/*
* Activate a standby. To do this, we need to change
*
* 1. Check that we're actually the standby
* 2. Remove standby from gp_segment_configuration.
*
* gp_activate_standby()
*
* Returns:
* true upon success, otherwise throws error.
*/
Datum
gp_activate_standby(PG_FUNCTION_ARGS)
{
cqContext cqc;
int numDel;
mirroring_sanity_check(SUPERUSER | UTILITY_MODE | STANDBY_ONLY,
PG_FUNCNAME_MACRO);
if (!AmIStandby())
elog(ERROR, "%s must be run on the standby master",
PG_FUNCNAME_MACRO);
/* remove standby from gp_segment_configuration */
Relation rel = heap_open(GpSegmentConfigRelationId, AccessExclusiveLock);
numDel= caql_getcount(caql_addrel(cqclr(&cqc), rel),
cql("DELETE FROM gp_segment_configuration "
" WHERE role = :1",
CharGetDatum(SEGMENT_ROLE_STANDBY_CONFIG)));
elog(LOG, "Remove standby while activating it, count : %d.", numDel);
heap_close(rel, NoLock);
/* done */
PG_RETURN_BOOL(true);
}
/*
* Remove the master standby.
*
* gp_remove_master_standby()
*
* Returns:
* true upon success otherwise false
*/
Datum
gp_remove_master_standby(PG_FUNCTION_ARGS)
{
int numDel;
cqContext cqc;
mirroring_sanity_check(SUPERUSER | MASTER_ONLY | UTILITY_MODE,
"gp_remove_master_standby");
if (!standby_exists())
elog(ERROR, "no master standby defined");
Relation rel = heap_open(GpSegmentConfigRelationId, AccessExclusiveLock);
numDel= caql_getcount(caql_addrel(cqclr(&cqc), rel),
cql("DELETE FROM gp_segment_configuration "
" WHERE role = :1",
CharGetDatum(SEGMENT_ROLE_STANDBY_CONFIG)));
elog(LOG, "Remove standby, count : %d.", numDel);
heap_close(rel, NoLock);
update_gp_master_mirroring("Not Configured");
PG_RETURN_BOOL(true);
}
/*
* Add a master standby.
*
* gp_add_master_standby(hostname, address)
*
* Args:
* hostname - as above
* address - as above
*
* Returns:
* dbid of the new standby
*/
Datum
gp_add_master_standby(PG_FUNCTION_ARGS)
{
CdbComponentDatabaseInfo *master = NULL;
Relation gprel;
Datum values[Natts_gp_segment_configuration];
bool nulls[Natts_gp_segment_configuration];
HeapTuple tuple;
cqContext cqc;
cqContext *pcqCtx = NULL;
if (PG_ARGISNULL(0))
elog(ERROR, "host name cannot be NULL");
if (PG_ARGISNULL(1))
elog(ERROR, "address cannot be NULL");
mirroring_sanity_check(MASTER_ONLY | UTILITY_MODE,
"gp_add_master_standby");
if (standby_exists())
elog(ERROR, "only a single master standby may be defined");
/* master */
master = registration_order_get_dbinfo(MASTER_ORDER_ID);
/* Lock exclusively to avoid concurrent changes */
gprel = heap_open(GpSegmentConfigRelationId, AccessExclusiveLock);
pcqCtx = caql_beginscan(
caql_addrel(cqclr(&cqc), gprel),
cql("INSERT INTO gp_segment_configuration ", NULL));
MemSet(nulls, false, sizeof(nulls));
values[Anum_gp_segment_configuration_registration_order - 1] = Int32GetDatum(STANDBY_ORDER_ID);
values[Anum_gp_segment_configuration_role - 1] = CharGetDatum(SEGMENT_ROLE_STANDBY_CONFIG);
values[Anum_gp_segment_configuration_status - 1] = CharGetDatum('u');
values[Anum_gp_segment_configuration_port - 1] = Int32GetDatum(master->port);
values[Anum_gp_segment_configuration_hostname - 1] = PG_GETARG_DATUM(0);
values[Anum_gp_segment_configuration_address - 1] = PG_GETARG_DATUM(1);
nulls[Anum_gp_segment_configuration_description - 1] = true;
tuple = caql_form_tuple(pcqCtx, values, nulls);
/* insert a new tuple */
caql_insert(pcqCtx, tuple); /* implicit update of index as well */
caql_endscan(pcqCtx);
if(master)
pfree(master);
heap_close(gprel, NoLock);
PG_RETURN_INT16(1);
}
/*
* Remove knowledge of a segment from the master.
*
* gp_remove_segment(order)
*
* Args:
* order - order of registration
*
* Returns:
* true on success, otherwise error.
*/
Datum
gp_remove_segment(PG_FUNCTION_ARGS)
{
int16 order;
if (PG_ARGISNULL(0))
elog(ERROR, "Registration id cannot be NULL");
order = PG_GETARG_INT16(0);
mirroring_sanity_check(MASTER_ONLY | SUPERUSER | UTILITY_MODE,
"gp_remove_segment");
if (order == MASTER_ORDER_ID || order == STANDBY_ORDER_ID)
elog(ERROR, "Cannot remove master or standby");
remove_segment(order);
PG_RETURN_BOOL(true);
}
