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Fejlfinding for PostgreSQL-clusteret

Info

Hele proceduren skal udføres som root. For at hæve dine privilegier til root kan du bruge kommandoen su -.

Advarsel

For at følge denne procedure skal du have udført de yderligere konfigurationer for patronictl.

Forbindelsesfejl til databasen i PostgreSQL-clusteret for CyberElements Bastion kan have forskellige årsager. Dette afsnit præsenterer en generel fejlfindingsmetode, som skal tilpasses til din situation.

Kontrol af clusterets status

Info

Ved at kontrollere clusterets status kan du hurtigt finde den eller de noder, der svigter.

Du kan kontrollere clusterets status med følgende kommando, som skal køres på hver node i PostgreSQL-clusteret:

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patronictl -c /etc/patroni/config.yml topology
Eksempel på resultat på en platform, der fungerer 

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+ Cluster: 15-cleanroomvault5 ------+---------+---------+----+-----------+
| Member           | Host           | Role    | State   | TL | Lag in MB |
+------------------+----------------+---------+---------+----+-----------+
| PSQL_3           | psql_3         | Leader  | running | 2  |           |
| + PSQL_1         | psql_1         | Replica | running | 2  |         0 |
| + PSQL_2         | psql_2         | Replica | running | 2  |         0 |
+------------------+----------------+---------+---------+----+-----------+
I resultatet ovenfor tyder alt på, at PostgreSQL-clusteret fungerer: forsinkelsen (lag) er 0 MB for alle Replica-noder, og alle noder står på listen med status running. Du skal få dette resultat på alle noder for at bekræfte, at patroni og etcd fungerer.

Eksempel på resultat, når der er et kommunikationsproblem mellem noderne 

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+ Cluster: 15-cleanroomvault5 ------+---------+---------+----+-----------+
| Member           | Host           | Role    | State   | TL | Lag in MB |
+------------------+----------------+---------+---------+----+-----------+
| PSQL_3           | psql_3         | Leader  | running | 2  |           |
| + PSQL_1         | psql_1         | Replica | running | 2  |       230 |
| + PSQL_2         | psql_2         | Replica | running | 2  |         0 |
+------------------+----------------+---------+---------+----+-----------+
I resultatet ovenfor er forsinkelsen på 230 MB unormal: den kan tyde på et kommunikationsproblem mellem node 3 og node 1.
Hvis problemet varer ved efter flere timer, er det bekræftet.

Eksempel på resultat, når en node ikke er startet eller stoppet korrekt 

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+ Cluster: 15-cleanroomvault5 ------+---------+---------+----+-----------+
| Member           | Host           | Role    | State   | TL | Lag in MB |
+------------------+----------------+---------+---------+----+-----------+
| PSQL_3           | psql_3         | Leader  | running | 2  |           |
| + PSQL_1         | psql_1         | Replica | started | 2  |   unknown |
| + PSQL_2         | psql_2         | Replica | stopped | 2  |   unknown |
+------------------+----------------+---------+---------+----+-----------+
I resultatet ovenfor viser tilstanden (kolonnen State), at node 1 er ved at starte. Hvis status started varer ved i flere minutter eller endda timer, kan der være et problem med patroni eller etcd på den pågældende node.
Node 2 har tilstanden stopped: den er stoppet. Når en node i clusteret svigter, vises denne oplysning kun midlertidigt, før noden fjernes fra listen.

Eksempel på resultat, når etcd svigter på den aktuelle node 

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2026-04-09 16:21:39,482 - WARNING - Retrying (Retry(total=1, connect=None, read=None, redirect=0, status=None)) after connection broken by 'NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7fcaa1618390>: Failed to establish a new connection: [Errno 111] Connection refused')': /version
2026-04-09 16:21:39,482 - WARNING - Retrying (Retry(total=0, connect=None, read=None, redirect=0, status=None)) after connection broken by 'NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7fcaa1618c10>: Failed to establish a new connection: [Errno 111] Connection refused')': /version
2026-04-09 16:21:39,483 - ERROR - Failed to get list of machines from https://PSQL_3:2379/v2: MaxRetryError("HTTPSConnectionPool(host='psql_3', port=2379): Max retries exceeded with url: /version (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7fcaa1619490>: Failed to establish a new connection: [Errno 111] Connection refused'))")
Resultatet ovenfor viser en forbindelsesfejl til etcd, som forhindrer, at PostgreSQL-clusterets status kan hentes.

