static void
cdb_position_to_end(void)
{
XLogRecPtr redoCheckpointLoc;
CheckPoint redoCheckpoint;
XLogRecPtr endLocation;
// Throw in extra new line to make log more readable.
elog(LOG,"--------------------------");
XLogGetRecoveryStart("QDSYNC", "to get initial restart location", &redoCheckpointLoc, &redoCheckpoint);
syncRedoLoc = redoCheckpoint.redo;
// UNDONE: Minimum of redoCheckpointLoc and redoCheckpoint.redo?
XLogScanForStandbyEndLocation(&syncRedoLoc, &endLocation);
ereport(LOG,
(errmsg("QDSYNC: reporting recovery start location %s and scanned end location %s",
XLogLocationToString(&syncRedoLoc),
XLogLocationToString2(&endLocation))));
// Throw in extra new line to make log more readable.
elog(LOG,"--------------------------");
/*
* Open up end location segment and set offset to end.
*/
openXlogEnd(&endLocation);
/*
* Extra reply information that gives our standby master XLOG end location
* to the primary.
*/
putEndLocationReply(&endLocation);
}
static void
WalSendServerDoRequest(WalSendRequest *walSendRequest)
{
bool successful;
struct timeval standbyTimeout;
WalSendServerGetStandbyTimeout(&standbyTimeout);
switch (walSendRequest->command)
{
case PositionToEnd:
elog((Debug_print_qd_mirroring ? LOG : DEBUG5), "PositionToEnd");
successful = write_position_to_end(&originalEndLocation,
NULL, &walsend_shutdown_requested);
if (successful)
elog(LOG,"Standby master returned transaction log end location %s",
XLogLocationToString(&originalEndLocation));
else
{
disableQDMirroring_ConnectionError(
"Unable to connect to standby master and determine transaction log end location",
GetStandbyErrorString());
disconnectMirrorQD_SendClose();
}
break;
case Catchup:
elog((Debug_print_qd_mirroring ? LOG : DEBUG5), "Catchup");
if (isQDMirroringCatchingUp())
{
bool tooFarBehind = false;
elog(LOG,"Current master transaction log is flushed through location %s",
XLogLocationToString(&walSendRequest->flushedLocation));
if (XLByteLT(originalEndLocation, walSendRequest->flushedLocation))
{
/*
* Standby master is behind the primary. Send catchup WAL.
*/
/*
* Use a TRY block to catch errors from our attempt to read
* the primary's WAL. Errors from sending to the standby
* come up as a boolean return (successful).
*/
PG_TRY();
{
successful = XLogCatchupQDMirror(
&originalEndLocation,
&walSendRequest->flushedLocation,
&standbyTimeout,
&walsend_shutdown_requested);
}
PG_CATCH();
{
/*
* Report the error related to reading the primary's WAL
* to the server log
*/
/*
* But first demote the error to something much less
* scary.
*/
if (!elog_demote(WARNING))
{
elog(LOG,"unable to demote error");
PG_RE_THROW();
}
EmitErrorReport();
FlushErrorState();
successful = false;
tooFarBehind = true;
}
PG_END_TRY();
if (successful)
{
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),
"catchup send from standby end %s through primary flushed location %s",
XLogLocationToString(&originalEndLocation),
XLogLocationToString2(&walSendRequest->flushedLocation));
}
}
else if (XLByteEQ(originalEndLocation, walSendRequest->flushedLocation))
{
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),"Mirror was already caught up");
successful = true;
}
else
{
elog(WARNING,"Standby master transaction log location %s is beyond the current master end location %s",
XLogLocationToString(&originalEndLocation),
XLogLocationToString2(&walSendRequest->flushedLocation));
successful = false;
}
if (successful)
{
char detail[200];
int count;
count = snprintf(
detail, sizeof(detail),
"Transaction log copied from locations %s through %s to the standby master",
XLogLocationToString(&originalEndLocation),
XLogLocationToString2(&walSendRequest->flushedLocation));
if (count >= sizeof(detail))
{
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("format command string failure")));
}
enableQDMirroring("Master mirroring is now synchronized", detail);
currentEndLocation = walSendRequest->flushedLocation;
periodicLen = 0;
periodicLocation = currentEndLocation;
}
else
{
if (tooFarBehind)
{
disableQDMirroring_TooFarBehind(
"The current master was unable to synchronize the standby master "
"because the transaction logs on the current master were recycled. "
"A gpinitstandby (at an appropriate time) will be necessary to copy "
"over the whole master database to the standby master so it may be synchronized");
}
else
{
disableQDMirroring_ConnectionError(
"Connection to the standby master was lost during transaction log catchup",
GetStandbyErrorString());
}
disconnectMirrorQD_SendClose();
}
}
else if (isQDMirroringDisabled())
{
elog((Debug_print_qd_mirroring ? LOG : DEBUG5), "Master Mirror Send: Master mirroring not catching-up (state is disabled)");
}
else
{
elog(ERROR,"unexpected master mirroring state %s",
QDMirroringStateString());
}
break;
case WriteWalPages:
if (Debug_print_qd_mirroring)
elog(LOG, "WriteWalPages");
if (isQDMirroringEnabled())
{
char *from;
Size nbytes;
bool more= false;
/*
* For now, save copy of data until flush. This could be
* optimized.
