SERVER-37560 Allow change streams to work with speculative majority reads

This patch allows change stream queries to use speculative majority reads so that they can be used even when enableMajorityReadConcern:false. Change stream aggregation commands are allowed to use speculative majority reads as well as 'find' commands that specify a special flag. This commit also enables all change streams tests and suites on the enableMajorityReadConcern:false Evergreen variant. No optimizations for speculative majority change streams are included in this commit.

1 files changed, 8 insertions, 0 deletions

diff --git a/jstests/sharding/change_stream_update_lookup_collation.js b/jstests/sharding/change_stream_update_lookup_collation.js
index 6c57aba30e0..eefff9d463f 100644
--- a/jstests/sharding/change_stream_update_lookup_collation.js
+++ b/jstests/sharding/change_stream_update_lookup_collation.js
@@ -9,6 +9,14 @@
     // For supportsMajorityReadConcern().
     load("jstests/multiVersion/libs/causal_consistency_helpers.js");
 
+    // TODO (SERVER-38673): Remove this once BACKPORT-3428, BACKPORT-3429 are completed.
+    if (!jsTestOptions().enableMajorityReadConcern &&
+        jsTestOptions().mongosBinVersion === 'last-stable') {
+        jsTestLog(
+            "Skipping test since 'last-stable' mongos doesn't support speculative majority update lookup queries.");
+        return;
+    }
+
     if (!supportsMajorityReadConcern()) {
         jsTestLog("Skipping test since storage engine doesn't support majority read concern.");
         return;