I am having a problem with what appears (to me) to be ‘stale’ TCP connections for syncrepl between the master and a pair of slaves.  After restarting all, I see changes on the master replicated to both slaves.  BUT, if I wait about 30 minutes or more, then make a change, the replication fails (most of the time).  netstat on the LDAP port show the connections still established, but queued packets at the master server.  After about 15 minutes, the master server drops the connection.  An overnight tcpdump on the master showed LDAP occasionally sending a keep-alive, with 2hrs between the keep-alive messages (these keep-alives are inconsistent, though, some nights I see none).  

 

I am running Red Hat EL5 and Openldap 2.3.43 on all servers with no TLS or SASL (in our integration/test facility).

 

I don’t see anything in the documentation pertaining to keep-alives, other than ITS#4708 for 2.3.38.

 

Here’s the syncrepl for one slave:

 

syncrepl        rid=004

                type=refreshAndPersist

                provider=ldap://172.24.1.191

                retry="30 10 300 3"

                searchbase="o=partner_x,dc=ourcompany-int,dc=net"

                filter="(objectClass=*)"

                scope=sub

                schemachecking=off

                bindmethod=simple

                binddn="cn=syncRepl,o=partner_x,dc=ourcompany-int,dc=net "

                credentials="secret"

updateref       ldap://172.24.1.191

 

 

The other slave’s slapd.conf is indentical except rid=002.

 

On the master I have:

 

overlay syncprov

syncprov-checkpoint 100 30

syncprov-sessionlog 100

 

 

Note:  The 2 slaves are running on blades in an IBM chassis, and the master is on a 1U Linux server, just ‘one-hop’ away.   Prior to this, when I had a master/slave pair running on the blades, syncRepl was working fine for several months.  It was not until I moved the master to the another server did the failures start.

 

Thanks in advance for any help or info.

 

John Kane

 

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