mirror of
https://git.postgresql.org/git/postgresql.git
synced 2026-02-07 23:37:33 +08:00
2bef06d516
The logical decoding machinery already preserved all the required catalog tuples, which is sufficient in the course of normal logical decoding, but did not guarantee that non-catalog tuples were preserved during computation of the initial snapshot when creating a slot over the replication protocol. This could cause a corrupted initial snapshot being exported. The time window for issues is usually not terribly large, but on a busy server it's perfectly possible to it hit it. Ongoing decoding is not affected by this bug. To avoid increased overhead for the SQL API, only retain additional tuples when a logical slot is being created over the replication protocol. To do so this commit changes the signature of CreateInitDecodingContext(), but it seems unlikely that it's being used in an extension, so that's probably ok. In a drive-by fix, fix handling of ReplicationSlotsComputeRequiredXmin's already_locked argument, which should only apply to ProcArrayLock, not ReplicationSlotControlLock. Reported-By: Erik Rijkers Analyzed-By: Petr Jelinek Author: Petr Jelinek, heavily editorialized by Andres Freund Reviewed-By: Andres Freund Discussion: https://postgr.es/m/9a897b86-46e1-9915-ee4c-da02e4ff6a95@2ndquadrant.com Backport: 9.4, where logical decoding was introduced.
109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
/*-------------------------------------------------------------------------
|
|
* logical.h
|
|
* PostgreSQL logical decoding coordination
|
|
*
|
|
* Copyright (c) 2012-2017, PostgreSQL Global Development Group
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef LOGICAL_H
|
|
#define LOGICAL_H
|
|
|
|
#include "replication/slot.h"
|
|
|
|
#include "access/xlog.h"
|
|
#include "access/xlogreader.h"
|
|
#include "replication/output_plugin.h"
|
|
|
|
struct LogicalDecodingContext;
|
|
|
|
typedef void (*LogicalOutputPluginWriterWrite) (
|
|
struct LogicalDecodingContext *lr,
|
|
XLogRecPtr Ptr,
|
|
TransactionId xid,
|
|
bool last_write
|
|
);
|
|
|
|
typedef LogicalOutputPluginWriterWrite LogicalOutputPluginWriterPrepareWrite;
|
|
|
|
typedef struct LogicalDecodingContext
|
|
{
|
|
/* memory context this is all allocated in */
|
|
MemoryContext context;
|
|
|
|
/* The associated replication slot */
|
|
ReplicationSlot *slot;
|
|
|
|
/* infrastructure pieces for decoding */
|
|
XLogReaderState *reader;
|
|
struct ReorderBuffer *reorder;
|
|
struct SnapBuild *snapshot_builder;
|
|
|
|
OutputPluginCallbacks callbacks;
|
|
OutputPluginOptions options;
|
|
|
|
/*
|
|
* User specified options
|
|
*/
|
|
List *output_plugin_options;
|
|
|
|
/*
|
|
* User-Provided callback for writing/streaming out data.
|
|
*/
|
|
LogicalOutputPluginWriterPrepareWrite prepare_write;
|
|
LogicalOutputPluginWriterWrite write;
|
|
|
|
/*
|
|
* Output buffer.
|
|
*/
|
|
StringInfo out;
|
|
|
|
/*
|
|
* Private data pointer of the output plugin.
|
|
*/
|
|
void *output_plugin_private;
|
|
|
|
/*
|
|
* Private data pointer for the data writer.
|
|
*/
|
|
void *output_writer_private;
|
|
|
|
/*
|
|
* State for writing output.
|
|
*/
|
|
bool accept_writes;
|
|
bool prepared_write;
|
|
XLogRecPtr write_location;
|
|
TransactionId write_xid;
|
|
} LogicalDecodingContext;
|
|
|
|
|
|
extern void CheckLogicalDecodingRequirements(void);
|
|
|
|
extern LogicalDecodingContext *CreateInitDecodingContext(char *plugin,
|
|
List *output_plugin_options,
|
|
bool need_full_snapshot,
|
|
XLogPageReadCB read_page,
|
|
LogicalOutputPluginWriterPrepareWrite prepare_write,
|
|
LogicalOutputPluginWriterWrite do_write);
|
|
extern LogicalDecodingContext *CreateDecodingContext(
|
|
XLogRecPtr start_lsn,
|
|
List *output_plugin_options,
|
|
XLogPageReadCB read_page,
|
|
LogicalOutputPluginWriterPrepareWrite prepare_write,
|
|
LogicalOutputPluginWriterWrite do_write);
|
|
extern void DecodingContextFindStartpoint(LogicalDecodingContext *ctx);
|
|
extern bool DecodingContextReady(LogicalDecodingContext *ctx);
|
|
extern void FreeDecodingContext(LogicalDecodingContext *ctx);
|
|
|
|
extern void LogicalIncreaseXminForSlot(XLogRecPtr lsn, TransactionId xmin);
|
|
extern void LogicalIncreaseRestartDecodingForSlot(XLogRecPtr current_lsn,
|
|
XLogRecPtr restart_lsn);
|
|
extern void LogicalConfirmReceivedLocation(XLogRecPtr lsn);
|
|
|
|
extern void LagTrackerWrite(XLogRecPtr lsn, TimestampTz local_flush_time);
|
|
|
|
extern bool filter_by_origin_cb_wrapper(LogicalDecodingContext *ctx, RepOriginId origin_id);
|
|
|
|
#endif
|