* if the virtual machine has only one CPU.
Adding a second CPU increases the number of
transferred entries before the initialization gets
stuck. So it may me some thread/transaction
contention or deadlock.
* if the replication agreement uses SSL(port
636) or TLS(port389). Using port 389 with LDAP
protocol instead of TLS/SSL increases the number
of transferred entries before the initialization
gets stuck. Sometimes the initialization even ends
successfully in this case.
* decreasing nsslapd-db-checkpoint-interval
(say, to 5 seconds) also gets the problem worse
This indicates the issue is in the BDB?
Don't know. My hypotheses are :
* using plugin transactions compared to 1.2.10.x
* bdb version? but even with compat-db-47 and 1.2.10
the problem still happens on CentOS7, though much less
frequently. It never happens with 1.2.10 with rpm bdb on
CentOS5.
* change from mozilla ldap libraries to openldap
libraries?
seems to be some sort of thread or transaction
contention that is reduced when i add CPUs/increase
checkpoint interval. It really looks like the master
server just does not send entries any more at some
moment... SSL/TLS slows the things down so less entries
are sent before everything gets stuck...
I'll get back with more information (stacktraces)
tomorrrow.