It is very important that the access privileges for replication be set up
so that only trusted users can read the WAL stream, because it is
easy to extract privileged information from it. Standby servers must
- authenticate to the primary as an account that has the
- REPLICATION> privilege. So a role with the
- REPLICATION> and LOGIN> privileges needs to be
- created on the primary.
+ authenticate to the primary as a superuser or an account that has the
+ REPLICATION> privilege. It is recommended to create a
+ dedicated user account with REPLICATION> and LOGIN>
+ privileges for replication. While REPLICATION> privilege gives
+ very high permissions, it does not allow the user to modify any data on
+ the primary system, which the SUPERUSER> privilege does.
-
- It is recommended that a dedicated user account is used for replication.
- While the REPLICATION> privilege is granted to superuser
- accounts by default, it is not recommended to use superuser accounts
- for replication. While REPLICATION> privilege gives very high
- permissions, it does not allow the user to modify any data on the
- primary system, which the SUPERUSER> privilege does.
-
-
-
Client authentication for replication is controlled by a
pg_hba.conf> record specifying replication> in the
The connection string should specify the host name (or address)
of the primary server, as well as the port number if it is not
the same as the standby server's default.
- Also specify a user name corresponding to a role that has the
- REPLICATION> and LOGIN> privileges on the
- primary (see
+ Also specify a user name corresponding to a suitably-privileged role
+ on the primary (see
).
A password needs to be provided too, if the primary demands password
authentication. It can be provided in the
A role having the REPLICATION> attribute is a very
highly privileged role, and should only be used on roles actually
used for replication. If not specified,
- NOREPLICATION is the default for all roles except
- superusers.
+ NOREPLICATION is the default.
The backup is made over a regular
PostgreSQL
- connection, and uses the replication protocol. The connection must be
- made with a user having REPLICATION permissions (see
- ), and the user must be granted explicit
- permissions in pg_hba.conf. The server must also
- be configured with set high enough
- to leave at least one session available for the backup.
+ connection, and uses the replication protocol. The connection must be made
+ with a superuser or a user having REPLICATION
+ permissions (see ),
+ and pg_hba.conf must explicitly permit the replication
+ connection. The server must also be configured
+ with set high enough to leave at least
+ one session available for the backup.
The transaction log is streamed over a regular
-
PostgreSQL connection, and uses the
- replication protocol. The connection must be
- made with a user having REPLICATION permissions (see
- ), and the user must be granted explicit
- permissions in pg_hba.conf. The server must also
- be configured with set high enough
- to leave at least one session available for the stream.
+
PostgreSQL connection, and uses the
replication
+ protocol. The connection must be made with a superuser or a user
+ having REPLICATION permissions (see
+ ), and pg_hba.conf
+ must explicitly permit the replication connection. The server must also be
+ configured with set high enough to
+ leave at least one session available for the stream.
A database superuser bypasses all permission checks, except the right
- to log in or the right to initiate replication. This is a
- dangerous privilege and should not be used carelessly; it is best
- to do most of your work as a role that is not a superuser.
- To create a new database superuser, use CREATE ROLE
- name SUPERUSER. You must do
- this as a role that is already a superuser. Creating a superuser
- will by default also grant permissions to initiate streaming
- replication. For increased security this can be disallowed using
- CREATE ROLE name SUPERUSER
- NOREPLICATION.
+ to log in. This is a dangerous privilege and should not be used
+ carelessly; it is best to do most of your work as a role that is not a
+ superuser. To create a new database superuser, use CREATE
+ ROLE name SUPERUSER. You must do
+ this as a role that is already a superuser.
A role must explicitly be given permission to initiate streaming
- replication. A role used for streaming replication must always
+ replication (except for superusers, since those bypass all permission
+ checks). A role used for streaming replication must always
have LOGIN> permission as well. To create such a role, use
CREATE ROLE name REPLICATION
LOGIN.
if (dpassword && dpassword->arg)
password = strVal(dpassword->arg);
if (dissuper)
- {
issuper = intVal(dissuper->arg) != 0;
-
- /*
- * Superusers get replication by default, but only if NOREPLICATION
- * wasn't explicitly mentioned
- */
- if (issuper && !(disreplication && intVal(disreplication->arg) == 0))
- isreplication = 1;
- }
if (dinherit)
inherit = intVal(dinherit->arg) != 0;
if (dcreaterole)
{
Assert(!bootstrap);
- /* must have authenticated as a replication role */
- if (!is_authenticated_user_replication_role())
+ if (!superuser() && !is_authenticated_user_replication_role())
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
- errmsg("must be replication role to start walsender")));
+ errmsg("must be superuser or replication role to start walsender")));
/* process any options passed in the startup packet */
if (MyProcPort != NULL)