Kontrol af tjenesternes status

Når den node, der svigter, er identificeret, skal du identificere den tjeneste, der ikke fungerer korrekt. PostgreSQL-clusterets to vigtigste tjenester er patroni og etcd.

Info

Tjenesten patroni afhænger af tjenesten etcd: hvis etcd ikke fungerer, fungerer patroni heller ikke.

For at identificere den tjeneste, der svigter, kan du køre følgende kommandoer:

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systemctl status etcd
systemctl status patroni

Disse kommandoer viser tjenestens status sammen med dens sidste 10 loglinjer.

Advarsel

En tjeneste med status active (running) fungerer ikke nødvendigvis: den kan køre og samtidig skrive fejllogs. Det er derfor vigtigt at læse tjenestens logs for at forstå dens faktiske tilstand.

Eksempel på resultat for etcd, når tjenesten fungerer 
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● etcd.service - etcd - highly-available key value store
   Loaded: loaded (/lib/systemd/system/etcd.service; enabled; preset: enabled)
   Active: active (running) since Thu 2026-04-09 16:40:01 CEST; 21h ago
   Docs: https://etcd.io/docs
           man:etcd
Main PID: 283425 (etcd)
   Tasks: 7 (limit: 2227)
   Memory: 73.2M
       CPU: 51min 9.223s
   CGroup: /system.slice/etcd.service
           └─283425 /usr/bin/etcd

Apr 10 09:26:31 PSQL_1 etcd[283425]: store.index: compact 1624026
Apr 10 09:26:31 PSQL_1 etcd[283425]: finished scheduled compaction at 1624026 (took 325.098µs)
Apr 10 10:26:31 PSQL_1 etcd[283425]: store.index: compact 1624386
Apr 10 10:26:31 PSQL_1 etcd[283425]: finished scheduled compaction at 1624386 (took 417.797µs)
Apr 10 11:26:31 PSQL_1 etcd[283425]: store.index: compact 1624746
Apr 10 11:26:31 PSQL_1 etcd[283425]: finished scheduled compaction at 1624746 (took 1.706489ms)
Apr 10 12:26:31 PSQL_1 etcd[283425]: store.index: compact 1625106
Apr 10 12:26:31 PSQL_1 etcd[283425]: finished scheduled compaction at 1625106 (took 300.098µs)
Apr 10 13:26:31 PSQL_1 etcd[283425]: store.index: compact 1625466
Apr 10 13:26:31 PSQL_1 etcd[283425]: finished scheduled compaction at 1625466 (took 311.398µs)
Eksempel på resultat for etcd, når tjenesten er i fejltilstand 

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× etcd.service - etcd - highly-available key value store
    Loaded: loaded (/lib/systemd/system/etcd.service; enabled; preset: enabled)
    Active: failed (Result: exit-code) since Fri 2026-04-10 14:15:26 CEST; 5s ago
Duration: 21h 35min 20.382s
    Docs: https://etcd.io/docs
            man:etcd
    Process: 454701 ExecStart=/usr/bin/etcd $DAEMON_ARGS (code=exited, status=1/FAILURE)
Main PID: 454701 (code=exited, status=1/FAILURE)
        CPU: 12ms

