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postgresql/src/backend/commands/subscriptioncmds.c

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/*-------------------------------------------------------------------------
*
* subscriptioncmds.c
* subscription catalog manipulation functions
*
* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/commands/subscriptioncmds.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/htup_details.h"
#include "access/table.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/objectaccess.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_subscription.h"
#include "catalog/pg_subscription_rel.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/subscriptioncmds.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "pgstat.h"
#include "replication/logicallauncher.h"
#include "replication/origin.h"
#include "replication/slot.h"
#include "replication/walreceiver.h"
#include "replication/walsender.h"
#include "replication/worker_internal.h"
#include "storage/lmgr.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/pg_lsn.h"
#include "utils/syscache.h"
/*
* Options that can be specified by the user in CREATE/ALTER SUBSCRIPTION
* command.
*/
#define SUBOPT_CONNECT 0x00000001
#define SUBOPT_ENABLED 0x00000002
#define SUBOPT_CREATE_SLOT 0x00000004
#define SUBOPT_SLOT_NAME 0x00000008
#define SUBOPT_COPY_DATA 0x00000010
#define SUBOPT_SYNCHRONOUS_COMMIT 0x00000020
#define SUBOPT_REFRESH 0x00000040
#define SUBOPT_BINARY 0x00000080
#define SUBOPT_STREAMING 0x00000100
#define SUBOPT_TWOPHASE_COMMIT 0x00000200
#define SUBOPT_DISABLE_ON_ERR 0x00000400
#define SUBOPT_LSN 0x00000800
/* check if the 'val' has 'bits' set */
#define IsSet(val, bits) (((val) & (bits)) == (bits))
/*
* Structure to hold a bitmap representing the user-provided CREATE/ALTER
* SUBSCRIPTION command options and the parsed/default values of each of them.
*/
typedef struct SubOpts
{
bits32 specified_opts;
char *slot_name;
char *synchronous_commit;
bool connect;
bool enabled;
bool create_slot;
bool copy_data;
bool refresh;
bool binary;
bool streaming;
bool twophase;
bool disableonerr;
XLogRecPtr lsn;
} SubOpts;
static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
static void check_duplicates_in_publist(List *publist, Datum *datums);
static List *merge_publications(List *oldpublist, List *newpublist, bool addpub, const char *subname);
static void ReportSlotConnectionError(List *rstates, Oid subid, char *slotname, char *err);
/*
* Common option parsing function for CREATE and ALTER SUBSCRIPTION commands.
*
* Since not all options can be specified in both commands, this function
* will report an error if mutually exclusive options are specified.
*/
static void
parse_subscription_options(ParseState *pstate, List *stmt_options,
bits32 supported_opts, SubOpts *opts)
{
ListCell *lc;
/* Start out with cleared opts. */
memset(opts, 0, sizeof(SubOpts));
/* caller must expect some option */
Assert(supported_opts != 0);
/* If connect option is supported, these others also need to be. */
Assert(!IsSet(supported_opts, SUBOPT_CONNECT) ||
IsSet(supported_opts, SUBOPT_ENABLED | SUBOPT_CREATE_SLOT |
SUBOPT_COPY_DATA));
/* Set default values for the boolean supported options. */
if (IsSet(supported_opts, SUBOPT_CONNECT))
opts->connect = true;
if (IsSet(supported_opts, SUBOPT_ENABLED))
opts->enabled = true;
if (IsSet(supported_opts, SUBOPT_CREATE_SLOT))
opts->create_slot = true;
if (IsSet(supported_opts, SUBOPT_COPY_DATA))
opts->copy_data = true;
if (IsSet(supported_opts, SUBOPT_REFRESH))
opts->refresh = true;
if (IsSet(supported_opts, SUBOPT_BINARY))
opts->binary = false;
if (IsSet(supported_opts, SUBOPT_STREAMING))
opts->streaming = false;
if (IsSet(supported_opts, SUBOPT_TWOPHASE_COMMIT))
opts->twophase = false;
if (IsSet(supported_opts, SUBOPT_DISABLE_ON_ERR))
opts->disableonerr = false;
/* Parse options */
foreach(lc, stmt_options)
{
DefElem *defel = (DefElem *) lfirst(lc);
if (IsSet(supported_opts, SUBOPT_CONNECT) &&
strcmp(defel->defname, "connect") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_CONNECT))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_CONNECT;
opts->connect = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_ENABLED) &&
strcmp(defel->defname, "enabled") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_ENABLED))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_ENABLED;
opts->enabled = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_CREATE_SLOT) &&
strcmp(defel->defname, "create_slot") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_CREATE_SLOT;
opts->create_slot = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_SLOT_NAME) &&
strcmp(defel->defname, "slot_name") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_SLOT_NAME))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_SLOT_NAME;
opts->slot_name = defGetString(defel);
/* Setting slot_name = NONE is treated as no slot name. */
if (strcmp(opts->slot_name, "none") == 0)
opts->slot_name = NULL;
else
ReplicationSlotValidateName(opts->slot_name, ERROR);
}
else if (IsSet(supported_opts, SUBOPT_COPY_DATA) &&
strcmp(defel->defname, "copy_data") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_COPY_DATA))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_COPY_DATA;
opts->copy_data = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_SYNCHRONOUS_COMMIT) &&
strcmp(defel->defname, "synchronous_commit") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_SYNCHRONOUS_COMMIT))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_SYNCHRONOUS_COMMIT;
opts->synchronous_commit = defGetString(defel);
/* Test if the given value is valid for synchronous_commit GUC. */
(void) set_config_option("synchronous_commit", opts->synchronous_commit,
PGC_BACKEND, PGC_S_TEST, GUC_ACTION_SET,
false, 0, false);
}
else if (IsSet(supported_opts, SUBOPT_REFRESH) &&
strcmp(defel->defname, "refresh") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_REFRESH))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_REFRESH;
opts->refresh = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_BINARY) &&
strcmp(defel->defname, "binary") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_BINARY))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_BINARY;
opts->binary = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_STREAMING) &&
strcmp(defel->defname, "streaming") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_STREAMING))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_STREAMING;
opts->streaming = defGetBoolean(defel);
}
else if (strcmp(defel->defname, "two_phase") == 0)
{
/*
* Do not allow toggling of two_phase option. Doing so could cause
* missing of transactions and lead to an inconsistent replica.
* See comments atop worker.c
*
* Note: Unsupported twophase indicates that this call originated
* from AlterSubscription.
