Re: Mirror mode replication breaks at times.

[pradyumna dash]

Hi,

Thanks you so much.  Let me try the same.

Regards,
/Pradyumna



On Tue, Jul 9, 2013 at 12:48 AM, Mark Cairney  wrote:

> Hi,
>
>
> On 08/07/2013 12:47, Pradyumna wrote:
>
>> Hi,
>>
>> I have configured mirror mode replication. It's 2 node. Everything works
>> fine but if I don't work on the server or say 30/40 mins or so and then
>> when I try to add or delete any users or groups it don't get replicated to
>> the other node. Am not getting any error in the logs and if I restart the
>> slapd service it's syncs again and giving expected results.  The same setup
>> I have in the test environment and its works like a charm the only
>> difference in this setup is that the 2 servers are hosted on 2 different DC
>> geographically separated where as in test they are in same DC.
>>
> In addition to what Quanah has said about running the latest stable
> release (there was a number of bug fixes for OpenLDAP between now and v
> 2.4.23) this sounds a bit like a clock syncing/drifting issue, particularly
> if you have 2 in close proximity that work fine but the 2 that aren't don't.
>
> Having been bitten by this myself in the past for MMR to be reliable and
> successful the clocks on the servers have to match up almost to the
> millisecond. I'd recommend using ntpd and syncing them all to a common NTP
> time source.
>
> I have a line like this in my /etc/ntp.conf:
>
> server my.ntp.servers.IP minpoll 4 maxpoll 6 prefer
>
>
>
>  Am using the openldap version which comes by default with RHEL 6.3. If it
>> would have been a version issue then I should have expected the same result
>> in test as well? Please help.
>>
>>  Kind regards,
>
> Mark
>
>
> --
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>

Re: Mirror mode replication breaks at times.

[Mark Cairney]

Hi,

On 08/07/2013 12:47, Pradyumna wrote:

Hi,

I have configured mirror mode replication. It's 2 node. Everything works fine 
but if I don't work on the server or say 30/40 mins or so and then when I try 
to add or delete any users or groups it don't get replicated to the other node. 
Am not getting any error in the logs and if I restart the slapd service it's 
syncs again and giving expected results.  The same setup I have in the test 
environment and its works like a charm the only difference in this setup is 
that the 2 servers are hosted on 2 different DC geographically separated where 
as in test they are in same DC.
In addition to what Quanah has said about running the latest stable 
release (there was a number of bug fixes for OpenLDAP between now and v 
2.4.23) this sounds a bit like a clock syncing/drifting issue, 
particularly if you have 2 in close proximity that work fine but the 2 
that aren't don't.


Having been bitten by this myself in the past for MMR to be reliable and 
successful the clocks on the servers have to match up almost to the 
millisecond. I'd recommend using ntpd and syncing them all to a common 
NTP time source.


I have a line like this in my /etc/ntp.conf:

server my.ntp.servers.IP minpoll 4 maxpoll 6 prefer



Am using the openldap version which comes by default with RHEL 6.3. If it would 
have been a version issue then I should have expected the same result in test 
as well? Please help.


Kind regards,

Mark


--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.

Re: Mirror mode replication breaks at times.

[Quanah Gibson-Mount]

--On Monday, July 08, 2013 9:47 PM +1000 Pradyumna  
wrote:



Am using the openldap version which comes by default with RHEL 6.3. If it
would have been a version issue then I should have expected the same
result in test as well? Please help.


The RHEL6 builds of OpenLDAP are ancient, and known to be problematic for a 
large number of reasons.  As is often noted, it is generally best to avoid 
distribution builds of OpenLDAP.  If you are using RHEL, I suggest looking 
at 


--Quanah

--

Quanah Gibson-Mount
Sr. Member of Technical Staff
Zimbra, Inc
A Division of VMware, Inc.

Zimbra ::  the leader in open source messaging and collaboration

Mirror mode replication breaks at times.

[Pradyumna]

Hi,

I have configured mirror mode replication. It's 2 node. Everything works fine 
but if I don't work on the server or say 30/40 mins or so and then when I try 
to add or delete any users or groups it don't get replicated to the other node. 
Am not getting any error in the logs and if I restart the slapd service it's 
syncs again and giving expected results.  The same setup I have in the test 
environment and its works like a charm the only difference in this setup is 
that the 2 servers are hosted on 2 different DC geographically separated where 
as in test they are in same DC.

Am using the openldap version which comes by default with RHEL 6.3. If it would 
have been a version issue then I should have expected the same result in test 
as well? Please help.

Regards,
/Pradyumna
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