Re: How to monitor Postgres real memory usage

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Justin

   Thanks for your update.

   Postgres is just an OS Process, so should be monitored like any other.

What OS are you using ?

>  I am using Centos 7.5.

Know that the OS may attribute "shared buffers" to different processes, or multiple processes.

It's almost always a bad idea to kill postgres with kill -9.

> I unable to connect to database server. I have to kill some process to release memory. Then I could connect it. 

  What settings have you used in postgres ?
https://wiki.postgresql.org/wiki/Server_Configuration


> Please reference my attachment.

You can check memory use of an individual query with "explain (analyze,buffers) .."
https://wiki.postgresql.org/wiki/Slow_Query_Questions

Thanks for your update.  This memory allocation failed issue impact the whole database running. not a slow query.
Is there any commands or method could get totally Postgres memory utilization ? Thanks .

Justin Pryzby <pryzby@xxxxxxxxxxxxx> 于2022年5月25日周三 01:40写道:
On Wed, May 25, 2022 at 12:25:28AM +0800, 徐志宇徐 wrote:
> Hi All
>
>   I am a Database DBA. I focus on PostgreSQL and DB2.
>   Recently. I experience some memory issue. The postgres unable allocate
> memory. I don't know how to monitor Postgres memory usage.

Postgres is just an OS Process, so should be monitored like any other.

What OS are you using ?

Know that the OS may attribute "shared buffers" to different processes, or
multiple processes.

>  This server have 16G memory. On that time. The free command display only 3
> G memory used. The share_buffers almost 6G.
>
>  On that time. The server have 100 active applications.
>  New connection failed. I have to kill some application by os command "kill -9"

It's almost always a bad idea to kill postgres with kill -9.

> The checkpoint command execute very slow. almost need 5-10 seconds.

Do you mean an interactive checkpoint command ?
Or logs from log_checkpoint ?

>   Is there any useful command to summary PostgreSQL memory usage ?

You can check memory use of an individual query with "explain (analyze,buffers) .."
https://wiki.postgresql.org/wiki/Slow_Query_Questions

What settings have you used in postgres ?
https://wiki.postgresql.org/wiki/Server_Configuration

What postgres version ?
How was it installed ?  From souce?  From a package ?

--
Justin

Attachment: postgresql.auto.conf
Description: Binary data

Attachment: postgresql.conf
Description: Binary data


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux