on Lambda - and need to understand why the issue is occurring.
The lambda is also setup in the vpc on private subnets.
As a test I ran this code as an image in Lambda and was able to connect and query just fine.

Shiny - My Redshift Database Won't Connect Once Published

My Shiny application connects to my Redshift instance locally, but I get the following error when I try to run the application once I publish it to shinyapps.io
Warning: Error in connection_create: could not connect to server:
Connection timed out
Is the server running on host "redshift.bi.tmmp.io" (23.23.70.97)
and accepting TCP/IP connections on port 5439?
How would I allow connection to pass once published online?
A time-out normally indicates that the application could not connect to the server (as opposed to the server rejecting the connection).
You should start by checking the Security Group associated with the Redshift instance to confirm that it will accept incoming connections from the application.
The best configuration is:
A Security Group on your application instance (App-SG), which is associated with the application instance(s)
A Security Group on the Redshift instance (DB-SG) that permits inbound Redshift (port 5439) connections from App-SG, which is associated with the Redshift instance
That is, the Redshift security group refers to the application security group.

Restarting MariaDB Services on Swisscom Cloud

I have some issues connecting to the db since I have reached the max_user_connections limit, it would be possibile to restart the service or to reset all the connection from web console or cli?
See KILL CONNECTION in the manual: https://dev.mysql.com/doc/refman/5.6/en/kill.html

Azure Scheduler Job: SendFailure The underlying connection was closed

I have created Scheduler Job in Azure using HTTPS action to periodically ping ASP.NET Web application deployed on VM. Web application is configured with HTTPS binding using SSL certificate. I have configured IIS security using IIS Crypto 2.0 tool.
Scheduler Job fails with an error:
Http Action - Request to host 'www.somesamplehost.com' failed: SendFailure The
underlying connection was closed: An unexpected error occurred on a
send.
The same URL works fine when I try to access it from any browser.
Screenshot from Azure Portal:
The issue was due to SSL certificate. I have ECC SSL certificate for my Web Application and Azure Scheduler Job does not support making requests to Web Application that has that kind of certificate.
Guys from MS suggested alternative for Scheduler Job. It is a feature in Azure Portal called "Logic Apps". You can set it up in a way that it periodically makes requests to specific URL, but "Logic Apps" has much more capabilities compared to Scheduler Job.

SocketException: No connection could be made because the target machine actively refused it XX.XXX.XX.XXX:443

I got 2 servers with two equal wcf services hosted on them and one client application server. I can connect to endpoints and send a requests to both services using test wcf client app (.NET Web Service Studio) from my local machine successfully. But when I am trying to connect from client application server using the same test wcf client app I successfully connected only to the one wcf service server, but I have got an error when connecting to another one:
System.Net.WebException: There was an error downloading 'https://XXX/XXX?wsdl'. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it XX.XXX.XX.XXX:443
I performed netstat -an | find "443" command in command prompt on the client server and on my local machine to find out the difference and here what I have got:
1. On my local machine:
2. On the client app server:
What I already tried to do on client application server is:
- turned off firewall;
- stopped windows firewall service
- uninstalled mcafee virusscan enterprise application.
(I tried to set "prevent mass mailing worms from send mail" first, but mcafee was in foreign language that I don't understand, so I just uninstalled it)
after running command netstat -aon | findstr "443" on client application server I have got this result:
but I still got an error.
Does anybody know how to solve this issue?
Could be the problem on the wcf service server side?
The solution was predictable simple one - firewall was blocking the port,
but it's important to notice that the issue was caused by firewall on the wcf service server side, but not on client application server, which is making the request to that service.
I asked the technical support of that server, and they made firewall changes.
After that error was disappeared.
I faced the same issue and tried different ways to fix this. Nothing works. Later i found the issue which is, the application i tried to run is https and in my IIS, https binding was not created. I created binding https with the website and it works.

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