pyNetX 2.0.3

NETCONF client with truly async capabilities

pyNetX

pyNetX is a Python library that facilitates both synchronous and asynchronous client-side scripting and application development around the NETCONF protocol. Developed by Sambhu Nampoothiri G, pyNetX provides a modern, efficient interface for interacting with NETCONF-enabled network devices — with truly asynchronous capabilities using non blocking connections.

Current Versions: Stable: v2.0.3

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v2.0.3 — 2026-05-28

Highlights

• Hardened NETCONF notification handling

  • Fixed a crash path where exceptions from the notification reactor thread could escape into C++ std::thread and terminate the Python process.
  • Notification reactor callbacks now log read failures, unregister the affected file descriptor, mark the subscription inactive, and allow the Python process to continue running.
  • The notification reactor now stores weak references to NetconfClient instances, preventing stale raw-pointer access if a Python client object is destroyed while a notification FD is still registered.

• Safer notification subscription startup

  • Notification sockets are now registered with the epoll reactor only after the <create-subscription> RPC has completed successfully.
  • This prevents the reactor thread from accidentally reading the subscription <rpc-reply> before subscribe_async() / subscribe_sync() receives it.

• Improved notification cleanup

  • Added mutex protection around notification resources, including the notification session, channel, socket, and subscription state flags.
  • Cleanup paths now unregister notification FDs before resetting notification resources.
  • is_subscription_active() now safely reports whether the notification subscription is still usable.

• Hardened async bridge and worker threads

  • Detached pybind11 watcher threads now have top-level exception guards, so Python event-loop shutdown or callback scheduling errors are logged instead of terminating the process.
  • Thread-pool worker tasks now have defensive exception guards to prevent unexpected C++ exceptions from escaping worker threads.

• Notification queue behavior

  • notif_queue_size=-1 means the notification queue is unbounded.
  • A non-negative notif_queue_size limits the number of queued notifications.
  • When the queue is full, new notifications are dropped and a message is logged.

Upgrade notes

• This release is intended to be a drop-in stability update.
• set_notification_reactor_count(n) is optional. If it is not called, pyNetX creates one notification reactor automatically when the first subscription is registered.
• For large deployments, call set_notification_reactor_count(n) before creating many subscriptions.
• next_notification() is a synchronous polling method. Do not use await client.next_notification(). Use client.next_notification() directly, even inside an async function.
• set_threadpool_size(n) should be called before starting async NETCONF operations. Runtime resizing during active operations is not recommended.
• If the Python event loop closes before an async operation completes, pyNetX logs the callback scheduling failure instead of aborting the interpreter.

pip install pyNetX==2.0.3

v2.0.2 — 2026-04-01

Highlights

• Improved exception handling to prevent Python process crashes

  • Fixes a critical issue introduced in v1.0.9 where, under high load, destructors did not reliably release memory objects. In some cases this raised an exception, triggered std::terminate, and caused Python processes to crash.
  • This release improves memory cleanup and adds safer exception handling across the API surface to prevent those crashes.

• Added notif_queue_size for internal notification queues

  • A new notif_queue_size parameter is available when creating the internal notification queue for each device.
  • This setting controls how many notifications are buffered until they are consumed.
  • If the queue exceeds that limit, newer notifications are discarded and a message is logged to the console.
  • The default value is -1, which means the queue size is unbounded.
  • This parameter must be specified when creating the NetconfClient object.

• Global release build with builds for 3.11, 3.12, 3.13 and 3.14

  • This version of pyNetX supports multiple python versions upto 3.14.

• Why it matters

  • This release improves runtime stability under load, reduces the risk of unexpected Python process termination, and gives users better control over notification queue growth to help prevent memory pressure and queue overflows.

Internal changes

• Minor cleanup and implementation updates in the pybind11 wrapper lambdas.

Bug fixes

• Fixes the crash behavior introduced in v1.0.9.
• No new functional regressions were introduced in v2.0.2.

Upgrade notes

• Safe drop-in upgrade. There are no API-breaking changes compared with v1.0.9.
• If you previously installed pyNetX from Test PyPI, install the updated wheel with:

pip install pyNetX==2.0.2

v1.0.9 — 2025-07-03

Highlights

• Cancellation-safe asyncio bridge
  • Added a guard (fut_pending()) in the C++ wrapper so callbacks skip set_result()/set_exception() if the Python asyncio.Future has already been cancelled or finished.
  • Why it matters: eliminates sporadic
    asyncio.exceptions.InvalidStateError: invalid state seen when a running task is cancelled or times out while waiting for an RPC reply.

Internal changes

• Minor code changes in the pybind11 wrapper lambdas.

Bug fixes

• No functional regressions introduced by v1.0.8.

Upgrade notes

• Safe to drop-in. There are no API changes compared with v1.0.8.
• If you previously installed pyNetX from Test PyPI, grab the new wheel with

  pip install pyNetX==1.0.9
  

v1.0.8 — 2025-06-30

Highlights

• Epoll-based Notification Subsystem

  • Re-implemented the internal notification reactor on top of Linux epoll, eliminating the legacy select-based notification loop.
  • Why it matters:
    • Scales linearly with the number of active NETCONF notification streams.
    • Dramatically reduces CPU wake-ups under heavy load (measured ~85 % drop at 500 FDs).
    • Lower latency for bursts of notifications, especially when many devices are idle most of the time.
    • No new threads are created for each notification arrival; a fixed pool started at program launch can handle hundreds of devices per thread.

• Smarter Task-Pool Sharing

  • The global task pool now assigns workers to devices dynamically based on real-time queue depth rather than static round-robin.
  • This allows tasks to be spread across queues more efficiently as per current load, minimizing task queue depth and improving aggregate throughput by up to 40 % in mixed-traffic scenarios.

Internal changes

• Added set_notification_reactor_count() to let applications resize the epoll reactor pool on the fly.
• Reworked set_threadpool_size() so the pool can grow or shrink without restarting clients; existing futures stay intact.

Bug fixes

• Fixed a hard-coded NETCONF base 1.0 header in send_rpc_async(rpc="…"); the call now follows the user mentioned version.

Deprecations

• receive_notification_async() has been removed; migrate to next_notification() before v1.0.8.

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Upgrade tip: If you scaled your own thread/reactor counts manually, call the new setters after creating all client objects to rebalance existing connections.

Documentation

The full documentation (with detailed API references and more usage examples) is here.

pyNetX Official Documentation GitHub Repository PyPI Medium

Requirements

• Python: 3.11+
• Build Dependencies: setuptools, wheel, cmake, scikit-build, and pybind11
• System Libraries:
  • libxml2, libxslt (for XML processing)
  • libssh2, tinyxml2, and audit tools (if required, install via your system’s package manager)

Note: On Debian/Ubuntu, you might install the system libraries with:

sudo apt-get install libxml2-dev libxslt1-dev libssh2-dev tinyxml2-dev audit

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Installation

You can install pyNetX in either of the following ways:

1. From PyPI:

   pip install pyNetX
   

2. From Source:

   git clone https://github.com/jackofsometrades99/pyNetX.git
   cd pyNetX
   python setup.py install
   

Examples

Synchronous Usage

Below is an example of how to retrieve a device’s running configuration synchronously:

from pyNetX import (
  NetconfClient,
  NetconfConnectionRefusedError,
  NetconfAuthError,
  NetconfChannelError,
  NetconfException
)
try:
  # Create a NETCONF client instance
  client = NetconfClient(
      hostname="192.168.1.1",
      port=830,
      username="admin",
      password="admin",
      connect_timeout=30, # CONNECT TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
      read_timeout=30 # READ TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
  )

  # Establish a connection
  status = client.connect_sync()

  # Retrieve the running configuration
  config = client.get_config_sync(source="running")
  print("Running Configuration:")
  print(config)

  # Disconnect from the device
  client.disconnect_sync()
except (Exception, NetconfConnectionRefusedError, NetconfAuthError, NetconfChannelError, NetconfException) as error:
  pass

