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pglogical_sync.c
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pglogical_sync.c
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/*-------------------------------------------------------------------------
*
* pglogical_sync.c
* table synchronization functions
*
* Copyright (c) 2015, PostgreSQL Global Development Group
*
* IDENTIFICATION
* pglogical_sync.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#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 "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 "pglogical_relcache.h"
#include "pglogical_repset.h"
#include "pglogical_rpc.h"
#include "pglogical_sync.h"
#include "pglogical_worker.h"
#include "pglogical.h"
#define CATALOG_LOCAL_SYNC_STATUS "local_sync_status"
#if PG_VERSION_NUM < 90500
#define PGDUMP_BINARY "pglogical_dump"
#else
#define PGDUMP_BINARY "pg_dump"
#endif
#define PGRESTORE_BINARY "pg_restore"
#define Natts_local_sync_state 5
#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
void pglogical_sync_main(Datum main_arg);
static PGLogicalSyncWorker *MySyncWorker = NULL;
static void
dump_structure(PGLogicalSubscription *sub, const char *destfile,
const char *snapshot)
{
char pg_dump[MAXPGPATH];
uint32 version;
int res;
StringInfoData schema_filter;
StringInfoData command;
if (find_other_exec_version(my_exec_path, PGDUMP_BINARY, &version, pg_dump))
elog(ERROR, "pglogical subscriber init failed to find pg_dump relative to binary %s",
my_exec_path);
if (version / 100 != PG_VERSION_NUM / 100)
elog(ERROR, "pglogical subscriber init found pg_dump with wrong major version %d.%d, expected %d.%d",
version / 100 / 100, version / 100 % 100,
PG_VERSION_NUM / 100 / 100, PG_VERSION_NUM / 100 % 100);
initStringInfo(&schema_filter);
appendStringInfo(&schema_filter, "-N %s", EXTENSION_NAME);
/* Filter out pglogical_origin schema iff it exists (GH #45) */
StartTransactionCommand();
if (OidIsValid(LookupExplicitNamespace("pglogical_origin", true)))
appendStringInfoString(&schema_filter, " -N pglogical_origin");
CommitTransactionCommand();
initStringInfo(&command);
appendStringInfo(&command, "\"%s\" --snapshot=\"%s\" %s -s -F c -f \"%s\" \"%s\"",
pg_dump, snapshot, schema_filter.data, destfile,
sub->origin_if->dsn);
res = system(command.data);
if (res != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not execute command \"%s\"",
command.data)));
}
/* TODO: switch to SPI? */
static void
restore_structure(PGLogicalSubscription *sub, const char *srcfile,
const char *section)
{
char pg_restore[MAXPGPATH];
uint32 version;
int res;
StringInfoData command;
if (find_other_exec_version(my_exec_path, PGRESTORE_BINARY, &version, pg_restore))
elog(ERROR, "pglogical subscriber init failed to find pg_restore relative to binary %s",
my_exec_path);
if (version / 100 != PG_VERSION_NUM / 100)
elog(ERROR, "pglogical subscriber init found pg_restore with wrong major version %d.%d, expected %d.%d",
version / 100 / 100, version / 100 % 100,
PG_VERSION_NUM / 100 / 100, PG_VERSION_NUM / 100 % 100);
initStringInfo(&command);
appendStringInfo(&command,
"\"%s\" --section=\"%s\" --exit-on-error -1 -d \"%s\" \"%s\"",
pg_restore, section, sub->target_if->dsn, srcfile);
res = system(command.data);
if (res != 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not execute command \"%s\"",
command.data)));
}
/*
* Ensure slot exists.