*/
if (!IsSet(supported_opts, SUBOPT_TWOPHASE_COMMIT))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unrecognized subscription parameter: \"%s\"", defel->defname)));
if (IsSet(opts->specified_opts, SUBOPT_TWOPHASE_COMMIT))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_TWOPHASE_COMMIT;
opts->twophase = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_DISABLE_ON_ERR) &&
strcmp(defel->defname, "disable_on_error") == 0)
{
if (IsSet(opts->specified_opts, SUBOPT_DISABLE_ON_ERR))
errorConflictingDefElem(defel, pstate);
opts->specified_opts |= SUBOPT_DISABLE_ON_ERR;
opts->disableonerr = defGetBoolean(defel);
}
else if (IsSet(supported_opts, SUBOPT_LSN) &&
strcmp(defel->defname, "lsn") == 0)
{
char *lsn_str = defGetString(defel);
XLogRecPtr lsn;
if (IsSet(opts->specified_opts, SUBOPT_LSN))
errorConflictingDefElem(defel, pstate);
/* Setting lsn = NONE is treated as resetting LSN */
if (strcmp(lsn_str, "none") == 0)
lsn = InvalidXLogRecPtr;
else
{
/* Parse the argument as LSN */
lsn = DatumGetLSN(DirectFunctionCall1(pg_lsn_in,
CStringGetDatum(lsn_str)));
if (XLogRecPtrIsInvalid(lsn))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid WAL location (LSN): %s", lsn_str)));
}
opts->specified_opts |= SUBOPT_LSN;
opts->lsn = lsn;
}
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("unrecognized subscription parameter: \"%s\"", defel->defname)));
}
/*
* We've been explicitly asked to not connect, that requires some
* additional processing.
*/
if (!opts->connect && IsSet(supported_opts, SUBOPT_CONNECT))
{
/* Check for incompatible options from the user. */
if (opts->enabled &&
IsSet(opts->specified_opts, SUBOPT_ENABLED))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
/*- translator: both %s are strings of the form "option = value" */
errmsg("%s and %s are mutually exclusive options",
"connect = false", "enabled = true")));
if (opts->create_slot &&
IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s and %s are mutually exclusive options",
"connect = false", "create_slot = true")));
if (opts->copy_data &&
IsSet(opts->specified_opts, SUBOPT_COPY_DATA))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s and %s are mutually exclusive options",
"connect = false", "copy_data = true")));
/* Change the defaults of other options. */
opts->enabled = false;
opts->create_slot = false;
opts->copy_data = false;
}
/*
* Do additional checking for disallowed combination when slot_name = NONE
* was used.
*/
if (!opts->slot_name &&
IsSet(opts->specified_opts, SUBOPT_SLOT_NAME))
{
if (opts->enabled)
{
if (IsSet(opts->specified_opts, SUBOPT_ENABLED))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
/*- translator: both %s are strings of the form "option = value" */
errmsg("%s and %s are mutually exclusive options",
"slot_name = NONE", "enabled = true")));
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
/*- translator: both %s are strings of the form "option = value" */
errmsg("subscription with %s must also set %s",
"slot_name = NONE", "enabled = false")));
}
if (opts->create_slot)
{
if (IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
/*- translator: both %s are strings of the form "option = value" */
errmsg("%s and %s are mutually exclusive options",
"slot_name = NONE", "create_slot = true")));
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
/*- translator: both %s are strings of the form "option = value" */
errmsg("subscription with %s must also set %s",
"slot_name = NONE", "create_slot = false")));
}
}
}
/*
* Add publication names from the list to a string.
*/
static void
get_publications_str(List *publications, StringInfo dest, bool quote_literal)
{
ListCell *lc;
bool first = true;
Assert(list_length(publications) > 0);
foreach(lc, publications)
{
char *pubname = strVal(lfirst(lc));
if (first)
first = false;
else
appendStringInfoString(dest, ", ");
if (quote_literal)
appendStringInfoString(dest, quote_literal_cstr(pubname));
else
{
appendStringInfoChar(dest, '"');
appendStringInfoString(dest, pubname);
appendStringInfoChar(dest, '"');
}
}
}
/*
* Check the specified publication(s) is(are) present in the publisher.
*/
static void
check_publications(WalReceiverConn *wrconn, List *publications)
{
WalRcvExecResult *res;
StringInfo cmd;
TupleTableSlot *slot;
List *publicationsCopy = NIL;
Oid tableRow[1] = {TEXTOID};
cmd = makeStringInfo();
appendStringInfoString(cmd, "SELECT t.pubname FROM\n"
" pg_catalog.pg_publication t WHERE\n"
" t.pubname IN (");
get_publications_str(publications, cmd, true);
appendStringInfoChar(cmd, ')');
res = walrcv_exec(wrconn, cmd->data, 1, tableRow);
pfree(cmd->data);
pfree(cmd);
if (res->status != WALRCV_OK_TUPLES)
ereport(ERROR,
errmsg_plural("could not receive publication from the publisher: %s",
"could not receive list of publications from the publisher: %s",
list_length(publications),
res->err));
publicationsCopy = list_copy(publications);
/* Process publication(s). */
slot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
{
char *pubname;
bool isnull;
pubname = TextDatumGetCString(slot_getattr(slot, 1, &isnull));
Assert(!isnull);
/* Delete the publication present in publisher from the list. */
publicationsCopy = list_delete(publicationsCopy, makeString(pubname));
ExecClearTuple(slot);
}
ExecDropSingleTupleTableSlot(slot);
walrcv_clear_result(res);
if (list_length(publicationsCopy))
{
/* Prepare the list of non-existent publication(s) for error message. */
StringInfo pubnames = makeStringInfo();
get_publications_str(publicationsCopy, pubnames, false);
ereport(WARNING,
errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg_plural("publication %s does not exist in the publisher",
"publications %s do not exist in the publisher",
list_length(publicationsCopy),
pubnames->data));
}
}
/*
* Auxiliary function to build a text array out of a list of String nodes.
*/
static Datum
publicationListToArray(List *publist)
{
ArrayType *arr;
Datum *datums;
MemoryContext memcxt;
MemoryContext oldcxt;
/* Create memory context for temporary allocations. */
memcxt = AllocSetContextCreate(CurrentMemoryContext,
"publicationListToArray to array",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(memcxt);
datums = (Datum *) palloc(sizeof(Datum) * list_length(publist));
check_duplicates_in_publist(publist, datums);
MemoryContextSwitchTo(oldcxt);
arr = construct_array(datums, list_length(publist),
TEXTOID, -1, false, TYPALIGN_INT);
MemoryContextDelete(memcxt);
return PointerGetDatum(arr);
}
/*
* Create new subscription.
