diff options
Diffstat (limited to 'src/backend/replication/logical/decode.c')
| -rw-r--r-- | src/backend/replication/logical/decode.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/src/backend/replication/logical/decode.c b/src/backend/replication/logical/decode.c index 8fe7bb65f1f..5508cc21777 100644 --- a/src/backend/replication/logical/decode.c +++ b/src/backend/replication/logical/decode.c @@ -152,11 +152,39 @@ xlog_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf) * can restart from there. */ break; + case XLOG_PARAMETER_CHANGE: + { + xl_parameter_change *xlrec = + (xl_parameter_change *) XLogRecGetData(buf->record); + + /* + * If wal_level on the primary is reduced to less than + * logical, we want to prevent existing logical slots from + * being used. Existing logical slots on the standby get + * invalidated when this WAL record is replayed; and further, + * slot creation fails when wal_level is not sufficient; but + * all these operations are not synchronized, so a logical + * slot may creep in while the wal_level is being + * reduced. Hence this extra check. + */ + if (xlrec->wal_level < WAL_LEVEL_LOGICAL) + { + /* + * This can occur only on a standby, as a primary would + * not allow to restart after changing wal_level < logical + * if there is pre-existing logical slot. + */ + Assert(RecoveryInProgress()); + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("logical decoding on a standby requires wal_level to be at least logical on the primary"))); + } + break; + } case XLOG_NOOP: case XLOG_NEXTOID: case XLOG_SWITCH: case XLOG_BACKUP_END: - case XLOG_PARAMETER_CHANGE: case XLOG_RESTORE_POINT: case XLOG_FPW_CHANGE: case XLOG_FPI_FOR_HINT: |