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spock_sync.c
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/*-------------------------------------------------------------------------
*
* spock_sync.c
* table synchronization functions
*
* Copyright (c) 2022-2024, pgEdge, Inc.
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, The Regents of the University of California
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#ifdef WIN32
#include <process.h>
#else
#include <sys/wait.h>
#endif
#include "libpq-fe.h"
#include "miscadmin.h"
#include "access/genam.h"
#include "access/hash.h"
#include "access/heapam.h"
#include "access/skey.h"
#include "access/stratnum.h"
#include "access/xact.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "commands/dbcommands.h"
#include "commands/tablecmds.h"
#include "lib/stringinfo.h"
#include "utils/memutils.h"
#include "nodes/makefuncs.h"
#include "nodes/parsenodes.h"
#include "pgstat.h"
#include "replication/origin.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "tcop/utility.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/pg_lsn.h"
#include "utils/rel.h"
#include "utils/resowner.h"
#include "spock_relcache.h"
#include "spock_repset.h"
#include "spock_rpc.h"
#include "spock_sync.h"
#include "spock_worker.h"
#include "spock.h"
#define CATALOG_LOCAL_SYNC_STATUS "local_sync_status"
#define PGDUMP_BINARY "pg_dump"
#define PGRESTORE_BINARY "pg_restore"
#define Natts_local_sync_state 6
#define Anum_sync_kind 1
#define Anum_sync_subid 2
#define Anum_sync_nspname 3
#define Anum_sync_relname 4
#define Anum_sync_status 5
#define Anum_sync_statuslsn 6
PGDLLEXPORT void spock_sync_main(Datum main_arg);
static SpockSyncWorker *MySyncWorker = NULL;
#ifdef WIN32
static int exec_cmd_win32(const char *cmd, char *cmdargv[]);
#endif
/*
* Run a command and wait for it to exit, then return its exit code
* in the same format as waitpid() including on Windows.
*
* Does not elog(ERROR).
*
* 'cmd' must be a full relative or absolute path to the executable to
* start. The PATH is not searched.
*
* Preserves each argument in cmdargv as a discrete argument to the child
* process. The first entry in cmdargv is passed as the child process's
* argv[0], so the first "real" argument begins at index 1.
*
* Uses the current environment and working directory.
*
* Note that if we elog(ERROR) or elog(FATAL) here we won't kill the
* child proc.
*/
static int
exec_cmd(const char *cmd, char *cmdargv[])
{
pid_t pid;
int stat;
/* Fire off execv in child */
fflush(stdout);
fflush(stderr);
#ifndef WIN32
if ((pid = fork()) == 0)
{
if (execv(cmd, cmdargv) < 0)
{
ereport(ERROR,
(errmsg("could not execute \"%s\": %m", cmd)));
/* We're already in the child process here, can't return */
exit(1);
}
}
if (waitpid(pid, &stat, 0) != pid)
stat = -1;
#else
stat = exec_cmd_win32(cmd, cmdargv);
#endif
return stat;
}
static void
get_pg_executable(char *cmdname, char *cmdbuf)
{
uint32 version;
if (find_other_exec_version(my_exec_path, cmdname, &version, cmdbuf))
elog(ERROR, "spock subscriber init failed to find %s relative to binary %s",
cmdname, my_exec_path);
if (version / 100 != PG_VERSION_NUM / 100)
elog(ERROR, "spock subscriber init found %s with wrong major version %d.%d, expected %d.%d",
cmdname, version / 100 / 100, version / 100 % 100,
PG_VERSION_NUM / 100 / 100, PG_VERSION_NUM / 100 % 100);
}
static void
dump_structure(SpockSubscription *sub, const char *destfile,
const char *snapshot)
{
char *dsn;
char *err_msg;
char pg_dump[MAXPGPATH];
char *cmdargv[20];
int cmdargc = 0;
bool has_spk_origin;
bool has_snowflake;
StringInfoData s;
dsn = spk_get_connstr((char *) sub->origin_if->dsn, NULL, NULL, &err_msg);
if (dsn == NULL)
elog(ERROR, "invalid connection string \"%s\": %s",
sub->origin_if->dsn, err_msg);
get_pg_executable(PGDUMP_BINARY, pg_dump);
cmdargv[cmdargc++] = pg_dump;
/* custom format */
cmdargv[cmdargc++] = "-Fc";
/* schema only */
cmdargv[cmdargc++] = "-s";
/* snapshot */
