view roundup/actions.py @ 6565:2c2dbfc332ba

Try to handle multiple connections better. The session database is a hot spot. When multiple requests (e.g. 20) come in at the same time session database contention can get great. The original code didn't retry session database access when the open failed. This resulted in errors at the client. The second pass delayed 0.01 seconds and retried. It was better but we still had multiple second stalls. I think the first request got in, everybody else backed up and then retried at the same time. Again they stepped on each other. With logging I would see many counters go all the way to low single digits or to -1 indicating falure. This pass uses randomint to generate delays from 0-.125 seconds in 5ms increments. This performs better in testing. I rarely saw a counter less than 13 (2 failed retries). Current logging starts after 6 failures and counts down until success or failure.
author John Rouillard <rouilj@ieee.org>
date Thu, 16 Dec 2021 20:02:00 -0500
parents 48a1f919f894
children 4c9acc580769
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#
# Copyright (C) 2009 Stefan Seefeld
# All rights reserved.
# For license terms see the file COPYING.txt.
# Actions used in REST and XMLRPC APIs
#

from roundup.exceptions import Unauthorised
from roundup import hyperdb


class Action:
    def __init__(self, db, translator):
        self.db = db
        self.translator = translator

    def handle(self, *args):
        """Action handler procedure"""
        raise NotImplementedError

    def execute(self, *args):
        """Execute the action specified by this object."""

        self.permission(*args)
        return self.handle(*args)

    def permission(self, *args):
        """Check whether the user has permission to execute this action.

        If not, raise Unauthorised."""

        pass

    def gettext(self, msgid):
        """Return the localized translation of msgid"""
        return self.translator.gettext(msgid)

    _ = gettext


class PermCheck(Action):
    def permission(self, designator):

        classname, itemid = hyperdb.splitDesignator(designator)
        perm = self.db.security.hasPermission

        if not perm('Retire', self.db.getuid(), classname=classname,
                    itemid=itemid):
            raise Unauthorised(self._('You do not have permission to retire '
                                      'or restore the %(classname)s class.')
                               % locals())


class Retire(PermCheck):

    def handle(self, designator):

        classname, itemid = hyperdb.splitDesignator(designator)

        # make sure we don't try to retire admin or anonymous
        if (classname == 'user' and
               self.db.user.get(itemid, 'username') in ('admin', 'anonymous')):
            raise ValueError(self._(
                'You may not retire the admin or anonymous user'))

        # do the retire
        self.db.getclass(classname).retire(itemid)
        self.db.commit()


class Restore(PermCheck):

    def handle(self, designator):

        classname, itemid = hyperdb.splitDesignator(designator)

        # do the restore
        self.db.getclass(classname).restore(itemid)
        self.db.commit()

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