Ensure that the sync slots reach a consistent state after promotion without losing data.
We were directly copying the LSN locations while syncing the slots on the standby. Now, it is possible that at some particular restart_lsn there are some running xacts, which means if we start reading the WAL from that location after promotion, we won't reach a consistent snapshot state at that point. However, on the primary, we would have already been in a consistent snapshot state at that restart_lsn so we would have just serialized the existing snapshot. To avoid this problem we will use the advance_slot functionality unless the snapshot already exists at the synced restart_lsn location. This will help us to ensure that snapbuilder/slot statuses are updated properly without generating any changes. Note that the synced slot will remain as RS_TEMPORARY till the decoding from corresponding restart_lsn can reach a consistent snapshot state after which they will be marked as RS_PERSISTENT. Per buildfarm Author: Hou Zhijie Reviewed-by: Bertrand Drouvot, Shveta Malik, Bharath Rupireddy, Amit Kapila Discussion: https://postgr.es/m/OS0PR01MB5716B3942AE49F3F725ACA92943B2@OS0PR01MB5716.jpnprd01.prod.outlook.com
This commit is contained in:
parent
e37662f221
commit
2ec005b4e2
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@ -36,6 +36,7 @@
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#include "replication/decode.h"
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#include "replication/logical.h"
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#include "replication/reorderbuffer.h"
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#include "replication/slotsync.h"
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#include "replication/snapbuild.h"
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#include "storage/proc.h"
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#include "storage/procarray.h"
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@ -516,17 +517,23 @@ CreateDecodingContext(XLogRecPtr start_lsn,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("cannot use physical replication slot for logical decoding")));
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if (slot->data.database != MyDatabaseId)
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/*
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* We need to access the system tables during decoding to build the
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* logical changes unless we are in fast_forward mode where no changes are
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* generated.
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*/
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if (slot->data.database != MyDatabaseId && !fast_forward)
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("replication slot \"%s\" was not created in this database",
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NameStr(slot->data.name))));
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/*
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* Do not allow consumption of a "synchronized" slot until the standby
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* gets promoted.
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* The slots being synced from the primary can't be used for decoding as
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* they are used after failover. However, we do allow advancing the LSNs
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* during the synchronization of slots. See update_local_synced_slot.
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*/
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if (RecoveryInProgress() && slot->data.synced)
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if (RecoveryInProgress() && slot->data.synced && !IsSyncingReplicationSlots())
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ereport(ERROR,
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errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("cannot use replication slot \"%s\" for logical decoding",
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@ -2034,3 +2041,135 @@ LogicalReplicationSlotHasPendingWal(XLogRecPtr end_of_wal)
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return has_pending_wal;
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}
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/*
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* Helper function for advancing our logical replication slot forward.
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*
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* The slot's restart_lsn is used as start point for reading records, while
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* confirmed_flush is used as base point for the decoding context.
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*
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* We cannot just do LogicalConfirmReceivedLocation to update confirmed_flush,
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* because we need to digest WAL to advance restart_lsn allowing to recycle
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* WAL and removal of old catalog tuples. As decoding is done in fast_forward
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* mode, no changes are generated anyway.
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*
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* *found_consistent_snapshot will be true if the initial decoding snapshot has
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* been built; Otherwise, it will be false.
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*/
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XLogRecPtr
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LogicalSlotAdvanceAndCheckSnapState(XLogRecPtr moveto,
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bool *found_consistent_snapshot)
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{
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LogicalDecodingContext *ctx;
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ResourceOwner old_resowner = CurrentResourceOwner;
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XLogRecPtr retlsn;
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Assert(moveto != InvalidXLogRecPtr);
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if (found_consistent_snapshot)
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*found_consistent_snapshot = false;
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PG_TRY();
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{
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/*
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* Create our decoding context in fast_forward mode, passing start_lsn
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* as InvalidXLogRecPtr, so that we start processing from my slot's
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* confirmed_flush.
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*/
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ctx = CreateDecodingContext(InvalidXLogRecPtr,
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NIL,
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true, /* fast_forward */
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XL_ROUTINE(.page_read = read_local_xlog_page,
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.segment_open = wal_segment_open,
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.segment_close = wal_segment_close),
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NULL, NULL, NULL);
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/*
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* Wait for specified streaming replication standby servers (if any)
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* to confirm receipt of WAL up to moveto lsn.