*/
ObjectAddress
CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
bool isTopLevel)
{
Relation rel;
ObjectAddress myself;
Oid subid;
bool nulls[Natts_pg_subscription];
Datum values[Natts_pg_subscription];
Oid owner = GetUserId();
HeapTuple tup;
char *conninfo;
char originname[NAMEDATALEN];
List *publications;
bits32 supported_opts;
SubOpts opts = {0};
/*
* Parse and check options.
*
* Connection and publication should not be specified here.
*/
supported_opts = (SUBOPT_CONNECT | SUBOPT_ENABLED | SUBOPT_CREATE_SLOT |
SUBOPT_SLOT_NAME | SUBOPT_COPY_DATA |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
SUBOPT_DISABLE_ON_ERR);
parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
/*
* Since creating a replication slot is not transactional, rolling back
* the transaction leaves the created replication slot. So we cannot run
* CREATE SUBSCRIPTION inside a transaction block if creating a
* replication slot.
*/
if (opts.create_slot)
PreventInTransactionBlock(isTopLevel, "CREATE SUBSCRIPTION ... WITH (create_slot = true)");
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to create subscriptions")));
/*
* If built with appropriate switch, whine when regression-testing
* conventions for subscription names are violated.
*/
#ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
if (strncmp(stmt->subname, "regress_", 8) != 0)
elog(WARNING, "subscriptions created by regression test cases should have names starting with \"regress_\"");
#endif
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
/* Check if name is used */
subid = GetSysCacheOid2(SUBSCRIPTIONNAME, Anum_pg_subscription_oid,
MyDatabaseId, CStringGetDatum(stmt->subname));
if (OidIsValid(subid))
{
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("subscription \"%s\" already exists",
stmt->subname)));
}
if (!IsSet(opts.specified_opts, SUBOPT_SLOT_NAME) &&
opts.slot_name == NULL)
opts.slot_name = stmt->subname;
/* The default for synchronous_commit of subscriptions is off. */
if (opts.synchronous_commit == NULL)
opts.synchronous_commit = "off";
conninfo = stmt->conninfo;
publications = stmt->publication;
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
/* Check the connection info string. */
walrcv_check_conninfo(conninfo);
/* Everything ok, form a new tuple. */
memset(values, 0, sizeof(values));
memset(nulls, false, sizeof(nulls));
subid = GetNewOidWithIndex(rel, SubscriptionObjectIndexId,
Anum_pg_subscription_oid);
values[Anum_pg_subscription_oid - 1] = ObjectIdGetDatum(subid);
values[Anum_pg_subscription_subdbid - 1] = ObjectIdGetDatum(MyDatabaseId);
values[Anum_pg_subscription_subskiplsn - 1] = LSNGetDatum(InvalidXLogRecPtr);
values[Anum_pg_subscription_subname - 1] =
DirectFunctionCall1(namein, CStringGetDatum(stmt->subname));
values[Anum_pg_subscription_subowner - 1] = ObjectIdGetDatum(owner);
values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(opts.enabled);
values[Anum_pg_subscription_subbinary - 1] = BoolGetDatum(opts.binary);
values[Anum_pg_subscription_substream - 1] = BoolGetDatum(opts.streaming);
values[Anum_pg_subscription_subtwophasestate - 1] =
CharGetDatum(opts.twophase ?
LOGICALREP_TWOPHASE_STATE_PENDING :
LOGICALREP_TWOPHASE_STATE_DISABLED);
values[Anum_pg_subscription_subdisableonerr - 1] = BoolGetDatum(opts.disableonerr);
values[Anum_pg_subscription_subconninfo - 1] =
CStringGetTextDatum(conninfo);
if (opts.slot_name)
values[Anum_pg_subscription_subslotname - 1] =
DirectFunctionCall1(namein, CStringGetDatum(opts.slot_name));
else
nulls[Anum_pg_subscription_subslotname - 1] = true;
values[Anum_pg_subscription_subsynccommit - 1] =
CStringGetTextDatum(opts.synchronous_commit);
values[Anum_pg_subscription_subpublications - 1] =
publicationListToArray(publications);
tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
/* Insert tuple into catalog. */
CatalogTupleInsert(rel, tup);
heap_freetuple(tup);
recordDependencyOnOwner(SubscriptionRelationId, subid, owner);
snprintf(originname, sizeof(originname), "pg_%u", subid);
replorigin_create(originname);
/*
* Connect to remote side to execute requested commands and fetch table
* info.
*/
if (opts.connect)
{
char *err;
WalReceiverConn *wrconn;
List *tables;
ListCell *lc;
char table_state;
/* Try to connect to the publisher. */
wrconn = walrcv_connect(conninfo, true, stmt->subname, &err);
if (!wrconn)
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not connect to the publisher: %s", err)));
PG_TRY();
{
check_publications(wrconn, publications);
/*
* Set sync state based on if we were asked to do data copy or
* not.
*/
table_state = opts.copy_data ? SUBREL_STATE_INIT : SUBREL_STATE_READY;
/*
* Get the table list from publisher and build local table status
* info.
*/
tables = fetch_table_list(wrconn, publications);
foreach(lc, tables)
{
RangeVar *rv = (RangeVar *) lfirst(lc);
Oid relid;
relid = RangeVarGetRelid(rv, AccessShareLock, false);
/* Check for supported relkind. */
CheckSubscriptionRelkind(get_rel_relkind(relid),
rv->schemaname, rv->relname);
AddSubscriptionRelState(subid, relid, table_state,
InvalidXLogRecPtr);
}
/*
* If requested, create permanent slot for the subscription. We
* won't use the initial snapshot for anything, so no need to
* export it.
*/
if (opts.create_slot)
{
bool twophase_enabled = false;
Assert(opts.slot_name);
/*
* Even if two_phase is set, don't create the slot with
* two-phase enabled. Will enable it once all the tables are
* synced and ready. This avoids race-conditions like prepared
* transactions being skipped due to changes not being applied
* due to checks in should_apply_changes_for_rel() when
* tablesync for the corresponding tables are in progress. See
* comments atop worker.c.
*
* Note that if tables were specified but copy_data is false
* then it is safe to enable two_phase up-front because those
* tables are already initially in READY state. When the
* subscription has no tables, we leave the twophase state as
* PENDING, to allow ALTER SUBSCRIPTION ... REFRESH
* PUBLICATION to work.