*/
if (saveBuffer == NULL)
{
uint32 totalBufferLen = XLOGbuffers * XLOG_BLCKSZ;
saveBuffer = malloc(totalBufferLen);
if (saveBuffer == NULL)
elog(ERROR,"Could not allocate buffer for xlog data (%d bytes)",
totalBufferLen);
saveBufferLen = 0;
}
XLogGetBuffer(walSendRequest->startidx, walSendRequest->npages,
&from, &nbytes);
if (saveBufferLen == 0)
{
more = false;
writeLogId = walSendRequest->logId;
writeLogSeg = walSendRequest->logSeg;
writeLogOff = walSendRequest->logOff;
memcpy(saveBuffer, from, nbytes);
saveBufferLen = nbytes;
}
else
{
more = true;
memcpy(&saveBuffer[saveBufferLen], from, nbytes);
saveBufferLen += nbytes;
}
if (Debug_print_qd_mirroring)
elog(LOG,
"Master Mirror Send: WriteWalPages (%s) startidx %d, npages %d, timeLineID %d, logId %u, logSeg %u, logOff 0x%X, nbytes 0x%X",
(more ? "more" : "new"),
walSendRequest->startidx,
walSendRequest->npages,
walSendRequest->timeLineID,
walSendRequest->logId,
walSendRequest->logSeg,
walSendRequest->logOff,
(int)nbytes);
}
case FlushWalPages:
if (Debug_print_qd_mirroring)
elog(LOG, "FlushWalPages");
if (isQDMirroringEnabled())
{
char cmd[MAXFNAMELEN + 50];
if (saveBufferLen == 0)
successful = true;
else
{
if (snprintf(cmd, sizeof(cmd),"xlog %d %d %d %d",
writeLogId, writeLogSeg, writeLogOff,
(int)saveBufferLen) >= sizeof(cmd))
elog(ERROR,"could not create cmd for qd mirror logid %d seg %d",
writeLogId, writeLogSeg);
successful = write_qd_sync(cmd, saveBuffer, saveBufferLen,
&standbyTimeout,
&walsend_shutdown_requested);
if (successful)
{
XLogRecPtr oldEndLocation;
oldEndLocation = currentEndLocation;
currentEndLocation.xlogid = writeLogId;
currentEndLocation.xrecoff = writeLogSeg * XLogSegSize + writeLogOff;
if (currentEndLocation.xrecoff >= XLogFileSize)
{
(currentEndLocation.xlogid)++;
currentEndLocation.xrecoff = 0;
}
if (XLByteLT(oldEndLocation,currentEndLocation))
{
periodicLen += saveBufferLen;
if (periodicLen > periodicReportLen)
{
elog(LOG,
"Master mirroring periodic report: %d bytes successfully send to standby master for locations %s through %s",
periodicLen,
XLogLocationToString(&periodicLocation),
XLogLocationToString2(¤tEndLocation));
periodicLen = 0;
periodicLocation = currentEndLocation;
}
}
else
{
if (Debug_print_qd_mirroring)
elog(LOG,
"Send to Master mirror successful. New end location %s (old %s)",
XLogLocationToString(¤tEndLocation),
XLogLocationToString2(&oldEndLocation));
}
}
else
{
disableQDMirroring_ConnectionError(
"Connection to the standby master was lost attempting to send new transaction log",
GetStandbyErrorString());
disconnectMirrorQD_SendClose();
}
/*
* Reset so WriteWalPages can fill the buffer again.