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*/
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WaitForStandbyConfirmation(moveto);
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/*
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* Start reading at the slot's restart_lsn, which we know to point to
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* a valid record.
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*/
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XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
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/* invalidate non-timetravel entries */
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InvalidateSystemCaches();
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/* Decode records until we reach the requested target */
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while (ctx->reader->EndRecPtr < moveto)
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{
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char *errm = NULL;
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XLogRecord *record;
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/*
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* Read records. No changes are generated in fast_forward mode,
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* but snapbuilder/slot statuses are updated properly.
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*/
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record = XLogReadRecord(ctx->reader, &errm);
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if (errm)
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elog(ERROR, "could not find record while advancing replication slot: %s",
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errm);
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/*
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* Process the record. Storage-level changes are ignored in
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* fast_forward mode, but other modules (such as snapbuilder)
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* might still have critical updates to do.
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*/
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if (record)
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LogicalDecodingProcessRecord(ctx, ctx->reader);
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CHECK_FOR_INTERRUPTS();
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}
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if (found_consistent_snapshot && DecodingContextReady(ctx))
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*found_consistent_snapshot = true;
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/*
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* Logical decoding could have clobbered CurrentResourceOwner during
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* transaction management, so restore the executor's value. (This is
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* a kluge, but it's not worth cleaning up right now.)
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*/
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CurrentResourceOwner = old_resowner;
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if (ctx->reader->EndRecPtr != InvalidXLogRecPtr)
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{
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LogicalConfirmReceivedLocation(moveto);
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/*
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* If only the confirmed_flush LSN has changed the slot won't get
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* marked as dirty by the above. Callers on the walsender
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* interface are expected to keep track of their own progress and
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* don't need it written out. But SQL-interface users cannot
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* specify their own start positions and it's harder for them to
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* keep track of their progress, so we should make more of an
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* effort to save it for them.
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*
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* Dirty the slot so it is written out at the next checkpoint. The
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* LSN position advanced to may still be lost on a crash but this
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* makes the data consistent after a clean shutdown.
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*/
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ReplicationSlotMarkDirty();
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}
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retlsn = MyReplicationSlot->data.confirmed_flush;
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/* free context, call shutdown callback */
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FreeDecodingContext(ctx);
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InvalidateSystemCaches();
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}
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PG_CATCH();
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{
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/* clear all timetravel entries */
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InvalidateSystemCaches();
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PG_RE_THROW();
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}
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PG_END_TRY();
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return retlsn;
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}
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@ -25,6 +25,15 @@
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* which slot sync worker can perform the sync periodically or user can call
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* pg_sync_replication_slots() periodically to perform the syncs.
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*
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* If synchronized slots fail to build a consistent snapshot from the
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* restart_lsn before reaching confirmed_flush_lsn, they would become
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* unreliable after promotion due to potential data loss from changes
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* before reaching a consistent point. This can happen because the slots can
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* be synced at some random time and we may not reach the consistent point
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* at the same WAL location as the primary. So, we mark such slots as
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* RS_TEMPORARY. Once the decoding from corresponding LSNs can reach a
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* consistent point, they will be marked as RS_PERSISTENT.
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*
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* The slot sync worker waits for some time before the next synchronization,
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* with the duration varying based on whether any slots were updated during
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* the last cycle. Refer to the comments above wait_for_slot_activity() for
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@ -49,8 +58,9 @@
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#include "postmaster/fork_process.h"
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#include "postmaster/interrupt.h"
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#include "postmaster/postmaster.h"
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#include "replication/slot.h"
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#include "replication/logical.h"
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#include "replication/slotsync.h"
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#include "replication/snapbuild.h"
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#include "storage/ipc.h"
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#include "storage/lmgr.h"
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#include "storage/proc.h"
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@ -147,50 +157,85 @@ static void slotsync_failure_callback(int code, Datum arg);
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*
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* If no update was needed (the data of the remote slot is the same as the
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* local slot) return false, otherwise true.
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*
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* *found_consistent_snapshot will be true iff the remote slot's LSN or xmin is
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* modified, and decoding from the corresponding LSN's can reach a
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* consistent snapshot.
