Re: Fix 035_standby_logical_decoding.pl race conditions

On Tue, Apr 08, 2025 at 02:00:35AM +0000, Hayato Kuroda (Fujitsu) wrote:
> Your patch looks good to me and it could pass on my env. PSA patches for PG16.
> Patch for PG17 is not changed, just renamed.

@@ -1287,6 +1288,17 @@ LogStandbySnapshot(void)
 
     Assert(XLogStandbyInfoActive());
 
+#ifdef USE_INJECTION_POINTS
+    if (IS_INJECTION_POINT_ATTACHED("skip-log-running-xacts"))
+    {
+        /*
+         * This record could move slot's xmin forward during decoding, leading
+         * to unpredictable results, so skip it when requested by the test.
+         */
+        return GetInsertRecPtr();
+    }
+#endif

I have unfortunately not been able to pay much attention to this
thread, but using an injection point as a trick to disable the
generation of these random standby snapshot records is an interesting
approach to stabilize the test, and it should make it faster as well.
Nice.
--
Michael