On 2020-Jul-20, jian xu wrote: > we are seeing this issue again, the checkpoint process is eating up all the memory, > based on the htop, the checkpointer process has > VIRT: 103G > RES: 103G > SHR: 4099M > MEM%: 41% > > I use ps_mem.py to check the process, > https://github.com/pixelb/ps_mem > ================================= > Private + Shared = RAM used Program > > 99.5 GiB + 37.5 MiB = 99.5 GiB postgres > --------------------------------- > 99.5 GiB > ================================= > my pg version is 10.3 , shared_buffer size is 4GB. work_mem 64MB. there are about 120 connections on the db side. most of them are idle. > does anyone have idea how to troubleshooting this kind of issue? I see no reason for checkpointer to use that much memory. Accounting for the whole of shared_buffers is okay (as Laurenz explaijned), which in other installations may account for several gigabytes of memory. But if shared_buffers is 4GB, then 99GB is clearly overboard. I see no explanation for checkpointer using 25x shared_buffers. Maybe looking at /proc/<PID>/smaps would tell you where that memory is going? Have a look there are see if you can figure out some obviously absurd entries. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
