PG 9.4.4 (RDS)
I'm experiencing an issue when trying to update many rows in a single table (one row at a time, but parallelized across ~12 connections). The issue we see is that the writes will periodically be blocked for a duration of several minutes and then pick back up. After digging through our monitoring stack, I was able to uncover these stats which seem to allude to it being a background writer performance problem:
(apologies for the image)
Our settings for the background writer are pretty standard OOB (I threw in some others that I thought might be helpful, too):
name | setting | unit
-------------------------+---------+------
bgwriter_delay | 200 | ms
bgwriter_lru_maxpages | 100 |
bgwriter_lru_multiplier | 2 |
maintenance_work_mem | 65536 | kB
max_worker_processes | 8 |
work_mem | 32768 | kB
The table that is being written to contains a jsonb column with a GIN index:
Table "public.ced"
Column | Type | Modifiers
---------------+--------------------------+-----------
id | bigint | not null
created_at | timestamp with time zone |
modified_at | timestamp with time zone |
bean_version | bigint | default 0
account_id | bigint | not null
data | jsonb | not null
Indexes:
"ced_pkey" PRIMARY KEY, btree (id)
"ced_data" gin (data jsonb_path_ops)
"partition_key_idx" btree (account_id, id)
It seems to me that the background writer just can't keep up with the amount of writes that I am trying to do and freezes all the updates. What are my options to improve the background writer performance here?
thanks
--Cory
