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New to KubeDB? Please start here.

Reconfigure Pgpool

This guide will show you how to use KubeDB Ops-manager operator to reconfigure a Pgpool.

Before You Begin

  • At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster.

  • Install KubeDB Provisioner and Ops-manager operator in your cluster following the steps here.

  • You should be familiar with the following KubeDB concepts:

To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace/demo created

Note: YAML files used in this tutorial are stored in docs/examples/pgpool directory of kubedb/docs repository.

Prepare Postgres

For a Pgpool surely we will need a Postgres server so, prepare a KubeDB Postgres cluster using this tutorial, or you can use any externally managed postgres but in that case you need to create an appbinding yourself. In this tutorial we will use 3 node Postgres cluster named ha-postgres.

Now, we are going to deploy a Pgpool using a supported version by KubeDB operator. Then we are going to apply PgpoolOpsRequest to reconfigure its configuration.

Prepare Pgpool

Now, we are going to deploy a Pgpool with version 4.5.0.

Deploy Pgpool

At first, we will create pgpool.conf file containing required configuration settings.

$ cat pgpool.conf
max_pool = 60

Here, max_pool is set to 60, whereas the default value is numberof replicas * 15.

Now, we will create a secret with this configuration file.

$ kubectl create secret generic -n demo pp-custom-config --from-file=./pgpool.conf
secret/pp-custom-config created

In this section, we are going to create a Pgpool object specifying spec.configSecret field to apply this custom configuration. Below is the YAML of the Pgpool CR that we are going to create,

apiVersion: kubedb.com/v1alpha2
kind: Pgpool
metadata:
  name: pp-custom
  namespace: demo
spec:
  version: "4.5.0"
  replicas: 1
  configSecret:
    name: pp-custom-config
  postgresRef:
    name: ha-postgres
    namespace: demo
  deletionPolicy: WipeOut

Let’s create the Pgpool CR we have shown above,

$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.8.21/docs/examples/pgpool/reconfigure/pp-custom-config.yaml
pgpool.kubedb.com/pp-custom created

Now, wait until pp-custom has status Ready. i.e,

$ kubectl get pp -n demo
NAME        TYPE                  VERSION   STATUS   AGE
pp-custom   kubedb.com/v1alpha2   4.5.0     Ready    112s

Now, we will check if the pgpool has started with the custom configuration we have provided.

Now, you can exec into the pgpool pod and find if the custom configuration is there,

$ kubectl exec -it -n demo pp-custom-0 -- bash
pp-custom-0:/$ cat opt/pgpool-II/etc/pgpool.conf
backend_hostname0 = 'ha-postgres.demo.svc'
backend_port0 = 5432
backend_weight0 = 1
backend_flag0 = 'ALWAYS_PRIMARY|DISALLOW_TO_FAILOVER'
backend_hostname1 = 'ha-postgres-standby.demo.svc'
backend_port1 = 5432
backend_weight1 = 1
backend_flag1 = 'DISALLOW_TO_FAILOVER'
max_pool = 60
enable_pool_hba = on
listen_addresses = *
port = 9999
socket_dir = '/var/run/pgpool'
pcp_listen_addresses = *
pcp_port = 9595
pcp_socket_dir = '/var/run/pgpool'
log_per_node_statement = on
sr_check_period = 0
health_check_period = 0
backend_clustering_mode = 'streaming_replication'
num_init_children = 5
child_life_time = 300
child_max_connections = 0
connection_life_time = 0
client_idle_limit = 0
connection_cache = on
load_balance_mode = on
ssl = 'off'
failover_on_backend_error = 'off'
log_min_messages = 'warning'
statement_level_load_balance = 'off'
memory_cache_enabled = 'off'
memqcache_oiddir = '/tmp/oiddir/'
allow_clear_text_frontend_auth = 'false'
failover_on_backend_error = 'off'
pp-custom-0:/$ exit
exit

As we can see from the configuration of running pgpool, the value of max_pool has been set to 60.

Reconfigure using new secret

Now we will reconfigure this pgpool to set max_pool to 50.

Now, we will edit the pgpool.conf file containing required configuration settings.

$ cat pgpool.conf
max_pool=50

Then, we will create a new secret with this configuration file.

