8000 Revert "Fix replay of create database records on standby" · postgres/postgres@adc943b · GitHub
[go: up one dir, main page]
Skip to content

Commit adc943b

Browse files
alvherrealvherre
committed
Revert "Fix replay of create database records on standby"
This reverts commit 49d9cfc. The approach taken by this patch has problems, so we'll come up with a radically different fix. Discussion: https://postgr.es/m/CA+TgmoYcUPL+WOJL2ZzhH=zmrhj0iOQ=iCFM0SuYqBbqZEamEg@mail.gmail.com
1 parent 6b262f3 commit adc943b

File tree

6 files changed

+1
-243
lines changed

6 files changed

+1
-243
lines changed

‎src/backend/access/transam/xlog.c‎

Lines changed: 0 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -8255,12 +8255,6 @@ CheckRecoveryConsistency(void)
82558255
*/
82568256
XLogCheckInvalidPages();
82578257

8258-
/*
8259-
* Check if the XLOG sequence contained any unresolved references to
8260-
* missing directories.
8261-
*/
8262-
XLogCheckMissingDirs();
8263-
82648258
reachedConsistency = true;
82658259
ereport(LOG,
82668260
(errmsg("consistent recovery state reached at %X/%X",

‎src/backend/access/transam/xlogutils.c‎

Lines changed: 1 addition & 158 deletions
Original file line numberDiff line numberDiff line change
@@ -34,164 +34,6 @@
3434
/* GUC variable */
3535
bool ignore_invalid_pages = false;
3636

37-
38-
/*
39-
* If a create database WAL record is being replayed more than once during
40-
* crash recovery on a standby, it is possible that either the tablespace
41-
* directory or the template database directory is missing. This happens when
42-
* the directories are removed by replay of subsequent drop records. Note
43-
* that this problem happens only on standby and not on master. On master, a
44-
* checkpoint is created at the end of create database operation. On standby,
45-
* however, such a strategy (creating restart points during replay) is not
46-
* viable because it will slow down WAL replay.
47-
*
48-
* The alternative is to track references to each missing directory
49-
* encountered when performing crash recovery in the following hash table.
50-
* Similar to invalid page table above, the expectation is that each missing
51-
* directory entry should be matched with a drop database or drop tablespace
52-
* WAL record by the end of crash recovery.
53-
*/
54-
typedef struct xl_missing_dir_key
55-
{
56-
Oid spcNode;
57-
Oid dbNode;
58-
} xl_missing_dir_key;
59-
60-
typedef struct xl_missing_dir
61-
{
62-
xl_missing_dir_key key;
63-
char path[MAXPGPATH];
64-
} xl_missing_dir;
65-
66-
static HTAB *missing_dir_tab = NULL;
67-
68-
69-
/*
70-
* Keep track of a directory that wasn't found while replaying database
71-
* creation records. These should match up with tablespace removal records
72-
* later in the WAL stream; we verify that before reaching consistency.
73-
*/
74-
void
75-
XLogRememberMissingDir(Oid spcNode, Oid dbNode, char *path)
76-
{
77-
xl_missing_dir_key key;
78-
bool found;
79-
xl_missing_dir *entry;
80-
81-
/*
82-
* Database OID may be invalid but tablespace OID must be valid. If
83-
* dbNode is InvalidOid, we are logging a missing tablespace directory,
84-
