Hi, we want to setup a Multi Master Replication that represents a scenario with several mobile environments which need to replicate with some immobile server from time to time. Is it possible - and reasonable - to group the servers of a mobile environment together to a kind of sub-level MMR which replicates with the higher level MMR of the immobile environment. This replication between the different "levels" would be triggered somehow externally, because there would not always be a (sufficient) connection between them. This would represent some kind of combination of MMR and cascading replication. Is there someone with experience with such kind of scenarios? Thanks, Eugen
On 1 Oct 2020, at 20:27, Eugen Lamers eugen.lamers@br-automation.com wrote:
Hi, we want to setup a Multi Master Replication that represents a scenario with several mobile environments which need to replicate with some immobile server from time to time. Is it possible - and reasonable - to group the servers of a mobile environment together to a kind of sub-level MMR which replicates with the higher level MMR of the immobile environment. This replication between the different "levels" would be triggered somehow externally, because there would not always be a (sufficient) connection between them. This would represent some kind of combination of MMR and cascading replication. Is there someone with experience with such kind of scenarios?
I haven't heard of such a scenario but I'd ask "what are you trying to achieve" rather than commenting on the design too much.
An early issue you will hit is that replication is *push* based, so the "immobile" servers need to be continually updated to know where the "mobile" server is in order to know how to contact it. It's not "pull" based where the moving server could always access the static server.
Additionally, because it's "push" based, the sending server sets the schedule of when to replicate. Certainly, there is a window of validity where a server can be "caugh up" (the changelog max age parameter is how long a server can be disconnected and still replicated to later to "update" it). Again, if this were "pull" based, the mobile server could "choose" when to recieve it's update.
But saying this, I think you have a problem space in mind, and while this may be a solution, knowing more about the challenge you want to solve may help us give better advice about how to configure your topology and potentially the integrating applications.
Thanks,
— Sincerely,
William Brown
Senior Software Engineer, 389 Directory Server SUSE Labs, Australia
On 10/2/20 12:11 AM, William Brown wrote:
On 1 Oct 2020, at 20:27, Eugen Lamers eugen.lamers@br-automation.com wrote:
Hi, we want to setup a Multi Master Replication that represents a scenario with several mobile environments which need to replicate with some immobile server from time to time. Is it possible - and reasonable - to group the servers of a mobile environment together to a kind of sub-level MMR which replicates with the higher level MMR of the immobile environment. This replication between the different "levels" would be triggered somehow externally, because there would not always be a (sufficient) connection between them. This would represent some kind of combination of MMR and cascading replication. Is there someone with experience with such kind of scenarios?
I haven't heard of such a scenario but I'd ask "what are you trying to achieve" rather than commenting on the design too much.
An early issue you will hit is that replication is *push* based, so the "immobile" servers need to be continually updated to know where the "mobile" server is in order to know how to contact it. It's not "pull" based where the moving server could always access the static server.
Additionally, because it's "push" based, the sending server sets the schedule of when to replicate. Certainly, there is a window of validity where a server can be "caugh up" (the changelog max age parameter is how long a server can be disconnected and still replicated to later to "update" it). Again, if this were "pull" based, the mobile server could "choose" when to recieve it's update.
But saying this, I think you have a problem space in mind, and while this may be a solution, knowing more about the challenge you want to solve may help us give better advice about how to configure your topology and potentially the integrating applications.
Thanks,
My understanding is that some hosts may get temporary offline (mobile) while others are always online (immobile). Replication can manage with hosts being online-offline. With limitations how long the hosts are offline (by default a host should not be offline more than 7 days) and on the update rate if a host an not the capacity (#received updates) to catch up.
regards theirry
— Sincerely,
William Brown
Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users@lists.fedoraproject.org To unsubscribe send an email to 389-users-leave@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject....
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