initStringInfo(&s);
appendStringInfo(&s, "--snapshot=%s", snapshot);
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
/* Dumping database, filter out our extension. */
appendStringInfo(&s, "--exclude-schema=%s", EXTENSION_NAME);
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
/* Skip the spock_origin and snowflake if it exists locally. */
StartTransactionCommand();
has_spk_origin = OidIsValid(LookupExplicitNamespace("spock_origin",
true));
has_snowflake = OidIsValid(LookupExplicitNamespace("snowflake",
true));
CommitTransactionCommand();
if (has_spk_origin)
{
appendStringInfo(&s, "--exclude-schema=%s", "spock_origin");
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
}
if (has_snowflake)
{
appendStringInfo(&s, "--exclude-schema=%s", "snowflake");
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
}
/* destination file */
appendStringInfo(&s, "--file=%s", destfile);
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
/* connection string */
appendStringInfo(&s, "--dbname=%s", dsn);
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
free(dsn);
cmdargv[cmdargc++] = NULL;
if (exec_cmd(pg_dump, cmdargv) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not execute pg_dump (\"%s\"): %m",
pg_dump)));
}
static void
restore_structure(SpockSubscription *sub, const char *srcfile,
const char *section)
{
char *dsn;
char *err_msg;
char pg_restore[MAXPGPATH];
char *cmdargv[20];
int cmdargc = 0;
StringInfoData s;
dsn = spk_get_connstr((char *) sub->target_if->dsn, NULL,
"-cspock.subscription_schema_restore=true",
&err_msg);
if (dsn == NULL)
elog(ERROR, "invalid connection string \"%s\": %s",
sub->target_if->dsn, err_msg);
get_pg_executable(PGRESTORE_BINARY, pg_restore);
cmdargv[cmdargc++] = pg_restore;
/* section */
if (section)
{
initStringInfo(&s);
appendStringInfo(&s, "--section=%s", section);
cmdargv[cmdargc++] = pstrdup(s.data);
resetStringInfo(&s);
}
/* stop execution on any error */
cmdargv[cmdargc++] = "--exit-on-error";
/* apply everything in single tx */
cmdargv[cmdargc++] = "-1";
/* connection string */
initStringInfo(&s);
appendStringInfo(&s, "--dbname=%s", dsn);
cmdargv[cmdargc++] = pstrdup(s.data);
free(dsn);
/* source file */
cmdargv[cmdargc++] = pstrdup(srcfile);
cmdargv[cmdargc++] = NULL;
if (exec_cmd(pg_restore, cmdargv) != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not execute pg_restore (\"%s\"): %m",
pg_restore)));
}
/*
* Create slot and get the exported snapshot.
*
* This will try to recreate slot if already exists and not active.
*
* The reported LSN is the confirmed flush LSN at the point the slot reached
* consistency and exported its snapshot.
*/
static char *
ensure_replication_slot_snapshot(PGconn *sql_conn, PGconn *repl_conn,
char *slot_name, bool use_failover_slot,
XLogRecPtr *lsn)
{
PGresult *res;
StringInfoData query;
char *snapshot;
retry:
initStringInfo(&query);
appendStringInfo(&query, "CREATE_REPLICATION_SLOT \"%s\" LOGICAL %s",
slot_name, "spock_output");
/* TODO: Should we ever use FAILOVER here? */
/*
if (use_failover_slot)
appendStringInfo(&query, " FAILOVER");
*/
res = PQexec(repl_conn, query.data);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
const char *sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
/*
* If our slot already exist but is not used, it's leftover from
* previous unsucessful attempt to synchronize table, try dropping
* it and recreating.
*/
if (sqlstate &&
strcmp(sqlstate, "42710" /*ERRCODE_DUPLICATE_OBJECT*/) == 0 &&
!spock_remote_slot_active(sql_conn, slot_name))
{
pfree(query.data);
PQclear(res);
spock_drop_remote_slot(sql_conn, slot_name);
goto retry;
}
elog(ERROR, "could not create replication slot on provider: %s\n"
"query: %s",
PQresultErrorMessage(res), query.data);
}
*lsn = DatumGetLSN(DirectFunctionCall1Coll(pg_lsn_in, InvalidOid,
CStringGetDatum(PQgetvalue(res, 0, 1))));
snapshot = pstrdup(PQgetvalue(res, 0, 2));
PQclear(res);
return snapshot;
}
/*
* Get or create replication origin for a given slot.
