Tutorial on modifying database parameters with yaml

Some parameters of the database cannot take effect immediately after modification. Therefore, you need to apply yaml to modify parameters and restart the database. Modifying parameters in yaml will cause the database to restart, and the whole process will take about 20 seconds. The following uses the Postgres database as an example to modify parameters:

1. Access the terminal：

2. Edit pg-config.yaml：

$ vim pg-config.yaml

3. Copy yaml to pg-config.yaml and save pg-config.yaml：

apiVersion: apps.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: test
spec:
  clusterRef: test-pg  #Change the database name to your own
  reconfigure:
    componentName: postgresql
    configurations: #The following configuration is for reference only. You only need to keep the part to be modified and modify the corresponding parameter values
      - keys:
          - key: postgresql.conf
            parameters:
              - key: max_connections #Sets the maximum number of simultaneous connections that can be made to the database
                value: "1000"
        name: postgresql-configuration
  ttlSecondsAfterSucceed: 0
  type: Reconfiguring

Common PostgreSQL Parameters:

Parameter Name	Description
max_connections	Sets the maximum number of connections that can be established with the database simultaneously.
max_wal_size	Sets the maximum size of WAL (Write-Ahead Logging) files.
min_wal_size	Sets the minimum size of WAL files.
max_worker_processes	Sets the maximum number of background processes that PostgreSQL can start.
shared_buffers	The size of memory used for data caching.

Common MySQL Parameters:

Parameter Name	Description
innodb_buffer_pool_size	Sets the size of the InnoDB buffer pool.
max_connections	The maximum number of concurrent connections allowed.
query_cache_size	The size of the query cache.
thread_cache_size	The size of the thread cache.
max_allowed_packet	The maximum packet size.
innodb_log_file_size	The size of the InnoDB log file.

Common MongoDB Parameters:

Parameter Name	Description
storage.dbPath	The path for storing data files.
storage.journal.enabled	Sets the maximum size of WAL (Write-Ahead Logging) files.
min_wal_size	Enables logging.
net.port	The server port.
net.bindIp	The bound IP address.

Common Redis Parameters:

Parameter Name	Description
maxclients	The maximum number of client connections.
maxmemory	The maximum amount of memory usage.
maxmemory-policy	The memory eviction policy.
appendonly	Switch for AOF persistence.
appendfsync	The frequency of AOF file flushing.

4. Apply pg-config.yaml：

$ kubectl apply -f pg-config.yaml

5. Check whether pg-config.yaml is successfully applied：

# If the status of OpsRequest is Succeed and the status of pod is Running, the application is successfully configured
$ kubectl get OpsRequest
$ kubectl get pod

6. Access the database to check whether the configuration takes effect：

$ show max_connections;