$ kubectl create secret generic -n demo new-custom-config --from-file=./pgpool.conf
secret/new-custom-config created

Create PgpoolOpsRequest

Now, we will use this secret to replace the previous secret using a PgpoolOpsRequest CR. The PgpoolOpsRequest yaml is given below,

apiVersion: ops.kubedb.com/v1alpha1
kind: PgpoolOpsRequest
metadata:
  name: ppops-reconfigure
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: pp-custom
  configuration:
    configSecret:
      name: new-custom-config
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are reconfiguring pp-csutom pgpool.
  • spec.type specifies that we are performing Reconfigure on our pgpool.
  • spec.configuration.configSecret.name specifies the name of the new secret.
  • Have a look here on the respective sections to understand the timeout & apply fields.

Let’s create the PgpoolOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.8.21/docs/examples/pgpool/reconfigure/ppops-reconfigure.yaml
pgpoolopsrequest.ops.kubedb.com/ppops-reconfigure created

Verify the new configuration is working

If everything goes well, KubeDB Ops-manager operator will update the configSecret of Pgpool object.

Let’s wait for PgpoolOpsRequest to be Successful. Run the following command to watch PgpoolOpsRequest CR,

$ watch kubectl get pgpoolopsrequest -n demo
Every 2.0s: kubectl get pgpoolopsrequest -n demo
NAME                TYPE          STATUS       AGE
ppops-reconfigure   Reconfigure   Successful   63s

We can see from the above output that the PgpoolOpsRequest has succeeded. If we describe the PgpoolOpsRequest we will get an overview of the steps that were followed to reconfigure the pgpool.

$ kubectl describe pgpoolopsrequest -n demo ppops-reconfigure
Name:         ppops-reconfigure
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         PgpoolOpsRequest
Metadata:
  Creation Timestamp:  2024-07-30T05:42:56Z
  Generation:          1
  Resource Version:    95239
  UID:                 54a12624-048c-49a6-b852-6286da587535
Spec:
  Apply:  IfReady
  Configuration:
    Config Secret:
      Name:  new-custom-config
  Database Ref:
    Name:   pp-custom
  Timeout:  5m
  Type:     Reconfigure
Status:
  Conditions:
    Last Transition Time:  2024-07-30T05:42:56Z
    Message:               Pgpool ops-request has started to `Reconfigure` the Pgpool nodes
    Observed Generation:   1
    Reason:                Reconfigure
    Status:                True
    Type:                  Reconfigure
    Last Transition Time:  2024-07-30T05:42:59Z
    Message:               Successfully paused database
    Observed Generation:   1
    Reason:                DatabasePauseSucceeded
    Status:                True
    Type:                  DatabasePauseSucceeded
    Last Transition Time:  2024-07-30T05:43:00Z
    Message:               Successfully updated PetSet
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-07-30T05:43:00Z
    Message:               Successfully updated Pgpool
    Observed Generation:   1
    Reason:                UpdateDatabase
    Status:                True
    Type:                  UpdateDatabase
    Last Transition Time:  2024-07-30T05:43:45Z
    Message:               Successfully Restarted Pods With Resources
    Observed Generation:   1
    Reason:                RestartPods
    Status:                True
    Type:                  RestartPods
    Last Transition Time:  2024-07-30T05:43:05Z
    Message:               get pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--pp-custom-0
    Last Transition Time:  2024-07-30T05:43:05Z
    Message:               evict pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--pp-custom-0
    Last Transition Time:  2024-07-30T05:43:40Z
    Message:               check pod running; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  CheckPodRunning--pp-custom-0
    Last Transition Time:  2024-07-30T05:43:45Z
    Message:               Successfully completed the reconfigure for Pgpool
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                         Age   From                         Message
  ----     ------                                                         ----  ----                         -------
  Normal   Starting                                                       100s  KubeDB Ops-manager Operator  Start processing for PgpoolOpsRequest: demo/ppops-reconfigure
  Normal   Starting                                                       100s  KubeDB Ops-manager Operator  Pausing Pgpool databse: demo/pp-custom
  Normal   Successful                                                     100s  KubeDB Ops-manager Operator  Successfully paused Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure
  Normal   UpdatePetSets                                                  96s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdatePetSets                                                  96s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdateDatabase                                                 96s   KubeDB Ops-manager Operator  Successfully updated Pgpool
  Warning  get pod; ConditionStatus:True; PodName:pp-custom-0             91s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  evict pod; ConditionStatus:True; PodName:pp-custom-0           91s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:False; PodName:pp-custom-0  86s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:False; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:True; PodName:pp-custom-0   56s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:True; PodName:pp-custom-0
  Normal   RestartPods                                                    51s   KubeDB Ops-manager Operator  Successfully Restarted Pods With Resources
  Normal   Starting                                                       51s   KubeDB Ops-manager Operator  Resuming Pgpool database: demo/pp-custom
  Normal   Successful                                                     51s   KubeDB Ops-manager Operator  Successfully resumed Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure

Now let’s exec into the pgpool pod and check the new configuration we have provided.