*/
if (opts.twophase && !opts.copy_data && tables != NIL)
twophase_enabled = true;
walrcv_create_slot(wrconn, opts.slot_name, false, twophase_enabled,
CRS_NOEXPORT_SNAPSHOT, NULL);
if (twophase_enabled)
UpdateTwoPhaseState(subid, LOGICALREP_TWOPHASE_STATE_ENABLED);
ereport(NOTICE,
(errmsg("created replication slot \"%s\" on publisher",
opts.slot_name)));
}
}
PG_FINALLY();
{
walrcv_disconnect(wrconn);
}
PG_END_TRY();
}
else
ereport(WARNING,
/* translator: %s is an SQL ALTER statement */
(errmsg("tables were not subscribed, you will have to run %s to subscribe the tables",
"ALTER SUBSCRIPTION ... REFRESH PUBLICATION")));
table_close(rel, RowExclusiveLock);
pgstat_create_subscription(subid);
if (opts.enabled)
ApplyLauncherWakeupAtCommit();
ObjectAddressSet(myself, SubscriptionRelationId, subid);
InvokeObjectPostCreateHook(SubscriptionRelationId, subid, 0);
return myself;
}
static void
AlterSubscription_refresh(Subscription *sub, bool copy_data,
List *validate_publications)
{
char *err;
List *pubrel_names;
List *subrel_states;
Oid *subrel_local_oids;
Oid *pubrel_local_oids;
ListCell *lc;
int off;
int remove_rel_len;
Relation rel = NULL;
typedef struct SubRemoveRels
{
Oid relid;
char state;
} SubRemoveRels;
SubRemoveRels *sub_remove_rels;
WalReceiverConn *wrconn;
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
/* Try to connect to the publisher. */
wrconn = walrcv_connect(sub->conninfo, true, sub->name, &err);
if (!wrconn)
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not connect to the publisher: %s", err)));
PG_TRY();
{
if (validate_publications)
check_publications(wrconn, validate_publications);
/* Get the table list from publisher. */
pubrel_names = fetch_table_list(wrconn, sub->publications);
/* Get local table list. */
subrel_states = GetSubscriptionRelations(sub->oid);
/*
* Build qsorted array of local table oids for faster lookup. This can
* potentially contain all tables in the database so speed of lookup
* is important.
*/
subrel_local_oids = palloc(list_length(subrel_states) * sizeof(Oid));
off = 0;
foreach(lc, subrel_states)
{
SubscriptionRelState *relstate = (SubscriptionRelState *) lfirst(lc);
subrel_local_oids[off++] = relstate->relid;
}
qsort(subrel_local_oids, list_length(subrel_states),
sizeof(Oid), oid_cmp);
/*
* Rels that we want to remove from subscription and drop any slots
* and origins corresponding to them.
*/
sub_remove_rels = palloc(list_length(subrel_states) * sizeof(SubRemoveRels));
/*
* Walk over the remote tables and try to match them to locally known
* tables. If the table is not known locally create a new state for
* it.
*
* Also builds array of local oids of remote tables for the next step.
*/
off = 0;
pubrel_local_oids = palloc(list_length(pubrel_names) * sizeof(Oid));
foreach(lc, pubrel_names)
{
RangeVar *rv = (RangeVar *) lfirst(lc);
Oid relid;
relid = RangeVarGetRelid(rv, AccessShareLock, false);
/* Check for supported relkind. */
CheckSubscriptionRelkind(get_rel_relkind(relid),
rv->schemaname, rv->relname);
pubrel_local_oids[off++] = relid;
if (!bsearch(&relid, subrel_local_oids,
list_length(subrel_states), sizeof(Oid), oid_cmp))
{
AddSubscriptionRelState(sub->oid, relid,
copy_data ? SUBREL_STATE_INIT : SUBREL_STATE_READY,
InvalidXLogRecPtr);
ereport(DEBUG1,
(errmsg_internal("table \"%s.%s\" added to subscription \"%s\"",
rv->schemaname, rv->relname, sub->name)));
}
}
/*
* Next remove state for tables we should not care about anymore using
* the data we collected above
*/
qsort(pubrel_local_oids, list_length(pubrel_names),
sizeof(Oid), oid_cmp);
remove_rel_len = 0;
for (off = 0; off < list_length(subrel_states); off++)
{
Oid relid = subrel_local_oids[off];
if (!bsearch(&relid, pubrel_local_oids,
list_length(pubrel_names), sizeof(Oid), oid_cmp))
{
char state;
XLogRecPtr statelsn;
/*
* Lock pg_subscription_rel with AccessExclusiveLock to
* prevent any race conditions with the apply worker
* re-launching workers at the same time this code is trying
* to remove those tables.
*
* Even if new worker for this particular rel is restarted it
* won't be able to make any progress as we hold exclusive
* lock on subscription_rel till the transaction end. It will
* simply exit as there is no corresponding rel entry.
*
* This locking also ensures that the state of rels won't
* change till we are done with this refresh operation.
*/
if (!rel)
rel = table_open(SubscriptionRelRelationId, AccessExclusiveLock);
/* Last known rel state. */
state = GetSubscriptionRelState(sub->oid, relid, &statelsn);
sub_remove_rels[remove_rel_len].relid = relid;
sub_remove_rels[remove_rel_len++].state = state;
RemoveSubscriptionRel(sub->oid, relid);
logicalrep_worker_stop(sub->oid, relid);
/*
* For READY state, we would have already dropped the
* tablesync origin.
*/
if (state != SUBREL_STATE_READY)
{
char originname[NAMEDATALEN];
/*
* Drop the tablesync's origin tracking if exists.
*
* It is possible that the origin is not yet created for
* tablesync worker, this can happen for the states before
* SUBREL_STATE_FINISHEDCOPY. The apply worker can also
* concurrently try to drop the origin and by this time
* the origin might be already removed. For these reasons,
* passing missing_ok = true.
*/
ReplicationOriginNameForTablesync(sub->oid, relid, originname,
sizeof(originname));
replorigin_drop_by_name(originname, true, false);
}
ereport(DEBUG1,
(errmsg_internal("table \"%s.%s\" removed from subscription \"%s\"",
get_namespace_name(get_rel_namespace(relid)),
get_rel_name(relid),
sub->name)));
}
}
/*
* Drop the tablesync slots associated with removed tables. This has
* to be at the end because otherwise if there is an error while doing
* the database operations we won't be able to rollback dropped slots.
*/
for (off = 0; off < remove_rel_len; off++)
{
if (sub_remove_rels[off].state != SUBREL_STATE_READY &&
sub_remove_rels[off].state != SUBREL_STATE_SYNCDONE)
{
char syncslotname[NAMEDATALEN] = {0};
/*
* For READY/SYNCDONE states we know the tablesync slot has
* already been dropped by the tablesync worker.
