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Re: 2.3.39 syncrepl lost connection

On 1/31/08 4:31 PM, Aaron Richton wrote:
A 2.3.39 replica should know the connection was lost, via the underlying OS, because it requests SO_KEEPALIVE. I assume these are (pseudo-?)dedicated servers, given the size of your OpenLDAP installation. As such, you may want to investigate your kernel tunable parameters to make keepalives more aggressive.

Yep, I'll bet that's it. These are dedicated servers and they had the RedHat default values for the keepalive settings (which means about 2hours 15minutes before the replica knows that the connection got axed -- and nagios yells really loud after 10 minutes). We have never waited the full 2 hours and 15 minutes to see it recover itself. I have changed the times to be 300/5/5 (instead of 7200/75/9). So, it should figure out it's dead within 5 minutes 30 seconds.

On 1/31/08 4:12 PM, Quanah Gibson-Mount wrote: > Was the connection between the replica and master still open? What bind > mechanism are you using?

I wasn't the one that worked on it. I was told "the connection still thought it was up". I believe that means that netstat was used on the replica and a connection to the master was reported back. And as we didn't wait for keepalive to figure out it had died, it would have reported as ESTABLISHED. I don't know that anyone checked on the master, where I'll bet the connection was not still showing up.

The bind mechanism is simple to prevent external services (like Kerberos) being required for the LDAP servers to be operational.

Frank Swasey                    | http://www.uvm.edu/~fcs
Sr Systems Administrator        | Always remember: You are UNIQUE,
University of Vermont           |    just like everyone else.
  "I am not young enough to know everything." - Oscar Wilde (1854-1900)

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