$ kubectl exec -it -n demo pp-custom-0 -- bash
pp-custom-0:/$ cat opt/pgpool-II/etc/pgpool.conf
backend_hostname0 = 'ha-postgres.demo.svc'
backend_port0 = 5432
backend_weight0 = 1
backend_flag0 = 'ALWAYS_PRIMARY|DISALLOW_TO_FAILOVER'
backend_hostname1 = 'ha-postgres-standby.demo.svc'
backend_port1 = 5432
backend_weight1 = 1
backend_flag1 = 'DISALLOW_TO_FAILOVER'
listen_addresses = *
log_per_node_statement = on
num_init_children = 5
max_pool = 50
child_life_time = '300'
child_max_connections = 0
connection_life_time = 0
client_idle_limit = 0
connection_cache = on
load_balance_mode = on
log_min_messages = 'warning'
statement_level_load_balance = 'off'
memory_cache_enabled = 'off'
enable_pool_hba = on
port = 9999
socket_dir = '/var/run/pgpool'
pcp_listen_addresses = *
pcp_port = 9595
pcp_socket_dir = '/var/run/pgpool'
sr_check_period = 0
health_check_period = 0
backend_clustering_mode = 'streaming_replication'
ssl = 'off'
failover_on_backend_error = 'off'
memqcache_oiddir = '/tmp/oiddir/'
allow_clear_text_frontend_auth = 'false'
failover_on_backend_error = 'off'
pp-custom-0:/$ exit
exit

As we can see from the configuration of running pgpool, the value of max_pool has been changed from 60 to 50. So the reconfiguration of the pgpool is successful.

Reconfigure using apply config

Now we will reconfigure this pgpool again to set max_pool to 75. This time we won’t use a new secret. We will use the applyConfig field of the PgpoolOpsRequest. This will merge the new config in the existing secret.

Create PgpoolOpsRequest

Now, we will use the new configuration in the data field in the PgpoolOpsRequest CR. The PgpoolOpsRequest yaml is given below,

apiVersion: ops.kubedb.com/v1alpha1
kind: PgpoolOpsRequest
metadata:
  name: ppops-reconfigure-apply
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: pp-custom
  configuration:
    applyConfig:
      pgpool.conf: |-
        max_pool = 75        
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are reconfiguring pp-custom pgpool.
  • spec.type specifies that we are performing Reconfigure on our pgpool.
  • spec.configuration.applyConfig specifies the new configuration that will be merged in the existing secret.

Let’s create the PgpoolOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.8.21/docs/examples/pgpool/reconfigure/ppops-reconfigure-apply.yaml
pgpoolopsrequest.ops.kubedb.com/ppops-reconfigure-apply created

Verify the new configuration is working

If everything goes well, KubeDB Ops-manager operator will merge this new config with the existing configuration.

Let’s wait for PgpoolOpsRequest to be Successful. Run the following command to watch PgpoolOpsRequest CR,

$ watch kubectl get pgpoolopsrequest -n demo
Every 2.0s: kubectl get pgpoolopsrequest -n demo
NAME                      TYPE          STATUS       AGE
ppops-reconfigure         Reconfigure   Successful   9m15s
ppops-reconfigure-apply   Reconfigure   Successful   53s

We can see from the above output that the PgpoolOpsRequest has succeeded. If we describe the PgpoolOpsRequest we will get an overview of the steps that were followed to reconfigure the pgpool.