*
* For other states, there is no certainty, maybe the slot
* does not exist yet. Also, if we fail after removing some of
* the slots, next time, it will again try to drop already
* dropped slots and fail. For these reasons, we allow
* missing_ok = true for the drop.
*/
ReplicationSlotNameForTablesync(sub->oid, sub_remove_rels[off].relid,
syncslotname, sizeof(syncslotname));
ReplicationSlotDropAtPubNode(wrconn, syncslotname, true);
}
}
}
PG_FINALLY();
{
walrcv_disconnect(wrconn);
}
PG_END_TRY();
if (rel)
table_close(rel, NoLock);
}
/*
* Alter the existing subscription.
*/
ObjectAddress
AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
bool isTopLevel)
{
Relation rel;
ObjectAddress myself;
bool nulls[Natts_pg_subscription];
bool replaces[Natts_pg_subscription];
Datum values[Natts_pg_subscription];
HeapTuple tup;
Oid subid;
bool update_tuple = false;
Subscription *sub;
Form_pg_subscription form;
bits32 supported_opts;
SubOpts opts = {0};
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
/* Fetch the existing tuple. */
tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, MyDatabaseId,
CStringGetDatum(stmt->subname));
if (!HeapTupleIsValid(tup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("subscription \"%s\" does not exist",
stmt->subname)));
form = (Form_pg_subscription) GETSTRUCT(tup);
subid = form->oid;
/* must be owner */
if (!pg_subscription_ownercheck(subid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
stmt->subname);
sub = GetSubscription(subid, false);
/* Lock the subscription so nobody else can do anything with it. */
LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
/* Form a new tuple. */
memset(values, 0, sizeof(values));
memset(nulls, false, sizeof(nulls));
memset(replaces, false, sizeof(replaces));
switch (stmt->kind)
{
case ALTER_SUBSCRIPTION_OPTIONS:
{
supported_opts = (SUBOPT_SLOT_NAME |
SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR);
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
{
/*
* The subscription must be disabled to allow slot_name as
* 'none', otherwise, the apply worker will repeatedly try
* to stream the data using that slot_name which neither
* exists on the publisher nor the user will be allowed to
* create it.
*/
if (sub->enabled && !opts.slot_name)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot set %s for enabled subscription",
"slot_name = NONE")));
if (opts.slot_name)
values[Anum_pg_subscription_subslotname - 1] =
DirectFunctionCall1(namein, CStringGetDatum(opts.slot_name));
else
nulls[Anum_pg_subscription_subslotname - 1] = true;
replaces[Anum_pg_subscription_subslotname - 1] = true;
}
if (opts.synchronous_commit)
{
values[Anum_pg_subscription_subsynccommit - 1] =
CStringGetTextDatum(opts.synchronous_commit);
replaces[Anum_pg_subscription_subsynccommit - 1] = true;
}
if (IsSet(opts.specified_opts, SUBOPT_BINARY))
{
values[Anum_pg_subscription_subbinary - 1] =
BoolGetDatum(opts.binary);
replaces[Anum_pg_subscription_subbinary - 1] = true;
}
if (IsSet(opts.specified_opts, SUBOPT_STREAMING))
{
values[Anum_pg_subscription_substream - 1] =
BoolGetDatum(opts.streaming);
replaces[Anum_pg_subscription_substream - 1] = true;
}
if (IsSet(opts.specified_opts, SUBOPT_DISABLE_ON_ERR))
{
values[Anum_pg_subscription_subdisableonerr - 1]
= BoolGetDatum(opts.disableonerr);
replaces[Anum_pg_subscription_subdisableonerr - 1]
= true;
}
update_tuple = true;
break;
}
case ALTER_SUBSCRIPTION_ENABLED:
{
parse_subscription_options(pstate, stmt->options,
SUBOPT_ENABLED, &opts);
Assert(IsSet(opts.specified_opts, SUBOPT_ENABLED));
if (!sub->slotname && opts.enabled)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot enable subscription that does not have a slot name")));
values[Anum_pg_subscription_subenabled - 1] =
BoolGetDatum(opts.enabled);
replaces[Anum_pg_subscription_subenabled - 1] = true;
if (opts.enabled)
ApplyLauncherWakeupAtCommit();
update_tuple = true;
break;
}
case ALTER_SUBSCRIPTION_CONNECTION:
/* Load the library providing us libpq calls. */
load_file("libpqwalreceiver", false);
/* Check the connection info string. */
walrcv_check_conninfo(stmt->conninfo);
values[Anum_pg_subscription_subconninfo - 1] =
CStringGetTextDatum(stmt->conninfo);
replaces[Anum_pg_subscription_subconninfo - 1] = true;
update_tuple = true;
break;
case ALTER_SUBSCRIPTION_SET_PUBLICATION:
{
supported_opts = SUBOPT_COPY_DATA | SUBOPT_REFRESH;
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
values[Anum_pg_subscription_subpublications - 1] =
publicationListToArray(stmt->publication);
replaces[Anum_pg_subscription_subpublications - 1] = true;
update_tuple = true;
/* Refresh if user asked us to. */
if (opts.refresh)
{
if (!sub->enabled)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("ALTER SUBSCRIPTION with refresh is not allowed for disabled subscriptions"),
errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION ... WITH (refresh = false).")));
/*
* See ALTER_SUBSCRIPTION_REFRESH for details why this is
* not allowed.
*/
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
errhint("Use ALTER SUBSCRIPTION ...SET PUBLICATION with refresh = false, or with copy_data = false"
", or use DROP/CREATE SUBSCRIPTION.")));
PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");
/* Make sure refresh sees the new list of publications. */
sub->publications = stmt->publication;
AlterSubscription_refresh(sub, opts.copy_data,
stmt->publication);
}
break;
}
case ALTER_SUBSCRIPTION_ADD_PUBLICATION:
case ALTER_SUBSCRIPTION_DROP_PUBLICATION:
{
List *publist;
bool isadd = stmt->kind == ALTER_SUBSCRIPTION_ADD_PUBLICATION;
supported_opts = SUBOPT_REFRESH | SUBOPT_COPY_DATA;
parse_subscription_options(pstate, stmt->options,
supported_opts, &opts);
publist = merge_publications(sub->publications, stmt->publication, isadd, stmt->subname);
values[Anum_pg_subscription_subpublications - 1] =
publicationListToArray(publist);
replaces[Anum_pg_subscription_subpublications - 1] = true;
update_tuple = true;
/* Refresh if user asked us to. */
if (opts.refresh)
{
/* We only need to validate user specified publications. */
List *validate_publications = (isadd) ? stmt->publication : NULL;
if (!sub->enabled)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("ALTER SUBSCRIPTION with refresh is not allowed for disabled subscriptions"),
errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION ... WITH (refresh = false).")));
/*
* See ALTER_SUBSCRIPTION_REFRESH for details why this is
* not allowed.
