Re: BUG #17744: Fail Assert while recoverying from pg_basebackup

At Tue, 10 Jan 2023 07:45:45 +0000, PG Bug reporting form <noreply@postgresql.org> wrote in 
> #2  0x0000000000b378e9 in ExceptionalCondition (
>     conditionName=0xd13697 "TransactionIdIsValid(initial)", 
>     errorType=0xd12df4 "FailedAssertion", fileName=0xd12de8 "procarray.c",
> 
>     lineNumber=1750) at assert.c:69
> #3  0x0000000000962195 in ComputeXidHorizons (h=0x7ffe93de25e0)
>     at procarray.c:1750
> #4  0x00000000009628a3 in GetOldestTransactionIdConsideredRunning ()
>     at procarray.c:2050
> #5  0x00000000005972bf in CreateRestartPoint (flags=256) at xlog.c:7153
> #6  0x00000000008cae37 in CheckpointerMain () at checkpointer.c:464

The function requires a valid value in
ShmemVariableCache->latestCompleteXid. But it is not initialized and
maintained in this case.  The attached quick hack seems working, but
of course more decent fix is needed.


diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 0070d56b0b..667c990301 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -5363,7 +5363,7 @@ StartupXLOG(void)
          * control file and we've established a recovery snapshot from a
          * running-xacts WAL record.
          */
-        if (ArchiveRecoveryRequested && EnableHotStandby)
+        if (1 || (ArchiveRecoveryRequested && EnableHotStandby))
         {
             TransactionId *xids;
             int            nxids;
diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c
index 94cc860f5f..c814c991f8 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -1161,7 +1161,7 @@ standby_redo(XLogReaderState *record)
     Assert(!XLogRecHasAnyBlockRefs(record));
 
     /* Do nothing if we're not in hot standby mode */
-    if (standbyState == STANDBY_DISABLED)
+    if (standbyState == STANDBY_DISABLED && info != XLOG_RUNNING_XACTS)
         return;
 
     if (info == XLOG_STANDBY_LOCK)

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center