Apr 10 14:15:26 PSQL_1 etcd[454701]: [WARNING] Deprecated '--logger=capnslog' flag is set; use '--logger=zap' flag instead
Apr 10 14:15:26 PSQL_1 etcd[454701]: etcd Version: 3.4.23
Apr 10 14:15:26 PSQL_1 etcd[454701]: Git SHA: Not provided (use ./build instead of go build)
Apr 10 14:15:26 PSQL_1 etcd[454701]: Go Version: go1.19.8
Apr 10 14:15:26 PSQL_1 etcd[454701]: Go OS/Arch: linux/amd64
Apr 10 14:15:26 PSQL_1 etcd[454701]: setting maximum number of CPUs to 1, total number of available CPUs is 1
Apr 10 14:15:26 PSQL_1 etcd[454701]: error listing data dir: /var/lib/etcd/cleanroom
Apr 10 14:15:26 PSQL_1 systemd[1]: etcd.service: Main process exited, code=exited, status=1/FAILURE
Apr 10 14:15:26 PSQL_1 systemd[1]: etcd.service: Failed with result 'exit-code'.
Apr 10 14:15:26 PSQL_1 systemd[1]: Failed to start etcd.service - etcd - highly-available key value store.
I resultatet ovenfor har tjenesten etcd status failed, og den fejl, der forhindrede den i at starte, er den på linje 17: tjenesten kan ikke læse indholdet af mappen /var/lib/etcd/cleanroom. I så fald skal du justere tilladelserne til mappen.

Eksempel på resultat for patroni, når tjenesten fungerer 
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● patroni.service - Runners to orchestrate a high-availability PostgreSQL
   Loaded: loaded (/lib/systemd/system/patroni.service; enabled; preset: enabled)
   Drop-In: /etc/systemd/system/patroni.service.d
           └─local.conf
   Active: active (running) since Thu 2026-04-09 16:40:06 CEST; 22h ago
   Process: 283510 ExecStartPre=/usr/bin/testetcd.py (code=exited, status=0/SUCCESS)
Main PID: 283517 (patroni)
   Tasks: 13 (limit: 2227)
   Memory: 56.1M
       CPU: 26min 54.918s
   CGroup: /system.slice/patroni.service
           ├─283517 /usr/bin/python3 /usr/bin/patroni /etc/patroni/config.yml
           ├─283537 /usr/lib/postgresql/15/bin/postgres -D /var/lib/postgresql/15/cleanroomvault5 --config-file=/etc/postgresql/15/cleanroomvault5/postgresql.conf"--listen_addresses=*" --port=5432 --cluster_name=15-cleanroomvault5 --wal_level=replica --hot_standby=on --max_connections=100 --max_wal_senders=10--max_prepared_transactions=0 --max_locks_per_transaction=64 --track_commit_timestamp=off --max_replication_slots=10 --max_worker_processes=8 --wal_log_hints=on
          ├─283538 "postgres: 15-cleanroomvault5: logger "
          ├─283540 "postgres: 15-cleanroomvault5: checkpointer "
           ├─283541 "postgres: 15-cleanroomvault5: background writer "
          ├─283542 "postgres: 15-cleanroomvault5: startup recovering 00000003000000000000000F"
          ├─283545 "postgres: 15-cleanroomvault5: walreceiver "
          └─283547 "postgres: 15-cleanroomvault5: postgres postgres [local] idle"
Apr 10 14:51:07 PSQL_1 patroni[283517]: 2026-04-10 14:51:07,381 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:51:17 PSQL_1 patroni[283517]: 2026-04-10 14:51:17,428 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:51:27 PSQL_1 patroni[283517]: 2026-04-10 14:51:27,381 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:51:37 PSQL_1 patroni[283517]: 2026-04-10 14:51:37,428 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:51:47 PSQL_1 patroni[283517]: 2026-04-10 14:51:47,381 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:51:57 PSQL_1 patroni[283517]: 2026-04-10 14:51:57,428 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:52:07 PSQL_1 patroni[283517]: 2026-04-10 14:52:07,381 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:52:17 PSQL_1 patroni[283517]: 2026-04-10 14:52:17,428 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:52:27 PSQL_1 patroni[283517]: 2026-04-10 14:52:27,381 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Apr 10 14:52:37 PSQL_1 patroni[283517]: 2026-04-10 14:52:37,474 INFO: no action. I am (PSQL_1), a secondary, and following a leader (PSQL_2)
Eksempel på resultat for patroni, når tjenesten er i fejltilstand 

