Plesk Mirroring / Redundancy - What do others do?

[Mr Fett]

Hi all,

Apologies if this has been asked before - I've searched and searched and all the answers I can find are responses saying that Parallels are working towards a Plesk Redundancy solution but nothing concrete and most posts a few years old.

1) Is there any sort of mirroring, synchronization or redundancy currently available for Plesk?
So far I have avoided using my server for email because without redundancy I'm just too concerned about down time and loss of emails.

2) What are other hostmasters doing with Plesk to ensure service uptime?

Many thanks for any information or suggestions!

Bob

 

[Valeria M]

Well no idea about this, so can't help you. I think you should take help from Google.

 

[Huskynarr]

http://www.odin.com/de/products/plesk-automation/

 

[trialotto]

Bob, @Mr Fett,

1) Is there any sort of mirroring, synchronization or redundancy currently available for Plesk?
So far I have avoided using my server for email because without redundancy I'm just too concerned about down time and loss of emails.

No, there is not.

In fact, mirroring/synchronization/redundancy is more easy to be achieved by using the async command line tool and/or the setup of failover or high-availability clusters.

However, all these measures are not required when desiring a redundant mail server, given the nature of mail servers (i.e. each mail server is retrying delivery of undelivered mail, implying that undelivered mail is not completely lost, it is just delivered later) AND the possibility to use MX records: install a (secondary) mail server on another domain or even another physical server and point a MX record with high priority (for instance, 10) to the primary server, while using a MX record with lower priority (for instance, 20) to point to the secondary mail server.

If the primary mail server is down (it fails, or it is down for maintenance) and a mail is not delivered to the primary mail server (with MX 10), it will go to the secondary mail server (with MX 20) and the secondary mail server will resend the mail to primary mail server, as soon as the primary mail server is up again.

Note that the above is overly simplified, in order to illustrate the possibility to use MX records.

2) What are other hostmasters doing with Plesk to ensure service uptime?

Actually, Plesk is very (very) stable, if standard out-of-the-box installations and corresponding updates/upgrades are used.

In principle, Plesk will not fail, unless you make some errors in customizations and/or when the network fails.

The "in principle" part still implies that there are some scenario´s in which downtime occurs, such as the scenario´s of CPU/Memory overload (i.e. buy a server with enough capacity) OR of traffic overload (ascertain that enough bandwidth is present) OR of "hack attacks" of various kinds (ascertain that a solid firewall setup is present, use Fail2Ban etc.) and so on.

However, a reasonable amount of downtime is acceptable and even unpreventable.

Even high-availability clusters (with 2 or more mirrored installations) do not get the full 100% service uptime, that everyone would like to see.

In short, keep the Plesk installation clean, safe, secure and well-maintained and most of the worries about service uptime are reduced, at least to an acceptable minimum.

Kind regards.....

 

[Janko1000]

Hi,
is it possible to make a Cronjob for Migrate every Night to second Server?

 

[trialotto]

@Janko1000

Hi,
is it possible to make a Cronjob for Migrate every Night to second Server?

Yes, that is possible: just use the commands given here https://docs.plesk.com/en-US/12.5/c...es/migrate-mass-migration-and-transfer.73526/

Note that one really has to wrap those commands in a decent (and often relatively complex) script, which script should be scheduled as a crontask.

In general, it is not recommended to use "frequent migration" as a tool to mirror data across servers.

In fact, migration is intended as a method to (infrequently) transfer all or almost all data to a target server, which method is associated with many disadvantages.

For instance, using migration tools will also result in the migration of all unchanged data, which can imply that

- data is lost and overwritten,
- too much data is transferred (read: unchanged data is transferred, while there is no need to do so)
- the whole process is time-consuming (read: with a slow backbone, one really will not be able to execute the task overnight)
- the whole process requires a lot of resources

and so on.

Again, for the purpose of mirroring and/or the purpose of transferring unchanged data only, one should really use command line tools like rsync.

Regards......

 

[Janko1000]

Hi,

thanks for Answer.
But Rsync does not Sync the Plesk Settings...

 

[trialotto]

@Janko1000

There is the difference between file data and database data, with the latter including Plesk settings and other Plesk relevant data.

Mirroring regular file data with rsync is a very good option, not the best by the way (it is not real-time mirroring, but rsync will suffice in most common scenario´s).

Mirroring database data simply requires a cluster with a Master/Slave setup: this is possible for almost every normal sql based database server.

The challenge in mirroring databases is the setup of a proper configuration, network infrastructure AND specific Plesk settings (allowing to connect to the cluster).

In most cases, database mirroring is a huge effort and sometimes it is not worthwhile, so be careful when setting up such a structure.

As an easy but costly alternative (to setting up your own cluster), you can consider (cloud based) database providers like ClearDB, who are effectively selling MySQL database clusters.

Regards.....