$ kubectl describe pgpoolopsrequest -n demo ppops-reconfigure-apply
Name:         ppops-reconfigure-apply
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         PgpoolOpsRequest
Metadata:
  Creation Timestamp:  2024-07-30T05:51:18Z
  Generation:          1
  Resource Version:    95874
  UID:                 92b0f18c-a329-4bb7-85d0-ef66f32bf57a
Spec:
  Apply:  IfReady
  Configuration:
    Apply Config:
      pgpool.conf:  max_pool = 75
  Database Ref:
    Name:   pp-custom
  Timeout:  5m
  Type:     Reconfigure
Status:
  Conditions:
    Last Transition Time:  2024-07-30T05:51:18Z
    Message:               Pgpool ops-request has started to `Reconfigure` the Pgpool nodes
    Observed Generation:   1
    Reason:                Reconfigure
    Status:                True
    Type:                  Reconfigure
    Last Transition Time:  2024-07-30T05:51:21Z
    Message:               Successfully paused database
    Observed Generation:   1
    Reason:                DatabasePauseSucceeded
    Status:                True
    Type:                  DatabasePauseSucceeded
    Last Transition Time:  2024-07-30T05:51:21Z
    Message:               Successfully updated PetSet
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-07-30T05:51:22Z
    Message:               Successfully updated Pgpool
    Observed Generation:   1
    Reason:                UpdateDatabase
    Status:                True
    Type:                  UpdateDatabase
    Last Transition Time:  2024-07-30T05:52:07Z
    Message:               Successfully Restarted Pods With Resources
    Observed Generation:   1
    Reason:                RestartPods
    Status:                True
    Type:                  RestartPods
    Last Transition Time:  2024-07-30T05:51:27Z
    Message:               get pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--pp-custom-0
    Last Transition Time:  2024-07-30T05:51:27Z
    Message:               evict pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--pp-custom-0
    Last Transition Time:  2024-07-30T05:52:02Z
    Message:               check pod running; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  CheckPodRunning--pp-custom-0
    Last Transition Time:  2024-07-30T05:52:07Z
    Message:               Successfully completed the reconfigure for Pgpool
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                         Age   From                         Message
  ----     ------                                                         ----  ----                         -------
  Normal   Starting                                                       77s   KubeDB Ops-manager Operator  Start processing for PgpoolOpsRequest: demo/ppops-reconfigure-apply
  Normal   Starting                                                       77s   KubeDB Ops-manager Operator  Pausing Pgpool databse: demo/pp-custom
  Normal   Successful                                                     77s   KubeDB Ops-manager Operator  Successfully paused Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure-apply
  Normal   UpdatePetSets                                                  74s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdatePetSets                                                  73s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdateDatabase                                                 73s   KubeDB Ops-manager Operator  Successfully updated Pgpool
  Warning  get pod; ConditionStatus:True; PodName:pp-custom-0             68s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  evict pod; ConditionStatus:True; PodName:pp-custom-0           68s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:False; PodName:pp-custom-0  63s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:False; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:True; PodName:pp-custom-0   33s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:True; PodName:pp-custom-0
  Normal   RestartPods                                                    28s   KubeDB Ops-manager Operator  Successfully Restarted Pods With Resources
  Normal   Starting                                                       28s   KubeDB Ops-manager Operator  Resuming Pgpool database: demo/pp-custom
  Normal   Successful                                                     28s   KubeDB Ops-manager Operator  Successfully resumed Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure-apply

Now let’s exec into the pgpool pod and check the new configuration we have provided.

$ kubectl exec -it -n demo pp-custom-0 -- bash 
pp-custom-0:/$ cat opt/pgpool-II/etc/pgpool.conf
memory_cache_enabled = 'off'
num_init_children = 5
pcp_socket_dir = '/var/run/pgpool'
port = '9999'
enable_pool_hba = on
log_min_messages = 'warning'
pcp_port = '9595'
sr_check_period = 0
ssl = 'off'
backend_weight1 = 1
load_balance_mode = on
backend_weight0 = 1
backend_port0 = '5432'
connection_cache = on
backend_hostname1 = 'ha-postgres-standby.demo.svc'
health_check_period = 0
memqcache_oiddir = '/tmp/oiddir/'
statement_level_load_balance = 'off'
allow_clear_text_frontend_auth = 'false'
log_per_node_statement = on
backend_hostname0 = 'ha-postgres.demo.svc'
backend_flag1 = 'DISALLOW_TO_FAILOVER'
listen_addresses = *
failover_on_backend_error = 'off'
pcp_listen_addresses = *
child_max_connections = 0
socket_dir = '/var/run/pgpool'
backend_flag0 = 'ALWAYS_PRIMARY|DISALLOW_TO_FAILOVER'
backend_port1 = '5432'
backend_clustering_mode = 'streaming_replication'
connection_life_time = 0
child_life_time = '300'
max_pool = 75
client_idle_limit = 0
failover_on_backend_error = 'off'
pp-custom-0:/$ exit
exit

As we can see from the configuration of running pgpool, the value of max_pool has been changed from 50 to 75. So the reconfiguration of the pgpool using the applyConfig field is successful.

