Example #1
0
    def acquire(self):
        basedir = os.path.dirname(self.fname)

        if not os.path.exists(basedir):
            fileutils.ensure_tree(basedir)
            LOG.info(_LI('Created lock path: %s'), basedir)

        self.lockfile = open(self.fname, 'w')

        while True:
            try:
                # Using non-blocking locks since green threads are not
                # patched to deal with blocking locking calls.
                # Also upon reading the MSDN docs for locking(), it seems
                # to have a laughable 10 attempts "blocking" mechanism.
                self.trylock()
                LOG.debug('Got file lock "%s"', self.fname)
                return True
            except IOError as e:
                if e.errno in (errno.EACCES, errno.EAGAIN):
                    # external locks synchronise things like iptables
                    # updates - give it some time to prevent busy spinning
                    time.sleep(0.01)
                else:
                    raise threading.ThreadError(_("Unable to acquire lock on"
                                                  " `%(filename)s` due to"
                                                  " %(exception)s") %
                                                {'filename': self.fname,
                                                    'exception': e})
Example #2
0
    def acquire(self):
        basedir = os.path.dirname(self.fname)

        if not os.path.exists(basedir):
            fileutils.ensure_tree(basedir)
            LOG.info(_LI('Created lock path: %s'), basedir)

        self.lockfile = open(self.fname, 'w')

        while True:
            try:
                # Using non-blocking locks since green threads are not
                # patched to deal with blocking locking calls.
                # Also upon reading the MSDN docs for locking(), it seems
                # to have a laughable 10 attempts "blocking" mechanism.
                self.trylock()
                LOG.debug('Got file lock "%s"', self.fname)
                return True
            except IOError as e:
                if e.errno in (errno.EACCES, errno.EAGAIN):
                    # external locks synchronise things like iptables
                    # updates - give it some time to prevent busy spinning
                    time.sleep(0.01)
                else:
                    raise threading.ThreadError(
                        _("Unable to acquire lock on"
                          " `%(filename)s` due to"
                          " %(exception)s") % {
                              'filename': self.fname,
                              'exception': e
                          })
Example #3
0
def drop_old_duplicate_entries_from_table(migrate_engine, table_name, use_soft_delete, *uc_column_names):
    """Drop all old rows having the same values for columns in uc_columns.

    This method drop (or mark ad `deleted` if use_soft_delete is True) old
    duplicate rows form table with name `table_name`.

    :param migrate_engine:  Sqlalchemy engine
    :param table_name:      Table with duplicates
    :param use_soft_delete: If True - values will be marked as `deleted`,
                            if False - values will be removed from table
    :param uc_column_names: Unique constraint columns
    """
    meta = MetaData()
    meta.bind = migrate_engine

    table = Table(table_name, meta, autoload=True)
    columns_for_group_by = [table.c[name] for name in uc_column_names]

    columns_for_select = [func.max(table.c.id)]
    columns_for_select.extend(columns_for_group_by)

    duplicated_rows_select = sqlalchemy.sql.select(
        columns_for_select, group_by=columns_for_group_by, having=func.count(table.c.id) > 1
    )

    for row in migrate_engine.execute(duplicated_rows_select):
        # NOTE(boris-42): Do not remove row that has the biggest ID.
        delete_condition = table.c.id != row[0]
        is_none = None  # workaround for pyflakes
        delete_condition &= table.c.deleted_at == is_none
        for name in uc_column_names:
            delete_condition &= table.c[name] == row[name]

        rows_to_delete_select = sqlalchemy.sql.select([table.c.id]).where(delete_condition)
        for row in migrate_engine.execute(rows_to_delete_select).fetchall():
            LOG.info(
                _LI("Deleting duplicated row with id: %(id)s from table: " "%(table)s")
                % dict(id=row[0], table=table_name)
            )

        if use_soft_delete:
            delete_statement = (
                table.update()
                .where(delete_condition)
                .values(
                    {
                        "deleted": literal_column("id"),
                        "updated_at": literal_column("updated_at"),
                        "deleted_at": timeutils.utcnow(),
                    }
                )
            )
        else:
            delete_statement = table.delete().where(delete_condition)
        migrate_engine.execute(delete_statement)
Example #4
0
    def __init__(cls, names, bases, dict_):
        """Metaclass that allows us to collect decorated periodic tasks."""
        super(_PeriodicTasksMeta, cls).__init__(names, bases, dict_)

        # NOTE(sirp): if the attribute is not present then we must be the base
        # class, so, go ahead an initialize it. If the attribute is present,
        # then we're a subclass so make a copy of it so we don't step on our
        # parent's toes.
        try:
            cls._periodic_tasks = cls._periodic_tasks[:]
        except AttributeError:
            cls._periodic_tasks = []

        try:
            cls._periodic_spacing = cls._periodic_spacing.copy()
        except AttributeError:
            cls._periodic_spacing = {}

        for value in cls.__dict__.values():
            if getattr(value, '_periodic_task', False):
                task = value
                name = task.__name__

                if task._periodic_spacing < 0:
                    LOG.info(_LI('Skipping periodic task %(task)s because '
                                 'its interval is negative'),
                             {'task': name})
                    continue
                if not task._periodic_enabled:
                    LOG.info(_LI('Skipping periodic task %(task)s because '
                                 'it is disabled'),
                             {'task': name})
                    continue

