Source code for bokeh.server.tornado

# Copyright (c) 2012 - 2024, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
# The full license is in the file LICENSE.txt, distributed with this software.
''' Provides the Bokeh Server Tornado application.


# Boilerplate
from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

# Imports

# Standard library imports
import gc
import os
from pprint import pformat
from types import ModuleType
from typing import (
from urllib.parse import urljoin

# External imports
from tornado.ioloop import PeriodicCallback
from tornado.web import Application as TornadoApplication, StaticFileHandler
from tornado.websocket import WebSocketClosedError

    from tornado.ioloop import IOLoop

# Bokeh imports
from ..application import Application
from ..document import Document
from ..model import Model
from ..resources import Resources
from ..settings import settings
from ..util.dependencies import import_optional
from ..util.strings import format_docstring
from ..util.tornado import fixup_windows_event_loop_policy
from .auth_provider import NullAuth
from .connection import ServerConnection
from .contexts import ApplicationContext
from .session import ServerSession
from .urls import per_app_patterns, toplevel_patterns
from .views.ico_handler import IcoHandler
from .views.root_handler import RootHandler
from .views.static_handler import StaticHandler
from import WSHandler

    from ..application.handlers.function import ModifyDoc
    from ..core.types import ID
    from ..protocol import Protocol
    from .auth_provider import AuthProvider
    from .urls import RouteContext, URLRoutes

# Globals and constants

DEFAULT_CHECK_UNUSED_MS                  = 17000
DEFAULT_KEEP_ALIVE_MS                    = 37000  # heroku, nginx default to 60s timeout, so use less than that
DEFAULT_MEM_LOG_FREQ_MS                  = 0
DEFAULT_STATS_LOG_FREQ_MS                = 15000
DEFAULT_UNUSED_LIFETIME_MS               = 15000

__all__ = (

psutil = import_optional("psutil")

GB = 2**20
PID = os.getpid()
if psutil:
    PROC = psutil.Process(PID)

# General API

[docs] class BokehTornado(TornadoApplication): ''' A Tornado Application used to implement the Bokeh Server. Args: applications (dict[str,Application] or Application) : A map from paths to ``Application`` instances. If the value is a single Application, then the following mapping is generated: .. code-block:: python applications = {{ '/' : applications }} When a connection comes in to a given path, the associate Application is used to generate a new document for the session. prefix (str, optional) : A URL prefix to use for all Bokeh server paths. (default: None) ico_path (str, optional) : A path to a .ico file to return for ``/favicon.ico``. extra_websocket_origins (list[str], optional) : A list of hosts that can connect to the websocket. This is typically required when embedding a Bokeh server app in an external web site using :func:`~bokeh.embed.server_document` or similar. If None, ``["localhost"]`` will be assumed (default: None) extra_patterns (seq[tuple], optional) : A list of tuples of (str, http or websocket handler) Use this argument to add additional endpoints to custom deployments of the Bokeh Server. If None, then ``[]`` will be used. (default: None) secret_key (str, optional) : A secret key for signing session IDs. Defaults to the current value of the environment variable ``BOKEH_SECRET_KEY`` sign_sessions (bool, optional) : Whether to cryptographically sign session IDs Defaults to the current value of the environment variable ``BOKEH_SIGN_SESSIONS``. If ``True``, then ``secret_key`` must also be provided (either via environment setting or passed as a parameter value) generate_session_ids (bool, optional) : Whether to generate a session ID if one is not provided (default: True) keep_alive_milliseconds (int, optional) : Number of milliseconds between keep-alive pings (default: {DEFAULT_KEEP_ALIVE_MS}) Pings normally required to keep the websocket open. Set to 0 to disable pings. check_unused_sessions_milliseconds (int, optional) : Number of milliseconds between checking for unused sessions (default: {DEFAULT_CHECK_UNUSED_MS}) unused_session_lifetime_milliseconds (int, optional) : Number of milliseconds for unused session lifetime (default: {DEFAULT_UNUSED_LIFETIME_MS}) stats_log_frequency_milliseconds (int, optional) : Number of milliseconds between logging stats (default: {DEFAULT_STATS_LOG_FREQ_MS}) mem_log_frequency_milliseconds (int, optional) : Number of milliseconds between logging memory information (default: {DEFAULT_MEM_LOG_FREQ_MS}) Enabling this feature requires the optional dependency ``psutil`` to be installed. use_index (bool, optional) : Whether to generate an index of running apps in the ``RootHandler`` (default: True) index (str, optional) : Path to a Jinja2 template to serve as the index for "/" if use_index is True. If None, the basic built in app index template is used. (default: None) redirect_root (bool, optional) : When there is only a single running application, whether to redirect requests to ``"/"`` to that application automatically (default: True) If there are multiple Bokeh applications configured, this option has no effect. websocket_max_message_size_bytes (int, optional): Set the Tornado ``websocket_max_message_size`` value. (default: {DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES}) websocket_compression_level (int, optional): Set the Tornado WebSocket ``compression_level`` documented in websocket_compression_mem_level (int, optional): Set the Tornado WebSocket compression ``mem_level`` documented in index (str, optional): Path to a Jinja2 template to use for the root URL auth_provider (AuthProvider, optional): An AuthProvider instance include_headers (list, optional) : List of request headers to include in session context (by default all headers are included) exclude_headers (list, optional) : List of request headers to exclude in session context (by default all headers are included) include_cookies (list, optional) : List of cookies to include in session context (by default all cookies are included) exclude_cookies (list, optional) : List of cookies to exclude in session context (by default all cookies are included) session_token_expiration (int, optional) : Duration in seconds that a new session token is valid for session creation. After the expiry time has elapsed, the token will not be able create a new session (default: {DEFAULT_SESSION_TOKEN_EXPIRATION}) Any additional keyword arguments are passed to ``tornado.web.Application``. ''' _loop: IOLoop _applications: Mapping[str, ApplicationContext] _prefix: str _websocket_origins: set[str] auth_provider: AuthProvider _clients: set[ServerConnection] _mem_job: PeriodicCallback | None _ping_job: PeriodicCallback | None def __init__(self, applications: Mapping[str, Application | ModifyDoc] | Application | ModifyDoc, *, absolute_url: str | None = None, prefix: str | None = None, extra_websocket_origins: Sequence[str] | None = None, extra_patterns: URLRoutes | None = None, secret_key: bytes | None = settings.secret_key_bytes(), sign_sessions: bool = settings.sign_sessions(), generate_session_ids: bool = True, keep_alive_milliseconds: int = DEFAULT_KEEP_ALIVE_MS, check_unused_sessions_milliseconds: int = DEFAULT_CHECK_UNUSED_MS, unused_session_lifetime_milliseconds: int = DEFAULT_UNUSED_LIFETIME_MS, stats_log_frequency_milliseconds: int = DEFAULT_STATS_LOG_FREQ_MS, mem_log_frequency_milliseconds: int = DEFAULT_MEM_LOG_FREQ_MS, use_index: bool = True, redirect_root: bool = True, websocket_max_message_size_bytes: int = DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES, websocket_compression_level: int | None = None, websocket_compression_mem_level: int | None = None, ico_path: str = settings.ico_path(), index: str | None = None, auth_provider: AuthProvider = NullAuth(), xsrf_cookies: bool = False, include_headers: list[str] | None = None, include_cookies: list[str] | None = None, exclude_headers: list[str] | None = None, exclude_cookies: list[str] | None = None, session_token_expiration: int = DEFAULT_SESSION_TOKEN_EXPIRATION, **kwargs: Any): from ..application.handlers.document_lifecycle import DocumentLifecycleHandler from ..application.handlers.function import FunctionHandler if callable(applications): applications = Application(FunctionHandler(applications)) if isinstance(applications, Application): applications = {'/' : applications} else: applications = dict(applications) for url, app in list(applications.items()): if callable(app): applications[url] = app = Application(FunctionHandler(app)) if all(not isinstance(handler, DocumentLifecycleHandler) for handler in app._handlers): app.add(DocumentLifecycleHandler()) self._absolute_url = absolute_url if prefix is None: prefix = "" prefix = prefix.strip("/") if prefix: prefix = "/" + prefix self._prefix = prefix self._index = index if keep_alive_milliseconds < 0: # 0 means "disable" raise ValueError("keep_alive_milliseconds must be >= 0") else: if keep_alive_milliseconds == 0:"Keep-alive ping disabled") elif keep_alive_milliseconds != DEFAULT_KEEP_ALIVE_MS:"Keep-alive ping configured every %d milliseconds", keep_alive_milliseconds) self._keep_alive_milliseconds = keep_alive_milliseconds if check_unused_sessions_milliseconds <= 0: raise ValueError("check_unused_sessions_milliseconds must be > 0") elif check_unused_sessions_milliseconds != DEFAULT_CHECK_UNUSED_MS:"Check for unused sessions every %d milliseconds", check_unused_sessions_milliseconds) self._check_unused_sessions_milliseconds = check_unused_sessions_milliseconds if unused_session_lifetime_milliseconds <= 0: raise ValueError("unused_session_lifetime_milliseconds must be > 0") elif unused_session_lifetime_milliseconds != DEFAULT_UNUSED_LIFETIME_MS:"Unused sessions last for %d milliseconds", unused_session_lifetime_milliseconds) self._unused_session_lifetime_milliseconds = unused_session_lifetime_milliseconds if stats_log_frequency_milliseconds <= 0: raise ValueError("stats_log_frequency_milliseconds must be > 0") elif stats_log_frequency_milliseconds != DEFAULT_STATS_LOG_FREQ_MS:"Log statistics every %d milliseconds", stats_log_frequency_milliseconds) self._stats_log_frequency_milliseconds = stats_log_frequency_milliseconds if mem_log_frequency_milliseconds < 0: # 0 means "disable" raise ValueError("mem_log_frequency_milliseconds must be >= 0") elif mem_log_frequency_milliseconds > 0: if psutil is None: log.warning("Memory logging requested, but is disabled. Optional dependency 'psutil' is missing. " "Try 'pip install psutil' or 'conda install psutil'") mem_log_frequency_milliseconds = 0 elif mem_log_frequency_milliseconds != DEFAULT_MEM_LOG_FREQ_MS:"Log memory usage every %d milliseconds", mem_log_frequency_milliseconds) self._mem_log_frequency_milliseconds = mem_log_frequency_milliseconds if websocket_max_message_size_bytes <= 0: raise ValueError("websocket_max_message_size_bytes must be positive") elif websocket_max_message_size_bytes != DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES:"Torndado websocket_max_message_size set to %d bytes (%0.2f