2.3.1 Replication is throwing scary errors

[Gerald Galster]

Hi,

> There is also a second issue of a long standing race with replication occurring somewhere whereby if a mail comes in, is written to disk, is replicated and then deleted in short succession, it will reappear again to the MUA.  I suspect the mail is being replicated back from the remote.  A few people have reported it over the years but it's not reliable or consistent, so it has never been fixed.

sounds like my replication issue which is reproducible on 2.2.35 and does not occur on 2.2.33.2, so I assume something in the replication code has changed between these two versions.

dsync is copying the mail before expunge in this situation (no sieve filters involved):

(mail received on mx2a.example.com and delivered via dsync/ssh to mx2b.example.com, then expunged via pop3 on mx2b.example.com -> copy/duplicate)
Mar 26 15:35:58 mx2b.example.com dovecot[3825]: pop3(poptest at example.com): expunge: box=INBOX, uid=23, msgid=<ACD482CD-443E-479A-A9E9-67549E186E35 at example.com>, size=1210, subject=test 1535
Mar 26 15:35:58 mx2b.example.com dovecot[3825]: doveadm: Error: dsync-remote(poptest at example.com): Info: copy from INBOX: box=INBOX, uid=24, msgid=<ACD482CD-443E-479A-A9E9-67549E186E35 at example.com>, size=1210, subject=test 1535
Mar 26 15:35:58 mx2b.example.com dovecot[3825]: doveadm: Error: dsync-remote(poptest at example.com): Info: expunge: box=INBOX, uid=23, msgid=<ACD482CD-443E-479A-A9E9-67549E186E35 at example.com>, size=1210, subject=test 1535

For more details see mail from 2018-03-27 / Duplicate mails on pop3 expunge with dsync replication on 2.2.35 (2.2.33.2 works)

Best regards,
Gerald