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● patroni.service - Runners to orchestrate a high-availability PostgreSQL
    Loaded: loaded (/lib/systemd/system/patroni.service; enabled; preset: enabled)
    Drop-In: /etc/systemd/system/patroni.service.d
            └─local.conf
    Active: active (running) since Thu 2026-04-09 16:40:06 CEST; 23h ago
    Process: 283510 ExecStartPre=/usr/bin/testetcd.py (code=exited, status=0/SUCCESS)
Main PID: 283517 (patroni)
    Tasks: 12 (limit: 2227)
    Memory: 61.7M
        CPU: 28min 8.337s
    CGroup: /system.slice/patroni.service
            ├─283517 /usr/bin/python3 /usr/bin/patroni /etc/patroni/config.yml
            ├─283537 /usr/lib/postgresql/15/bin/postgres -D /var/lib/postgresql/15/cleanroomvault5 --config-file=/etc/postgresql/15/cleanroomvault5/postgresql.conf "--listen_addresses=*" --port=5432 --cluster_name=15-cleanroomvault5 --wal_level=replica --hot_standby=on --max_connections=100 --max_wal_senders=10 --max_prepared_transactions=0 --max_locks_per_transaction=64 --track_commit_timestamp=off --max_replication_slots=10 --max_worker_processes=8 --wal_log_hints=on
            ├─283538 "postgres: 15-cleanroomvault5: logger "
            ├─283540 "postgres: 15-cleanroomvault5: checkpointer "
            ├─283541 "postgres: 15-cleanroomvault5: background writer "
            ├─283542 "postgres: 15-cleanroomvault5: startup recovering 00000003000000000000000F"
            └─283547 "postgres: 15-cleanroomvault5: postgres postgres [local] idle"

Apr 10 15:52:37 PSQL_1 patroni[283517]: 2026-04-10 15:52:37,680 WARNING: Loop time exceeded, rescheduling immediately.
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:37,681 INFO: Lock owner: PSQL_2; I am PSQL_1
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,069 ERROR: Request to server https://PSQL_3:2379 failed: ReadTimeoutError("HTTPSConnectionPool(host='psql_3', port=2379): Read timed out. (read timeout=3.3331721344341836)")
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,069 INFO: Reconnection allowed, looking for another server.
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,069 INFO: Retrying on https://PSQL_1:2379
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,073 ERROR: Request to server https://PSQL_1:2379 failed: MaxRetryError("HTTPSConnectionPool(host='psql_1', port=2379): Max retries exceeded with url: /v3/lease/keepalive (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7fd77c411090>: Failed to establish a new connection: [Errno 111] Connection refused'))")
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,073 INFO: Reconnection allowed, looking for another server.
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,073 INFO: Retrying on https://PSQL_2:2379
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,074 ERROR: Request to server https://PSQL_2:2379 failed: MaxRetryError("HTTPSConnectionPool(host='psql_2', port=2379): Max retries exceeded with url: /v3/lease/keepalive (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7fd77c411090>: Failed to establish a new connection: [Errno 111] Connection refused'))")
Apr 10 15:52:41 PSQL_1 patroni[283517]: 2026-04-10 15:52:41,074 INFO: Reconnection allowed, looking for another server.
I tilfældet ovenfor har tjenesten status active (running) uden reelt at fungere: loggene viser forskellige forbindelsesfejl til etcd, som patroni har brug for.
I dette eksempel er det ikke nødvendigvis patroni, der er årsagen: da den afhænger af etcd, skal du først løse problemerne med etcd og derefter kontrollere status for patroni igen.

Fejlfindingsprocedurer for tjenesterne

Nedenfor finder du en fejlfindingsprocedure pr. tjeneste. Hvis både etcd og patroni fungerer forkert, skal du starte med etcd.