MB)", websocket_max_message_size_bytes, websocket_max_message_size_bytes/1024.0**2) self.auth_provider = auth_provider if self.auth_provider.get_user or self.auth_provider.get_user_async:"User authentication hooks provided (no default user)") else:"User authentication hooks NOT provided (default user enabled)") kwargs['xsrf_cookies'] = xsrf_cookies if xsrf_cookies:"XSRF cookie protection enabled") if session_token_expiration <= 0: raise ValueError("session_token_expiration must be > 0") else: self._session_token_expiration = session_token_expiration if exclude_cookies and include_cookies: raise ValueError("Declare either an include or an exclude list for the cookies, not both.") self._exclude_cookies = exclude_cookies self._include_cookies = include_cookies if exclude_headers and include_headers: raise ValueError("Declare either an include or an exclude list for the headers, not both.") self._exclude_headers = exclude_headers self._include_headers = include_headers if extra_websocket_origins is None: self._websocket_origins = set() else: self._websocket_origins = set(extra_websocket_origins) self._secret_key = secret_key self._sign_sessions = sign_sessions self._generate_session_ids = generate_session_ids log.debug(f"These host origins can connect to the websocket: {list(self._websocket_origins)!r}") # Wrap applications in ApplicationContext self._applications = {} for url, app in applications.items(): assert isinstance(app, Application) # TODO: unnecessary; improve type flow to remove this self._applications[url] = ApplicationContext(app, url=url, logout_url=self.auth_provider.logout_url) extra_patterns = extra_patterns or [] extra_patterns.extend(self.auth_provider.endpoints) if ico_path == "none": self._icon = None else: with open(ico_path, 'rb') as f: self._icon = all_patterns: URLRoutes = [(r'/favicon.ico', IcoHandler, dict(app=self))] for key, ctx in self._applications.items(): app_patterns: URLRoutes = [] for p in per_app_patterns: if key == "/": route = p[0] else: route = key + p[0] context: RouteContext = {"application_context": self._applications[key]} if issubclass(p[1], WSHandler): context['compression_level'] = websocket_compression_level context['mem_level'] = websocket_compression_mem_level route = self._prefix + route app_patterns.append((route, p[1], context)) websocket_path = None for r in app_patterns: if r[0].endswith("/ws"): websocket_path = r[0] if not websocket_path: raise RuntimeError("Couldn't find websocket path") for r in app_patterns: assert len(r) == 3 # TODO: handle two valued case as well r[2]["bokeh_websocket_path"] = websocket_path all_patterns.extend(app_patterns) # if the app requests a custom static path, use that, otherwise add Bokeh's standard static handler all_patterns.append(create_static_handler(self._prefix, key, ctx.application)) for p in extra_patterns + toplevel_patterns: if p[1] == RootHandler: if use_index: data = { "applications": self._applications, "prefix": self._prefix, "index": self._index, "use_redirect": redirect_root, } prefixed_pat = (self._prefix + p[0],) + p[1:] + (data,) all_patterns.append(prefixed_pat) # type: ignore[arg-type] # TODO: easy to fix types, but also easy to break logic else: prefixed_pat = (self._prefix + p[0],) + p[1:] all_patterns.append(prefixed_pat) # type: ignore[arg-type] # TODO: easy to fix types, but also easy to break logic log.debug("Patterns are:") for line in pformat(all_patterns, width=60).split("\n"): log.debug(" " + line) super().__init__(all_patterns, # type: ignore[arg-type] # TODO: this may be another bug in mypy (not sure; but looks suspicious) websocket_max_message_size=websocket_max_message_size_bytes, **kwargs)
[docs] def initialize(self, io_loop: IOLoop) -> None: ''' Start a Bokeh Server Tornado Application on a given Tornado IOLoop. ''' self._loop = io_loop for app_context in self._applications.values(): app_context._loop = self._loop self._clients = set() self._stats_job = PeriodicCallback(self._log_stats, self._stats_log_frequency_milliseconds) if self._mem_log_frequency_milliseconds > 0: self._mem_job = PeriodicCallback(self._log_mem, self._mem_log_frequency_milliseconds) else: self._mem_job = None self._cleanup_job = PeriodicCallback(self._cleanup_sessions, self._check_unused_sessions_milliseconds) if self._keep_alive_milliseconds > 0: self._ping_job = PeriodicCallback(self._keep_alive, self._keep_alive_milliseconds) else: self._ping_job = None
