Clarify that deprioritized servers are only for sharded

mongodb · Aug 21, 2023 · 4a98a13 · 4a98a13
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commit 4a98a13
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Showing 3 changed files with 13 additions and 9 deletions.
diff --git a/source/retryable-reads/retryable-reads.rst b/source/retryable-reads/retryable-reads.rst
@@ -268,7 +268,7 @@ selecting a server for a retry attempt.
 3a. Selecting the server for retry
 ''''''''''''''''''''''''''''''''''
 
-In sharded topology, the server on which the operation failed MUST be provided
+In sharded cluster, the server on which the operation failed MUST be provided
 to the server selection mechanism as a deprioritized server.
 
 If the driver cannot select a server for
@@ -692,7 +692,7 @@ degraded performance can simply disable ``retryableReads``.
 Changelog
 =========
 
-:2023-08-??: Require that in a sharded topology the server on which the
+:2023-08-??: Require that in a sharded cluster the server on which the
  operation failed MUST be provided to the server selection
  mechanism as a deprioritized server.
 :2022-11-09: CLAM must apply both events and log messages.

diff --git a/source/retryable-writes/retryable-writes.rst b/source/retryable-writes/retryable-writes.rst
@@ -395,8 +395,8 @@ of the following conditions is reached:
  <../client-side-operations-timeout/client-side-operations-timeout.rst#retryability>`__.
 - CSOT is not enabled and one retry was attempted.
 
-For each retry attempt, drivers MUST select a writable server. In sharded
-topology, the server on which the operation failed MUST be provided to
+For each retry attempt, drivers MUST select a writable server. In a sharded
+cluster, the server on which the operation failed MUST be provided to
 the server selection mechanism as a deprioritized server.
 
 If the driver cannot select a server for a retry attempt
@@ -829,7 +829,7 @@ inconsistent with the server and potentially confusing to developers.
 Changelog
 =========
 
-:2023-08-??: Require that in a sharded topology the server on which the
+:2023-08-??: Require that in a sharded cluster the server on which the
  operation failed MUST be provided to the server selection
  mechanism as a deprioritized server.
 :2022-11-17: Add logic for persisting "currentError" as "previousError" on first

diff --git a/source/server-selection/server-selection.rst b/source/server-selection/server-selection.rst
@@ -843,9 +843,11 @@ For multi-threaded clients, the server selection algorithm is as follows:
 2. If the topology wire version is invalid, raise an error and log a
  `"Server selection failed" message`_.
 
-3. Find suitable servers by topology type and operation type. In the case of
- sharded clusters, a list of deprioritized servers may be provided;
+3. Find suitable servers by topology type and operation type. If a list of
+ deprioritized servers is provided, and the topology is sharded cluster,
  these servers should be selected only if there are no other suitable servers.
+ The server selection algorithm MUST ignore the deprioritized servers if the
+ topology is not sharded cluster.
 
 4. Filter the suitable servers by calling the optional, application-provided server
  selector.
@@ -917,9 +919,11 @@ as follows:
 5. If the topology wire version is invalid, raise an error and log a
  `"Server selection failed" message`_.
 
-6. Find suitable servers by topology type and operation type. In the case of
- sharded clusters, a list of deprioritized servers may be provided;
+6. Find suitable servers by topology type and operation type. If a list of
+ deprioritized servers is provided, and the topology is sharded cluster,
  these servers should be selected only if there are no other suitable servers.
+ The server selection algorithm MUST ignore the deprioritized servers if the
+ topology is not sharded cluster.
 
 7. Filter the suitable servers by calling the optional, application-provided
  server selector.