Silence "missing contrecord" error.

Commit dd38ff28ad added a new error message "missing contrecord" when
we fail to reassemble a record.  Unfortunately that caused noisy
messages to be logged by pg_waldump at end of segment, and by walsender
when asked to shut down on a segment boundary.

Remove the new error message, so that this condition signals end-of-
WAL without a message.  It's arguably a reportable condition that should
not be silenced while performing crash recovery, but fixing that without
introducing noise in the other cases will require more research.

Back-patch to 15.

Reported-by: Tomas Vondra 
Discussion: https://postgr.es/m/6a1df56e-4656-b3ce-4b7a-a9cb41df8189%40enterprisedb.com

diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 2e7b1ba8e184fe50b88a03443a687f9d17bc9bb0..c9f9f6e98f0faaa1ef76c3e914382586c274abd3 100644 (file)
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -914,15 +914,11 @@ err:
        state->missingContrecPtr = targetPagePtr;
 
        /*
-        * If we got here without reporting an error, report one now so that
-        * XLogPrefetcherReadRecord() doesn't bring us back a second time and
-        * clobber the above state.  Otherwise, the existing error takes
-        * precedence.
+        * If we got here without reporting an error, make sure an error is
+        * queued so that XLogPrefetcherReadRecord() doesn't bring us back a
+        * second time and clobber the above state.
         */
-       if (!state->errormsg_buf[0])
-           report_invalid_record(state,
-                                 "missing contrecord at %X/%X",
-                                 LSN_FORMAT_ARGS(RecPtr));
+       state->errormsg_deferred = true;
    }
 
    if (decoded && decoded->oversized)