please appreciate that i am trying to help ....

after much testing i can now reporduce the replication issues at hand

I am running on freebsd 12 & 13 stable (both test and production servers)

sdram drives etc ...

Basically replication works fine until reaching a folder quantity of ~ 256 or more

to reproduce using doveadm i created folders like

INBOX/folder-0
INBOX/folder-1
INBOX/folder-2
INBOX/folder-3
and so forth ......

I created 200 folders and they replicated ok on both servers

I created another 200 (400 total) and the replicator got stuck and would not update the mbox on the alternate server anymore and is still updating 4 days later ?

basically replicator goes so far and either hangs or more likely bails on an error that is not reported to the debug reporting ?

however dsync will sync the two servers but only when run manually (ie all the folders will sync)

I have two test servers avaliable if you need any kind of access - again here to help.

[07:28:42] mail18.scom.ca [root:0] ~
# sync.status
Queued 'sync' requests        0                                                                          
Queued 'high' requests        6                                                                          
Queued 'low' requests         0                                                                          
Queued 'failed' requests      0                                                                          
Queued 'full resync' requests 0                                                                          
Waiting 'failed' requests     0                                                                          
Total number of known users   255                                                                        
 
username                       type        status                     
paul@scom.ca                   normal      Waiting for dsync to finish
keith@elirpa.com               incremental Waiting for dsync to finish
ed.hanna@dssmgmt.com           incremental Waiting for dsync to finish
ed@scom.ca                     incremental Waiting for dsync to finish
nick@elirpa.com                incremental Waiting for dsync to finish
paul@paulkudla.net             incremental Waiting for dsync to finish


i have been going through the c code and it seems the replication gets requested ok

replicator.db does get updated ok with the replicated request for the mbox in question.

however i am still looking for the actual replicator function in the lib's that do the actual replication requests

the number of folders & subfolders is defanately the issue - not the mbox pyhsical size as thought origionally.

if someone can point me in the right direction, it seems either the replicator is not picking up on the number of folders to replicat properly or it has a hard set limit like 256 / 512 / 65535 etc and stops the replication request thereafter.

I am mainly a machine code programmer from the 80's and have concentrated on python as of late, 'c' i am starting to go through just to give you a background on my talents.

It took 2 months to finger this out.

this issue also seems to be indirectly causing the duplicate messages supression not to work as well.

python programming to reproduce issue (loops are for last run started @ 200 - fyi) :

# cat mbox.gen
#!/usr/local/bin/python2

import os,sys

from lib import *


user = 'paul@paulkudla.net'

"""
for count in range (0,600) :
        box = 'INBOX/folder-%s' %count
        print count
        command = '/usr/local/bin/doveadm mailbox create -s -u %s %s' %(user,box)
        print command
        a = commands.getoutput(command)
        print a
"""

for count in range (0,600) :
        box = 'INBOX/folder-0/sub-%' %count
        print count
        command = '/usr/local/bin/doveadm mailbox create -s -u %s %s' %(user,box)
        print command
        a = commands.getoutput(command)
        print a



        #sys.exit()