database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-09 06:21:09 +03:00
Code Activity

Add new GUC reserved_connections.

Browse Source 
This provides a way to reserve connection slots for non-superusers.
The slots reserved via the new GUC are available only to users who
have the new predefined role pg_use_reserved_connections.
superuser_reserved_connections remains as a final reserve in case
reserved_connections has been exhausted.

Patch by Nathan Bossart. Reviewed by Tushar Ahuja and by me.

Discussion: http://postgr.es/m/20230119194601.GA4105788@nathanxps13
This commit is contained in:
Robert Haas
2023-01-20 15:36:36 -05:00
parent fe00fec1f5
commit 6e2775e4d4
10 changed files with 115 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
src/backend/utils/init/postinit.c
View File

@@ -719,6 +719,7 @@ InitPostgres(const char *in_dbname, Oid dboid,
bool am_superuser;
char *fullpath;
char dbname[NAMEDATALEN];
int nfree = 0;
elog(DEBUG3, "InitPostgres");
@@ -922,16 +923,30 @@ InitPostgres(const char *in_dbname, Oid dboid,
}
/*
* The last few connection slots are reserved for superusers. Replication
* connections are drawn from slots reserved with max_wal_senders and not
* limited by max_connections or superuser_reserved_connections.
* The last few connection slots are reserved for superusers and roles with
* privileges of pg_use_reserved_connections. Replication connections are
* drawn from slots reserved with max_wal_senders and are not limited by
* max_connections, superuser_reserved_connections, or
* reserved_connections.
*
* Note: At this point, the new backend has already claimed a proc struct,
* so we must check whether the number of free slots is strictly less than
* the reserved connection limits.
*/
if (!am_superuser && !am_walsender &&
SuperuserReservedConnections > 0 &&
!HaveNFreeProcs(SuperuserReservedConnections))
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("remaining connection slots are reserved for superusers")));
(SuperuserReservedConnections + ReservedConnections) > 0 &&
!HaveNFreeProcs(SuperuserReservedConnections + ReservedConnections, &nfree))
{
if (nfree < SuperuserReservedConnections)
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("remaining connection slots are reserved for superusers")));
if (!has_privs_of_role(GetUserId(), ROLE_PG_USE_RESERVED_CONNECTIONS))
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("remaining connection slots are reserved for roles with privileges of pg_use_reserved_connections")));
}
/* Check replication permissions needed for walsender processes. */
if (am_walsender)