diff options
Diffstat (limited to 'src/backend/replication')
| -rw-r--r-- | src/backend/replication/logical/slotsync.c | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/src/backend/replication/logical/slotsync.c b/src/backend/replication/logical/slotsync.c index e22d41891e6..656e66e0ae0 100644 --- a/src/backend/replication/logical/slotsync.c +++ b/src/backend/replication/logical/slotsync.c @@ -196,14 +196,14 @@ update_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid, * restart_lsn or the initial xmin_horizon computed for the local slot * is ahead of the remote slot. * - * If the slot is persistent, restart_lsn of the synced slot could - * still be ahead of the remote slot. Since we use slot advance - * functionality to keep snapbuild/slot updated, it is possible that - * the restart_lsn is advanced to a later position than it has on the - * primary. This can happen when slot advancing machinery finds - * running xacts record after reaching the consistent state at a later - * point than the primary where it serializes the snapshot and updates - * the restart_lsn. + * If the slot is persistent, both restart_lsn and catalog_xmin of the + * synced slot could still be ahead of the remote slot. Since we use + * slot advance functionality to keep snapbuild/slot updated, it is + * possible that the restart_lsn and catalog_xmin are advanced to a + * later position than it has on the primary. This can happen when + * slot advancing machinery finds running xacts record after reaching + * the consistent state at a later point than the primary where it + * serializes the snapshot and updates the restart_lsn. * * We LOG the message if the slot is temporary as it can help the user * to understand why the slot is not sync-ready. In the case of a @@ -221,16 +221,25 @@ update_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid, if (remote_slot_precedes) *remote_slot_precedes = true; + + /* + * Skip updating the configuration. This is required to avoid syncing + * two_phase_at without syncing confirmed_lsn. Otherwise, the prepared + * transaction between old confirmed_lsn and two_phase_at will + * unexpectedly get decoded and sent to the downstream after + * promotion. See comments in ReorderBufferFinishPrepared. + */ + return false; } /* * Attempt to sync LSNs and xmins only if remote slot is ahead of local * slot. */ - else if (remote_slot->confirmed_lsn > slot->data.confirmed_flush || - remote_slot->restart_lsn > slot->data.restart_lsn || - TransactionIdFollows(remote_slot->catalog_xmin, - slot->data.catalog_xmin)) + if (remote_slot->confirmed_lsn > slot->data.confirmed_flush || + remote_slot->restart_lsn > slot->data.restart_lsn || + TransactionIdFollows(remote_slot->catalog_xmin, + slot->data.catalog_xmin)) { /* * We can't directly copy the remote slot's LSN or xmin unless there @@ -294,6 +303,12 @@ update_local_synced_slot(RemoteSlot *remote_slot, Oid remote_dbid, SpinLockRelease(&slot->mutex); updated_config = true; + + /* + * Ensure that there is no risk of sending prepared transactions + * unexpectedly after the promotion. + */ + Assert(slot->data.two_phase_at <= slot->data.confirmed_flush); } /* |