From 11482da9077889afd701aa1f7c7b0a4a0cebe5db Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Thu, 18 Nov 2021 16:24:13 -0500
Subject: [PATCH] add min lease renewal time to the config object as well
---
src/_zkapauthorizer/_plugin.py | 57 +----------
src/_zkapauthorizer/config.py | 94 +++++++++++++++++++
src/_zkapauthorizer/lease_maintenance.py | 39 ++++----
src/_zkapauthorizer/tests/strategies.py | 1 +
.../tests/test_lease_maintenance.py | 20 +++-
5 files changed, 137 insertions(+), 74 deletions(-)
create mode 100644 src/_zkapauthorizer/config.py
diff --git a/src/_zkapauthorizer/_plugin.py b/src/_zkapauthorizer/_plugin.py
index fd2a669..2c80e2a 100644
--- a/src/_zkapauthorizer/_plugin.py
+++ b/src/_zkapauthorizer/_plugin.py
@@ -18,7 +18,7 @@ Tahoe-LAFS.
"""
import random
-from datetime import datetime, timedelta
+from datetime import datetime
from functools import partial
from weakref import WeakValueDictionary
@@ -27,13 +27,13 @@ from allmydata.client import _Client
from allmydata.interfaces import IAnnounceableStorageServer, IFoolscapStoragePlugin
from allmydata.node import MissingConfigEntry
from challenge_bypass_ristretto import SigningKey
-from isodate import parse_duration
from twisted.internet.defer import succeed
from twisted.logger import Logger
from twisted.python.filepath import FilePath
from zope.interface import implementer
from .api import ZKAPAuthorizerStorageClient, ZKAPAuthorizerStorageServer
+from .config import lease_maintenance_from_tahoe_config
from .controller import get_redeemer
from .lease_maintenance import (
SERVICE_NAME,
@@ -230,20 +230,7 @@ def _create_maintenance_service(reactor, node_config, client_node):
get_root_nodes=partial(get_root_nodes, client_node, node_config),
storage_broker=client_node.get_storage_broker(),
secret_holder=client_node._secret_holder,
- # The greater the min lease remaining time, the more of each lease
- # period is "wasted" by renewing the lease before it has expired. The
- # premise of ZKAPAuthorizer's use of leases is that if they expire,
- # the storage server is free to reclaim the storage by forgetting
- # about the share. However, since we do not know of any
- # ZKAPAuthorizer-enabled storage grids which will garbage collect
- # shares when leases expire, we have no reason not to use a zero
- # duration here - for now.
- #
- # In the long run, storage servers must run with garbage collection
- # enabled. Ideally, before that happens, we will have a system that
- # doesn't involve trading of wasted lease time against reliability of
- # leases being renewed before the shares are garbage collected.
- min_lease_remaining=timedelta(seconds=0),
+ min_lease_remaining=maint_config.min_lease_remaining,
progress=store.start_lease_maintenance,
get_now=get_now,
)
@@ -256,46 +243,10 @@ def _create_maintenance_service(reactor, node_config, client_node):
reactor,
last_run_path,
random,
- interval_mean=maint_config.crawl_interval_mean,
- interval_range=maint_config.crawl_interval_range,
+ lease_maint_config=maint_config,
)
-def lease_maintenance_from_tahoe_config(node_config):
- # type: (_Config) -> LeaseMaintenanceConfig
- """
- Return a ``LeaseMaintenanceConfig`` representing the values from the given
- configuration object.
- """
- return LeaseMaintenanceConfig(
- crawl_interval_mean=_read_duration(node_config, u"lease.crawl-interval.mean"),
- crawl_interval_range=_read_duration(node_config, u"lease.crawl-interval.range"),
- )
-
-
-def _read_duration(cfg, option):
- """
- Read an ISO8601 "duration" from the ZKAPAuthorizer section of a Tahoe-LAFS
- config.
-
- :param cfg: The Tahoe-LAFS config object to consult.
- :param option: The name of the option to read.
-
- :return: ``None`` if the option is missing, otherwise the parsed duration
- as a ``timedelta``.
- """
- # type: (_Config, str) -> Optional[timedelta]
- section_name = u"storageclient.plugins.privatestorageio-zkapauthz-v1"
- value_str = cfg.get_config(
- section=section_name,
- option=option,
- default=None,
- )
- if value_str is None:
- return None
- return parse_duration(value_str)
-
-
def get_root_nodes(client_node, node_config):
try:
rootcap = node_config.get_private_config(b"rootcap")
diff --git a/src/_zkapauthorizer/config.py b/src/_zkapauthorizer/config.py
new file mode 100644
index 0000000..f91dc35
--- /dev/null
+++ b/src/_zkapauthorizer/config.py
@@ -0,0 +1,94 @@
+# Copyright 2019 PrivateStorage.io, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from datetime import timedelta
+from isodate import parse_duration
+
+from .lease_maintenance import (
+ LeaseMaintenanceConfig,
+)
+
+class _EmptyConfig(object):
+ """
+ Weakly pretend to be a Tahoe-LAFS configuration object with no
+ configuration.
