Ubuntu Informix连接测试

Preparations for Ubuntu Informix Connection Testing Before testing the connection, ensure the following prerequisites are met:

• Informix Server Installation: Verify that IBM Informix Dynamic Server (IDS) is installed on the target Ubuntu machine. You can confirm this by running dpkg -l | grep informix or checking the /opt/informix directory (default installation path).
• Informix Client Tools: Install the Informix client utilities (e.g., informixsql, isql) on the Ubuntu machine where you’ll run the test. These tools are available via IBM’s official repository or package managers.
• Environment Variables: Configure essential environment variables in your shell profile (e.g., ~/.bashrc). Add the following lines, replacing /opt/informix with your actual Informix installation directory:

  export INFORMIXDIR=/opt/informix
  export LD_LIBRARY_PATH=$INFORMIXDIR/lib:$LD_LIBRARY_PATH
  export PATH=$INFORMIXDIR/bin:$PATH
  

  Run source ~/.bashrc to apply changes immediately.
  These steps ensure the necessary tools and configurations are in place before testing.

Step 1: Verify Informix Server Status Check if the Informix server is running on the target machine. Use the onstat command (part of the Informix client tools) to query the server status:

onstat -g srv

Look for the “Server State” field in the output. A value of “Up” indicates the server is running. If the server is down, start it using:

sudo service informix start
# or (depending on your system)
sudo systemctl start informix

If the server fails to start, check the Informix error log (typically located at /opt/informix/log/online.log) for details.

Step 2: Confirm Network Connectivity Ensure the Ubuntu machine can reach the Informix server over the network. Use the ping command with the server’s IP address or hostname:

ping <informix_server_ip>

If the ping fails, troubleshoot network issues (e.g., incorrect IP, subnet mask, gateway, or physical connectivity). For remote connections, ensure the server’s IP is reachable from your Ubuntu machine.

Step 3: Validate Listening Port Informix uses a default port (1526 for TCP/IP) to accept client connections. Verify the port is open and listening on the server:

sudo netstat -tuln | grep 1526
# or (modern systems)
sudo ss -tuln | grep 1526

The output should show a line like:

tcp   0   0 0.0.0.0:1526   0.0.0.0:*   LISTEN

If the port is not listed, check the Informix configuration file (onconfig) for the correct port (parameter: SERVICES) and restart the server.

Step 4: Configure SQLHOSTS File The sqlhosts file (located in $INFORMIXDIR/etc) maps server names to connection protocols and ports. Add an entry for your Informix server:

sudo nano $INFORMIXDIR/etc/sqlhosts

Add a line in the following format (adjust values for your environment):

my_server   onsoctcp   <informix_server_ip>   my_port

• my_server: A logical name for the server (used in client configurations).
• onsoctcp: The protocol (TCP/IP for remote connections).
• <informix_server_ip>: The server’s IP address.
• my_port: The port Informix is listening on (e.g., 1526).
  Save the file and exit.

Step 5: Test Connection Using isql Use the isql tool (Informix SQL client) to test the connection. Run the following command from your Ubuntu machine:

isql -v my_server <username> <password>

• Replace my_server with the logical name from the sqlhosts file.
• Replace <username> and <password> with valid Informix credentials.
  If the connection succeeds, you’ll see the Informix SQL prompt (SQL>). Enter a simple query (e.g., SELECT 1;) to verify functionality. If the connection fails, note the error message for further troubleshooting.

Step 6: Troubleshoot Common Issues If the connection test fails, address these common problems:

• Authentication Errors: Verify the username/password is correct. Check the Informix sysusers table for user permissions.
• Port/Protocol Mismatches: Ensure the sqlhosts file uses the same protocol (e.g., onsoctcp) and port as the Informix server configuration (onconfig).
• Firewall Blocking: Allow the Informix port (e.g., 1526) through the Ubuntu firewall. For ufw, run:

  sudo ufw allow 1526/tcp
  sudo ufw reload
  

• SELinux/AppArmor Restrictions: If SELinux or AppArmor is enabled, ensure they are not blocking Informix processes. Temporarily disable them to test (not recommended for production).