*/
static char *
ensure_replication_slot_snapshot(PGconn *origin_conn, char *slot_name,
bool use_failover_slot, XLogRecPtr *lsn)
{
PGresult *res;
StringInfoData query;
char *snapshot;
initStringInfo(&query);
appendStringInfo(&query, "CREATE_REPLICATION_SLOT \"%s\" LOGICAL %s%s",
slot_name, "pglogical_output",
use_failover_slot ? " FAILOVER" : "");
res = PQexec(origin_conn, query.data);
/* TODO: check and handle already existing slot. */
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
char *err = PQresultErrorMessage(res);
/*
* Report more pleasant message on snapshot too large
* (there is not ERRCODE for it).
*
* Note that retry is not hanled by us but by the fact that this
* function is only called when sync state is INIT.
*/
if (strstr(err, "snapshot too large"))
ereport(ERROR,
(errmsg("could not start synchronization, will retry later"),
errdetail("recieved \"snapshot too large\" from provider")));
else
elog(FATAL, "could not send replication command \"%s\": status %s: %s\n",
query.data,
PQresStatus(PQresultStatus(res)), err);
}
*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);
PQfinish(conn);
}
static int
physatt_in_attmap(PGLogicalRelation *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(PGLogicalRelation *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 (desc->attrs[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,
PGLogicalRemoteRel *remoterel, List *replication_sets)
{
PGLogicalRelation *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);
pglogical_relation_cache_updater(remoterel);
rel = pglogical_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);
pglogical_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;
ListCell *lc;
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 pglogical.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
{
/* 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);
}
/*
* 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 = pglogical_connect(origin_dsn, sub_name, "copy");
start_copy_origin_tx(origin_conn, origin_snapshot);
/* Connect to target node. */
target_conn = pglogical_connect(target_dsn, sub_name, "copy");
start_copy_target_tx(target_conn, origin_name);
/* Copy every table. */
foreach (lc, tables)
{
RangeVar *rv = lfirst(lc);
PGLogicalRemoteRel *remoterel;
remoterel = pg_logical_get_remote_repset_table(origin_conn, rv,
replication_sets);
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 = pglogical_connect(origin_dsn, sub_name, "copy");
start_copy_origin_tx(origin_conn, origin_snapshot);
/* Get tables to copy from origin node. */
tables = pg_logical_get_remote_repset_tables(origin_conn,
replication_sets);
/* Connect to target node. */
target_conn = pglogical_connect(target_dsn, sub_name, "copy");
start_copy_target_tx(target_conn, origin_name);
/* Copy every table. */
foreach (lc, tables)
{
PGLogicalRemoteRel *remoterel = lfirst(lc);
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
pglogical_sync_worker_cleanup(PGLogicalSubscription *sub)
{
PGconn *origin_conn;
/* Drop the slot on the remote side. */
origin_conn = pglogical_connect(sub->origin_if->dsn, sub->name,
"cleanup");
/* Wait for slot to be free. */
while (!got_SIGTERM)
{
int rc;
if (!pglogical_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);
}
pglogical_drop_remote_slot(origin_conn, sub->slot_name);
PQfinish(origin_conn);
/* Drop the origin tracking locally. */
if (replorigin_session_origin != InvalidRepOriginId)
{
replorigin_session_reset();
replorigin_drop(replorigin_session_origin);
