syncrepl and LDAP_BUSY on LDBM by ITS#7904

[Леонид Юрьев <leo@yuriev.ru>]

Hi all,

We got a trouble with 2.4.40 syncrepl in the the multi-master mode.
I think is too complex for analyse, and so not yet testcase is ready.

But I noticed a change in ITS#7904 and the impact of LDAP_BUSY upon syncrepl.
http://www.openldap.org/devel/gitweb.cgi?p=openldap.git&a=search&h=refs%2Ftags%2FOPENLDAP_REL_ENG_2_4_40&st=commit&s=7904

For instance, I assume that in case the LDAP_BUSY returned from
ldap_sync_search(), then a syncrepl-connection would be closed and
reestablished.

Let see around the line 1554 of server/slapd/syncrepl.c and below.
https://github.com/leo-yuriev/openldap-lmdb-challenge/blob/master/servers/slapd/syncrepl.c#L1545

Also, nowadays it is no repeatable read txn-isolation during the
search and transfer data over a network.
Does it influence upon syncrepl or not?

Could anybody dispel my doubts?

Leonid.