FAQ

I. Network Unreachable: Check Firewall (Take CentOS7 as an Example)

(I) Check if the Firewall is Enabled

# Check firewall status
systemctl status firewalld

(II) If the Firewall is Enabled, There are Two Handling Methods

1. Stop the Firewall

# Stop the firewall
systemctl stop firewalld

2. Open Ports Exposed by Middleware Built in the Docker Image

88: Web access port
8099: Backend Java service port
19876: RocketMQ namesrv port
6378: Cache Redis port
3307: Database MySQL port
2182: Zookeeper port
20880: Dubbo communication port
15555: Reserved Java debug port
10991: RocketMQ broker port

Example

Take adding port 88 as an example, you can execute the following command. After execution, you can use the telnet command from the outside to check if the port is successfully opened, such as telnet 192.168.0.121 3307

# Example of adding an open port in the firewall:
firewall-cmd --permanent --zone=public --add-port=88/tcp
# After adding, the firewall needs to be reloaded to take effect
systemctl reload firewalld
# Check if the port is successfully opened
firewall-cmd --list-ports

II. InvalidKeyException: Illegal key size During Runtime

(I) Cause

If the key is larger than 128, a java.security.InvalidKeyException: Illegal key size exception will be thrown. This is because the key length is restricted, and the Java runtime environment reads a restricted policy file located in ${java_home}/jre/lib/security. This restriction is due to U.S. export controls on software.

If JRE is installed, place the two jar files in the %JRE_HOME%\lib\security directory to overwrite the original files.
If JDK is installed, also place the two jar files in the %JDK_HOME%\jre\lib\security directory to overwrite the original files.

FAQ