Arvados

this is part of a 2.6G log file:

e51c5:/var/log/postgresql# ls -lh postgresql-9.3-main.log-20170326 
-rw-r----- 1 postgres adm 2.6G Mar 26 06:49 postgresql-9.3-main.log-20170326

2017-03-16 21:55:37 UTC ERROR:  duplicate key value violates unique constraint "index_nodes_on_slot_number" 
2017-03-16 21:55:37 UTC DETAIL:  Key (slot_number)=(6) already exists.
2017-03-16 21:55:37 UTC STATEMENT:  UPDATE "nodes" SET "last_ping_at" = '2017-03-16 21:55:37.327129', "ip_address" = '10.38.64.23', "first_ping_at" = '2017-03-16 21:55:37.3
27129', "slot_number" = 6, "updated_at" = '2017-03-16 21:55:37.347028', "modified_at" = '2017-03-16 21:55:37.347028', "modified_by_client_uuid" = NULL, "info" = '---
        ec2_instance_id: compute-z10duswzkdoq87w-e51c5
        last_action: Prepared by Node Manager
        ping_secret: 2louyeuuylbqdz1c6swx6fmfm93ocbhcppnb9onn7qgh47k7vr
        ', "properties" = '---
        cloud_node:
          price: 0.149
          size: Standard_D11_v2
        ' WHERE "nodes"."id" = 552

Theory is that this is actually a normal condition (uniqueness gets handled after return), but lazy/chatty logging by Rails.

We should fix this so the pg logs don't fill up the space and/or using CPU to compact the logfile, even if Rails ends up doing the right thing, it is CPU and I/O wasted for no reason. If we can't deal at the Rails level, Could there be a flag to avoid logging them at least?