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*/
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static bool
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update_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid)
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update_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid,
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bool *found_consistent_snapshot)
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{
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ReplicationSlot *slot = MyReplicationSlot;
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bool xmin_changed;
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bool restart_lsn_changed;
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NameData plugin_name;
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bool slot_updated = false;
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Assert(slot->data.invalidated == RS_INVAL_NONE);
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xmin_changed = (remote_slot->catalog_xmin != slot->data.catalog_xmin);
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restart_lsn_changed = (remote_slot->restart_lsn != slot->data.restart_lsn);
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if (found_consistent_snapshot)
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*found_consistent_snapshot = false;
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if (!xmin_changed &&
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!restart_lsn_changed &&
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remote_dbid == slot->data.database &&
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remote_slot->two_phase == slot->data.two_phase &&
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remote_slot->failover == slot->data.failover &&
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remote_slot->confirmed_lsn == slot->data.confirmed_flush &&
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strcmp(remote_slot->plugin, NameStr(slot->data.plugin)) == 0)
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return false;
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if (remote_slot->confirmed_lsn != slot->data.confirmed_flush ||
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remote_slot->restart_lsn != slot->data.restart_lsn ||
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remote_slot->catalog_xmin != slot->data.catalog_xmin)
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{
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/*
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* We can't directly copy the remote slot's LSN or xmin unless there
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* exists a consistent snapshot at that point. Otherwise, after
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* promotion, the slots may not reach a consistent point before the
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* confirmed_flush_lsn which can lead to a data loss. To avoid data
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* loss, we let slot machinery advance the slot which ensures that
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* snapbuilder/slot statuses are updated properly.
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*/
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if (SnapBuildSnapshotExists(remote_slot->restart_lsn))
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{
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/*
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* Update the slot info directly if there is a serialized snapshot
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* at the restart_lsn, as the slot can quickly reach consistency
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* at restart_lsn by restoring the snapshot.
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*/
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SpinLockAcquire(&slot->mutex);
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slot->data.restart_lsn = remote_slot->restart_lsn;
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slot->data.confirmed_flush = remote_slot->confirmed_lsn;
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slot->data.catalog_xmin = remote_slot->catalog_xmin;
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slot->effective_catalog_xmin = remote_slot->catalog_xmin;
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SpinLockRelease(&slot->mutex);
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/* Avoid expensive operations while holding a spinlock. */
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namestrcpy(&plugin_name, remote_slot->plugin);
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if (found_consistent_snapshot)
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*found_consistent_snapshot = true;
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}
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else
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{
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LogicalSlotAdvanceAndCheckSnapState(remote_slot->confirmed_lsn,
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found_consistent_snapshot);
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}
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SpinLockAcquire(&slot->mutex);
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slot->data.plugin = plugin_name;
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slot->data.database = remote_dbid;
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slot->data.two_phase = remote_slot->two_phase;
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slot->data.failover = remote_slot->failover;
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slot->data.restart_lsn = remote_slot->restart_lsn;
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slot->data.confirmed_flush = remote_slot->confirmed_lsn;
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slot->data.catalog_xmin = remote_slot->catalog_xmin;
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slot->effective_catalog_xmin = remote_slot->catalog_xmin;
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SpinLockRelease(&slot->mutex);
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if (xmin_changed)
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ReplicationSlotsComputeRequiredXmin(false);
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if (restart_lsn_changed)
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ReplicationSlotsComputeRequiredLSN();
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return true;
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slot_updated = true;
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}
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if (remote_dbid != slot->data.database ||
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remote_slot->two_phase != slot->data.two_phase ||
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remote_slot->failover != slot->data.failover ||
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strcmp(remote_slot->plugin, NameStr(slot->data.plugin)) != 0)
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{
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NameData plugin_name;
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/* Avoid expensive operations while holding a spinlock. */
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namestrcpy(&plugin_name, remote_slot->plugin);
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SpinLockAcquire(&slot->mutex);
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slot->data.plugin = plugin_name;
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slot->data.database = remote_dbid;
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slot->data.two_phase = remote_slot->two_phase;
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slot->data.failover = remote_slot->failover;
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SpinLockRelease(&slot->mutex);
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slot_updated = true;
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}
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return slot_updated;
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}
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/*
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@ -413,6 +458,7 @@ static bool
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update_and_persist_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid)
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{
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ReplicationSlot *slot = MyReplicationSlot;
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bool found_consistent_snapshot = false;
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/*
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* Check if the primary server has caught up. Refer to the comment atop
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@ -443,9 +489,22 @@ update_and_persist_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid)
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return false;
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}
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/* First time slot update, the function must return true */
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if (!update_local_synced_slot(remote_slot, remote_dbid))
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elog(ERROR, "failed to update slot");
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(void) update_local_synced_slot(remote_slot, remote_dbid,
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&found_consistent_snapshot);
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/*
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* Don't persist the slot if it cannot reach the consistent point from the
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* restart_lsn. See comments atop this file.