*/
saveBufferLen = 0;
writeLogId = 0;
writeLogSeg = 0;
writeLogOff = 0;
}
if (successful && walSendRequest->haveNewCheckpointLocation)
{
uint32 logid;
uint32 seg;
uint32 offset;
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),"New previous checkpoint location %s",
XLogLocationToString(&walSendRequest->newCheckpointLocation));
XLByteToSeg(walSendRequest->newCheckpointLocation, logid, seg);
offset = walSendRequest->newCheckpointLocation.xrecoff % XLogSegSize;
if (snprintf(cmd, sizeof(cmd),"new_checkpoint_location %d %d %d",
logid, seg, offset) >= sizeof(cmd))
elog(ERROR,"could not create cmd for qd mirror logid %d seg %d offset %d",
logid, seg, offset);
successful = write_qd_sync(cmd, NULL, 0,
NULL, &walsend_shutdown_requested);
if (successful)
{
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),"Send of new checkpoint location to master mirror successful");
}
else
{
disableQDMirroring_ConnectionError(
"Connection to the standby master was lost attempting to send new checkpoint location",
GetStandbyErrorString());
disconnectMirrorQD_SendClose();
}
}
}
else if (isQDMirroringDisabled())
{
elog((Debug_print_qd_mirroring ? LOG : DEBUG5), "Master Mirror Send: Master mirroring not enabled");
}
else
{
elog(ERROR,"unexpected master mirroring state %s",
QDMirroringStateString());
}
break;
case CloseForShutdown:
if (Debug_print_qd_mirroring)
elog(LOG, "CloseForShutdown");
/*
* Do the work we would normally do when signaled to stop.
*/
WalSendServer_ServiceShutdown();
break;
default:
elog(ERROR, "Unknown WalSendRequestCommand %d", walSendRequest->command);
}
}
void
cdb_perform_redo(XLogRecPtr *redoCheckPointLoc, CheckPoint *redoCheckPoint, XLogRecPtr *newCheckpointLoc)
{
CheckPoint oldRedoCheckpoint;
uint32 logid;
uint32 seg;
int nsegsremoved;
if (redoCheckPointLoc->xlogid == 0 && redoCheckPointLoc->xrecoff == 0)
{
XLogGetRecoveryStart("QDSYNC", "for redo apply", redoCheckPointLoc, redoCheckPoint);
}
XLogStandbyRecoverRange(redoCheckPointLoc, redoCheckPoint, newCheckpointLoc);
/*
* Sample the recovery start location now to see if appling redo
* processed checkpoint records and moved the restart location forward.
*/
oldRedoCheckpoint = *redoCheckPoint;
XLogGetRecoveryStart("QDSYNC", "for redo progress check", redoCheckPointLoc, redoCheckPoint);
if (XLByteLT(oldRedoCheckpoint.redo,redoCheckPoint->redo))
{
ereport(LOG,
(errmsg("QDSYNC: transaction redo moved the restart location from %s to %s",
XLogLocationToString(&oldRedoCheckpoint.redo),
XLogLocationToString2(&redoCheckPoint->redo))));
}
else
{
Assert(XLByteEQ(oldRedoCheckpoint.redo,redoCheckPoint->redo));
ereport(LOG,
(errmsg("QDSYNC: transaction redo did not move the restart location %s forward this pass",
XLogLocationToString(&oldRedoCheckpoint.redo))));
return;
}
XLByteToSeg(redoCheckPoint->redo, logid, seg);
/*
* Delete offline log files (those no longer needed even for previous
* checkpoint).
*/
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),
"QDSYNC: keep log files as far back as (logid %d, seg %d)",
logid, seg);
if (logid || seg)
{
PrevLogSeg(logid, seg);
elog((Debug_print_qd_mirroring ? LOG : DEBUG5),
"QDSYNC: delete offline log files up to (logid %d, seg %d)",
logid, seg);
XLogRemoveStandbyLogs(logid, seg, &nsegsremoved);
if (nsegsremoved > 0)
{
// Throw in extra new line to make log more readable.
ereport(LOG,
(errmsg("QDSYNC: %d logs removed through logid %d, seg %d\n",
nsegsremoved,
logid, seg)));
}
}
// Throw in extra new line to make log more readable.
elog(LOG,"--------------------------");
}