*/
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
errhint("Use ALTER SUBSCRIPTION ...SET PUBLICATION with refresh = false, or with copy_data = false"
", or use DROP/CREATE SUBSCRIPTION.")));
PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");
/* Refresh the new list of publications. */
sub->publications = publist;
AlterSubscription_refresh(sub, opts.copy_data,
validate_publications);
}
break;
}
case ALTER_SUBSCRIPTION_REFRESH:
{
if (!sub->enabled)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("ALTER SUBSCRIPTION ... REFRESH is not allowed for disabled subscriptions")));
parse_subscription_options(pstate, stmt->options,
SUBOPT_COPY_DATA, &opts);
/*
* The subscription option "two_phase" requires that
* replication has passed the initial table synchronization
* phase before the two_phase becomes properly enabled.
*
* But, having reached this two-phase commit "enabled" state
* we must not allow any subsequent table initialization to
* occur. So the ALTER SUBSCRIPTION ... REFRESH is disallowed
* when the user had requested two_phase = on mode.
*
* The exception to this restriction is when copy_data =
* false, because when copy_data is false the tablesync will
* start already in READY state and will exit directly without
* doing anything.
*
* For more details see comments atop worker.c.
*/
if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("ALTER SUBSCRIPTION ... REFRESH with copy_data is not allowed when two_phase is enabled"),
errhint("Use ALTER SUBSCRIPTION ... REFRESH with copy_data = false"
", or use DROP/CREATE SUBSCRIPTION.")));
PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... REFRESH");
AlterSubscription_refresh(sub, opts.copy_data, NULL);
break;
}
case ALTER_SUBSCRIPTION_SKIP:
{
parse_subscription_options(pstate, stmt->options, SUBOPT_LSN, &opts);
/* ALTER SUBSCRIPTION ... SKIP supports only LSN option */
Assert(IsSet(opts.specified_opts, SUBOPT_LSN));
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to skip transaction")));
/*
* If the user sets subskiplsn, we do a sanity check to make
* sure that the specified LSN is a probable value.
*/
if (!XLogRecPtrIsInvalid(opts.lsn))
{
RepOriginId originid;
char originname[NAMEDATALEN];
XLogRecPtr remote_lsn;
snprintf(originname, sizeof(originname), "pg_%u", subid);
originid = replorigin_by_name(originname, false);
remote_lsn = replorigin_get_progress(originid, false);
/* Check the given LSN is at least a future LSN */
if (!XLogRecPtrIsInvalid(remote_lsn) && opts.lsn < remote_lsn)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("skip WAL location (LSN %X/%X) must be greater than origin LSN %X/%X",
LSN_FORMAT_ARGS(opts.lsn),
LSN_FORMAT_ARGS(remote_lsn))));
}
values[Anum_pg_subscription_subskiplsn - 1] = LSNGetDatum(opts.lsn);
replaces[Anum_pg_subscription_subskiplsn - 1] = true;
update_tuple = true;
break;
}
default:
elog(ERROR, "unrecognized ALTER SUBSCRIPTION kind %d",
stmt->kind);
}
/* Update the catalog if needed. */
if (update_tuple)
{
tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
replaces);
CatalogTupleUpdate(rel, &tup->t_self, tup);
heap_freetuple(tup);
}
table_close(rel, RowExclusiveLock);
ObjectAddressSet(myself, SubscriptionRelationId, subid);
InvokeObjectPostAlterHook(SubscriptionRelationId, subid, 0);
return myself;
}
/*
* Drop a subscription
*/
void
DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
{
Relation rel;
ObjectAddress myself;
HeapTuple tup;
Oid subid;
Datum datum;
bool isnull;
char *subname;
char *conninfo;
char *slotname;
List *subworkers;
ListCell *lc;
char originname[NAMEDATALEN];
char *err = NULL;
WalReceiverConn *wrconn;
Form_pg_subscription form;
List *rstates;
/*
* Lock pg_subscription with AccessExclusiveLock to ensure that the
* launcher doesn't restart new worker during dropping the subscription
*/
rel = table_open(SubscriptionRelationId, AccessExclusiveLock);
tup = SearchSysCache2(SUBSCRIPTIONNAME, MyDatabaseId,
CStringGetDatum(stmt->subname));
if (!HeapTupleIsValid(tup))
{
table_close(rel, NoLock);
if (!stmt->missing_ok)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("subscription \"%s\" does not exist",
stmt->subname)));
else
ereport(NOTICE,
(errmsg("subscription \"%s\" does not exist, skipping",
stmt->subname)));
return;
}
form = (Form_pg_subscription) GETSTRUCT(tup);
subid = form->oid;
/* must be owner */
if (!pg_subscription_ownercheck(subid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
stmt->subname);
/* DROP hook for the subscription being removed */
InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
/*
* Lock the subscription so nobody else can do anything with it (including
* the replication workers).
*/
LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
/* Get subname */
datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
Anum_pg_subscription_subname, &isnull);
Assert(!isnull);
subname = pstrdup(NameStr(*DatumGetName(datum)));
/* Get conninfo */
datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
Anum_pg_subscription_subconninfo, &isnull);
Assert(!isnull);
conninfo = TextDatumGetCString(datum);
/* Get slotname */
datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
Anum_pg_subscription_subslotname, &isnull);
if (!isnull)
slotname = pstrdup(NameStr(*DatumGetName(datum)));
else
slotname = NULL;
/*
* Since dropping a replication slot is not transactional, the replication
* slot stays dropped even if the transaction rolls back. So we cannot
* run DROP SUBSCRIPTION inside a transaction block if dropping the
* replication slot. Also, in this case, we report a message for dropping
* the subscription to the cumulative stats system.
*
* XXX The command name should really be something like "DROP SUBSCRIPTION
* of a subscription that is associated with a replication slot", but we
* don't have the proper facilities for that.
*/
if (slotname)
PreventInTransactionBlock(isTopLevel, "DROP SUBSCRIPTION");
ObjectAddressSet(myself, SubscriptionRelationId, subid);
EventTriggerSQLDropAddObject(&myself, true, true);
/* Remove the tuple from catalog. */
CatalogTupleDelete(rel, &tup->t_self);
ReleaseSysCache(tup);
/*
* Stop all the subscription workers immediately.