+ """
+ def get_config(self, section, option, default=object(), boolean=False):
+ return default
+
+empty_config = _EmptyConfig()
+
+
+def lease_maintenance_from_tahoe_config(node_config):
+ # type: (_Config) -> LeaseMaintenanceConfig
+ """
+ Return a ``LeaseMaintenanceConfig`` representing the values from the given
+ configuration object.
+ """
+ return LeaseMaintenanceConfig(
+ crawl_interval_mean=_read_duration(
+ node_config,
+ u"lease.crawl-interval.mean",
+ timedelta(days=26),
+ ),
+ crawl_interval_range=_read_duration(
+ node_config,
+ u"lease.crawl-interval.range",
+ timedelta(days=4),
+ ),
+ # The greater the min lease remaining time, the more of each lease
+ # period is "wasted" by renewing the lease before it has expired. The
+ # premise of ZKAPAuthorizer's use of leases is that if they expire,
+ # the storage server is free to reclaim the storage by forgetting
+ # about the share. However, since we do not know of any
+ # ZKAPAuthorizer-enabled storage grids which will garbage collect
+ # shares when leases expire, we have no reason not to use a zero
+ # duration here - for now.
+ #
+ # In the long run, storage servers must run with garbage collection
+ # enabled. Ideally, before that happens, we will have a system that
+ # doesn't involve trading of wasted lease time against reliability of
+ # leases being renewed before the shares are garbage collected.
+ #
+ # Also, since this is configuration, you can set it to something else
+ # if you want.
+ min_lease_remaining=_read_duration(
+ node_config,
+ u"lease.min-time-remaining",
+ timedelta(days=0),
+ ),
+ )
+
+
+def _read_duration(cfg, option, default):
+ """
+ Read an ISO8601 "duration" from the ZKAPAuthorizer section of a Tahoe-LAFS
+ config.
+
+ :param cfg: The Tahoe-LAFS config object to consult.
+ :param option: The name of the option to read.
+
+ :return: ``None`` if the option is missing, otherwise the parsed duration
+ as a ``timedelta``.
+ """
+ # type: (_Config, str) -> Optional[timedelta]
+ section_name = u"storageclient.plugins.privatestorageio-zkapauthz-v1"
+ value_str = cfg.get_config(
+ section=section_name,
+ option=option,
+ default=None,
+ )
+ if value_str is None:
+ return default
+ return parse_duration(value_str)
diff --git a/src/_zkapauthorizer/lease_maintenance.py b/src/_zkapauthorizer/lease_maintenance.py
index d4f010d..37bd85d 100644
--- a/src/_zkapauthorizer/lease_maintenance.py
+++ b/src/_zkapauthorizer/lease_maintenance.py
@@ -357,8 +357,7 @@ def lease_maintenance_service(
reactor,
last_run_path,
random,
- interval_mean=None,
- interval_range=None,
+ lease_maint_config,
):
"""
Get an ``IService`` which will maintain leases on ``root_node`` and any
@@ -377,19 +376,15 @@ def lease_maintenance_service(
:param random: An object like ``random.Random`` which can be used as a
source of scheduling delay.
- :param timedelta interval_mean: The mean time between lease renewal checks.
-
- :param timedelta interval_range: The range of the uniform distribution of
- lease renewal checks (centered on ``interval_mean``).
+ :param lease_maint_config: Configuration for the tweakable lease
+ maintenance parameters.
:param maintain_leases: A no-argument callable which performs a round of
lease-maintenance. The resulting service calls this periodically.
"""
- if interval_mean is None:
- interval_mean = timedelta(days=26)
- if interval_range is None:
- interval_range = timedelta(days=4)
- halfrange = interval_range / 2
+ interval_mean = lease_maint_config.crawl_interval_mean
+ interval_range = lease_maint_config.crawl_interval_range
+ halfrange = lease_maint_config.crawl_interval_range / 2
def sample_interval_distribution():
return timedelta(
@@ -419,11 +414,8 @@ def lease_maintenance_service(
timedelta(0),
)
- def get_config():
- return LeaseMaintenanceConfig(
- crawl_interval_mean=interval_mean,
- crawl_interval_range=interval_range,
- )
+ def get_lease_maint_config():
+ return lease_maint_config
return _FuzzyTimerService(
SERVICE_NAME,
@@ -437,7 +429,7 @@ def lease_maintenance_service(
),
initial_interval,
sample_interval_distribution,
- get_config,
+ get_lease_maint_config,
reactor,
)
@@ -446,10 +438,19 @@ def lease_maintenance_service(
class LeaseMaintenanceConfig(object):
"""
Represent the configuration for a lease maintenance service.