*/
static RepOriginId
ensure_replication_origin(char *slot_name)
{
RepOriginId origin = replorigin_by_name(slot_name, true);
if (origin == InvalidRepOriginId)
origin = replorigin_create(slot_name);
return origin;
}
/*
* Transaction management for COPY.
*/
static void
start_copy_origin_tx(PGconn *conn, const char *snapshot)
{
PGresult *res;
char *s;
const char *setup_query =
"BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ, READ ONLY;\n"
"SET DATESTYLE = ISO;\n"
"SET INTERVALSTYLE = POSTGRES;\n"
"SET extra_float_digits TO 3;\n"
"SET statement_timeout = 0;\n"
"SET lock_timeout = 0;\n";
StringInfoData query;
initStringInfo(&query);
appendStringInfoString(&query, setup_query);
if (snapshot)
{
s = PQescapeLiteral(conn, snapshot, strlen(snapshot));
appendStringInfo(&query, "SET TRANSACTION SNAPSHOT %s;\n", s);
}
res = PQexec(conn, query.data);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
elog(ERROR, "BEGIN on origin node failed: %s",
PQresultErrorMessage(res));
PQclear(res);
}
static void
start_copy_target_tx(PGconn *conn, const char *origin_name)
{
PGresult *res;
char *s;
const char *setup_query =
"BEGIN TRANSACTION ISOLATION LEVEL READ COMMITTED;\n"
"SET session_replication_role = 'replica';\n"
"SET DATESTYLE = ISO;\n"
"SET INTERVALSTYLE = POSTGRES;\n"
"SET extra_float_digits TO 3;\n"
"SET statement_timeout = 0;\n"
"SET lock_timeout = 0;\n";
StringInfoData query;
initStringInfo(&query);
/*
* Set correct origin if target db supports it.
* We must do this before starting the transaction otherwise the status
* code bellow would get much more complicated.
*/
if (PQserverVersion(conn) >= 90500)
{
s = PQescapeLiteral(conn, origin_name, strlen(origin_name));
appendStringInfo(&query,
"SELECT pg_catalog.pg_replication_origin_session_setup(%s);\n",
s);
PQfreemem(s);
}
appendStringInfoString(&query, setup_query);
res = PQexec(conn, query.data);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
elog(ERROR, "BEGIN on target node failed: %s",
PQresultErrorMessage(res));
PQclear(res);
}
static void
finish_copy_origin_tx(PGconn *conn)
{
PGresult *res;
/* Close the transaction and connection on origin node. */
res = PQexec(conn, "ROLLBACK");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
elog(WARNING, "ROLLBACK on origin node failed: %s",
PQresultErrorMessage(res));
PQclear(res);
PQfinish(conn);
}
static void
finish_copy_target_tx(PGconn *conn)
{
PGresult *res;
/* Close the transaction and connection on target node. */
res = PQexec(conn, "COMMIT");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
elog(ERROR, "COMMIT on target node failed: %s",
PQresultErrorMessage(res));
PQclear(res);
/*
* Resetting the origin explicitly before the backend exits will help
* prevent races with other accesses to the same replication origin.
*/
if (PQserverVersion(conn) >= 90500)
{
res = PQexec(conn, "SELECT pg_catalog.pg_replication_origin_session_reset();\n");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
elog(WARNING, "Resetting session origin on target node failed: %s",
PQresultErrorMessage(res));
PQclear(res);
}
PQfinish(conn);
}
static int
physatt_in_attmap(SpockRelation *rel, int attid)
{
AttrNumber i;
for (i = 0; i < rel->natts; i++)
if (rel->attmap[i] == attid)
return i;
return -1;
}
/*
* Create list of columns for COPY based on logical relation mapping.
*/
static List *
make_copy_attnamelist(SpockRelation *rel)
{
List *attnamelist = NIL;
TupleDesc desc = RelationGetDescr(rel->rel);
int attnum;
for (attnum = 0; attnum < desc->natts; attnum++)
{
int remoteattnum = physatt_in_attmap(rel, attnum);
/* Skip dropped attributes. */
if (TupleDescAttr(desc,attnum)->attisdropped)
continue;
if (remoteattnum < 0)
continue;
attnamelist = lappend(attnamelist,
makeString(rel->attnames[remoteattnum]));
}
return attnamelist;
}
/*
* COPY single table over wire.
