An nód LEADER a aistriú

I gcásanna áirithe cothabhála, d'fhéadfadh sé a bheith úsáideach nód LEADER na braisle PostgreSQL a aistriú chun oibríochtaí a dhéanamh air.

Sular féidir leat an nód LEADER a athrú, aithin an nód LEADER reatha de chuid na braisle PostgreSQL agus ansin ceangail leis mar root.
Nuair a bheidh tú ceangailte mar root leis an nód LEADER, rith ordú cosúil leis an gceann seo a leanas chun aistriú láithreach a spreagadh:

patronictl -c /etc/patroni/config.yml failover --candidate PSQL_NODE --force

Cuir ainm an nóid a bheidh ina LEADER in ionad PSQL_NODE.

Teip

Má theipeann ar an ordú, b'fhéidir nár cuireadh na socruithe seo a leanas i bhfeidhm: socruithe do patronictl.

Sampla

Don bhraisle PostgreSQL seo a leanas:

+ 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         |
+------------------+----------------+---------+---------+----+-----------+

Is é an aidhm an nód PSQL_1 a dhéanamh ina LEADER.
Mar sin, ní mór ar dtús ceangal mar root leis an nód PSQL_3, arb é an LEADER reatha é.
Nuair a bheidh tú ceangailte, aistrítear an LEADER láithreach chuig an nód PSQL_1 tríd an ordú seo a leanas a rith:

patronictl -c /etc/patroni/config.yml failover --candidate PSQL_1 --force

Ansin, is féidir an t-athrú ar an topeolaíocht a fheiceáil agus a fhíorú:

+ Cluster: 15-cleanroomvault5 ------+---------+---------+----+-----------+
| Member           | Host           | Role    | State   | TL | Lag in MB |
+------------------+----------------+---------+---------+----+-----------+
| PSQL_1           | psql_1         | Leader  | running | 3  |           |
| + PSQL_3         | psql_3         | Replica | running | 3  | 0         |
| + PSQL_2         | psql_2         | Replica | running | 3  | 0         |
+------------------+----------------+---------+---------+----+-----------+