replorigin_session_origin = InvalidRepOriginId;
}
}
static void
pglogical_sync_worker_cleanup_error_cb(int code, Datum arg)
{
PGLogicalSubscription *sub = (PGLogicalSubscription *) DatumGetPointer(arg);
pglogical_sync_worker_cleanup(sub);
}
static void
pglogical_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 pglogical temporary dump file \"%s\" on exit/error",
tmpfile);
}
void
pglogical_sync_subscription(PGLogicalSubscription *sub)
{
PGLogicalSyncStatus *sync;
XLogRecPtr lsn;
char status;
MemoryContext myctx,
oldctx;
/* We need our own context for keeping things between transactions. */
myctx = AllocSetContextCreate(CurrentMemoryContext,
"pglogical_sync_subscription cxt",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
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 = pglogical_connect(sub->origin_if->dsn,
sub->name, "snap");
use_failover_slot = pglogical_remote_function_exists(origin_conn,
"pg_catalog",
"pg_create_logical_replication_slot",
3);
PQfinish(origin_conn);
origin_conn_repl = pglogical_connect_replica(sub->origin_if->dsn,
sub->name, "snap");
snapshot = ensure_replication_slot_snapshot(origin_conn_repl,
sub->slot_name,
use_failover_slot, &lsn);
PG_ENSURE_ERROR_CLEANUP(pglogical_sync_worker_cleanup_error_cb,
PointerGetDatum(sub));
{
char tmpfile[MAXPGPATH];
snprintf(tmpfile, MAXPGPATH, "%s/pglogical-%d.dump",
pglogical_temp_directory, MyProcPid);
canonicalize_path(tmpfile);
PG_ENSURE_ERROR_CLEANUP(pglogical_sync_tmpfile_cleanup_cb,
CStringGetDatum(tmpfile));
{
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_advance(originid, lsn, XactLastCommitEnd, true,
true);
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();
tables = copy_replication_sets_data(sub->name,
sub->origin_if->dsn,
sub->target_if->dsn,
snapshot,
sub->replication_sets,
sub->slot_name);
/* Store info about all the synchronized tables. */
StartTransactionCommand();
foreach (lc, tables)
{
PGLogicalRemoteRel *remoterel = lfirst(lc);
PGLogicalSyncStatus *oldsync;
oldsync = get_table_sync_status(sub->id,
remoterel->nspname,
remoterel->relname, true);
if (oldsync)
{
set_table_sync_status(sub->id, remoterel->nspname,
remoterel->relname,
SYNC_STATUS_READY);
}
else
{
PGLogicalSyncStatus newsync;
newsync.kind = SYNC_KIND_FULL;
newsync.subid = sub->id;
newsync.nspname = remoterel->nspname;
newsync.relname = remoterel->relname;
newsync.status = SYNC_STATUS_READY;
create_local_sync_status(&newsync);
}
}
CommitTransactionCommand();
}
/* Restore post-data structure (indexes, constraints, etc). */
if (SyncKindStructure(sync->kind))
{
elog(INFO, "synchronizing constraints");
status = SYNC_STATUS_CONSTAINTS;
StartTransactionCommand();
set_subscription_sync_status(sub->id, status);
CommitTransactionCommand();
restore_structure(sub, tmpfile, "post-data");
}
}
PG_END_ENSURE_ERROR_CLEANUP(pglogical_sync_tmpfile_cleanup_cb,
CStringGetDatum(tmpfile));
pglogical_sync_tmpfile_cleanup_cb(0,
CStringGetDatum(tmpfile));
}
PG_END_ENSURE_ERROR_CLEANUP(pglogical_sync_worker_cleanup_error_cb,
PointerGetDatum(sub));
PQfinish(origin_conn_repl);
status = SYNC_STATUS_CATCHUP;
StartTransactionCommand();
set_subscription_sync_status(sub->id, status);
CommitTransactionCommand();
}
if (status == SYNC_STATUS_CATCHUP)
{
/* Nothing to do here yet. */
status = SYNC_STATUS_READY;
StartTransactionCommand();
set_subscription_sync_status(sub->id, status);
CommitTransactionCommand();
elog(INFO, "finished synchronization of subscriber %s, ready to enter normal replication", sub->name);