*/
static void
copy_table_data(PGconn *origin_conn, PGconn *target_conn,
SpockRemoteRel *remoterel, List *replication_sets)
{
SpockRelation *rel;
PGresult *res;
int bytes;
char *copybuf;
List *attnamelist;
ListCell *lc;
bool first;
StringInfoData query;
StringInfoData attlist;
MemoryContext curctx = CurrentMemoryContext,
oldctx;
/* Build the relation map. */
StartTransactionCommand();
oldctx = MemoryContextSwitchTo(curctx);
spock_relation_cache_updater(remoterel);
rel = spock_relation_open(remoterel->relid, AccessShareLock);
attnamelist = make_copy_attnamelist(rel);
initStringInfo(&attlist);
first = true;
foreach (lc, attnamelist)
{
char *attname = strVal(lfirst(lc));
if (first)
first = false;
else
appendStringInfoString(&attlist, ",");
appendStringInfoString(&attlist,
PQescapeIdentifier(origin_conn, attname,
strlen(attname)));
}
MemoryContextSwitchTo(oldctx);
spock_relation_close(rel, AccessShareLock);
CommitTransactionCommand();
/* Build COPY TO query. */
initStringInfo(&query);
appendStringInfoString(&query, "COPY ");
/*
* If the table is row-filtered we need to run query over the table
* to execute the filter.
*/
if (remoterel->hasRowFilter)
{
StringInfoData relname;
StringInfoData repsetarr;
initStringInfo(&relname);
appendStringInfo(&relname, "%s.%s",
PQescapeIdentifier(origin_conn, remoterel->nspname,
strlen(remoterel->nspname)),
PQescapeIdentifier(origin_conn, remoterel->relname,
strlen(remoterel->relname)));
initStringInfo(&repsetarr);
first = true;
foreach (lc, replication_sets)
{
char *repset_name = lfirst(lc);
if (first)
first = false;
else
appendStringInfoChar(&repsetarr, ',');
appendStringInfo(&repsetarr, "%s",
PQescapeLiteral(origin_conn, repset_name,
strlen(repset_name)));
}
appendStringInfo(&query,
"(SELECT %s FROM spock.table_data_filtered(NULL::%s, %s::regclass, ARRAY[%s])) ",
list_length(attnamelist) ? attlist.data : "*",
relname.data,
PQescapeLiteral(origin_conn, relname.data, relname.len),
repsetarr.data);
}
else
{
if (remoterel->relkind == RELKIND_PARTITIONED_TABLE)
{
/* use COPY(SELECT...) for partitioned tables. */
appendStringInfo(&query, "(SELECT %s FROM %s.%s) ",
list_length(attnamelist) ? attlist.data : "*",
PQescapeIdentifier(origin_conn, remoterel->nspname,
strlen(remoterel->nspname)),
PQescapeIdentifier(origin_conn, remoterel->relname,
strlen(remoterel->relname)));
}
else
{
/* Otherwise just copy the table. */
appendStringInfo(&query, "%s.%s ",
PQescapeIdentifier(origin_conn, remoterel->nspname,
strlen(remoterel->nspname)),
PQescapeIdentifier(origin_conn, remoterel->relname,
strlen(remoterel->relname)));
if (list_length(attnamelist))
appendStringInfo(&query, "(%s) ", attlist.data);
}
}
appendStringInfoString(&query, "TO stdout");
/* Execute COPY TO. */
res = PQexec(origin_conn, query.data);
if (PQresultStatus(res) != PGRES_COPY_OUT)
{
ereport(ERROR,
(errmsg("table copy failed"),
errdetail("Query '%s': %s", query.data,
PQerrorMessage(origin_conn))));
}
/* Build COPY FROM query. */
resetStringInfo(&query);
appendStringInfo(&query, "COPY %s.%s ",
PQescapeIdentifier(origin_conn, remoterel->nspname,
strlen(remoterel->nspname)),
PQescapeIdentifier(origin_conn, remoterel->relname,
strlen(remoterel->relname)));
if (list_length(attnamelist))
appendStringInfo(&query, "(%s) ", attlist.data);
appendStringInfoString(&query, "FROM stdin");
/* Execute COPY FROM. */
res = PQexec(target_conn, query.data);
if (PQresultStatus(res) != PGRES_COPY_IN)
{
ereport(ERROR,
(errmsg("table copy failed"),
errdetail("Query '%s': %s", query.data,
PQerrorMessage(origin_conn))));
}
while ((bytes = PQgetCopyData(origin_conn, ©buf, false)) > 0)
{
if (PQputCopyData(target_conn, copybuf, bytes) != 1)
{
ereport(ERROR,
(errmsg("writing to target table failed"),
errdetail("destination connection reported: %s",
PQerrorMessage(target_conn))));
}
PQfreemem(copybuf);
CHECK_FOR_INTERRUPTS();
}
if (bytes != -1)
{
ereport(ERROR,
(errmsg("reading from origin table failed"),
errdetail("source connection returned %d: %s",
bytes, PQerrorMessage(origin_conn))));
}
/* Send local finish */
if (PQputCopyEnd(target_conn, NULL) != 1)
{
ereport(ERROR,
(errmsg("sending copy-completion to destination connection failed"),
errdetail("destination connection reported: %s",
PQerrorMessage(target_conn))));
}
PQclear(res);
elog(INFO, "finished synchronization of data for table %s.%s",
remoterel->nspname, remoterel->relname);
}
/*
* Copy data from origin node to target node.