+
+ :ivar crawl_interval_mean: The mean time between lease renewal checks.
+
+ :ivar crawl_interval_range: The range of the uniform distribution of lease
+ renewal checks (centered on ``interval_mean``).
+
+ :ivar min_lease_remaining: The minimum amount of time remaining to allow
+ on a lease without renewing it.
"""
crawl_interval_mean = attr.ib() # type: datetime.timedelta
crawl_interval_range = attr.ib() # type: datetime.timedelta
+ min_lease_remaining = attr.ib() # type: datetime.timedelta
def lease_maintenance_config_to_dict(lease_maint_config):
@@ -461,6 +462,9 @@ def lease_maintenance_config_to_dict(lease_maint_config):
"lease.crawl-interval.range": duration_isoformat(
lease_maint_config.crawl_interval_range,
),
+ "lease.min-time-remaining": duration_isoformat(
+ lease_maint_config.min_lease_remaining,
+ ),
}
@@ -469,6 +473,7 @@ def lease_maintenance_config_from_dict(d):
return LeaseMaintenanceConfig(
crawl_interval_mean=parse_duration(d["lease.crawl-interval.mean"]),
crawl_interval_range=parse_duration(d["lease.crawl-interval.range"]),
+ min_lease_remaining=parse_duration(d["lease.min-time-remaining"]),
)
diff --git a/src/_zkapauthorizer/tests/strategies.py b/src/_zkapauthorizer/tests/strategies.py
index ec952ec..4a61f8c 100644
--- a/src/_zkapauthorizer/tests/strategies.py
+++ b/src/_zkapauthorizer/tests/strategies.py
@@ -379,6 +379,7 @@ def lease_maintenance_configurations():
LeaseMaintenanceConfig,
interval_means(),
timedeltas(min_value=timedelta(0)),
+ timedeltas(min_value=timedelta(0)),
)
diff --git a/src/_zkapauthorizer/tests/test_lease_maintenance.py b/src/_zkapauthorizer/tests/test_lease_maintenance.py
index a0a9c3a..2aa0740 100644
--- a/src/_zkapauthorizer/tests/test_lease_maintenance.py
+++ b/src/_zkapauthorizer/tests/test_lease_maintenance.py
@@ -57,7 +57,9 @@ from twisted.python.filepath import FilePath
from zope.interface import implementer
from ..foolscap import ShareStat
+from ..config import lease_maintenance_from_tahoe_config, empty_config
from ..lease_maintenance import (
+ LeaseMaintenanceConfig,
MemoryMaintenanceObserver,
NoopMaintenanceObserver,
lease_maintenance_config_from_dict,
@@ -78,6 +80,7 @@ from .strategies import (
storage_indexes,
)
+default_lease_maint_config = lease_maintenance_from_tahoe_config(empty_config)
def dummy_maintain_leases():
pass
@@ -237,6 +240,7 @@ class LeaseMaintenanceServiceTests(TestCase):
clock,
FilePath(self.useFixture(TempDir()).join("last-run")),
random,
+ lease_maint_config=default_lease_maint_config,
)
self.assertThat(
service,
@@ -265,8 +269,11 @@ class LeaseMaintenanceServiceTests(TestCase):
clock,
FilePath(self.useFixture(TempDir()).join("last-run")),
random,
- mean,
- range_,
+ LeaseMaintenanceConfig(
+ mean,
+ range_,
+ timedelta(0),
+ ),
)
service.startService()
[maintenance_call] = clock.getDelayedCalls()
@@ -308,8 +315,11 @@ class LeaseMaintenanceServiceTests(TestCase):
clock,
last_run_path,
random,
- mean,
- range_,
+ LeaseMaintenanceConfig(
+ mean,
+ range_,
+ timedelta(0),
+ ),
)
service.startService()
[maintenance_call] = clock.getDelayedCalls()
@@ -355,6 +365,7 @@ class LeaseMaintenanceServiceTests(TestCase):
clock,
FilePath(self.useFixture(TempDir()).join("last-run")),
random,
+ lease_maint_config=default_lease_maint_config,
)
service.startService()
self.assertThat(
@@ -388,6 +399,7 @@ class LeaseMaintenanceServiceTests(TestCase):
clock,
FilePath(self.useFixture(TempDir()).join("last-run")),
random,
+ lease_maint_config=default_lease_maint_config,
)
service.startService()
[maintenance_call] = clock.getDelayedCalls()
--
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