                # A periodic spacing of zero indicates that this task should
                # be run on the default interval to avoid running too
                # frequently.
                if task._periodic_spacing == 0:
                    task._periodic_spacing = DEFAULT_INTERVAL

                cls._periodic_tasks.append((name, task))
                cls._periodic_spacing[name] = task._periodic_spacing
Example #5
0
def remove_external_lock_file(name, lock_file_prefix=None):
    """Remove an external lock file when it's not used anymore
    This will be helpful when we have a lot of lock files
    """
    with internal_lock(name):
        lock_file_path = _get_lock_path(name, lock_file_prefix)
        try:
            os.remove(lock_file_path)
        except OSError:
            LOG.info(_LI('Failed to remove file %(file)s'),
                     {'file': lock_file_path})
Example #6
0
def remove_external_lock_file(name, lock_file_prefix=None):
    """Remove an external lock file when it's not used anymore
    This will be helpful when we have a lot of lock files
    """
    with internal_lock(name):
        lock_file_path = _get_lock_path(name, lock_file_prefix)
        try:
            os.remove(lock_file_path)
        except OSError:
            LOG.info(_LI('Failed to remove file %(file)s'),
                     {'file': lock_file_path})
Example #7
0
    def __init__(cls, names, bases, dict_):
        """Metaclass that allows us to collect decorated periodic tasks."""
        super(_PeriodicTasksMeta, cls).__init__(names, bases, dict_)

        # NOTE(sirp): if the attribute is not present then we must be the base
        # class, so, go ahead an initialize it. If the attribute is present,
        # then we're a subclass so make a copy of it so we don't step on our
        # parent's toes.
        try:
            cls._periodic_tasks = cls._periodic_tasks[:]
        except AttributeError:
            cls._periodic_tasks = []

        try:
            cls._periodic_spacing = cls._periodic_spacing.copy()
        except AttributeError:
            cls._periodic_spacing = {}

        for value in cls.__dict__.values():
            if getattr(value, '_periodic_task', False):
                task = value
                name = task.__name__

                if task._periodic_spacing < 0:
                    LOG.info(_LI('Skipping periodic task %(task)s because '
                                 'its interval is negative'),
                             {'task': name})
                    continue
                if not task._periodic_enabled:
                    LOG.info(_LI('Skipping periodic task %(task)s because '
                                 'it is disabled'),
                             {'task': name})
                    continue

                # A periodic spacing of zero indicates that this task should
                # be run every pass
                if task._periodic_spacing == 0:
                    task._periodic_spacing = None

                cls._periodic_tasks.append((name, task))
                cls._periodic_spacing[name] = task._periodic_spacing
Example #8
0
def initialize_if_enabled():
    backdoor_locals = {
        'exit': _dont_use_this,  # So we don't exit the entire process
        'quit': _dont_use_this,  # So we don't exit the entire process
        'fo': _find_objects,
        'pgt': _print_greenthreads,
        'pnt': _print_nativethreads,
    }

    if CONF.backdoor_port is None:
        return None

    start_port, end_port = _parse_port_range(str(CONF.backdoor_port))

    # NOTE(johannes): The standard sys.displayhook will print the value of
    # the last expression and set it to __builtin__._, which overwrites
    # the __builtin__._ that gettext sets. Let's switch to using pprint
    # since it won't interact poorly with gettext, and it's easier to
    # read the output too.
    def displayhook(val):
        if val is not None:
            pprint.pprint(val)

    sys.displayhook = displayhook

    sock = _listen('localhost', start_port, end_port, eventlet.listen)

    # In the case of backdoor port being zero, a port number is assigned by
    # listen().  In any case, pull the port number out here.
    port = sock.getsockname()[1]
    LOG.info(
        _LI('Eventlet backdoor listening on %(port)s for process %(pid)d') % {
            'port': port,
            'pid': os.getpid()
        })
    eventlet.spawn_n(eventlet.backdoor.backdoor_server,
                     sock,
                     locals=backdoor_locals)
    return port
Example #9
0
def initialize_if_enabled():
    backdoor_locals = {
        'exit': _dont_use_this,      # So we don't exit the entire process
        'quit': _dont_use_this,      # So we don't exit the entire process
        'fo': _find_objects,
        'pgt': _print_greenthreads,
        'pnt': _print_nativethreads,
    }

    if CONF.backdoor_port is None:
        return None

    start_port, end_port = _parse_port_range(str(CONF.backdoor_port))

    # NOTE(johannes): The standard sys.displayhook will print the value of
    # the last expression and set it to __builtin__._, which overwrites
    # the __builtin__._ that gettext sets. Let's switch to using pprint
    # since it won't interact poorly with gettext, and it's easier to
    # read the output too.
    def displayhook(val):
        if val is not None:
            pprint.pprint(val)
    sys.displayhook = displayhook

    sock = _listen('localhost', start_port, end_port, eventlet.listen)

    # In the case of backdoor port being zero, a port number is assigned by
    # listen().  In any case, pull the port number out here.
    port = sock.getsockname()[1]
    LOG.info(
        _LI('Eventlet backdoor listening on %(port)s for process %(pid)d') %
        {'port': port, 'pid': os.getpid()}
    )
    eventlet.spawn_n(eventlet.backdoor.backdoor_server, sock,
                     locals=backdoor_locals)
    return port