[389-users] Repair replication

Herb Burnswell herbert.burnswell at gmail.com
Mon Apr 2 22:13:11 UTC 2012


On Fri, Mar 23, 2012 at 10:53 AM, Rich Megginson <rmeggins at redhat.com>wrote:

>  On 03/23/2012 11:09 AM, Herb Burnswell wrote:
>
> Thanks for the reply David.
>
> >> 1. How can I find out which system(s) is/are master, consumer, hub, etc?
> >>>>You should be able to determine the role of the Directory Server for
> each
> >>>>system by logging into the LDAP console under
> >>>>"Configuration->Replication".  The role is either "Single Master",
> "Hub" or
> >>>>"Dedicated Consumer".
>
> >I was able to determine that we have two "Multiple Master" systems.
> Let's call >them 'A' and 'B'.  System A has been the only system running
> for what appears to >be several years (it is being backed up nightly).
> System B has been off for some >time but is running now.
>
> >> 2. How do I confirm that the systems have the correct credentials for
> >replication? (I am receiving: "Unable to acquire replica: Permission
> >denied.")
>    >a. How can I change the bind dn "cn=replication,cn=config" credentials
> >on each system to ensure replication will work?
> >>>>You can do that on the console as well.  Just navigate down the
> directory
> >>>>tree and manually reset the password for the replication user account.
> >>>>There's a possibility that your replication user account's password
> expired.
>
> >I can navigate to the screen to reset the password for the replication
> user account.  I >have not reset the passwords yet as I am reading
> documentation to confirm that >system B will simply update it's data to
> system A's upon resuming replication.
>
> >When you change the password of the replication user on B, you'll also
> have to update >those credentials in the replication agreement on A for the
> agreement from A to B.
>
> >Note that if replication has been down for years, you will have to
> perform a manual >replica initialization procedure - replication will not
> automatically "catch up" if it has >been down that long.
>
> Rich - Thank you for the response. I was diverted to another urgent issue
but have come back to this replication fix.

I've confirmed that there are two Dedicated Consumer's (C and D) to go
along with the two Dual Master's (A and B). I want to replicate to one of
the dedicated consumers, C, prior to syncing the dual master B. I changed
the passwords for dn:cn=replication,cn=config on A via the Directory
Manager console, and via ldapmodify on C. I am confident that the passwords
are the same on both systems.

I followed section 8.10.5.1 on initializing the consumer replica from
backup files and it worked with the following:

[02/Apr/2012:11:58:03 -0700] - Add Attribute readonly Value off
[02/Apr/2012:11:58:03 -0700] - Add Attribute nsslapd-directory Value
/new/path/from/master/server
[02/Apr/2012:11:58:04 -0700] - Del Attribute nsslapd-directory Value
/old/path/from/consumer
[02/Apr/2012:11:58:04 -0700] - WARNING!!: current Instance Config is
different from backed up configuration; The backup is restored.

First, do I need to reset these attributes back to 'readonly' and the
original nsslapd-directory?

Second, I am now receiving the following error from the master A:
Unable to acquire replica: permission denied. The bind dn
"cn=replication,cn=config" does not have permission to supply replication
updates to the replica. Will retry later.

On another note, I see plain text passwords in the error logs on A for the
consumers but passwd = {SSHA}0bgDq2f1IM/2nNOOIHUh8lXfkG13XUOHTYD== for B,
the other master. Is there specific reason for this?

As always, any guidance that can be provided is greatly appreciated.