*
* Creates new connection to origin and target.
*/
static void
copy_tables_data(char *sub_name, const char *origin_dsn,
const char *target_dsn, const char *origin_snapshot,
List *tables, List *replication_sets,
const char *origin_name)
{
PGconn *origin_conn;
PGconn *target_conn;
ListCell *lc;
/* Connect to origin node. */
origin_conn = spock_connect(origin_dsn, sub_name, "copy");
start_copy_origin_tx(origin_conn, origin_snapshot);
/* Connect to target node. */
target_conn = spock_connect(target_dsn, sub_name, "copy");
start_copy_target_tx(target_conn, origin_name);
/* Copy every table. */
foreach (lc, tables)
{
RangeVar *rv = lfirst(lc);
SpockRemoteRel *remoterel;
remoterel = spock_get_remote_repset_table(origin_conn, rv,
replication_sets);
/*
* In case of table partitioning, we synchronize the partitioned
* (parent) table and skip the partitions. Other tables are synchronized
* normally.
*/
if (!remoterel->ispartition)
copy_table_data(origin_conn, target_conn, remoterel, replication_sets);
CHECK_FOR_INTERRUPTS();
}
/* Finish the transactions and disconnect. */
finish_copy_origin_tx(origin_conn);
finish_copy_target_tx(target_conn);
}
/*
* Copy data from origin node to target node.
*
* Creates new connection to origin and target.
*
* This is basically same as the copy_tables_data, but it can't be easily
* merged to single function because we need to get list of tables here after
* the transaction is bound to a snapshot.
*/
static List *
copy_replication_sets_data(char *sub_name, const char *origin_dsn,
const char *target_dsn,
const char *origin_snapshot,
List *replication_sets, const char *origin_name)
{
PGconn *origin_conn;
PGconn *target_conn;
List *tables;
ListCell *lc;
/* Connect to origin node. */
origin_conn = spock_connect(origin_dsn, sub_name, "copy");
start_copy_origin_tx(origin_conn, origin_snapshot);
/* Get tables to copy from origin node. */
tables = spock_get_remote_repset_tables(origin_conn,
replication_sets);
/* Connect to target node. */
target_conn = spock_connect(target_dsn, sub_name, "copy");
start_copy_target_tx(target_conn, origin_name);
/* Copy every table. */
foreach (lc, tables)
{
SpockRemoteRel *remoterel = lfirst(lc);
/*
* In case of table partitioning, we synchronize the partitioned
* (parent) table and skip the partitions. Other tables are synchronized
* normally.