@property def applications(self) -> Mapping[str, ApplicationContext]: ''' The configured applications ''' return self._applications @property def app_paths(self) -> set[str]: ''' A list of all application paths for all Bokeh applications configured on this Bokeh server instance. ''' return set(self._applications) @property def index(self) -> str | None: ''' Path to a Jinja2 template to serve as the index "/" ''' return self._index @property def icon(self) -> bytes | None: ''' Favicon.ico file data, or None ''' return self._icon @property def io_loop(self) -> IOLoop: ''' The Tornado IOLoop that this Bokeh Server Tornado Application is running on. ''' return self._loop @property def prefix(self) -> str: ''' A URL prefix for this Bokeh Server Tornado Application to use for all paths ''' return self._prefix @property def websocket_origins(self) -> set[str]: ''' A list of websocket origins permitted to connect to this server. ''' return self._websocket_origins @property def secret_key(self) -> bytes | None: ''' A secret key for this Bokeh Server Tornado Application to use when signing session IDs, if configured. ''' return self._secret_key @property def include_cookies(self) -> list[str] | None: ''' A list of request cookies to make available in the session context. ''' return self._include_cookies @property def include_headers(self) -> list[str] | None: ''' A list of request headers to make available in the session context. ''' return self._include_headers @property def exclude_cookies(self) -> list[str] | None: ''' A list of request cookies to exclude in the session context. ''' return self._exclude_cookies @property def exclude_headers(self) -> list[str] | None: ''' A list of request headers to exclude in the session context. ''' return self._exclude_headers @property def sign_sessions(self) -> bool: ''' Whether this Bokeh Server Tornado Application has been configured to cryptographically sign session IDs If ``True``, then ``secret_key`` must also have been configured. ''' return self._sign_sessions @property def generate_session_ids(self) -> bool: ''' Whether this Bokeh Server Tornado Application has been configured to automatically generate session IDs. ''' return self._generate_session_ids @property def session_token_expiration(self) -> int: ''' Duration in seconds that a new session token is valid for session creation. After the expiry time has elapsed, the token will not be able create a new session. ''' return self._session_token_expiration
[docs] def resources(self, absolute_url: str | bool | None = None) -> Resources: ''' Provide a :class:`~bokeh.resources.Resources` that specifies where Bokeh application sessions should load BokehJS resources from. Args: absolute_url (str, bool): An absolute URL prefix to use for locating resources. If ``True``, a prefix consisting of server's protocol, host and port will be used. Otherwise, root-relative URLs are used (default: ``None``) ''' mode = settings.resources(default="server") if mode == "server" or mode == "server-dev": if absolute_url is True: absolute_url = self._absolute_url if absolute_url is None or absolute_url is False: absolute_url = "/" root_url = urljoin(absolute_url, self._prefix) return Resources(mode=mode, root_url=root_url, path_versioner=StaticHandler.append_version) return Resources(mode=mode)
[docs] def start(self) -> None: ''' Start the Bokeh Server application. Starting the Bokeh Server Tornado application will run periodic callbacks for stats logging, cleanup, pinging, etc. Additionally, any startup hooks defined by the configured Bokeh applications will be run. ''' self._stats_job.start() if self._mem_job is not None: self._mem_job.start() self._cleanup_job.start() if self._ping_job is not None: self._ping_job.start() for context in self._applications.values(): self._loop.add_callback(context.run_load_hook)
[docs] def stop(self, wait: bool = True) -> None: ''' Stop the Bokeh Server application. Args: wait (bool): whether to wait for orderly cleanup (default: True) Returns: None ''' # TODO should probably close all connections and shut down all sessions here for context in self._applications.values(): context.run_unload_hook() self._stats_job.stop() if self._mem_job is not None: self._mem_job.stop() self._cleanup_job.stop() if self._ping_job is not None: self._ping_job.stop() self._clients.clear()
def new_connection(self, protocol: Protocol, socket: WSHandler, application_context: ApplicationContext, session: ServerSession) -> ServerConnection: connection = ServerConnection(protocol, socket, application_context, session) self._clients.add(connection) return connection def client_lost(self, connection: ServerConnection) -> None: self._clients.discard(connection) connection.detach_session()