* otherwise we are logging a missing database directory.
85-
*/
86-
Assert(OidIsValid(spcNode));
87-
88-
if (missing_dir_tab == NULL)
89-
{
90-
/* create hash table when first needed */
91-
HASHCTL ctl;
92-
93-
memset(&ctl, 0, sizeof(ctl));
94-
ctl.keysize = sizeof(xl_missing_dir_key);
95-
ctl.entrysize = sizeof(xl_missing_dir);
96-
97-
missing_dir_tab = hash_create("XLOG missing directory table",
98-
100,
99-
&ctl,
100-
HASH_ELEM | HASH_BLOBS);
101-
}
102-
103-
key.spcNode = spcNode;
104-
key.dbNode = dbNode;
105-
106-
entry = hash_search(missing_dir_tab, &key, HASH_ENTER, &found);
107-
108-
if (found)
109-
{
110-
if (dbNode == InvalidOid)
111-
elog(DEBUG1, "missing directory %s (tablespace %u) already exists: %s",
112-
path, spcNode, entry->path);
113-
else
114-
elog(DEBUG1, "missing directory %s (tablespace %u database %u) already exists: %s",
115-
path, spcNode, dbNode, entry->path);
116-
}
117-
else
118-
{
119-
strlcpy(entry->path, path, sizeof(entry->path));
120-
if (dbNode == InvalidOid)
121-
elog(DEBUG1, "logged missing dir %s (tablespace %u)",
122-
path, spcNode);
123-
else
124-
elog(DEBUG1, "logged missing dir %s (tablespace %u database %u)",
125-
path, spcNode, dbNode);
126-
}
127-
}
128-
129-
/*
130-
* Remove an entry from the list of directories not found. This is to be done
131-
* when the matching tablespace removal WAL record is found.
132-
*/
133-
void
134-
XLogForgetMissingDir(Oid spcNode, Oid dbNode)
135-
{
136-
xl_missing_dir_key key;
137-
138-
key.spcNode = spcNode;
139-
key.dbNode = dbNode;
140-
141-
/* Database OID may be invalid but tablespace OID must be valid. */
142-
Assert(OidIsValid(spcNode));
143-
144-
if (missing_dir_tab == NULL)
145-
return;
146-
147-
if (hash_search(missing_dir_tab, &key, HASH_REMOVE, NULL) != NULL)
148-
{
149-
if (dbNode == InvalidOid)
150-
{
151-
elog(DEBUG2, "forgot missing dir (tablespace %u)", spcNode);
152-
}
153-
else
154-
{
155-
char *path = GetDatabasePath(dbNode, spcNode);
156-
157-
elog(DEBUG2, "forgot missing dir %s (tablespace %u database %u)",
158-
path, spcNode, dbNode);
159-
pfree(path);
160-
}
161-
}
162-
}
163-
164-
/*
165-
* This is called at the end of crash recovery, before entering archive
166-
* recovery on a standby. PANIC if the hash table is not empty.
167-
*/
168-
void
169-
XLogCheckMissingDirs(void)
170-
{
171-
HASH_SEQ_STATUS status;
172-
xl_missing_dir *hentry;
173-
bool foundone = false;
174-
175-
if (missing_dir_tab == NULL)
176-
return; /* nothing to do */
177-
178-
hash_seq_init(&status, missing_dir_tab);
179-
180-
while ((hentry = (xl_missing_dir *) hash_seq_search(&status)) != NULL)
181-
{
182-
elog(WARNING, "missing directory \"%s\" tablespace %u database %u",
183-
hentry->path, hentry->key.spcNode, hentry->key.dbNode);
184-
foundone = true;
185-
}
186-
187-
if (foundone)
188-
elog(PANIC, "WAL contains references to missing directories");
189-
190-
hash_destroy(missing_dir_tab);
191-
missing_dir_tab = NULL;
192-
}
193-
194-
19537
/*
19638
* During XLOG replay, we may see XLOG records for incremental updates of
19739
* pages that no longer exist, because their relation was later dropped or
@@ -217,6 +59,7 @@ typedef struct xl_invalid_page
21759