*/
if (!remoterel->ispartition)
copy_table_data(origin_conn, target_conn, remoterel, replication_sets);
CHECK_FOR_INTERRUPTS();
}
/* Finish the transactions and disconnect. */
finish_copy_origin_tx(origin_conn);
finish_copy_target_tx(target_conn);
return tables;
}
static void
spock_sync_worker_cleanup(SpockSubscription *sub)
{
PGconn *origin_conn;
/* Drop the slot on the remote side. */
origin_conn = spock_connect(sub->origin_if->dsn, sub->name,
"cleanup");
/* Wait for slot to be free. */
while (!got_SIGTERM)
{
int rc;
if (!spock_remote_slot_active(origin_conn, sub->slot_name))
break;
rc = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
1000L);
ResetLatch(&MyProc->procLatch);
/* emergency bailout if postmaster has died */
if (rc & WL_POSTMASTER_DEATH)
proc_exit(1);
CHECK_FOR_INTERRUPTS();
}
spock_drop_remote_slot(origin_conn, sub->slot_name);
PQfinish(origin_conn);
/* Drop the origin tracking locally. */
if (replorigin_session_origin != InvalidRepOriginId)
{
replorigin_session_reset();
#if PG_VERSION_NUM >= 140000
replorigin_drop_by_name(sub->slot_name, true, true);
#else
replorigin_drop(replorigin_session_origin, true);
#endif
replorigin_session_origin = InvalidRepOriginId;
}
}
static void
spock_sync_worker_cleanup_error_cb(int code, Datum arg)
{
SpockSubscription *sub = (SpockSubscription *) DatumGetPointer(arg);
spock_sync_worker_cleanup(sub);
}
static void
spock_sync_tmpfile_cleanup_cb(int code, Datum arg)
{
const char *tmpfile = DatumGetCString(arg);
if (unlink(tmpfile) != 0 && errno != ENOENT)
elog(WARNING, "Failed to clean up spock temporary dump file \"%s\" on exit/error: %m",
tmpfile);
}
void
spock_sync_subscription(SpockSubscription *sub)
{
SpockSyncStatus *sync;
XLogRecPtr lsn;
char status;
MemoryContext myctx,
oldctx;
/* We need our own context for keeping things between transactions. */
myctx = AllocSetContextCreate(CurrentMemoryContext,
"spock_sync_subscription cxt",
ALLOCSET_DEFAULT_SIZES);
StartTransactionCommand();
oldctx = MemoryContextSwitchTo(myctx);
sync = get_subscription_sync_status(sub->id, false);
MemoryContextSwitchTo(oldctx);
CommitTransactionCommand();
status = sync->status;
switch (status)
{
/* Already synced, nothing to do except cleanup. */
case SYNC_STATUS_READY:
MemoryContextDelete(myctx);
return;
/* We can recover from crashes during these. */
case SYNC_STATUS_INIT:
case SYNC_STATUS_CATCHUP:
break;
default:
elog(ERROR,
"subscriber %s initialization failed during nonrecoverable step (%c), please try the setup again",
sub->name, status);
break;
}
if (status == SYNC_STATUS_INIT)
{
PGconn *origin_conn;
PGconn *origin_conn_repl;
RepOriginId originid;
char *snapshot;
bool use_failover_slot;
elog(INFO, "initializing subscriber %s", sub->name);
origin_conn = spock_connect(sub->origin_if->dsn,
sub->name, "snap");
/* 2QPG9.6 and 2QPG11 support failover slots */
use_failover_slot =
spock_remote_function_exists(origin_conn, "pg_catalog",
"pg_create_logical_replication_slot",
-1,
"failover");
origin_conn_repl = spock_connect_replica(sub->origin_if->dsn,
sub->name, "snap");
snapshot = ensure_replication_slot_snapshot(origin_conn,
origin_conn_repl,
sub->slot_name,
use_failover_slot, &lsn);
PQfinish(origin_conn);
PG_ENSURE_ERROR_CLEANUP(spock_sync_worker_cleanup_error_cb,
PointerGetDatum(sub));
{
char tmpfile[MAXPGPATH];
snprintf(tmpfile, MAXPGPATH, "%s/spock-%d.dump",
spock_temp_directory, MyProcPid);
canonicalize_path(tmpfile);
PG_ENSURE_ERROR_CLEANUP_SUFFIX(spock_sync_tmpfile_cleanup_cb,
CStringGetDatum(tmpfile), _suf);
{
Relation replorigin_rel;
StartTransactionCommand();
originid = ensure_replication_origin(sub->slot_name);
elog(DEBUG3, "advancing origin with oid %u for forwarded row to %X/%X during subscription sync",
originid,
(uint32)(XactLastCommitEnd>>32), (uint32)XactLastCommitEnd);
replorigin_rel = table_open(ReplicationOriginRelationId, RowExclusiveLock);
replorigin_advance(originid, lsn, XactLastCommitEnd, true,
true);
table_close(replorigin_rel, RowExclusiveLock);
CommitTransactionCommand();
if (SyncKindStructure(sync->kind))
{
elog(INFO, "synchronizing structure");
status = SYNC_STATUS_STRUCTURE;
StartTransactionCommand();
set_subscription_sync_status(sub->id, status);
CommitTransactionCommand();
/* Dump structure to temp storage. */
dump_structure(sub, tmpfile, snapshot);
/* Restore base pre-data structure (types, tables, etc). */
restore_structure(sub, tmpfile, "pre-data");
}
/* Copy data. */
if (SyncKindData(sync->kind))
{
List *tables;
ListCell *lc;
elog(INFO, "synchronizing data");
status = SYNC_STATUS_DATA;
StartTransactionCommand();
set_subscription_sync_status(sub->id, status);
CommitTransactionCommand();