*
* This is necessary if we are dropping the replication slot, so that the
* slot becomes accessible.
*
* It is also necessary if the subscription is disabled and was disabled
* in the same transaction. Then the workers haven't seen the disabling
* yet and will still be running, leading to hangs later when we want to
* drop the replication origin. If the subscription was disabled before
* this transaction, then there shouldn't be any workers left, so this
* won't make a difference.
*
* New workers won't be started because we hold an exclusive lock on the
* subscription till the end of the transaction.
*/
LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
subworkers = logicalrep_workers_find(subid, false);
LWLockRelease(LogicalRepWorkerLock);
foreach(lc, subworkers)
{
LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
logicalrep_worker_stop(w->subid, w->relid);
}
list_free(subworkers);
/*
* Cleanup of tablesync replication origins.
*
* Any READY-state relations would already have dealt with clean-ups.
*
* Note that the state can't change because we have already stopped both
* the apply and tablesync workers and they can't restart because of
* exclusive lock on the subscription.
*/
rstates = GetSubscriptionNotReadyRelations(subid);
foreach(lc, rstates)
{
SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
Oid relid = rstate->relid;
/* Only cleanup resources of tablesync workers */
if (!OidIsValid(relid))
continue;
/*
* Drop the tablesync's origin tracking if exists.
*
* It is possible that the origin is not yet created for tablesync
* worker so passing missing_ok = true. This can happen for the states
* before SUBREL_STATE_FINISHEDCOPY.
*/
ReplicationOriginNameForTablesync(subid, relid, originname,
sizeof(originname));
replorigin_drop_by_name(originname, true, false);
}
/* Clean up dependencies */
deleteSharedDependencyRecordsFor(SubscriptionRelationId, subid, 0);
/* Remove any associated relation synchronization states. */
RemoveSubscriptionRel(subid, InvalidOid);
/* Remove the origin tracking if exists. */
snprintf(originname, sizeof(originname), "pg_%u", subid);
replorigin_drop_by_name(originname, true, false);
/*
* If there is no slot associated with the subscription, we can finish
* here.
*/
if (!slotname && rstates == NIL)
{
table_close(rel, NoLock);
return;
}
/*
* Try to acquire the connection necessary for dropping slots.
*
* Note: If the slotname is NONE/NULL then we allow the command to finish
* and users need to manually cleanup the apply and tablesync worker slots
* later.
*
* This has to be at the end because otherwise if there is an error while
* doing the database operations we won't be able to rollback dropped
* slot.
*/
load_file("libpqwalreceiver", false);
wrconn = walrcv_connect(conninfo, true, subname, &err);
if (wrconn == NULL)
{
if (!slotname)
{
/* be tidy */
list_free(rstates);
table_close(rel, NoLock);
return;
}
else
{
ReportSlotConnectionError(rstates, subid, slotname, err);
}
}
PG_TRY();
{
foreach(lc, rstates)
{
SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
Oid relid = rstate->relid;
/* Only cleanup resources of tablesync workers */
if (!OidIsValid(relid))
continue;
/*
* Drop the tablesync slots associated with removed tables.
*
* For SYNCDONE/READY states, the tablesync slot is known to have
* already been dropped by the tablesync worker.
*
* For other states, there is no certainty, maybe the slot does
* not exist yet. Also, if we fail after removing some of the
* slots, next time, it will again try to drop already dropped
* slots and fail. For these reasons, we allow missing_ok = true
* for the drop.
*/
if (rstate->state != SUBREL_STATE_SYNCDONE)
{
char syncslotname[NAMEDATALEN] = {0};
ReplicationSlotNameForTablesync(subid, relid, syncslotname,
sizeof(syncslotname));
ReplicationSlotDropAtPubNode(wrconn, syncslotname, true);
}
}
list_free(rstates);
/*
* If there is a slot associated with the subscription, then drop the
* replication slot at the publisher.
*/
if (slotname)
ReplicationSlotDropAtPubNode(wrconn, slotname, false);
}
PG_FINALLY();
{
walrcv_disconnect(wrconn);
}
PG_END_TRY();
/*
* Tell the cumulative stats system that the subscription is getting dropped.
* We can safely report dropping the subscription statistics here if the
* subscription is associated with a replication slot since we cannot run
* DROP SUBSCRIPTION inside a transaction block. Subscription statistics
* will be removed later by (auto)vacuum either if it's not associated
* with a replication slot or if the message for dropping the subscription
* gets lost.
*/
if (slotname)
pgstat_drop_subscription(subid);
table_close(rel, NoLock);
}
/*
* Drop the replication slot at the publisher node using the replication
* connection.
*
* missing_ok - if true then only issue a LOG message if the slot doesn't
* exist.
