Add config settings for background update parameters (#11980)

3 files changed, 72 insertions, 0 deletions

diff --git a/synapse/config/_base.pyi b/synapse/config/_base.pyi
index 1eb5f5a68c..363d8b4554 100644
--- a/synapse/config/_base.pyi
+++ b/synapse/config/_base.pyi
@@ -19,6 +19,7 @@ from synapse.config import (
     api,
     appservice,
     auth,
+    background_updates,
     cache,
     captcha,
     cas,
@@ -113,6 +114,7 @@ class RootConfig:
     caches: cache.CacheConfig
     federation: federation.FederationConfig
     retention: retention.RetentionConfig
+    background_updates: background_updates.BackgroundUpdateConfig
 
     config_classes: List[Type["Config"]] = ...
     def __init__(self) -> None: ...
diff --git a/synapse/config/background_updates.py b/synapse/config/background_updates.py
new file mode 100644
index 0000000000..f6cdeacc4b
--- /dev/null
+++ b/synapse/config/background_updates.py
@@ -0,0 +1,68 @@
+# Copyright 2022 Matrix.org Foundation C.I.C.
+#
+# 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 ._base import Config
+
+
+class BackgroundUpdateConfig(Config):
+    section = "background_updates"
+
+    def generate_config_section(self, **kwargs) -> str:
+        return """\
+        ## Background Updates ##
+
+        # Background updates are database updates that are run in the background in batches.
+        # The duration, minimum batch size, default batch size, whether to sleep between batches and if so, how long to
+        # sleep can all be configured. This is helpful to speed up or slow down the updates.
+        #
+        background_updates:
+            # How long in milliseconds to run a batch of background updates for. Defaults to 100. Uncomment and set
+            # a time to change the default.
+            #
+            #background_update_duration_ms: 500
+
+            # Whether to sleep between updates. Defaults to True. Uncomment to change the default.
+            #
+            #sleep_enabled: false
+
+            # If sleeping between updates, how long in milliseconds to sleep for. Defaults to 1000. Uncomment
+            # and set a duration to change the default.
+            #
+            #sleep_duration_ms: 300
+
+            # Minimum size a batch of background updates can be. Must be greater than 0. Defaults to 1. Uncomment and
+            # set a size to change the default.
+            #
+            #min_batch_size: 10
+
+            # The batch size to use for the first iteration of a new background update. The default is 100.
+            # Uncomment and set a size to change the default.
+            #
+            #default_batch_size: 50
+        """
+
+    def read_config(self, config, **kwargs) -> None:
+        bg_update_config = config.get("background_updates") or {}
+
+        self.update_duration_ms = bg_update_config.get(
+            "background_update_duration_ms", 100
+        )
+
+        self.sleep_enabled = bg_update_config.get("sleep_enabled", True)
+
+        self.sleep_duration_ms = bg_update_config.get("sleep_duration_ms", 1000)
+
+        self.min_batch_size = bg_update_config.get("min_batch_size", 1)
+
+        self.default_batch_size = bg_update_config.get("default_batch_size", 100)
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index 001605c265..a4ec706908 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -16,6 +16,7 @@ from .account_validity import AccountValidityConfig
 from .api import ApiConfig
 from .appservice import AppServiceConfig
 from .auth import AuthConfig
+from .background_updates import BackgroundUpdateConfig
 from .cache import CacheConfig
 from .captcha import CaptchaConfig
 from .cas import CasConfig
@@ -99,4 +100,5 @@ class HomeServerConfig(RootConfig):
         WorkerConfig,
         RedisConfig,
         ExperimentalConfig,
+        BackgroundUpdateConfig,
     ]