On Wed, Jan 13, 2016 at 11:51 AM, Jeff Janes <jeff.ja...@gmail.com> wrote:
> Anyway, it looks to me like you have a checkpoint problem. The checkpoint > overwhelms your IO system. The overwhelmed IO system then backs up into > the bgwriter. What you see in the bgwriter is just a symptom, not the > cause. The background writer is usually not very useful in recent versions > of PostgreSQL, anyway. But, the same IO problem that is clogging up the > background writer is also clogging up either your buffer_backend, or your > WAL writes/fsyncs. And both of those will destroy your throughput. > That was my intuition too. Not enough I/O available from the hardware for the workload requested. As recommended, log your checkpoints and try tuning them to spread the load.