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*/
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if (!found_consistent_snapshot)
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{
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ereport(LOG,
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errmsg("could not sync slot \"%s\"", remote_slot->name),
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errdetail("Logical decoding cannot find consistent point from local slot's LSN %X/%X.",
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LSN_FORMAT_ARGS(slot->data.restart_lsn)));
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return false;
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}
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ReplicationSlotPersist();
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|
@ -578,7 +637,7 @@ synchronize_one_slot(RemoteSlot *remote_slot, Oid remote_dbid)
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LSN_FORMAT_ARGS(remote_slot->restart_lsn));
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/* Make sure the slot changes persist across server restart */
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if (update_local_synced_slot(remote_slot, remote_dbid))
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if (update_local_synced_slot(remote_slot, remote_dbid, NULL))
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{
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ReplicationSlotMarkDirty();
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ReplicationSlotSave();
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|
|
|
@ -2134,3 +2134,26 @@ CheckPointSnapBuild(void)
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}
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FreeDir(snap_dir);
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}
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/*
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* Check if a logical snapshot at the specified point has been serialized.
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*/
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bool
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SnapBuildSnapshotExists(XLogRecPtr lsn)
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{
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char path[MAXPGPATH];
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int ret;
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struct stat stat_buf;
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sprintf(path, "pg_logical/snapshots/%X-%X.snap",
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LSN_FORMAT_ARGS(lsn));
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ret = stat(path, &stat_buf);
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|
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if (ret != 0 && errno != ENOENT)
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ereport(ERROR,
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||||
(errcode_for_file_access(),
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errmsg("could not stat file \"%s\": %m", path)));
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return ret == 0;
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}
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||||
|
|
|
@ -492,125 +492,13 @@ pg_physical_replication_slot_advance(XLogRecPtr moveto)
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|||
}
|
||||
|
||||
/*
|
||||
* Helper function for advancing our logical replication slot forward.
|
||||
*
|
||||
* The slot's restart_lsn is used as start point for reading records, while
|
||||
* confirmed_flush is used as base point for the decoding context.
|
||||
*
|
||||
* We cannot just do LogicalConfirmReceivedLocation to update confirmed_flush,
|
||||
* because we need to digest WAL to advance restart_lsn allowing to recycle
|
||||
* WAL and removal of old catalog tuples. As decoding is done in fast_forward
|
||||
* mode, no changes are generated anyway.
|
||||
* Advance our logical replication slot forward. See
|
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* LogicalSlotAdvanceAndCheckSnapState for details.
|
||||
*/
|
||||
static XLogRecPtr
|
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pg_logical_replication_slot_advance(XLogRecPtr moveto)
|
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{
|
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LogicalDecodingContext *ctx;
|
||||
ResourceOwner old_resowner = CurrentResourceOwner;
|
||||
XLogRecPtr retlsn;
|
||||
|
||||
Assert(moveto != InvalidXLogRecPtr);
|
||||
|
||||
PG_TRY();
|
||||
{
|
||||
/*
|
||||
* Create our decoding context in fast_forward mode, passing start_lsn
|
||||
* as InvalidXLogRecPtr, so that we start processing from my slot's
|
||||
* confirmed_flush.
|
||||
*/
|
||||
ctx = CreateDecodingContext(InvalidXLogRecPtr,
|
||||
NIL,
|
||||
true, /* fast_forward */
|
||||
XL_ROUTINE(.page_read = read_local_xlog_page,
|
||||
.segment_open = wal_segment_open,
|
||||
.segment_close = wal_segment_close),
|
||||
NULL, NULL, NULL);
|
||||
|
||||
/*
|
||||
* Wait for specified streaming replication standby servers (if any)
|
||||
* to confirm receipt of WAL up to moveto lsn.
