Update code to refer to "workers". (#15606)

A bunch of comments and variables are out of date and use
obsolete terms.

6 files changed, 14 insertions, 25 deletions

diff --git a/synapse/storage/databases/main/account_data.py b/synapse/storage/databases/main/account_data.py
index a9843f6e17..8f7bdbc61a 100644
--- a/synapse/storage/databases/main/account_data.py
+++ b/synapse/storage/databases/main/account_data.py
@@ -85,13 +85,10 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
                 writers=hs.config.worker.writers.account_data,
             )
         else:
+            # Multiple writers are not supported for SQLite.
+            #
             # We shouldn't be running in worker mode with SQLite, but its useful
             # to support it for unit tests.
-            #
-            # If this process is the writer than we need to use
-            # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
-            # updated over replication. (Multiple writers are not supported for
-            # SQLite).
             self._account_data_id_gen = StreamIdGenerator(
                 db_conn,
                 hs.get_replication_notifier(),
diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index bd07d20171..46fa0a73f9 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -274,11 +274,11 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
     async def invalidate_cache_and_stream(
         self, cache_name: str, keys: Tuple[Any, ...]
     ) -> None:
-        """Invalidates the cache and adds it to the cache stream so slaves
+        """Invalidates the cache and adds it to the cache stream so other workers
         will know to invalidate their caches.
 
-        This should only be used to invalidate caches where slaves won't
-        otherwise know from other replication streams that the cache should
+        This should only be used to invalidate caches where other workers won't
+        otherwise have known from other replication streams that the cache should
         be invalidated.
         """
         cache_func = getattr(self, cache_name, None)
@@ -297,11 +297,11 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
         cache_func: CachedFunction,
         keys: Tuple[Any, ...],
     ) -> None:
-        """Invalidates the cache and adds it to the cache stream so slaves
+        """Invalidates the cache and adds it to the cache stream so other workers
         will know to invalidate their caches.
 
-        This should only be used to invalidate caches where slaves won't
-        otherwise know from other replication streams that the cache should
+        This should only be used to invalidate caches where other workers won't
+        otherwise have known from other replication streams that the cache should
         be invalidated.
         """
         txn.call_after(cache_func.invalidate, keys)
@@ -310,7 +310,7 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
     def _invalidate_all_cache_and_stream(
         self, txn: LoggingTransaction, cache_func: CachedFunction
     ) -> None:
-        """Invalidates the entire cache and adds it to the cache stream so slaves
+        """Invalidates the entire cache and adds it to the cache stream so other workers
         will know to invalidate their caches.
         """
 
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py
index 5503621ad6..a67fdb3c22 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -105,8 +105,6 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
             is_writer=hs.config.worker.worker_app is None,
         )
 
-        # Type-ignore: _device_list_id_gen is mixed in from either DataStore (as a
-        # StreamIdGenerator) or SlavedDataStore (as a SlavedIdTracker).
         device_list_max = self._device_list_id_gen.get_current_token()
         device_list_prefill, min_device_list_id = self.db_pool.get_cache_dict(
             db_conn,
diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py
index 0ff3fc7369..53aa5933d5 100644
--- a/synapse/storage/databases/main/events_worker.py
+++ b/synapse/storage/databases/main/events_worker.py
@@ -213,13 +213,10 @@ class EventsWorkerStore(SQLBaseStore):
                 writers=hs.config.worker.writers.events,
             )
         else:
+            # Multiple writers are not supported for SQLite.
+            #
             # We shouldn't be running in worker mode with SQLite, but its useful
             # to support it for unit tests.
-            #
-            # If this process is the writer than we need to use
-            # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
-            # updated over replication. (Multiple writers are not supported for
-            # SQLite).
             self._stream_id_gen = StreamIdGenerator(
                 db_conn,
                 hs.get_replication_notifier(),
diff --git a/synapse/storage/databases/main/receipts.py b/synapse/storage/databases/main/receipts.py
index 074942b167..5ee5c7ad9f 100644
--- a/synapse/storage/databases/main/receipts.py
+++ b/synapse/storage/databases/main/receipts.py
@@ -85,13 +85,10 @@ class ReceiptsWorkerStore(SQLBaseStore):
         else:
             self._can_write_to_receipts = True
 
+            # Multiple writers are not supported for SQLite.
+            #
             # We shouldn't be running in worker mode with SQLite, but its useful
             # to support it for unit tests.
-            #
-            # If this process is the writer than we need to use
-            # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
-            # updated over replication. (Multiple writers are not supported for
-            # SQLite).
             self._receipts_id_gen = StreamIdGenerator(
                 db_conn,
                 hs.get_replication_notifier(),
diff --git a/synapse/storage/schema/main/delta/34/cache_stream.py b/synapse/storage/schema/main/delta/34/cache_stream.py
index 682c86da1a..882f9b893b 100644
--- a/synapse/storage/schema/main/delta/34/cache_stream.py
+++ b/synapse/storage/schema/main/delta/34/cache_stream.py
@@ -21,7 +21,7 @@ from synapse.storage.prepare_database import get_statements
 logger = logging.getLogger(__name__)
 
 
-# This stream is used to notify replication slaves that some caches have
+# This stream is used to notify workers over replication that some caches have
 # been invalidated that they cannot infer from the other streams.
 CREATE_TABLE = """
 CREATE TABLE cache_invalidation_stream (