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| author | Amit Kapila <akapila@postgresql.org> | 2021-03-01 09:11:18 +0530 |
|---|---|---|
| committer | Amit Kapila <akapila@postgresql.org> | 2021-03-01 09:11:18 +0530 |
| commit | 8bdb1332eb51837c15a10a972c179b84f654279e (patch) | |
| tree | badfa4657b5a985fb4d13564e9fc810f0d425f88 /src/include/replication | |
| parent | 6230912f23904aa6cb2a1f948ca9b08235b4f54a (diff) | |
| download | postgresql-8bdb1332eb51837c15a10a972c179b84f654279e.tar.gz | |
Avoid repeated decoding of prepared transactions after a restart.
In commit a271a1b50e, we allowed decoding at prepare time and the prepare
was decoded again if there is a restart after decoding it. It was done
that way because we can't distinguish between the cases where we have not
decoded the prepare because it was prior to consistent snapshot or we have
decoded it earlier but restarted. To distinguish between these two cases,
we have introduced an initial_consistent_point at the slot level which is
an LSN at which we found a consistent point at the time of slot creation.
This is also the point where we have exported a snapshot for the initial
copy. So, prepare transaction prior to this point are sent along with
commit prepared.
This commit bumps SNAPBUILD_VERSION because of change in SnapBuild. It
will break existing slots which is fine in a major release.
Author: Ajin Cherian, based on idea by Andres Freund
Reviewed-by: Amit Kapila and Vignesh C
Discussion: https://postgr.es/m/d0f60d60-133d-bf8d-bd70-47784d8fabf3@enterprisedb.com
Diffstat (limited to 'src/include/replication')
| -rw-r--r-- | src/include/replication/reorderbuffer.h | 1 | ||||
| -rw-r--r-- | src/include/replication/slot.h | 7 | ||||
| -rw-r--r-- | src/include/replication/snapbuild.h | 4 |
3 files changed, 11 insertions, 1 deletions
diff --git a/src/include/replication/reorderbuffer.h b/src/include/replication/reorderbuffer.h index bab31bf7af..565a961d6a 100644 --- a/src/include/replication/reorderbuffer.h +++ b/src/include/replication/reorderbuffer.h @@ -643,6 +643,7 @@ void ReorderBufferCommit(ReorderBuffer *, TransactionId, TimestampTz commit_time, RepOriginId origin_id, XLogRecPtr origin_lsn); void ReorderBufferFinishPrepared(ReorderBuffer *rb, TransactionId xid, XLogRecPtr commit_lsn, XLogRecPtr end_lsn, + XLogRecPtr initial_consistent_point, TimestampTz commit_time, RepOriginId origin_id, XLogRecPtr origin_lsn, char *gid, bool is_commit); diff --git a/src/include/replication/slot.h b/src/include/replication/slot.h index 38a9a0b3fc..5c3fde20c6 100644 --- a/src/include/replication/slot.h +++ b/src/include/replication/slot.h @@ -91,6 +91,13 @@ typedef struct ReplicationSlotPersistentData */ XLogRecPtr confirmed_flush; + /* + * LSN at which we found a consistent point at the time of slot creation. + * This is also the point where we have exported a snapshot for the + * initial copy. + */ + XLogRecPtr initial_consistent_point; + /* plugin name */ NameData plugin; } ReplicationSlotPersistentData; diff --git a/src/include/replication/snapbuild.h b/src/include/replication/snapbuild.h index d9f187a58e..fbabce6764 100644 --- a/src/include/replication/snapbuild.h +++ b/src/include/replication/snapbuild.h @@ -61,7 +61,8 @@ extern void CheckPointSnapBuild(void); extern SnapBuild *AllocateSnapshotBuilder(struct ReorderBuffer *cache, TransactionId xmin_horizon, XLogRecPtr start_lsn, - bool need_full_snapshot); + bool need_full_snapshot, + XLogRecPtr initial_consistent_point); extern void FreeSnapshotBuilder(SnapBuild *cache); extern void SnapBuildSnapDecRefcount(Snapshot snap); @@ -75,6 +76,7 @@ extern Snapshot SnapBuildGetOrBuildSnapshot(SnapBuild *builder, TransactionId xid); extern bool SnapBuildXactNeedsSkip(SnapBuild *snapstate, XLogRecPtr ptr); +extern XLogRecPtr SnapBuildInitialConsistentPoint(SnapBuild *builder); extern void SnapBuildCommitTxn(SnapBuild *builder, XLogRecPtr lsn, TransactionId xid, int nsubxacts, |