|
||||
*/
|
||||
WaitForStandbyConfirmation(moveto);
|
||||
|
||||
/*
|
||||
* Start reading at the slot's restart_lsn, which we know to point to
|
||||
* a valid record.
|
||||
*/
|
||||
XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
|
||||
|
||||
/* invalidate non-timetravel entries */
|
||||
InvalidateSystemCaches();
|
||||
|
||||
/* Decode records until we reach the requested target */
|
||||
while (ctx->reader->EndRecPtr < moveto)
|
||||
{
|
||||
char *errm = NULL;
|
||||
XLogRecord *record;
|
||||
|
||||
/*
|
||||
* Read records. No changes are generated in fast_forward mode,
|
||||
* but snapbuilder/slot statuses are updated properly.
|
||||
*/
|
||||
record = XLogReadRecord(ctx->reader, &errm);
|
||||
if (errm)
|
||||
elog(ERROR, "could not find record while advancing replication slot: %s",
|
||||
errm);
|
||||
|
||||
/*
|
||||
* Process the record. Storage-level changes are ignored in
|
||||
* fast_forward mode, but other modules (such as snapbuilder)
|
||||
* might still have critical updates to do.
|
||||
*/
|
||||
if (record)
|
||||
LogicalDecodingProcessRecord(ctx, ctx->reader);
|
||||
|
||||
CHECK_FOR_INTERRUPTS();
|
||||
}
|
||||
|
||||
/*
|
||||
* Logical decoding could have clobbered CurrentResourceOwner during
|
||||
* transaction management, so restore the executor's value. (This is
|
||||
* a kluge, but it's not worth cleaning up right now.)
|
||||
*/
|
||||
CurrentResourceOwner = old_resowner;
|
||||
|
||||
if (ctx->reader->EndRecPtr != InvalidXLogRecPtr)
|
||||
{
|
||||
LogicalConfirmReceivedLocation(moveto);
|
||||
|
||||
/*
|
||||
* If only the confirmed_flush LSN has changed the slot won't get
|
||||
* marked as dirty by the above. Callers on the walsender
|
||||
* interface are expected to keep track of their own progress and
|
||||
* don't need it written out. But SQL-interface users cannot
|
||||
* specify their own start positions and it's harder for them to
|
||||
* keep track of their progress, so we should make more of an
|
||||
* effort to save it for them.
|
||||
*
|
||||
* Dirty the slot so it is written out at the next checkpoint. The
|
||||
* LSN position advanced to may still be lost on a crash but this
|
||||
* makes the data consistent after a clean shutdown.
|
||||
*/
|
||||
ReplicationSlotMarkDirty();
|
||||
}
|
||||
|
||||
retlsn = MyReplicationSlot->data.confirmed_flush;
|
||||
|
||||
/* free context, call shutdown callback */
|
||||
FreeDecodingContext(ctx);
|
||||
|
||||
InvalidateSystemCaches();
|
||||
}
|
||||
PG_CATCH();
|
||||
{
|
||||
/* clear all timetravel entries */
|
||||
InvalidateSystemCaches();
|
||||
|
||||
PG_RE_THROW();
|
||||
}
|
||||
PG_END_TRY();
|
||||
|
||||
return retlsn;
|
||||
return LogicalSlotAdvanceAndCheckSnapState(moveto, NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
@ -149,5 +149,7 @@ extern void ResetLogicalStreamingState(void);
|
|||
extern void UpdateDecodingStats(LogicalDecodingContext *ctx);
|
||||
|
||||
extern bool LogicalReplicationSlotHasPendingWal(XLogRecPtr end_of_wal);
|
||||
extern XLogRecPtr LogicalSlotAdvanceAndCheckSnapState(XLogRecPtr moveto,
|
||||
bool *found_consistent_snapshot);
|
||||
|
||||
#endif
|
||||
|
|
|
@ -91,4 +91,6 @@ extern void SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn,
|
|||
struct xl_running_xacts *running);
|
||||
extern void SnapBuildSerializationPoint(SnapBuild *builder, XLogRecPtr lsn);
|
||||
|
||||
extern bool SnapBuildSnapshotExists(XLogRecPtr lsn);
|
||||
|
||||
#endif /* SNAPBUILD_H */
|
||||
|
|
|
@ -365,6 +365,68 @@ ok( $stderr =~
|
|||
|
||||
$cascading_standby->stop;
