X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/d78f0ba80470a33a7a76edfe3ace5108684873cd..2af20f8df88461f2593c7fa0851e3841f20d66c3:/nominatim/tools/replication.py diff --git a/nominatim/tools/replication.py b/nominatim/tools/replication.py index 86405168..846b9c34 100644 --- a/nominatim/tools/replication.py +++ b/nominatim/tools/replication.py @@ -1,34 +1,201 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# This file is part of Nominatim. (https://nominatim.org) +# +# Copyright (C) 2022 by the Nominatim developer community. +# For a full list of authors see the git log. """ Functions for updating a database from a replication source. """ -import datetime +from typing import ContextManager, MutableMapping, Any, Generator, cast, Iterator +from contextlib import contextmanager +import datetime as dt +from enum import Enum import logging +import time +import types +import urllib.request as urlrequest -from osmium.replication.server import ReplicationServer +import requests +from nominatim.db import status +from nominatim.db.connection import Connection +from nominatim.tools.exec_utils import run_osm2pgsql +from nominatim.errors import UsageError -from ..db import status +try: + from osmium.replication.server import ReplicationServer + from osmium import WriteHandler + from osmium import version as pyo_version +except ImportError as exc: + logging.getLogger().critical("pyosmium not installed. Replication functions not available.\n" + "To install pyosmium via pip: pip3 install osmium") + raise UsageError("replication tools not available") from exc LOG = logging.getLogger() -def init_replication(conn, base_url): +def init_replication(conn: Connection, base_url: str, + socket_timeout: int = 60) -> None: """ Set up replication for the server at the given base URL. """ LOG.info("Using replication source: %s", base_url) date = status.compute_database_date(conn) # margin of error to make sure we get all data - date -= datetime.timedelta(hours=3) + date -= dt.timedelta(hours=3) - repl = ReplicationServer(base_url) - - seq = repl.timestamp_to_sequence(date) + with _make_replication_server(base_url, socket_timeout) as repl: + seq = repl.timestamp_to_sequence(date) if seq is None: LOG.fatal("Cannot reach the configured replication service '%s'.\n" "Does the URL point to a directory containing OSM update data?", base_url) - raise RuntimeError("Failed to reach replication service") + raise UsageError("Failed to reach replication service") status.set_status(conn, date=date, seq=seq) - LOG.warning("Updates intialised at sequence %s (%s)", seq, date) + LOG.warning("Updates initialised at sequence %s (%s)", seq, date) + + +def check_for_updates(conn: Connection, base_url: str, + socket_timeout: int = 60) -> int: + """ Check if new data is available from the replication service at the + given base URL. + """ + _, seq, _ = status.get_status(conn) + + if seq is None: + LOG.error("Replication not set up. " + "Please run 'nominatim replication --init' first.") + return 254 + + with _make_replication_server(base_url, socket_timeout) as repl: + state = repl.get_state_info() + + if state is None: + LOG.error("Cannot get state for URL %s.", base_url) + return 253 + + if state.sequence <= seq: + LOG.warning("Database is up to date.") + return 2 + + LOG.warning("New data available (%i => %i).", seq, state.sequence) + return 0 + +class UpdateState(Enum): + """ Possible states after an update has run. + """ + + UP_TO_DATE = 0 + MORE_PENDING = 2 + NO_CHANGES = 3 + + +def update(conn: Connection, options: MutableMapping[str, Any], + socket_timeout: int = 60) -> UpdateState: + """ Update database from the next batch of data. Returns the state of + updates according to `UpdateState`. + """ + startdate, startseq, indexed = status.get_status(conn) + + if startseq is None: + LOG.error("Replication not set up. " + "Please run 'nominatim replication --init' first.") + raise UsageError("Replication not set up.") + + assert startdate is not None + + if not indexed and options['indexed_only']: + LOG.info("Skipping update. There is data that needs indexing.") + return UpdateState.MORE_PENDING + + last_since_update = dt.datetime.now(dt.timezone.utc) - startdate + update_interval = dt.timedelta(seconds=options['update_interval']) + if last_since_update < update_interval: + duration = (update_interval - last_since_update).seconds + LOG.warning("Sleeping for %s sec before next update.", duration) + time.sleep(duration) + + if options['import_file'].exists(): + options['import_file'].unlink() + + # Read updates into file. + with _make_replication_server(options['base_url'], socket_timeout) as repl: + outhandler = WriteHandler(str(options['import_file'])) + endseq = repl.apply_diffs(outhandler, startseq + 1, + max_size=options['max_diff_size'] * 1024) + outhandler.close() + + if endseq is None: + return UpdateState.NO_CHANGES + + run_osm2pgsql_updates(conn, options) + + # Write the current status to the file + endstate = repl.get_state_info(endseq) + status.set_status(conn, endstate.timestamp if endstate else None, + seq=endseq, indexed=False) + + return UpdateState.UP_TO_DATE + + +def run_osm2pgsql_updates(conn: Connection, options: MutableMapping[str, Any]) -> None: + """ Run osm2pgsql in append mode. + """ + # Remove any stale deletion marks. + with conn.cursor() as cur: + cur.execute('TRUNCATE place_to_be_deleted') + conn.commit() + + # Consume updates with osm2pgsql. + options['append'] = True + options['disable_jit'] = conn.server_version_tuple() >= (11, 0) + run_osm2pgsql(options) + + # Handle deletions + with conn.cursor() as cur: + cur.execute('SELECT flush_deleted_places()') + conn.commit() + + +def _make_replication_server(url: str, timeout: int) -> ContextManager[ReplicationServer]: + """ Returns a ReplicationServer in form of a context manager. + + Creates a light wrapper around older versions of pyosmium that did + not support the context manager interface. + """ + if hasattr(ReplicationServer, '__enter__'): + # Patches the open_url function for pyosmium >= 3.2 + # where the socket timeout is no longer respected. + def patched_open_url(self: ReplicationServer, url: urlrequest.Request) -> Any: + """ Download a resource from the given URL and return a byte sequence + of the content. + """ + headers = {"User-Agent" : f"Nominatim (pyosmium/{pyo_version.pyosmium_release})"} + + if self.session is not None: + return self.session.get(url.get_full_url(), + headers=headers, timeout=timeout or None, + stream=True) + + @contextmanager + def _get_url_with_session() -> Iterator[requests.Response]: + with requests.Session() as session: + request = session.get(url.get_full_url(), + headers=headers, timeout=timeout or None, + stream=True) + yield request + + return _get_url_with_session() + + repl = ReplicationServer(url) + setattr(repl, 'open_url', types.MethodType(patched_open_url, repl)) + + return cast(ContextManager[ReplicationServer], repl) + + @contextmanager + def get_cm() -> Generator[ReplicationServer, None, None]: + yield ReplicationServer(url) + + return get_cm()