*/
void
ReplicationSlotDropAtPubNode(WalReceiverConn *wrconn, char *slotname, bool missing_ok)
{
StringInfoData cmd;
Assert(wrconn);
load_file("libpqwalreceiver", false);
initStringInfo(&cmd);
appendStringInfo(&cmd, "DROP_REPLICATION_SLOT %s WAIT", quote_identifier(slotname));
PG_TRY();
{
WalRcvExecResult *res;
res = walrcv_exec(wrconn, cmd.data, 0, NULL);
if (res->status == WALRCV_OK_COMMAND)
{
/* NOTICE. Success. */
ereport(NOTICE,
(errmsg("dropped replication slot \"%s\" on publisher",
slotname)));
}
else if (res->status == WALRCV_ERROR &&
missing_ok &&
res->sqlstate == ERRCODE_UNDEFINED_OBJECT)
{
/* LOG. Error, but missing_ok = true. */
ereport(LOG,
(errmsg("could not drop replication slot \"%s\" on publisher: %s",
slotname, res->err)));
}
else
{
/* ERROR. */
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not drop replication slot \"%s\" on publisher: %s",
slotname, res->err)));
}
walrcv_clear_result(res);
}
PG_FINALLY();
{
pfree(cmd.data);
}
PG_END_TRY();
}
/*
* Internal workhorse for changing a subscription owner
*/
static void
AlterSubscriptionOwner_internal(Relation rel, HeapTuple tup, Oid newOwnerId)
{
Form_pg_subscription form;
form = (Form_pg_subscription) GETSTRUCT(tup);
if (form->subowner == newOwnerId)
return;
if (!pg_subscription_ownercheck(form->oid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
NameStr(form->subname));
/* New owner must be a superuser */
if (!superuser_arg(newOwnerId))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied to change owner of subscription \"%s\"",
NameStr(form->subname)),
errhint("The owner of a subscription must be a superuser.")));
form->subowner = newOwnerId;
CatalogTupleUpdate(rel, &tup->t_self, tup);
/* Update owner dependency reference */
changeDependencyOnOwner(SubscriptionRelationId,
form->oid,
newOwnerId);
InvokeObjectPostAlterHook(SubscriptionRelationId,
form->oid, 0);
ApplyLauncherWakeupAtCommit();
}
/*
* Change subscription owner -- by name
*/
ObjectAddress
AlterSubscriptionOwner(const char *name, Oid newOwnerId)
{
Oid subid;
HeapTuple tup;
Relation rel;
ObjectAddress address;
Form_pg_subscription form;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, MyDatabaseId,
CStringGetDatum(name));
if (!HeapTupleIsValid(tup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("subscription \"%s\" does not exist", name)));
form = (Form_pg_subscription) GETSTRUCT(tup);
subid = form->oid;
AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
ObjectAddressSet(address, SubscriptionRelationId, subid);
heap_freetuple(tup);
table_close(rel, RowExclusiveLock);
return address;
}
/*
* Change subscription owner -- by OID
*/
void
AlterSubscriptionOwner_oid(Oid subid, Oid newOwnerId)
{
HeapTuple tup;
Relation rel;
rel = table_open(SubscriptionRelationId, RowExclusiveLock);
tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
if (!HeapTupleIsValid(tup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("subscription with OID %u does not exist", subid)));
AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
heap_freetuple(tup);
table_close(rel, RowExclusiveLock);
}
/*
* Get the list of tables which belong to specified publications on the
* publisher connection.
*/
static List *
fetch_table_list(WalReceiverConn *wrconn, List *publications)
{
WalRcvExecResult *res;
StringInfoData cmd;
TupleTableSlot *slot;
Oid tableRow[2] = {TEXTOID, TEXTOID};
List *tablelist = NIL;
initStringInfo(&cmd);
appendStringInfoString(&cmd, "SELECT DISTINCT t.schemaname, t.tablename\n"
" FROM pg_catalog.pg_publication_tables t\n"
" WHERE t.pubname IN (");
get_publications_str(publications, &cmd, true);
appendStringInfoChar(&cmd, ')');
res = walrcv_exec(wrconn, cmd.data, 2, tableRow);
pfree(cmd.data);
if (res->status != WALRCV_OK_TUPLES)
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not receive list of replicated tables from the publisher: %s",
res->err)));
/* Process tables. */
slot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
{
char *nspname;
char *relname;
bool isnull;
RangeVar *rv;
nspname = TextDatumGetCString(slot_getattr(slot, 1, &isnull));
Assert(!isnull);
relname = TextDatumGetCString(slot_getattr(slot, 2, &isnull));
Assert(!isnull);
rv = makeRangeVar(nspname, relname, -1);
tablelist = lappend(tablelist, rv);
ExecClearTuple(slot);
}
ExecDropSingleTupleTableSlot(slot);
walrcv_clear_result(res);
return tablelist;
}
/*
* This is to report the connection failure while dropping replication slots.
* Here, we report the WARNING for all tablesync slots so that user can drop
* them manually, if required.
*/
static void
ReportSlotConnectionError(List *rstates, Oid subid, char *slotname, char *err)
{
ListCell *lc;
foreach(lc, rstates)
{
SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
Oid relid = rstate->relid;
/* Only cleanup resources of tablesync workers */
if (!OidIsValid(relid))
continue;
/*
* Caller needs to ensure that relstate doesn't change underneath us.
* See DropSubscription where we get the relstates.
*/
if (rstate->state != SUBREL_STATE_SYNCDONE)
{
char syncslotname[NAMEDATALEN] = {0};
ReplicationSlotNameForTablesync(subid, relid, syncslotname,
sizeof(syncslotname));
elog(WARNING, "could not drop tablesync replication slot \"%s\"",
syncslotname);
}
}
ereport(ERROR,
(errcode(ERRCODE_CONNECTION_FAILURE),
errmsg("could not connect to publisher when attempting to "
"drop replication slot \"%s\": %s", slotname, err),
/* translator: %s is an SQL ALTER command */
errhint("Use %s to disassociate the subscription from the slot.",
"ALTER SUBSCRIPTION ... SET (slot_name = NONE)")));
}
/*
* Check for duplicates in the given list of publications and error out if
* found one. Add publications to datums as text datums, if datums is not
* NULL.
*/
static void
check_duplicates_in_publist(List *publist, Datum *datums)
{
ListCell *cell;
int j = 0;
foreach(cell, publist)
{
char *name = strVal(lfirst(cell));
ListCell *pcell;
foreach(pcell, publist)
{
char *pname = strVal(lfirst(pcell));
if (pcell == cell)
break;
if (strcmp(name, pname) == 0)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("publication name \"%s\" used more than once",
pname)));
}
if (datums)
datums[j++] = CStringGetTextDatum(name);
}
}
/*
* Merge current subscription's publications and user-specified publications
* from ADD/DROP PUBLICATIONS.
*
* If addpub is true, we will add the list of publications into oldpublist.
* Otherwise, we will delete the list of publications from oldpublist. The
* returned list is a copy, oldpublist itself is not changed.
*
* subname is the subscription name, for error messages.
*/
static List *
merge_publications(List *oldpublist, List *newpublist, bool addpub, const char *subname)
{
ListCell *lc;
oldpublist = list_copy(oldpublist);
check_duplicates_in_publist(newpublist, NULL);
foreach(lc, newpublist)
{
char *name = strVal(lfirst(lc));
ListCell *lc2;
bool found = false;
foreach(lc2, oldpublist)
{
char *pubname = strVal(lfirst(lc2));
if (strcmp(name, pubname) == 0)
{
found = true;
if (addpub)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("publication \"%s\" is already in subscription \"%s\"",
name, subname)));
else
oldpublist = foreach_delete_current(oldpublist, lc2);
break;
}
}
if (addpub && !found)
oldpublist = lappend(oldpublist, makeString(name));
else if (!addpub && !found)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("publication \"%s\" is not in subscription \"%s\"",
name, subname)));
}
/*
* XXX Probably no strong reason for this, but for now it's to make ALTER
* SUBSCRIPTION ... DROP PUBLICATION consistent with SET PUBLICATION.
*/
if (!oldpublist)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot drop all the publications from a subscription")));
return oldpublist;
}
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