|
||||
|
||||
##################################################
|
||||
# Create a failover slot and advance the restart_lsn to a position where a
|
||||
# running transaction exists. This setup is for testing that the synced slots
|
||||
# can achieve the consistent snapshot state starting from the restart_lsn
|
||||
# after promotion without losing any data that otherwise would have been
|
||||
# received from the primary.
|
||||
##################################################
|
||||
|
||||
$primary->safe_psql('postgres',
|
||||
"SELECT pg_create_logical_replication_slot('snap_test_slot', 'test_decoding', false, false, true);"
|
||||
);
|
||||
|
||||
$standby1->safe_psql('postgres', "SELECT pg_sync_replication_slots();");
|
||||
|
||||
# Two xl_running_xacts logs are generated here. When decoding the first log, it
|
||||
# only serializes the snapshot, without advancing the restart_lsn to the latest
|
||||
# position. This is because if a transaction is running, the restart_lsn can
|
||||
# only move to a position before that transaction. Hence, the second
|
||||
# xl_running_xacts log is needed, the decoding for which allows the restart_lsn
|
||||
# to advance to the last serialized snapshot's position (the first log).
|
||||
$primary->safe_psql(
|
||||
'postgres', qq(
|
||||
BEGIN;
|
||||
SELECT txid_current();
|
||||
SELECT pg_log_standby_snapshot();
|
||||
COMMIT;
|
||||
BEGIN;
|
||||
SELECT txid_current();
|
||||
SELECT pg_log_standby_snapshot();
|
||||
COMMIT;
|
||||
));
|
||||
|
||||
$primary->wait_for_replay_catchup($standby1);
|
||||
|
||||
# Advance the restart_lsn to the position of the first xl_running_xacts log
|
||||
# generated above. Note that there might be concurrent xl_running_xacts logs
|
||||
# written by the bgwriter, which could cause the position to be advanced to an
|
||||
# unexpected point, but that would be a rare scenario and doesn't affect the
|
||||
# test results.
|
||||
$primary->safe_psql('postgres',
|
||||
"SELECT pg_replication_slot_advance('snap_test_slot', pg_current_wal_lsn());"
|
||||
);
|
||||
|
||||
# Log a message that will be consumed on the standby after promotion using the
|
||||
# synced slot. See the test where we promote standby (Promote the standby1 to
|
||||
# primary.)
|
||||
$primary->safe_psql('postgres',
|
||||
"SELECT pg_logical_emit_message(false, 'test', 'test');"
|
||||
);
|
||||
|
||||
# Get the confirmed_flush_lsn for the logical slot snap_test_slot on the primary
|
||||
my $confirmed_flush_lsn = $primary->safe_psql('postgres',
|
||||
"SELECT confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'snap_test_slot';");
|
||||
|
||||
$standby1->safe_psql('postgres', "SELECT pg_sync_replication_slots();");
|
||||
|
||||
# Verify that confirmed_flush_lsn of snap_test_slot slot is synced to the standby
|
||||
ok( $standby1->poll_query_until(
|
||||
'postgres',
|
||||
"SELECT '$confirmed_flush_lsn' = confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'snap_test_slot' AND synced AND NOT temporary;"),
|
||||
'confirmed_flush_lsn of slot snap_test_slot synced to standby');
|
||||
|
||||
##################################################
|
||||
# Test to confirm that the slot synchronization is protected from malicious
|
||||
# users.
|
||||
|
@ -458,8 +520,8 @@ $standby1->wait_for_log(qr/slot sync worker started/,
|
|||
$log_offset);
|
||||
|
||||
##################################################
|
||||
# Test to confirm that restart_lsn and confirmed_flush_lsn of the logical slot
|
||||
# on the primary is synced to the standby via the slot sync worker.
|
||||
# Test to confirm that confirmed_flush_lsn of the logical slot on the primary
|
||||
# is synced to the standby via the slot sync worker.
|
||||
##################################################
|
||||
|
||||
# Insert data on the primary
|
||||
|
@ -479,8 +541,8 @@ $subscriber1->safe_psql(
|
|||
|
||||
$subscriber1->wait_for_subscription_sync;