TIA,

Herb

>
> >> 3. I assume that upon repairing replication (apparently it has not been
> working for several years) the systems will all replicate to the most
> recent information.  Correct?
> >>>>I think that's the tricky part.  Make sure you backup your directory
> on all
> >>>>the LDAP first so you have something to roll back.  I *believe* the
> last
> >>>>step when setting up replication is initializing the directory and that
> >>>>will wipe out directory on the other LDAP.  Someone on the list might
>  be
> >>>>able to provide a better on this but I am just giving you a heads up
> that
> >>>>this can be a complicated process.
>
> Given the fact that system B has not been running for some time, ideally
> it would simply replicate to the current data on system A.  After
> replication is reestablished the systems are set up to "Always keep
> directories in sync".  If anyone can confirm the behavior that will occur
> upon replication on these two systems it would be greatly appreciated.
>
> Thanks in advance,
>
> Herb
>
>
>  ------------------------------
>>
>> Message: 2
>> Date: Thu, 22 Mar 2012 10:40:34 -0400
>> From: Chun Tat David Chu <beyonddc.storage at gmail.com>
>> To: "General discussion list for the 389 Directory server project."
>>        <389-users at lists.fedoraproject.org>
>> Subject: Re: [389-users] Repair replication
>> Message-ID:
>>        <
>> CANCf8oLYKet99sB_ou4U3CER8U89UgwZhGUBTHekcF9HWNKL9g at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> Hey Herb,
>>
>> You should refer to the Red Hat Directory Server administration guide for
>> detail about setting up replication which you can locate in here.
>> http://docs.redhat.com/docs/en-US/Red_Hat_Directory_Server/
>>
>> >> 1. How can I find out which system(s) is/are master, consumer, hub,
>> etc?
>> You should be able to determine the role of the Directory Server for each
>> system by logging into the LDAP console under
>> "Configuration->Replication".  The role is either "Single Master", "Hub"
>> or
>> "Dedicated Consumer".
>>
>> >> 2. How do I confirm that the systems have the correct credentials for
>> replication? (I am receiving: "Unable to acquire replica: Permission
>> denied.")
>>    a. How can I change the bind dn "cn=replication,cn=config" credentials
>> on each system to ensure replication will work?
>> You can do that on the console as well.  Just navigate down the directory
>> tree and manually reset the password for the replication user account.
>> There's a possibility that your replication user account's password
>> expired.
>>
>> >> 3. I assume that upon repairing replication (apparently it has not been
>> working for several years) the systems will all replicate to the most
>> recent information.  Correct?
>> I think that's the tricky part.  Make sure you backup your directory on
>> all
>> the LDAP first so you have something to roll back.  I *believe* the last
>> step when setting up replication is initializing the directory and that
>> will wipe out directory on the other LDAP.  Someone on the list might  be
>> able to provide a better on this but I am just giving you a heads up that
>> this can be a complicated process.
>>
>> Good luck
>>
>> - David
>>
>> 2012/3/21 Herb Burnswell <herbert.burnswell at gmail.com>
>>
>> > Hi All,
>> >
>> > I'm new to LDAP administration and have been tasked with fixing the
>> system
>> > replication of 4 Linux systems running Fedora Directory Services.  I am
>> > very comfortable working with Linux/Unix but am not experienced with
>> LDAP.
>> > I've been reading the communications from this user group and reading as
>> > much as I can from documentation.  I believe this environment is not too
>> > complex but I am looking for some guidance, any assistance is greatly
>> > appreciated.
>> >
>> > Info:
>> >
>> > OS: Fedora Core 4
>> > LDAP: Fedora Directory Server v 7.1
>> >
>> > First, I know that both the systems and FDS versions are ancient.
>> > However, at this point I need to get the replication working prior to
>> > putting together a migration plan.  I have access to the Directory
>> Manager
>> > console and am comfortable running command line commands as well.
>>  Either
>> > way is fine.
>> >
>> > Questions:
>> >
>> > 1. How can I find out which system(s) is/are master, consumer, hub, etc?
>> >
>> > 2. How do I confirm that the systems have the correct credentials for
>> > replication? (I am receiving: "Unable to acquire replica: Permission
>> > denied.")
>> >     a. How can I change the bind dn "cn=replication,cn=config"
>> credentials
>> > on each system to ensure replication will work?
>> >
>> > 3. I assume that upon repairing replication (apparently it has not been
>> > working for several years) the systems will all replicate to the most
>> > recent information.  Correct?
>> >
>> > Again, any guidance is greatly appreciated.
>> >
>> > Thanks in advance,
>> >
>> > Herb
>> >
>> > --
>> > 389 users mailing list
>> > 389-users at lists.fedoraproject.org
>> > https://admin.fedoraproject.org/mailman/listinfo/389-users
>> >
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