[docs] def get_session(self, app_path: str, session_id: ID) -> ServerSession: ''' Get an active a session by name application path and session ID. Args: app_path (str) : The configured application path for the application to return a session for. session_id (str) : The session ID of the session to retrieve. Returns: ServerSession ''' if app_path not in self._applications: raise ValueError("Application %s does not exist on this server" % app_path) return self._applications[app_path].get_session(session_id)
[docs] def get_sessions(self, app_path: str) -> list[ServerSession]: ''' Gets all currently active sessions for an application. Args: app_path (str) : The configured application path for the application to return sessions for. Returns: list[ServerSession] ''' if app_path not in self._applications: raise ValueError("Application %s does not exist on this server" % app_path) return list(self._applications[app_path].sessions)
# Periodic Callbacks ------------------------------------------------------ async def _cleanup_sessions(self) -> None: log.trace("Running session cleanup job") # type: ignore[attr-defined] for app in self._applications.values(): await app._cleanup_sessions(self._unused_session_lifetime_milliseconds) return None def _log_stats(self) -> None: log.trace("Running stats log job") # type: ignore[attr-defined] if log.getEffectiveLevel() > logging.DEBUG: # avoid the work below if we aren't going to log anything return log.debug("[pid %d] %d clients connected", PID, len(self._clients)) for app_path, app in self._applications.items(): sessions = list(app.sessions) unused_count = 0 for s in sessions: if s.connection_count == 0: unused_count += 1 log.debug("[pid %d] %s has %d sessions with %d unused", PID, app_path, len(sessions), unused_count) def _log_mem(self) -> None: # we should be able to assume PROC is define, if psutil is not installed # then the _log_mem callback is not started at all mem = PROC.memory_info()"[pid %d] Memory usage: %0.2f MB (RSS), %0.2f MB (VMS)", PID, mem.rss/GB, mem.vms/GB) del mem # skip the rest if we would not log it anyway if log.getEffectiveLevel() > logging.DEBUG: return #from collections import Counter # pprint.pprint(Counter([str(type(x)) for x in gc.get_objects() if "DataFrame" in str(type(x))]).most_common(30)) all_objs = gc.get_objects() for name, typ in [('Documents', Document), ('Sessions', ServerSession), ('Models', Model)]: objs = [x for x in all_objs if isinstance(x, typ)] log.debug(f" uncollected {name}: {len(objs)}") # uncomment for potentially voluminous referrers output # if name == 'Models' and len(objs): # import pprint # for i in range(10): # print(i, objs[i], gc.get_referents(objs[i])) objs = [x for x in gc.get_objects() if isinstance(x, ModuleType) and "bokeh_app_" in str(x)] log.debug(f" uncollected modules: {len(objs)}") import pandas as pd objs = [x for x in all_objs if isinstance(x, pd.DataFrame)] log.debug(" uncollected DataFrames: %d", len(objs)) # uncomment (and install pympler) for mem usage by type report # from operator import itemgetter # import pprint # from pympler import tracker # mem = tracker.SummaryTracker() # pprint.pprint(sorted(mem.create_summary(), reverse=True, key=itemgetter(2))[:30]) def _keep_alive(self) -> None: log.trace("Running keep alive job") # type: ignore[attr-defined] for c in list(self._clients): try: c.send_ping() except WebSocketClosedError: self.client_lost(c)
#----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- def create_static_handler(prefix: str, key: str, app: Application) -> tuple[str, type[StaticFileHandler | StaticHandler], dict[str, Any]]: route = prefix route += "/static/(.*)" if key == "/" else key + "/static/(.*)" if app.static_path is not None: return (route, StaticFileHandler, {"path" : app.static_path}) return (route, StaticHandler, {}) #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #----------------------------------------------------------------------------- BokehTornado.__doc__ = format_docstring( BokehTornado.__doc__, DEFAULT_CHECK_UNUSED_MS=DEFAULT_CHECK_UNUSED_MS, DEFAULT_KEEP_ALIVE_MS=DEFAULT_KEEP_ALIVE_MS, DEFAULT_MEM_LOG_FREQ_MS=DEFAULT_MEM_LOG_FREQ_MS, DEFAULT_STATS_LOG_FREQ_MS=DEFAULT_STATS_LOG_FREQ_MS, DEFAULT_UNUSED_LIFETIME_MS=DEFAULT_UNUSED_LIFETIME_MS, DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES=DEFAULT_WEBSOCKET_MAX_MESSAGE_SIZE_BYTES, DEFAULT_SESSION_TOKEN_EXPIRATION=DEFAULT_SESSION_TOKEN_EXPIRATION, ) fixup_windows_event_loop_policy()