On Wed, Jun 30, 2021 at 03:29:41PM +0900, Michael Paquier wrote:
> On Tue, May 18, 2021 at 01:04:18PM +0200, Drouvot, Bertrand wrote:
> > On 5/17/21 8:56 PM, Andres Freund wrote:
> >> On 2021-05-17 20:14:40 +0200, Drouvot, Bertrand wrote:
> >>> I was also wondering if:
> >>>
> >>> * We should keep the old behavior in case pg_resetwal -x is being used
> >>> without -u?
(The proposed patch does not set an arbitrary oldestXID
> >>> anymore in
case -x is used)
> >> I don't think we should. I don't see anything in the old behaviour worth
> >> maintaining.
>
> So, pg_resetwal logic with the oldest XID assignment is causing some
> problem here. This open item is opened for some time now and it is
> idle for a couple of weeks. It looks that we have some solution
> drafted, to be able to move forward, with the following things (no
> patches yet):
> - More robustness safety checks in procarray.c.
> - A rework of oldestXid in pg_resetwal.
>
> Is there somebody working on that?
Bertrand sent a patch which is awaiting review.
This allows both of Tom's reproducers to pass pg_upgrade (with assertions and
delays).
http://cfbot.cputube.org/bertrand-drouvot.html
I re-arranged the pg_upgrade output of that patch: it was in the middle of the
two halves: "Setting next transaction ID and epoch for new cluster"
--
Justin
>From 30204d85005d6288d2dc93bcd28ff4fb2454a703 Mon Sep 17 00:00:00 2001
From: Tom Lane <t...@sss.pgh.pa.us>
Date: Sun, 16 May 2021 16:23:02 -0400
Subject: [PATCH 1/3] prion failed with ERROR: missing chunk number 0 for toast
value 14334 in pg_toast_2619
It also seems like some assertions in procarray.c would be a
good idea. With the attached patch, we get through core
regression just fine, but the pg_upgrade test fails immediately
after the "Resetting WAL archives" step.
---
src/backend/storage/ipc/procarray.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 4c91e721d0..324e105c59 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -2486,6 +2486,15 @@ GetSnapshotData(Snapshot snapshot)
oldestfxid);
/* accurate value known */
GlobalVisTempRels.maybe_needed = GlobalVisTempRels.definitely_needed;
+
+ /* Do basic sanity check on these XIDs */
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisSharedRels.maybe_needed,
+ GlobalVisSharedRels.definitely_needed));
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisCatalogRels.maybe_needed,
+ GlobalVisCatalogRels.definitely_needed));
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisDataRels.maybe_needed,
+ GlobalVisDataRels.definitely_needed));
+ /* not much point in checking GlobalVisTempRels, given the above */
}
RecentXmin = xmin;
@@ -4020,6 +4029,8 @@ GlobalVisTestFor(Relation rel)
Assert(FullTransactionIdIsValid(state->definitely_needed) &&
FullTransactionIdIsValid(state->maybe_needed));
+ Assert(FullTransactionIdPrecedesOrEquals(state->maybe_needed,
+ state->definitely_needed));
return state;
}
@@ -4085,6 +4096,15 @@ GlobalVisUpdateApply(ComputeXidHorizonsResult *horizons)
GlobalVisDataRels.definitely_needed);
GlobalVisTempRels.definitely_needed = GlobalVisTempRels.maybe_needed;
+ /* Do basic sanity check on these XIDs */
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisSharedRels.maybe_needed,
+ GlobalVisSharedRels.definitely_needed));
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisCatalogRels.maybe_needed,
+ GlobalVisCatalogRels.definitely_needed));
+ Assert(FullTransactionIdPrecedesOrEquals(GlobalVisDataRels.maybe_needed,
+ GlobalVisDataRels.definitely_needed));
+ /* not much point in checking GlobalVisTempRels, given the above */
+
ComputeXidHorizonsResultLastXmin = RecentXmin;
}
--
2.17.0
>From 544a88b1651b0db177d5883219c7ae75f1100f7b Mon Sep 17 00:00:00 2001
From: "Drouvot, Bertrand" <bdrou...@amazon.com>
Date: Tue, 18 May 2021 13:26:38 +0200
Subject: [PATCH 2/3] pg_upgrade can result in early wraparound on databases
with high transaction load
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
On 5/4/21 10:17 AM, Drouvot, Bertrand wrote:
Copy/pasting Andres feedback (Thanks Andres for this feedback) on those
questions from another thread [1].
> I was also wondering if:
>
> * We should keep the old behavior in case pg_resetwal -x is being used
> without -u?
(The proposed patch does not set an arbitrary oldestXID
> anymore in
case -x is used)
Andres: I don't think we should. I don't see anything in the old
behaviour worth
maintaining.
> * We should ensure that the xid provided with -x or -u is
> >=
FirstNormalTransactionId (Currently the only check is that it is
> # 0)?
