FAQ - Revision history

Admin: /* Why does "show pool_nodes" show replication_delay as "0" even when the standby is not up-to-date? Why doesn't "show pool_nodes" show replication_state and replication_sync_state? */

2025-05-20T08:22:19Z

Why does "show pool_nodes" show replication_delay as "0" even when the standby is not up-to-date? Why doesn't "show pool_nodes" show replication_state and replication_sync_state?

← Older revision		Revision as of 08:22, 20 May 2025
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	: There are two possible reasons		: There are two possible reasons
	: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. sr_check_user needs to be PostgreSQL superuser or in pg_monitor group. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.		: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. sr_check_user needs to be PostgreSQL superuser or in pg_monitor group. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.
	~~: Grant pg_monitor to pgpool:~~

	~~postgres=# GRANT pg_monitor TO pgpool;~~
	~~postgres=# \q~~

	: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.		: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.

Admin: /* Why show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1? */

2025-05-20T08:21:13Z

Why show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1?

← Older revision		Revision as of 08:21, 20 May 2025
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	: </ul>		: </ul>

	=== '''Why show pool_nodes ~~does not~~ show ~~replication delay~~ even ~~I set delay_threshold_by_time~~ to 1?''' ===		=== '''Why does "show pool_nodes" show replication_delay as "0" even when the standby is not up-to-date? Why doesn't "show pool_nodes" show replication_state and replication_sync_state?''' ===
	: There are two possible reasons.		: There are two possible reasons
	: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.		: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. sr_check_user needs to be PostgreSQL superuser or in pg_monitor group. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.
			: Grant pg_monitor to pgpool:

			postgres=# GRANT pg_monitor TO pgpool;
			postgres=# \q

	: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.		: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.

Ishii: /* Pgpool-II Frequently Asked Questions */

2025-03-03T04:49:13Z

Pgpool-II Frequently Asked Questions

← Older revision		Revision as of 04:49, 3 March 2025
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	: See this email thread.		: See this email thread.
	: [https://www.pgpool.net/pipermail/pgpool-general/2023-August/001572.html][pgpool-general: 8897] pgpool forwarding database users/passwords		: [https://www.pgpool.net/pipermail/pgpool-general/2023-August/001572.html][pgpool-general: 8897] pgpool forwarding database users/passwords

			=== '''When I enable SSL, Pgpool-II eats CPU lot. Why?''' ===
			: Pgpool-II uses OpenSSL. It has known performance issues with 3.0.2.
			Some OS use the version of OpenSSL, including Ubuntu 22.04 and 24.04. The issue of OpenSSL has been fixed in 3.1 but never backported to 3.0. In Ubuntu 24.10 the issue has been fixed but 24.10 is not LTS.
			: This original information is provided here.
			https://github.com/pgpool/pgpool2/issues/93#issuecomment-2691037744

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* For client authentication I want to avoid maintaining pool_passwd file. What's the recommended way to do that? */

2025-01-06T23:33:55Z

For client authentication I want to avoid maintaining pool_passwd file. What's the recommended way to do that?

← Older revision		Revision as of 23:33, 6 January 2025
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	=== '''For client authentication I want to avoid maintaining pool_passwd file. What's the recommended way to do that?''' ===		=== '''For client authentication I want to avoid maintaining pool_passwd file. What's the recommended way to do that?''' ===
	: See this email thread.		: See this email thread.
	: https://www.pgpool.net/pipermail/pgpool-general/2023-August/~~008958~~.html		: [https://www.pgpool.net/pipermail/pgpool-general/2023-August/001572.html][pgpool-general: 8897] pgpool forwarding database users/passwords

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* Pgpool-II Frequently Asked Questions */

2023-08-02T04:17:41Z

Pgpool-II Frequently Asked Questions

← Older revision		Revision as of 04:17, 2 August 2023
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	: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.		: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.
	: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.		: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.

			=== '''For client authentication I want to avoid maintaining pool_passwd file. What's the recommended way to do that?''' ===
			: See this email thread.
			: https://www.pgpool.net/pipermail/pgpool-general/2023-August/008958.html

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* Why show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1? */

2022-12-28T00:42:41Z

Why show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1?

← Older revision		Revision as of 00:42, 28 December 2022
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	: There are two possible reasons.		: There are two possible reasons.
	: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.		: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.
			: Another reason can be the setting of backend_application_name parameter of the standby node in pgpool.conf. It must match with the application_name in primary_coninfo parameter in postgresql.conf.

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* I am getting an authentication error when Pgpool-II connects to Azure PostgreSQL. Why? */

2022-12-28T00:39:30Z

I am getting an authentication error when Pgpool-II connects to Azure PostgreSQL. Why?

← Older revision		Revision as of 00:39, 28 December 2022
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	: </ul>		: </ul>

	=== '''~~When~~ show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1?'''		=== '''Why show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1?''' ===
	: There are two possible reasons. First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.		: There are two possible reasons.
			: First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* Pgpool-II Frequently Asked Questions */

2022-12-28T00:38:23Z

Pgpool-II Frequently Asked Questions

← Older revision		Revision as of 00:38, 28 December 2022
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	: <li> https://www.pgpool.net/mantisbt/view.php?id=699		: <li> https://www.pgpool.net/mantisbt/view.php?id=699
	: </ul>		: </ul>

			=== '''When show pool_nodes does not show replication delay even I set delay_threshold_by_time to 1?'''
			: There are two possible reasons. First one is sr_check_user does not have enough previlege to query against pg_stat_replication view. Please consult [https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-STATS-VIEWS PostgreSQL manual] for more details.

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==

Ishii: /* Why does not Pgpool-II automatically recognize a database comes back online? */

2022-12-28T00:25:34Z

Why does not Pgpool-II automatically recognize a database comes back online?

← Older revision		Revision as of 00:25, 28 December 2022
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	# If b1 and b2 agree with the authentication, the whole md5 auth process succeeds.		# If b1 and b2 agree with the authentication, the whole md5 auth process succeeds.

	=== '''Why ~~does not~~ Pgpool-II automatically recognize a database comes back online?''' ===		=== '''Why Pgpool-II does not automatically recognize a database comes back online?''' ===
	: It would be technically possible but we don't think it's a safe feature.		: It would be technically possible but we don't think it's a safe feature.
	: Consider a streaming replication configuration. When a standby comes back online, it does not necessarily means it connects to the current primary node. It may connect to a different primary node , or even it's not a standby any more. If Pgpool-II automatically recognizes such that standby as online, SELECTs to the standby node will return different result as the primary, which is a disaster for database applications.		: Consider a streaming replication configuration. When a standby comes back online, it does not necessarily means it connects to the current primary node. It may connect to a different primary node , or even it's not a standby any more. If Pgpool-II automatically recognizes such that standby as online, SELECTs to the standby node will return different result as the primary, which is a disaster for database applications.

Ishii: /* Pgpool-II Frequently Asked Questions */

2021-11-11T08:33:14Z

Pgpool-II Frequently Asked Questions

← Older revision		Revision as of 08:33, 11 November 2021
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	</q>		</q>

	~~=== '''When I connect to Pgpool-II, I get an error: "kind does not match between main(52) slot[1] (45)". Why?''' ===~~


	:This kind of error could happen for multiple reasons. Here "52" is ASCII code point in hexa decimal number, that is ASCII 'R'. 'R' is normal response from backend. "45" is 'E' in ASCII, which means PostgreSQL complains something. In summary backend 0 accepts the connection request normaly, while backend 1 complains. To solve the problem, you need to look into pgpool.log. For example, If you set "reject" entry for the connection request in backend 1's pg_hba.conf:		:This kind of error could happen for multiple reasons. Here "52" is ASCII code point in hexa decimal number, that is ASCII 'R'. 'R' is normal response from backend. "45" is 'E' in ASCII, which means PostgreSQL complains something. In summary backend 0 accepts the connection request normaly, while backend 1 complains. To solve the problem, you need to look into pgpool.log. For example, If you set "reject" entry for the connection request in backend 1's pg_hba.conf:

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	:</ul>		:</ul>
	: Note that "main" in the error message is "master" in Pgpool-II 4.1 or before. Also note that the detailed error info ("error message from 1 th backend:...") is not available in Pgpool-II 3.6 or before.		: Note that "main" in the error message is "master" in Pgpool-II 4.1 or before. Also note that the detailed error info ("error message from 1 th backend:...") is not available in Pgpool-II 3.6 or before.

			=== '''I am getting an authentication error when Pgpool-II connects to Azure PostgreSQL. Why?''' ===
			: Auzre PostgreSQL only accepts clear text password. md5 authentication nor SCRAM-SHA-256 cannot be used. You need to set clear text password in pool_passwd.
			: related bug track entries:
			: <ul>
			: <li> https://www.pgpool.net/mantisbt/view.php?id=737
			: <li> https://www.pgpool.net/mantisbt/view.php?id=699
			: </ul>

	== pgpoolAdmin Frequently Asked Questions ==		== pgpoolAdmin Frequently Asked Questions ==