}
MemoryContextDelete(myctx);
}
char
pglogical_sync_table(PGLogicalSubscription *sub, RangeVar *table)
{
XLogRecPtr lsn;
PGconn *origin_conn_repl;
RepOriginId originid;
char *snapshot;
PGLogicalSyncStatus *sync;
StartTransactionCommand();
/* Sanity check. */
sync = get_subscription_sync_status(sub->id, false);
if (sync->status != SYNC_STATUS_READY)
{
elog(ERROR,
"subscriber %s is not ready, cannot synchronzie individual tables", sub->name);
}
/* Check current state of the table. */
sync = get_table_sync_status(sub->id, table->schemaname, table->relname, false);
/* Already synchronized, nothing to do here. */
if (sync->status == SYNC_STATUS_READY)
return SYNC_STATUS_READY;
/* If previous sync attempt failed, we need to start from beginning. */
if (sync->status != SYNC_STATUS_INIT)
set_table_sync_status(sub->id, table->schemaname, table->relname, SYNC_STATUS_INIT);
CommitTransactionCommand();
origin_conn_repl = pglogical_connect_replica(sub->origin_if->dsn,
sub->name, "copy");
snapshot = ensure_replication_slot_snapshot(origin_conn_repl,
sub->slot_name, false, &lsn);
/* Make sure we cleanup the slot if something goes wrong. */
PG_ENSURE_ERROR_CLEANUP(pglogical_sync_worker_cleanup_error_cb,
PointerGetDatum(sub));
{
StartTransactionCommand();
originid = ensure_replication_origin(sub->slot_name);
elog(DEBUG2, "advancing origin %s (oid %u) for forwarded row to %X/%X after sync error",
MySubscription->slot_name, originid,
(uint32)(XactLastCommitEnd>>32), (uint32)XactLastCommitEnd);
replorigin_advance(originid, lsn, XactLastCommitEnd, true, true);
set_table_sync_status(sub->id, table->schemaname, table->relname,
SYNC_STATUS_DATA);
CommitTransactionCommand();
/* Copy data. */
copy_tables_data(sub->name, sub->origin_if->dsn,sub->target_if->dsn,
snapshot, list_make1(table), sub->replication_sets,
sub->slot_name);
}
PG_END_ENSURE_ERROR_CLEANUP(pglogical_sync_worker_cleanup_error_cb,
PointerGetDatum(sub));
PQfinish(origin_conn_repl);
return SYNC_STATUS_SYNCWAIT;
}
void
pglogical_sync_worker_finish(void)
{
PGLogicalWorker *apply;
StartTransactionCommand();
/* Mark local table as ready. */
set_table_sync_status(MyApplyWorker->subid,
NameStr(MyPGLogicalWorker->worker.sync.nspname),
NameStr(MyPGLogicalWorker->worker.sync.relname),
SYNC_STATUS_READY);
pglogical_sync_worker_cleanup(MySubscription);
CommitTransactionCommand();
/*
* In case there is apply process running, it might be waiting
* for the table status change so tell it to check.
*/
LWLockAcquire(PGLogicalCtx->lock, LW_EXCLUSIVE);
apply = pglogical_apply_find(MyPGLogicalWorker->dboid,
MyApplyWorker->subid);
if (pglogical_worker_running(apply))
SetLatch(&apply->proc->procLatch);
LWLockRelease(PGLogicalCtx->lock);
elog(LOG, "finished sync of table %s.%s for subscriber %s",
NameStr(MySyncWorker->nspname), NameStr(MySyncWorker->relname),
MySubscription->name);
}
void
pglogical_sync_main(Datum main_arg)
{
int slot = DatumGetInt32(main_arg);
PGconn *streamConn;
RepOriginId originid;
XLogRecPtr origin_startpos;
StringInfoData slot_name;
RangeVar *copytable = NULL;
MemoryContext saved_ctx;
char *tablename;
/* Setup shmem. */
pglogical_worker_attach(slot, PGLOGICAL_WORKER_SYNC);
MySyncWorker = &MyPGLogicalWorker->worker.sync;
MyApplyWorker = &MySyncWorker->apply;
/* Establish signal handlers. */
pqsignal(SIGTERM, handle_sigterm);
BackgroundWorkerUnblockSignals();
/* Attach to dsm segment. */
Assert(CurrentResourceOwner == NULL);
CurrentResourceOwner = ResourceOwnerCreate(NULL, "pglogical sync");