Andres: Applying TransactionIdIsNormal() seems like a good idea.
=> I am attaching a new version that makes use of
TransactionIdIsNormal() checks.
Andres: I think it's important to verify that the xid provided with -x
is within a reasonable range of the oldest xid.
=> What do you mean by "a reasonable range"?
Thanks
Bertrand
---
src/bin/pg_resetwal/pg_resetwal.c | 65 ++++++++++++++++++-------------
src/bin/pg_upgrade/controldata.c | 17 +++++++-
src/bin/pg_upgrade/pg_upgrade.c | 6 +++
src/bin/pg_upgrade/pg_upgrade.h | 1 +
4 files changed, 60 insertions(+), 29 deletions(-)
diff --git a/src/bin/pg_resetwal/pg_resetwal.c b/src/bin/pg_resetwal/pg_resetwal.c
index 805dafef07..5e864760ed 100644
--- a/src/bin/pg_resetwal/pg_resetwal.c
+++ b/src/bin/pg_resetwal/pg_resetwal.c
@@ -65,6 +65,7 @@ static bool guessed = false; /* T if we had to guess at any values */
static const char *progname;
static uint32 set_xid_epoch = (uint32) -1;
static TransactionId set_xid = 0;
+static TransactionId set_oldest_unfrozen_xid = 0;
static TransactionId set_oldest_commit_ts_xid = 0;
static TransactionId set_newest_commit_ts_xid = 0;
static Oid set_oid = 0;
@@ -102,6 +103,7 @@ main(int argc, char *argv[])
{"next-oid", required_argument, NULL, 'o'},
{"multixact-offset", required_argument, NULL, 'O'},
{"next-transaction-id", required_argument, NULL, 'x'},
+ {"oldest-transaction-id", required_argument, NULL, 'u'},
{"wal-segsize", required_argument, NULL, 1},
{NULL, 0, NULL, 0}
};
@@ -135,7 +137,7 @@ main(int argc, char *argv[])
}
- while ((c = getopt_long(argc, argv, "c:D:e:fl:m:no:O:x:", long_options, NULL)) != -1)
+ while ((c = getopt_long(argc, argv, "c:D:e:fl:m:no:O:x:u:", long_options, NULL)) != -1)
{
switch (c)
{
@@ -176,9 +178,24 @@ main(int argc, char *argv[])
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
- if (set_xid == 0)
+ if (!TransactionIdIsNormal(set_xid))
{
- pg_log_error("transaction ID (-x) must not be 0");
+ pg_log_error("transaction ID (-x) must be greater or equal to %u", FirstNormalTransactionId);
+ exit(1);
+ }
+ break;
+
+ case 'u':
+ set_oldest_unfrozen_xid = strtoul(optarg, &endptr, 0);
+ if (endptr == optarg || *endptr != '\0')
+ {
+ pg_log_error("invalid argument for option %s", "-u");
+ fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
+ exit(1);
+ }
+ if (!TransactionIdIsNormal(set_oldest_unfrozen_xid))
+ {
+ pg_log_error("oldest unfrozen transaction ID (-u) must be greater or equal to %u", FirstNormalTransactionId);
exit(1);
}
break;
@@ -429,21 +446,12 @@ main(int argc, char *argv[])
XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
if (set_xid != 0)
- {
ControlFile.checkPointCopy.nextXid =
FullTransactionIdFromEpochAndXid(EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
set_xid);
- /*
- * For the moment, just set oldestXid to a value that will force
- * immediate autovacuum-for-wraparound. It's not clear whether adding
- * user control of this is useful, so let's just do something that's
- * reasonably safe. The magic constant here corresponds to the
- * maximum allowed value of autovacuum_freeze_max_age.
