From 03f8f13ca905ac32f9870177fb05926d9bb8d3b5 Mon Sep 17 00:00:00 2001 From: Craig Ringer Date: Wed, 1 Jun 2016 14:05:58 +0800 Subject: [PATCH 12/21] Don't attempt to export a snapshot from CREATE_REPLICATION_SLOT when in recovery Exporting a snapshot requires us to start an xact, and we can't do that from a server in recovery. So skip snapshot export. The client must handle syncing of initial state via some external means like a slot on the master or manually stopping replay from a physical copy at the same LSN. --- src/backend/replication/walsender.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index ac8c2c3..957ae36 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -842,7 +842,18 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd) * Export a plain (not of the snapbuild.c type) snapshot to the user * that can be imported into another session. */ - snapshot_name = SnapBuildExportSnapshot(ctx->snapshot_builder); + if (!RecoveryInProgress()) + { + snapshot_name = SnapBuildExportSnapshot(ctx->snapshot_builder); + } + else + { + /* + * Can't assign an xid during recovery so we can't export a + * snapshot. + */ + snapshot_name = ""; + } /* don't need the decoding context anymore */ FreeDecodingContext(ctx); -- 2.5.5