dovecot: doveconf: Fatal: block_alloc(134217728): Out of memory

[Brent Clark]

Good day Guys

Currently on Debian Stretch (2.2.27). This morning we enabled SNI for 
our clients (file per domain).

On going live with the new server configuration, we started getting the 
following on our shared hosting servers.

Jun 30 07:25:04 REMOVED_HOSTNAME dovecot: doveconf: Fatal: 
block_alloc(134217728): Out of memory
Jun 30 07:25:04 REMOVED_HOSTNAME dovecot: config: Fatal: 
block_alloc(134217728): Out of memory
Jun 30 07:25:04 REMOVED_HOSTNAME dovecot: config: Fatal: master: 
service(config): child 64008 returned error 83 (Out of memory (service 
config { vsz_limit=512 MB }, you may need to increase it) - set 
CORE_OUTOFMEM=1 environment to get core dump)
Jun 30 07:25:34 REMOVED_HOSTNAME dovecot: doveconf: Panic: data stack: 
Out of memory when allocating 2147483688 bytes
Jun 30 07:25:37 REMOVED_HOSTNAME dovecot: config: Panic: data stack: Out 
of memory when allocating 2147483688 bytes

This is a server with 2414 domains.

On a few of our servers, to buy time, we had to set:
default_vsz_limit =10096M

A question I would like to ask is.
Based on the following change notice, could the following be the problem.
https://dovecot.org/pipermail/dovecot-news/2019-July/000412.html

- config: Memory leak in config process when ssl_dh setting wasn't
   set and there was no ssl-parameters.dat file.
   This caused config process to die once in a while
   with "out of memory".

If anyone could provide any assistance or share a tip on where we can 
look it would be appreciated. This one has my team and I stumped.

Kind regards
Brent Clark