- */
- ControlFile.checkPointCopy.oldestXid = set_xid - 2000000000;
- if (ControlFile.checkPointCopy.oldestXid < FirstNormalTransactionId)
- ControlFile.checkPointCopy.oldestXid += FirstNormalTransactionId;
+ if (set_oldest_unfrozen_xid != 0) {
+ ControlFile.checkPointCopy.oldestXid = set_oldest_unfrozen_xid;
ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
}
@@ -1209,20 +1217,21 @@ usage(void)
printf(_("Usage:\n %s [OPTION]... DATADIR\n\n"), progname);
printf(_("Options:\n"));
printf(_(" -c, --commit-timestamp-ids=XID,XID\n"
- " set oldest and newest transactions bearing\n"
- " commit timestamp (zero means no change)\n"));
- printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
- printf(_(" -e, --epoch=XIDEPOCH set next transaction ID epoch\n"));
- printf(_(" -f, --force force update to be done\n"));
- printf(_(" -l, --next-wal-file=WALFILE set minimum starting location for new WAL\n"));
- printf(_(" -m, --multixact-ids=MXID,MXID set next and oldest multitransaction ID\n"));
- printf(_(" -n, --dry-run no update, just show what would be done\n"));
- printf(_(" -o, --next-oid=OID set next OID\n"));
- printf(_(" -O, --multixact-offset=OFFSET set next multitransaction offset\n"));
- printf(_(" -V, --version output version information, then exit\n"));
- printf(_(" -x, --next-transaction-id=XID set next transaction ID\n"));
- printf(_(" --wal-segsize=SIZE size of WAL segments, in megabytes\n"));
- printf(_(" -?, --help show this help, then exit\n"));
+ " set oldest and newest transactions bearing\n"
+ " commit timestamp (zero means no change)\n"));
+ printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
+ printf(_(" -e, --epoch=XIDEPOCH set next transaction ID epoch\n"));
+ printf(_(" -f, --force force update to be done\n"));
+ printf(_(" -l, --next-wal-file=WALFILE set minimum starting location for new WAL\n"));
+ printf(_(" -m, --multixact-ids=MXID,MXID set next and oldest multitransaction ID\n"));
+ printf(_(" -n, --dry-run no update, just show what would be done\n"));
+ printf(_(" -o, --next-oid=OID set next OID\n"));
+ printf(_(" -O, --multixact-offset=OFFSET set next multitransaction offset\n"));
+ printf(_(" -u, --oldest-transaction-id=XID set oldest unfrozen transaction ID\n"));
+ printf(_(" -V, --version output version information, then exit\n"));
+ printf(_(" -x, --next-transaction-id=XID set next transaction ID\n"));
+ printf(_(" --wal-segsize=SIZE size of WAL segments, in megabytes\n"));
+ printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}
diff --git a/src/bin/pg_upgrade/controldata.c b/src/bin/pg_upgrade/controldata.c
index 4f647cdf33..a4b6375403 100644
--- a/src/bin/pg_upgrade/controldata.c
+++ b/src/bin/pg_upgrade/controldata.c
@@ -44,6 +44,7 @@ get_control_data(ClusterInfo *cluster, bool live_check)
bool got_oid = false;
bool got_multi = false;
bool got_oldestmulti = false;
+ bool got_oldestxid = false;
bool got_mxoff = false;
bool got_nextxlogfile = false;
bool got_float8_pass_by_value = false;
@@ -312,6 +313,17 @@ get_control_data(ClusterInfo *cluster, bool live_check)
cluster->controldata.chkpnt_nxtmulti = str2uint(p);
got_multi = true;
}
+ else if ((p = strstr(bufin, "Latest checkpoint's oldestXID:")) != NULL)
+ {
+ p = strchr(p, ':');
+
+ if (p == NULL || strlen(p) <= 1)
+ pg_fatal("%d: controldata retrieval problem\n", __LINE__);
+
+ p++; /* remove ':' char */
+ cluster->controldata.chkpnt_oldstxid = str2uint(p);
+ got_oldestxid = true;
+ }
else if ((p = strstr(bufin, "Latest checkpoint's oldestMultiXid:")) != NULL)
{
p = strchr(p, ':');
@@ -544,7 +556,7 @@ get_control_data(ClusterInfo *cluster, bool live_check)
/* verify that we got all the mandatory pg_control data */
if (!got_xid || !got_oid ||
- !got_multi ||
+ !got_multi || !got_oldestxid ||
(!got_oldestmulti &&
cluster->controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER) ||
!got_mxoff || (!live_check && !got_nextxlogfile) ||
@@ -575,6 +587,9 @@ get_control_data(ClusterInfo *cluster, bool live_check)
cluster->controldata.cat_ver >= MULTIXACT_FORMATCHANGE_CAT_VER)
pg_log(PG_REPORT, " latest checkpoint oldest MultiXactId\n");
+ if (!got_oldestxid)
+ pg_log(PG_REPORT, " latest checkpoint oldestXID\n");
+
if (!got_mxoff)
pg_log(PG_REPORT, " latest checkpoint next MultiXactOffset\n");
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index e23b8ca88d..0d877f6456 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -485,6 +485,12 @@ copy_xact_xlog_xid(void)
old_cluster.controldata.chkpnt_nxtxid,
new_cluster.pgdata);
check_ok();
+ prep_status("Setting oldest XID for new cluster");
+ exec_prog(UTILITY_LOG_FILE, NULL, true, true,
+ "\"%s/pg_resetwal\" -f -u %u \"%s\"",
+ new_cluster.bindir, old_cluster.controldata.chkpnt_oldstxid,
+ new_cluster.pgdata);
+ check_ok();
/*
* If the old server is before the MULTIXACT_FORMATCHANGE_CAT_VER change
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index f7eb2349e6..db96627ccb 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -207,6 +207,7 @@ typedef struct
uint32 chkpnt_nxtmulti;
uint32 chkpnt_nxtmxoff;
uint32 chkpnt_oldstMulti;
+ uint32 chkpnt_oldstxid;
uint32 align;
uint32 blocksz;
uint32 largesz;
--
2.17.0
