Обсуждение: Postgresql database terminates abruptly with too many open files error

Hello Team,

  We have a postgresql VDB(virtual database- Delphix) that keeps 
terminating due "to too many open files".

Below are few alerts that we could see from the postgresql.log


< 2025-01-14 11:37:20.724 GMT >LOG:  out of file descriptors: Too many 
open files in system; release and retry

< 2025-01-14 11:37:20.724 GMT >FATAL:  epoll_create1 failed: Too many 
open files in system


The number of allowed openfiles at OS level are 65000. even then we see 
these all these being utilised and causing the database to terminate.


Is there a way we could avoid this.


Thanks,

Sri

Hello,


Have you checked something like lsof to see open file descriptors to see?

Cheers,
frank

Am 14.01.25 um 13:58 schrieb Sri Mrudula Attili:
> Hello Team,
> 
>   We have a postgresql VDB(virtual database- Delphix) that keeps terminating due "to too many open files".
> 
> Below are few alerts that we could see from the postgresql.log
> 
> 
> < 2025-01-14 11:37:20.724 GMT >LOG:  out of file descriptors: Too many open files in system; release and retry
> 
> < 2025-01-14 11:37:20.724 GMT >FATAL:  epoll_create1 failed: Too many open files in system
> 
> 
> The number of allowed openfiles at OS level are 65000. even then we see these all these being utilised and causing
thedatabase to terminate.
 
> 
> 
> Is there a way we could avoid this.
> 
> 
> Thanks,
> 
> Sri
> 
> 
> 

Sri Mrudula Attili <sri@ebi.ac.uk> writes:
>   We have a postgresql VDB(virtual database- Delphix) that keeps 
> terminating due "to too many open files".

What do you have max_connections set to, and how many actually-live
server processes are there typically?

> The number of allowed openfiles at OS level are 65000.

I'm suspecting that you either need to increase that, decrease
max_files_per_process (which defaults to 1000), or decrease
max_connections.

            regards, tom lane

Hello Tom,


The max_connections =200 and max_files_per_process =1000 as you mentioned.

So should a max_files_per_process =500 helps?


I could see from the number of connections to the databaseis not 
exceeding 20. But still these 20 are causing all the damage or using up 
all the openfiles quota.


Thanks,

Sri

On 14/01/2025 14:19, Tom Lane wrote:
> Sri Mrudula Attili <sri@ebi.ac.uk> writes:
>>    We have a postgresql VDB(virtual database- Delphix) that keeps
>> terminating due "to too many open files".
> What do you have max_connections set to, and how many actually-live
> server processes are there typically?
>
>> The number of allowed openfiles at OS level are 65000.
> I'm suspecting that you either need to increase that, decrease
> max_files_per_process (which defaults to 1000), or decrease
> max_connections.
>
>             regards, tom lane