Re: Unable to Connect to DB Instance

On Wed, Jul 4, 2018, 15:19 Boblitz John <john(dot)boblitz(at)bertschi(dot)com> wrote:

> Good Morning,
>
>
>
> Beginning yesterday morning, users have been unable to fully connect to
> our DB Instance.
>
>
>
> 1. At the time of the initial report – I was connected to the DB
> via pgAdmin and could perform queries without problem.
>
> 2. Users reported messages similar to “could not open file
> "global/11801": No such file or directory”
>
> 3. At that time, connection logging was turned off and there were
> no messages in the log files.
>
> 4. As this is a development environment, I turned logging on in the
> config and restarted the DB
>
> 5. After restart, neither I, nor the Users could fully reconnect.
>
> 6. I have performed a SYS Level backup (tar of the whole postgres
> directory tree)
>
> 7. I cannot perform a DB level Backup (same errors occur)
>
>
>
> System Details
>
> Linux Debian 7.11
>
> Postgres 9.1 (9.1.24lts-0+d)
>
>
>
Please send your queries to pgsql-general(at)postgresql(dot)org for database
server issues.
This is a pgAdmin support list.

-- Thanks, Ashesh

> It appears that we can connect to the DB Server itself as I get
> “connection received” and “connection authorized” – but when trying to
> access the DB itself, several errors are raised (see below).
>
> I am assuming that some internals are no longer consistent – the file
> “global/11801” for instance really does not exist on the system.
>
>
>
> Questions:
>
>
>
> 1. Is there any way to recover from this (backup is unfortunately
> rather old)
>
> 2. What are possible causes? I’d like to prevent this from
> happening on my production servers.
>
>
>
> ** I am aware that we are on older releases, and yes, we plan to migrate
> to more current releases “soon” ™ …
>
>
>
>
>
> Thanks in advance.
>
>
>
> John Boblitz
>
>
>
>
>
> Exceprt from Log:
>
> 2018-07-04 09:15:13 CEST 192.168.250.50(28559) [unknown]LOG: connection
> received: host=192.168.250.50 port=28559
>
> 2018-07-04 09:15:14 CEST 192.168.250.50(28559) postgresLOG: connection
> authorized: user=dbadmin database=postgres
>
> 2018-07-04 09:15:14 CEST 192.168.250.50(28559) postgresERROR: could not
> open file "global/11801": No such file or directory
>
> 2018-07-04 09:15:14 CEST 192.168.250.50(28559) postgresSTATEMENT: SELECT
> usecreatedb, usesuper, CASE WHEN usesuper THEN pg_postmaster_start_time()
> ELSE NULL END as upsince, CASE WHEN usesuper THEN pg_conf_load_time() ELSE
> NULL END as confloadedsince, CASE WHEN usesuper THEN pg_is_in_recovery()
> ELSE NULL END as inrecovery, CASE WHEN usesuper THEN
> pg_last_xlog_receive_location() ELSE NULL END as receiveloc, CASE WHEN
> usesuper THEN pg_last_xlog_replay_location() ELSE NULL END as replayloc,
> CASE WHEN usesuper THEN pg_last_xact_replay_timestamp() ELSE NULL END as
> replay_timestamp, CASE WHEN usesuper AND pg_is_in_recovery() THEN
> pg_is_xlog_replay_paused() ELSE NULL END as isreplaypaused
>
> FROM pg_user WHERE usename=current_user
>
> 2018-07-04 09:15:19 CEST 192.168.250.50(28559) postgresERROR: could not
> open file "global/11801": No such file or directory
>
> 2018-07-04 09:15:19 CEST 192.168.250.50(28559) postgresSTATEMENT: SELECT
> rolcreaterole, rolcreatedb FROM pg_roles WHERE rolname = current_user;
>
> 2018-07-04 09:15:22 CEST 192.168.250.50(28561) [unknown]LOG: connection
> received: host=192.168.250.50 port=28561
>
> 2018-07-04 09:15:22 CEST 192.168.250.50(28561) g11BaseLOG: connection
> authorized: user=dbadmin database=g11Base
>
> 2018-07-04 09:15:23 CEST 192.168.250.50(28561) g11BaseERROR: could not
> open file "pg_tblspc/24579/PG_9.1_201105231/24580/11866": No such file or
> directory
>
> 2018-07-04 09:15:23 CEST 192.168.250.50(28561) g11BaseSTATEMENT: SELECT
> CASE WHEN nspname LIKE E'pg\\_temp\\_%' THEN 1
>
> WHEN (nspname LIKE E'pg\\_%') THEN 0
>
> ELSE 3 END AS nsptyp,
>
> nsp.nspname, nsp.oid, pg_get_userbyid(nspowner) AS
> namespaceowner, nspacl, description, has_schema_privilege(nsp.oid,
> 'CREATE') as cancreate,
>
> (SELECT array_agg(label) FROM pg_seclabels sl1 WHERE
> sl1.objoid=nsp.oid) AS labels,
>
> (SELECT array_agg(provider) FROM pg_seclabels sl2 WHERE
> sl2.objoid=nsp.oid) AS providers
>
> FROM pg_namespace nsp
>
> LEFT OUTER JOIN pg_description des ON
> (des.objoid=nsp.oid AND des.classoid='pg_namespace'::regclass)
>
> WHERE NOT ((nspname = 'pg_catalog' AND EXISTS (SELECT 1
> FROM pg_class WHERE relname = 'pg_class' AND relnamespace = nsp.oid LIMIT
> 1)) OR
>
> (nspname = 'pgagent' AND EXISTS (SELECT 1 FROM pg_class
> WHERE relname = 'pga_job' AND relnamespace = nsp.oid LIMIT 1)) OR
>
> (nspname = 'information_schema' AND EXISTS (SELECT 1 FROM
> pg_class WHERE relname = 'tables' AND relnamespace = nsp.oid LIMIT 1)) OR
>
> (nspname LIKE '_%' AND EXISTS (SELECT 1 FROM pg_proc WHERE
> proname='slonyversion' AND pronamespace = nsp.oid LIMIT 1))
>
> ) AND nspname NOT LIKE E'pg\\_temp\\_%'AND nspname NOT
> LIKE E'pg\\_toast_temp\\_%' ORDER BY 1, nspname
>