Remove config

Now we will reconfigure this pgpool to remove the custom config provided and get it back to the default config. We will use the removeCustomConfig field of the PgpoolOpsRequest. This will remove all the custom config provided and get the pgpool back to the default config.

Create PgpoolOpsRequest

Now, we will use the removeCustomConfig field in the PgpoolOpsRequest CR. The PgpoolOpsRequest yaml is given below,

apiVersion: ops.kubedb.com/v1alpha1
kind: PgpoolOpsRequest
metadata:
  name: ppops-reconfigure-remove
  namespace: demo
spec:
  type: Reconfigure
  databaseRef:
    name: pp-custom
  configuration:
    removeCustomConfig: true
  timeout: 5m
  apply: IfReady

Here,

  • spec.databaseRef.name specifies that we are reconfiguring pp-custom pgpool.
  • spec.type specifies that we are performing Reconfigure on our pgpool.
  • spec.configuration.removeCustomConfig specifies for boolean values to remove custom configuration.

Let’s create the PgpoolOpsRequest CR we have shown above,

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2024.8.21/docs/examples/pgpool/reconfigure/ppops-reconfigure-remove.yaml
pgpoolopsrequest.ops.kubedb.com/ppops-reconfigure-remove created

Verify if the configuration is removed

If everything goes well, KubeDB Ops-manager operator will remove the custom configuration and move back to the default configuration.

Let’s wait for PgpoolOpsRequest to be Successful. Run the following command to watch PgpoolOpsRequest CR,

$ watch kubectl get pgpoolopsrequest -n demo
Every 2.0s: kubectl get pgpoolopsrequest -n demo
kubectl get pgpoolopsrequest -n demo
NAME                       TYPE          STATUS       AGE
ppops-reconfigure          Reconfigure   Successful   71m
ppops-reconfigure-apply    Reconfigure   Successful   63m
ppops-reconfigure-remove   Reconfigure   Successful   57s

We can see from the above output that the PgpoolOpsRequest has succeeded. If we describe the PgpoolOpsRequest we will get an overview of the steps that were followed to reconfigure the pgpool.