|
||||
|
||||
# Do not allow any further advancement of the restart_lsn and
|
||||
# confirmed_flush_lsn for the lsub1_slot.
|
||||
# Do not allow any further advancement of the confirmed_flush_lsn for the
|
||||
# lsub1_slot.
|
||||
$subscriber1->safe_psql('postgres', "ALTER SUBSCRIPTION regress_mysub1 DISABLE");
|
||||
|
||||
# Wait for the replication slot to become inactive on the publisher
|
||||
|
@ -489,20 +551,15 @@ $primary->poll_query_until(
|
|||
"SELECT COUNT(*) FROM pg_catalog.pg_replication_slots WHERE slot_name = 'lsub1_slot' AND active='f'",
|
||||
1);
|
||||
|
||||
# Get the restart_lsn for the logical slot lsub1_slot on the primary
|
||||
my $primary_restart_lsn = $primary->safe_psql('postgres',
|
||||
"SELECT restart_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot';");
|
||||
|
||||
# Get the confirmed_flush_lsn for the logical slot lsub1_slot on the primary
|
||||
my $primary_flush_lsn = $primary->safe_psql('postgres',
|
||||
"SELECT confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot';");
|
||||
|
||||
# Confirm that restart_lsn and confirmed_flush_lsn of lsub1_slot slot are synced
|
||||
# to the standby
|
||||
# Confirm that confirmed_flush_lsn of lsub1_slot slot is synced to the standby
|
||||
ok( $standby1->poll_query_until(
|
||||
'postgres',
|
||||
"SELECT '$primary_restart_lsn' = restart_lsn AND '$primary_flush_lsn' = confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot' AND synced AND NOT temporary;"),
|
||||
'restart_lsn and confirmed_flush_lsn of slot lsub1_slot synced to standby');
|
||||
"SELECT '$primary_flush_lsn' = confirmed_flush_lsn from pg_replication_slots WHERE slot_name = 'lsub1_slot' AND synced AND NOT temporary;"),
|
||||
'confirmed_flush_lsn of slot lsub1_slot synced to standby');
|
||||
|
||||
##################################################
|
||||
# Test that logical failover replication slots wait for the specified
|
||||
|
@ -744,8 +801,9 @@ $primary->reload;
|
|||
|
||||
##################################################
|
||||
# Promote the standby1 to primary. Confirm that:
|
||||
# a) the slot 'lsub1_slot' is retained on the new primary
|
||||
# a) the slot 'lsub1_slot' and 'snap_test_slot' are retained on the new primary
|
||||
# b) logical replication for regress_mysub1 is resumed successfully after failover
|
||||
# c) changes can be consumed from the synced slot 'snap_test_slot'
|
||||
##################################################
|
||||
$standby1->start;
|
||||
$primary->wait_for_replay_catchup($standby1);
|
||||
|
@ -759,8 +817,8 @@ $subscriber1->safe_psql('postgres',
|
|||
|
||||
# Confirm the synced slot 'lsub1_slot' is retained on the new primary
|
||||
is($standby1->safe_psql('postgres',
|
||||
q{SELECT slot_name FROM pg_replication_slots WHERE slot_name = 'lsub1_slot' AND synced AND NOT temporary;}),
|
||||
'lsub1_slot',
|
||||
q{SELECT count(*) = 2 FROM pg_replication_slots WHERE slot_name IN ('lsub1_slot', 'snap_test_slot') AND synced AND NOT temporary;}),
|
||||
't',
|
||||
'synced slot retained on the new primary');
|
||||
|
||||
# Insert data on the new primary
|
||||
|
@ -773,4 +831,13 @@ is( $subscriber1->safe_psql('postgres', q{SELECT count(*) FROM tab_int;}),
|
|||
"20",
|
||||
'data replicated from the new primary');
|
||||
|
||||
# Consume the data from the snap_test_slot. The synced slot should reach a
|
||||
# consistent point by restoring the snapshot at the restart_lsn serialized
|
||||
# during slot synchronization.
|
||||
$result = $standby1->safe_psql('postgres',
|
||||
"SELECT count(*) FROM pg_logical_slot_get_changes('snap_test_slot', NULL, NULL) WHERE data ~ 'message*';"
|
||||
);
|
||||
|
||||
is($result, '1', "data can be consumed using snap_test_slot");
|
||||
|
||||
done_testing();
|
||||
|
|
Loading…
Reference in New Issue