21860
static HTAB *invalid_page_tab = NULL;
21961

62+
22063
/* Report a reference to an invalid page */
22164
static void
22265
report_invalid_page(int elevel, RelFileNode node, ForkNumber forkno,

‎src/backend/commands/dbcommands.c‎

Lines changed: 0 additions & 56 deletions
Original file line numberDiff line numberDiff line change
@@ -2185,9 +2185,7 @@ dbase_redo(XLogReaderState *record)
21852185
xl_dbase_create_rec *xlrec = (xl_dbase_create_rec *) XLogRecGetData(record);
21862186
char *src_path;
21872187
char *dst_path;
2188-
char *parent_path;
21892188
struct stat st;
2190-
bool skip = false;
21912189

21922190
src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
21932191
dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
@@ -2205,56 +2203,6 @@ dbase_redo(XLogReaderState *record)
22052203
(errmsg("some useless files may be left behind in old database directory \"%s\"",
22062204
dst_path)));
22072205
}
2208-
else if (!reachedConsistency)
2209-
{
2210-
/*
2211-
* It is possible that a drop tablespace record appearing later in
2212-
* WAL has already been replayed -- in other words, that we are
2213-
* replaying the database creation record a second time with no
2214-
* intervening checkpoint. In that case, the tablespace directory
2215-
* has already been removed and the create database operation
2216-
* cannot be replayed. Skip the replay itself, but remember the
2217-
* fact that the tablespace directory is missing, to be matched
2218-
* with the expected tablespace drop record later.
2219-
*/
2220-
parent_path = pstrdup(dst_path);
2221-
get_parent_directory(parent_path);
2222-
if (!(stat(parent_path, &st) == 0 && S_ISDIR(st.st_mode)))
2223-
{
2224-
XLogRememberMissingDir(xlrec->tablespace_id, InvalidOid, parent_path);
2225-
skip = true;
2226-
ereport(WARNING,
2227-
(errmsg("skipping replay of database creation WAL record"),
2228-
errdetail("The target tablespace \"%s\" directory was not found.",
2229-
parent_path),
2230-
errhint("A future WAL record that removes the directory before reaching consistent mode is expected.")));
2231-
}
2232-
pfree(parent_path);
2233-
}
2234-
2235-
/*
2236-
* If the source directory is missing, skip the copy and make a note of
2237-
* it for later.
2238-
*
2239-
* One possible reason for this is that the template database used for
2240-
* creating this database may have been dropped, as noted above.
2241-
* Moving a database from one tablespace may also be a partner in the
2242-
* crime.
2243-
*/
2244-
if (!(stat(src_path, &st) == 0 && S_ISDIR(st.st_mode)) &&
2245-
!reachedConsistency)
2246-
{
2247-
XLogRememberMissingDir(xlrec->src_tablespace_id, xlrec->src_db_id, src_path);
2248-
skip = true;
2249-
ereport(WARNING,
2250-
(errmsg("skipping replay of database creation WAL record"),
2251-
errdetail("The source database directory \"%s\" was not found.",
2252-
src_path),
2253-
errhint("A future WAL record that removes the directory before reaching consistent mode is expected.")));
2254-
}
2255-
2256-
if (skip)
2257-
return;
22582206

22592207
/*
22602208
* Force dirty buffers out to disk, to ensure source database is
@@ -2312,10 +2260,6 @@ dbase_redo(XLogReaderState *record)
23122260
ereport(WARNING,
23132261
(errmsg("some useless files may be left behind in old database directory \"%s\"",
23142262
dst_path)));
2315-
2316-
if (!reachedConsistency)
2317-
XLogForgetMissingDir(xlrec->tablespace_ids[i], xlrec->db_id);
2318-
23192263
pfree(dst_path);
23202264
}
23212265

‎src/backend/commands/tablespace.c‎

Lines changed: 0 additions & 17 deletions
Original file line numberDiff line numberDiff line change
@@ -58,7 +58,6 @@
5858
#include "access/xact.h"
5959
#include "access/xlog.h"
6060
#include "access/xloginsert.h"
61-
#include "access/xlogutils.h"
6261
#include "catalog/catalog.h"
6362
#include "catalog/dependency.h"
6463
#include "catalog/indexing.h"
@@ -1530,22 +1529,6 @@ tblspc_redo(XLogReaderState *record)
15301529
{
15311530
xl_tblspc_drop_rec *xlrec = (xl_tblspc_drop_rec *) XLogRecGetData(record);
15321531

1533-
if (!reachedConsistency)
1534-
XLogForgetMissingDir(xlrec->ts_id, InvalidOid);
1535-
1536-
/*
1537-
* Before we remove the tablespace directory, update minimum recovery
1538-
* point to cover this WAL record. Once the tablespace is removed,
1539-
* there's no going back. This manually enforces the WAL-first rule.
1540-
* Doing this before the removal means that if the removal fails for
1541-
* some reason, the directory is left alone and needs to be manually
1542-
* removed. Alternatively we could update the minimum recovery point
1543-
* after removal, but that would leave a small window where the
1544-
* WAL-first rule could be violated.
1545-
*/
1546-
if (!reachedConsistency)
1547-
XLogFlush(record->EndRecPtr);
1548-
15491532
/*
15501533
* If we issued a WAL record for a drop tablespace it implies that
15511534
* there were no files in it at all when the DROP was done. That means

‎src/include/access/xlogutils.h‎

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -23,10 +23,6 @@ extern void XLogDropDatabase(Oid dbid);
2323
extern void XLogTruncateRelation(RelFileNode rnode, ForkNumber forkNum,
2424
BlockNumber nblocks);
2525

26-
extern void XLogRememberMissingDir(Oid spcNode, Oid dbNode, char *path);
27-
extern void XLogForgetMissingDir(Oid spcNode, Oid dbNode);
28-
extern void XLogCheckMissingDirs(void);
29-
3026
/* Result codes for XLogReadBufferForRedo[Extended] */
3127
typedef enum
3228
{

‎src/tools/pgindent/typedefs.list‎

Lines changed: 0 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -3700,8 +3700,6 @@ xl_invalid_page
37003700
xl_invalid_page_key
37013701
xl_invalidations
37023702
xl_logical_message
3703-
xl_missing_dir_key
3704-
xl_missing_dir
37053703
xl_multi_insert_tuple
37063704
xl_multixact_create
37073705
xl_multixact_truncate

0 commit comments

Comments
 (0)
0