$ kubectl describe pgpoolopsrequest -n demo ppops-reconfigure-remove
Name:         ppops-reconfigure-remove
Namespace:    demo
Labels:       <none>
Annotations:  <none>
API Version:  ops.kubedb.com/v1alpha1
Kind:         PgpoolOpsRequest
Metadata:
  Creation Timestamp:  2024-07-30T06:53:27Z
  Generation:          1
  Resource Version:    99827
  UID:                 24c9cba3-5e85-40dc-96f3-373d2dd7a8ba
Spec:
  Apply:  IfReady
  Configuration:
    Remove Custom Config:  true
  Database Ref:
    Name:   pp-custom
  Timeout:  5m
  Type:     Reconfigure
Status:
  Conditions:
    Last Transition Time:  2024-07-30T06:53:28Z
    Message:               Pgpool ops-request has started to `Reconfigure` the Pgpool nodes
    Observed Generation:   1
    Reason:                Reconfigure
    Status:                True
    Type:                  Reconfigure
    Last Transition Time:  2024-07-30T06:53:31Z
    Message:               Successfully paused database
    Observed Generation:   1
    Reason:                DatabasePauseSucceeded
    Status:                True
    Type:                  DatabasePauseSucceeded
    Last Transition Time:  2024-07-30T06:53:31Z
    Message:               Successfully updated PetSet
    Observed Generation:   1
    Reason:                UpdatePetSets
    Status:                True
    Type:                  UpdatePetSets
    Last Transition Time:  2024-07-30T06:53:32Z
    Message:               Successfully updated Pgpool
    Observed Generation:   1
    Reason:                UpdateDatabase
    Status:                True
    Type:                  UpdateDatabase
    Last Transition Time:  2024-07-30T06:54:17Z
    Message:               Successfully Restarted Pods With Resources
    Observed Generation:   1
    Reason:                RestartPods
    Status:                True
    Type:                  RestartPods
    Last Transition Time:  2024-07-30T06:53:37Z
    Message:               get pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  GetPod--pp-custom-0
    Last Transition Time:  2024-07-30T06:53:37Z
    Message:               evict pod; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  EvictPod--pp-custom-0
    Last Transition Time:  2024-07-30T06:54:12Z
    Message:               check pod running; ConditionStatus:True; PodName:pp-custom-0
    Observed Generation:   1
    Status:                True
    Type:                  CheckPodRunning--pp-custom-0
    Last Transition Time:  2024-07-30T06:54:17Z
    Message:               Successfully completed the reconfigure for Pgpool
    Observed Generation:   1
    Reason:                Successful
    Status:                True
    Type:                  Successful
  Observed Generation:     1
  Phase:                   Successful
Events:
  Type     Reason                                                         Age   From                         Message
  ----     ------                                                         ----  ----                         -------
  Normal   Starting                                                       74s   KubeDB Ops-manager Operator  Start processing for PgpoolOpsRequest: demo/ppops-reconfigure-remove
  Normal   Starting                                                       74s   KubeDB Ops-manager Operator  Pausing Pgpool databse: demo/pp-custom
  Normal   Successful                                                     74s   KubeDB Ops-manager Operator  Successfully paused Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure-remove
  Normal   UpdatePetSets                                                  71s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdatePetSets                                                  70s   KubeDB Ops-manager Operator  Successfully updated PetSet
  Normal   UpdateDatabase                                                 70s   KubeDB Ops-manager Operator  Successfully updated Pgpool
  Warning  get pod; ConditionStatus:True; PodName:pp-custom-0             65s   KubeDB Ops-manager Operator  get pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  evict pod; ConditionStatus:True; PodName:pp-custom-0           65s   KubeDB Ops-manager Operator  evict pod; ConditionStatus:True; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:False; PodName:pp-custom-0  60s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:False; PodName:pp-custom-0
  Warning  check pod running; ConditionStatus:True; PodName:pp-custom-0   30s   KubeDB Ops-manager Operator  check pod running; ConditionStatus:True; PodName:pp-custom-0
  Normal   RestartPods                                                    25s   KubeDB Ops-manager Operator  Successfully Restarted Pods With Resources
  Normal   Starting                                                       25s   KubeDB Ops-manager Operator  Resuming Pgpool database: demo/pp-custom
  Normal   Successful                                                     25s   KubeDB Ops-manager Operator  Successfully resumed Pgpool database: demo/pp-custom for PgpoolOpsRequest: ppops-reconfigure-remove

Now let’s exec into the pgpool pod and check the configuration.

$ kubectl exec -it -n demo pp-custom-0 -- bash 
pp-custom-0:/$ cat opt/pgpool-II/etc/pgpool.conf
backend_hostname0 = 'ha-postgres.demo.svc'
backend_port0 = 5432
backend_weight0 = 1
backend_flag0 = 'ALWAYS_PRIMARY|DISALLOW_TO_FAILOVER'
backend_hostname1 = 'ha-postgres-standby.demo.svc'
backend_port1 = 5432
backend_weight1 = 1
backend_flag1 = 'DISALLOW_TO_FAILOVER'
enable_pool_hba = on
listen_addresses = *
port = 9999
socket_dir = '/var/run/pgpool'
pcp_listen_addresses = *
pcp_port = 9595
pcp_socket_dir = '/var/run/pgpool'
log_per_node_statement = on
sr_check_period = 0
health_check_period = 0
backend_clustering_mode = 'streaming_replication'
num_init_children = 5
max_pool = 15
child_life_time = 300
child_max_connections = 0
connection_life_time = 0
client_idle_limit = 0
connection_cache = on
load_balance_mode = on
ssl = 'off'
failover_on_backend_error = 'off'
log_min_messages = 'warning'
statement_level_load_balance = 'off'
memory_cache_enabled = 'off'
memqcache_oiddir = '/tmp/oiddir/'
allow_clear_text_frontend_auth = 'false'
failover_on_backend_error = 'off'
pp-custom-0:/$ exit
exit

As we can see from the configuration of running pgpool, the value of max_pool has been changed from 75 to 15 which is the default configuration number of repicas * 15. So the reconfiguration of the pgpool using the removeCustomConfig field is successful.

Cleaning Up

To clean up the Kubernetes resources created by this tutorial, run:

kubectl delete -n demo pp/pp-custom
kubectl delete pgpoolopsrequest -n demo ppops-reconfigure  ppops-reconfigure-apply ppops-reconfigure-remove
kubectl delete pg -n demo ha-postgres
kubectl delete ns demo

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