Fix: The client is working, but the target database server's listener is stopped. Check with your database administrator to start the listener on the remote server.
Switch to the oracle user, extract the archive, and launch the graphical installer (requires X11 forwarding if using SSH):
Locate the tnsnames.ora file: [Oracle Home]\network\admin\tnsnames.ora .
Add to /etc/profile.d/oracle.sh (system-wide) or your app user’s .bashrc :
Open tnsnames.ora in a text editor (Notepad, vi, nano). Add a definition: install oracle client 12c
ldconfig -p | grep clntsh # Output should show libclntsh.so.12.1
Complete Guide to Installing Oracle Client 12c on Windows and Linux
except Empty: # Pool empty, try to create new connection if below max size with self._lock: if len(self._active_connections) < self.max_pool_size: conn = self._create_connection() if conn: self._active_connections[conn] = datetime.now() self._stats.active_connections += 1 return conn
# Initialize pool with minimum connections self._initialize_pool() Fix: The client is working, but the target
import cx_Oracle import threading import time import logging from contextlib import contextmanager from typing import Dict, Any, Optional, List from dataclasses import dataclass from datetime import datetime from queue import Queue, Empty
# Switch to oracle user sudo su - oracle
Then test:
ORA-12154 could not resolve the connect identifier specified Add to /etc/profile
Then, navigate to the client directory and execute the runInstaller command with the -silent and -responseFile options to start the silent installation:
SysAdmin Archives Tags: Oracle, DevOps, Legacy Systems, Linux, Database Connectivity
The specific directory where the client software binaries will live (e.g., C:\app\client\ \product\12.2.0\client_1 ).
@patch('cx_Oracle.connect') def test_concurrent_connections(self, mock_connect): """Test multiple concurrent connections""" mock_connect.return_value = Mock() pool = OracleConnectionPool(self.config)
Fix: The client is working, but the target database server's listener is stopped. Check with your database administrator to start the listener on the remote server.
Switch to the oracle user, extract the archive, and launch the graphical installer (requires X11 forwarding if using SSH):
Locate the tnsnames.ora file: [Oracle Home]\network\admin\tnsnames.ora .
Add to /etc/profile.d/oracle.sh (system-wide) or your app user’s .bashrc :
Open tnsnames.ora in a text editor (Notepad, vi, nano). Add a definition:
ldconfig -p | grep clntsh # Output should show libclntsh.so.12.1
Complete Guide to Installing Oracle Client 12c on Windows and Linux
except Empty: # Pool empty, try to create new connection if below max size with self._lock: if len(self._active_connections) < self.max_pool_size: conn = self._create_connection() if conn: self._active_connections[conn] = datetime.now() self._stats.active_connections += 1 return conn
# Initialize pool with minimum connections self._initialize_pool()
import cx_Oracle import threading import time import logging from contextlib import contextmanager from typing import Dict, Any, Optional, List from dataclasses import dataclass from datetime import datetime from queue import Queue, Empty
# Switch to oracle user sudo su - oracle
Then test:
ORA-12154 could not resolve the connect identifier specified
Then, navigate to the client directory and execute the runInstaller command with the -silent and -responseFile options to start the silent installation:
SysAdmin Archives Tags: Oracle, DevOps, Legacy Systems, Linux, Database Connectivity
The specific directory where the client software binaries will live (e.g., C:\app\client\ \product\12.2.0\client_1 ).
@patch('cx_Oracle.connect') def test_concurrent_connections(self, mock_connect): """Test multiple concurrent connections""" mock_connect.return_value = Mock() pool = OracleConnectionPool(self.config)