尝试将NodeJS中的1个openshift应用程序与另一个openshift应用程序的MySQL连接时出现错误EHOSTUNREACH

Question

I have 2 applications on OpenShift: 1 with MySQL, and 1 with NodeJS that is going to connect to MySQL of the other app.

I've seen examples but none of them seem to work, these are the steps I'm taking:

rhc ssh -a mydbappname

then i get the enviroment variables with env | grep MYSQL

I get something like:

OPENSHIFT_MYSQL_DB_HOST=127.XX.XXX.X

OPENSHIFT_MYSQL_DB_PORT=3306

After that i try to use those on the other app, but it always throws EHOSTUNREACH, no matter if i create the OPENSHIFT_MYSQL_DB env variables on the Node app and use them, or if i put it directly on the code.

I have seen in other parts that the OPENSHIFT_MYSQL_DB_HOST is something like 54d10be2503e36378e0002db-mydbappname.apps.rhcloud.com.

If I use the port-forward and use 127.0.0.1 with the local port selected for mysql, and start the NodeJS application locally it works, only when i upload the changes to Openshift it fails

Answer 1

In this article:
https://blog.openshift.com/sharing-database-across-applications/
You can read:
"Step 1:
Create an application with a database
We will create a scalable PHP application using a MySQL database cartridge. In non-scalable applications, the database will be installed in the same gear as the application. In this case we want the database to be accessible from other gears. So creating a scalable application ensures that the database runs in its own gear that can be accessed from other gears."

So maybe this is the problem, check if this application you created is scalable.