Asynchronous Usage

The asynchronous API methods are provided with an _async suffix and integrate with Python’s asyncio. For example:

import asyncio
from pyNetX import (
  NetconfClient,
  NetconfConnectionRefusedError,
  NetconfAuthError,
  NetconfChannelError,
  NetconfException
)

async def main():
    try:
      client = NetconfClient(
          hostname="192.168.1.1",
          port=830,
          username="admin",
          password="admin",
          connect_timeout=30, # CONNECT TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
          read_timeout=30 # READ TIMEOUT FROM CHANNEL. DEFAULT IS 60 SECONDS
      )
      
      # Asynchronously connect to the device
      status = await client.connect_async()
      
      # Retrieve configuration asynchronously
      config = await client.get_config_async(source="running")
      print("Running Configuration:")
      print(config)
      
      # Asynchronously disconnect from the device
      await client.disconnect_async()
    except (Exception, NetconfConnectionRefusedError, NetconfAuthError, NetconfChannelError, NetconfException) as error:
      pass

# Run the asynchronous main function
asyncio.run(main())

API Overview

The main class provided by pyNetX is NetconfClient, which offers both synchronous and asynchronous methods for NETCONF operations.

Synchronous Methods

• connect_sync()
  Establishes a NETCONF session with the target device.

• disconnect_sync()
  Closes the NETCONF session.

• send_rpc_sync(rpc)
  Sends a custom RPC command.

• get_sync(filter="")
  Retrieves device information using an optional filter.

• get_config_sync(source="running", filter="")
  Retrieves the device configuration.

• copy_config_sync(target, source)
  Copies configuration from one datastore to another.

• delete_config_sync(target)
  Deletes configuration from the specified target.

• validate_sync(source="running")
  Validates the configuration.

• edit_config_sync(target, config, do_validate=False)
  Edits the device configuration.

• subscribe_sync(stream="NETCONF", filter="")
  Subscribes to NETCONF notifications.

• receive_notification_sync() Fetches a single received notification from the notification channel.

• lock_sync(target="running") and unlock_sync(target="running")
  Lock and unlock a configuration datastore, respectively.

• commit_sync()
  Commits any configuration changes.

• locked_edit_config_sync(target, config, do_validate=False)
  Performs an edit configuration operation while holding a lock.

Asynchronous Methods

For every synchronous method, there is an asynchronous counterpart that returns an asyncio Future:

• connect_async()
• disconnect_async()
• send_rpc_async(rpc="")
• next_notification() Polls the internal notification queue. This method is not awaitable; call it directly.
• get_async(filter="")
• get_config_async(source="running", filter="")
• copy_config_async(target, source)
• delete_config_async(target)
• validate_async(source="running")
• edit_config_async(target, config, do_validate=False)
• subscribe_async(stream="NETCONF", filter="")
• lock_async(target="running")
• unlock_async(target="running")
• commit_async()
• locked_edit_config_async(target, config, do_validate=False)

Common Methods.

These methods can be used in both synchronous and asynchronous operations:

• delete_subscription() Unsubscribe from recieving notifications.

• set_threadpool_size(nThreads) Sets the number of threads in the shared task pool. The default is 4 threads. The number of threads in the pool determines how many tasks or operations can run concurrently. Note that for each device, operations (such as get_async, edit_config_async, etc.) are executed sequentially using a lock to avoid channel corruption. This nThreads value controls the total number of concurrent operations across all clients (devices) in the application. To use this, you can simply:

  import pyNetX
  pyNetX.set_threadpool_size(10)
  

• set_notification_reactor_count(nThreads) Configures how many background epoll reactor threads pyNetX uses to monitor notification sockets.

  If this function is not called, pyNetX automatically creates one reactor when the first notification subscription is registered.

  For large deployments, call this before creating many subscriptions:

  import pyNetX
  # Create 8 epoll‐based reactors to handle your notification streams
  pyNetX.set_notification_reactor_count(8)
  

  Existing subscriptions are rebalanced when the reactor count is changed, but applications should prefer configuring this once during startup.

Exception Handling

pyNetX defines custom exceptions to handle various NETCONF-related errors:

• NetconfConnectionRefusedError
  Raised when a connection attempt is refused.

• NetconfAuthError
  Raised when authentication fails.

• NetconfChannelError
  Raised for channel-related errors.

• NetconfException
  The base exception for NETCONF-related issues.