Re: Help needed: "glued" object.

[Quanah Gibson-Mount <quanah@symas.com>]

--On Wednesday, April 03, 2019 4:36 PM -0300 Alex Hebra 
<hebraalex@gmail.com> wrote:

> Node A:
> # Accesslog database definitions
> database mdb
> suffix cn=accesslog
> directory /var/db/openldap-data/accesslog
> rootdn cn=accesslog
> index default eq
> index entryCSN,objectClass,reqEnd,reqResult,reqStart

Add an index for "reqDN" here as well.

> #####
>
>
> # primary db config
>
> overlay syncprov
> syncprov-checkpoint 100 10
> syncprov-sessionlog 2000000

As I noted in the previous email, you want it slightly larger than the 
total number of entries in the database.  If you have exactly 2 million, 
I'd probably set the session log to something like 2.1 million.


> # accesslog overlay definitions for primary db
> overlay accesslog
> logdb cn=accesslog
> logops writes
> logsuccess TRUE
> # scan the accesslog DB every day, and purge entries older than 7 days
> logpurge 07+00:00 01+00:00

Depending on how busy the system is in regards to write ops, you may want 
to "clean" the accesslog DB more frequently (I generally do 4 hour 
increments).  Otherwise the entire server can pause while the clean 
operation is executed if there is a large amount of data that needs 
deleting.

> # Global section
> serverID 1

I would note that the serverID should technically be one of the first lines 
of the slapd.conf file since it is a global option. I can't really tell 
from your snippets where it appears. ;)

> Node B:
>
>
>
> # Accesslog database definitions
> database mdb
> suffix cn=accesslog
> directory /var/db/openldap-data/accesslog
> rootdn cn=accesslog
> index default eq
> index entryCSN,objectClass,reqEnd,reqResult,reqStart

Same comment as before about reqDN

> syncprov-sessionlog 2000000

Same comment as before about the session log size.

> # scan the accesslog DB every day, and purge entries older than 7 days
> logpurge 07+00:00 01+00:00

Same comment as before as to the frequency of purging.

> # Global section
> serverID 2

Same comment as before about where this should be defined in the slapd.conf 
file


> After that I made a change on Node A and it replicated to node B, then I
> made a change on node B and it replicated to A. So seems it's working. My
> doubt is how can I make sure it's working with delta-sync mode?

If you have "stats" logging enabled, you can tell from the bind/search op 
of the syncrepl client to the other master by looking at the search filter 
and base in use of the default query.

> Another question, changing to delta-sync can I use more than 2 nodes, for
> instance, 3 servers receiving writing and replicating between them?

Delta-syncrepl is valid for N-way MMR, so yes, 3-way MMR is just fine.


One final note -- I don't know what overlays you have in use on your 
servers, nor the order they are instantiated against the primary DB.  This 
was covered in a different thread yesterday, but on the primary DB, it must 
be:

overlay syncprov
<syncprov overlay options>

overlay accesslog
<accesslog overlay options>

overlay WHATEVER
<options>

I.e., syncprov must be the first instantiated overlay, accesslog the second 
instantiated overlay.  All other overlays occurring after them.

Regards,
Quanah

--

Quanah Gibson-Mount
Product Architect
Symas Corporation
Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
<http://www.symas.com>