sysout error log being truncated

Good afternoon/evening

We run postgres 9.4. We are moving to a new datacenter and are doing the
requisite parallel performance testing.
One of our transactions is a queue processor that generates a ton of insert
statements per run of this transaction - as many as 1000 per run.
What has happened in new datacenter is that these transactions - while
running correctly and completely - do not write all the insert statements
to our sysout log - only some. Here are some of the postgres
configurations for your reference:

syslog_facility = 'LOCAL0'
#syslog_ident = 'postgres'
# This is only relevant when logging to eventlog (win32):
#event_source = 'PostgreSQL'
# - When to Log -
#client_min_messages = notice
log_min_messages = info
log_min_error_statement = info
log_min_duration_statement = 4000
# - What to Log -
#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = on
#log_checkpoints = off
#log_connections = off
#log_disconnections = off
#log_duration = off
#log_error_verbosity = default
#log_hostname = off
log_line_prefix = '%u(at)%h:%d '
#log_lock_waits = off
log_statement = 'ddl'
#log_temp_files = -1
log_timezone = 'US/Eastern'

The only other difference I can report is the minor version
CURRENT PRODUCTION: 9.4.8
NEW DATACENTER: 9.4.21

Any insights welcome - thank you,

--
*Mark Steben*
Database Administrator
@utoRevenue <http://www.autorevenue.com/> | Autobase
<http://www.autobase.net/>
CRM division of Dominion Dealer Solutions
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West Springfield, MA 01089
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