Hello all,
I am migrating to delta-syncrepl and have a couple questions.
I currently back-up my data.mdb file for restore purposes (using mdb_copy). Now that I am using delta-syncrepl, do I also need to be concerned with the accesslog data.mdb file in the event of a restore?
What is the sync behavior of a consumer if it is configured to use delta-syncrepl and the provider is restored but not the accesslog?(i.e. the accesslog would be new on initial start of slapd after a restore)?
Files in question: /var/lib/ldap/data.mdb /var/lib/ldap/accesslog/data.mdb
Thanks for any input, Paul
paul.jc@yahoo.com schrieb am 08.01.2021 um 01:51 in Nachricht
20210108005133.5262.83926@hypatia.openldap.org:
Hello all,
I am migrating to delta-syncrepl and have a couple questions.
I currently back-up my data.mdb file for restore purposes (using mdb_copy). Now that I am using delta-syncrepl, do I also need to be concerned with the accesslog data.mdb file in the event of a restore?
What is the sync behavior of a consumer if it is configured to use delta-syncrepl and the provider is restored but not the accesslog?(i.e. the accesslog would be new on initial start of slapd after a restore)?
In my understanding accesslog contains changes that should be sent out (i.e. information that is in the provider database already). With an empty accesslog anyn ew changes will be sent out after a restore. Whoever pending changes (before the restore) would be lost. So probably you want to force a resync-after a restore of the provider. When done cleverly, no unneeded changes will happen on the consumer.
Details may depend on the reason WHY yoiu need a restore of the provider.
Files in question: /var/lib/ldap/data.mdb /var/lib/ldap/accesslog/data.mdb
Thanks for any input, Paul
--On Friday, January 8, 2021 12:51 AM +0000 paul.jc@yahoo.com wrote:
Hello all,
I am migrating to delta-syncrepl and have a couple questions.
I currently back-up my data.mdb file for restore purposes (using mdb_copy). Now that I am using delta-syncrepl, do I also need to be concerned with the accesslog data.mdb file in the event of a restore?
What is the sync behavior of a consumer if it is configured to use delta-syncrepl and the provider is restored but not the accesslog?(i.e. the accesslog would be new on initial start of slapd after a restore)?
Files in question: /var/lib/ldap/data.mdb /var/lib/ldap/accesslog/data.mdb
Hi Paul,
The accesslog database is tied to the primary database for a specific point of time. I.e., the only way to generate an accesslog DB export that can be safely restored is if slapd is stopped, and both the primary database and the accesslog database are exported. The main purpose of accesslog DB exports is to be able to audit what happened at a specific point in time if replication issues are encountered. The other purpose would be for when doing a migration from system A to system B in a controlled manner where slapd is stopped as previously noted.
If the provider's primary DB is restored and there is no accesslog DB existing, the provider will generate a new empty accesslog DB, from which point any new changes will be written. If a consumer that is generally in sync with the provider connects, it will do a "mini REFRESH" to ensure it has all changes from the point at which it last received a given change from the provider.
I would note that in an MPR environment, other providers (say B,C,D) would have the changes they received from provider A in their accesslog as long as their DBs haven't been reset, so it provides a mechanism for consumers to stay up to date with where "A" was at prior to its regeneration (as long as B,C,D have not also had their accesslog DBs reset).
Hope that helps!
Regards, Quanah
--
Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: http://www.symas.com
openldap-technical@openldap.org
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paul.jc＠yahoo.com -
Quanah Gibson-Mount -
Ulrich Windl