pgagroal new commands: ‘ping’ and ìstatus details’

When I committed the major command refactoring in pgagroal-cli, I introduced also a simple way to deprecate a command, so that the user running the old version of a command is warned about switching to the new interface. This lead me to think I can not only refactor pgagroal-cli commands in a more coherent way, grouping similar commands together, but I can also change existing commands by means of deprecating them. That is what I did in this commitLink Text where I replaced the is-alive command with ping and details with status details.

The ping command

I have to confess: the name has been inspired by the MySQL Admin tool, that has a similar command. The idea of ping is to test if the connection pooler is alive, and it replaces the old command is-alive: 

$ pgagroal-cli ping --verbose
pgagroal-cli: Success (0)


$ pgagroal-cli is-alive --verbose
pgagroal-cli: command <is-alive> has been deprecated by <ping> since version 1.6
pgagroal-cli: Success (0)


Please note that, as documented, the ping command does not print anything if the pooler is running.

The status details command

The status command prints a summary information about the pooler, while the details command prints the same summary and a more verbose and detailed information about every connection. Why not group these two commands? This is the aim of having status details:
  • status will work as before;
  • status enhanced with details will provide more verbose output.


$ pgagroal-cli status
Status:              Running
Active connections:  0
Total connections:   0
Max connections:     15


$ pgagroal-cli status details
Status:              Running
Active connections:  0
Total connections:   0
Max connections:     15
---------------------
Server:              venkman
Host:                venkman
Port:                5432
State:               Not init
---------------------
---------------------
Server:              a
Host:                spengler
Port:                5432
State:               Not init
---------------------
---------------------
Server:              b
Host:                spengler
Port:                6432
State:               Not init
---------------------
---------------------
Database:            testdb
Username:            luca
Active connections:  0
Max connections:     2
Initial connections: 1
Min connections:     1
---------------------
---------------------
Database:            all
Username:            luca
Active connections:  0
Max connections:     10
Initial connections: 2
Min connections:     1
---------------------
---------------------
Database:            pgbench
Username:            pgbench
Active connections:  0
Max connections:     2
Initial connections: 1
Min connections:     1
---------------------
Connection    0:     Not init
Connection    1:     Not init
Connection    2:     Not init
Connection    3:     Not init
Connection    4:     Not init
Connection    5:     Not init
Connection    6:     Not init
Connection    7:     Not init
Connection    8:     Not init
Connection    9:     Not init
Connection   10:     Not init
Connection   11:     Not init
Connection   12:     Not init
Connection   13:     Not init
Connection   14:     Not init


Therefore, now the total number of main commands to pgagroal-cli has shrinked, since a few of them have been grouped.

Conclusions

While it may sound very trivial, having a coherent and easy to understand command line interface is a key value in make the project been approached by mere mortals. That’s why I strongly believe the refactoring of the commands in pgagroal-cli is going to play a very important role in the connection pooler adoption.

The article pgagroal new commands: 'ping' and ìstatus details' has been posted by Luca Ferrari on October 30, 2023

Tags: postgresql , planet-postgresql-org