Tar MK Cold Standby from an existing instance

[francisco_ribei]

Hi,

I have an existing Tarmk instance with an external datastore.

Now I am trying to have a standby on another machine.

I installed a fresh instance, and added the configuration for the cold standby installation.

But the process get stuck trying to get a segment that doesn't exist on primary.

For this process, do I need to copy the installation from the primary machine?

Is there something that I am missing?

Thanks

[Lokesh_Shivalingaiah · Accepted solution]

Normally, cold standby will be setup during the initial setup. Will check on this usecase.

However, did you try creating a standby instance from the repository of the primary instance and see if you it works fine.

[Kunal_Gaba_]

Yes the better approach is to clone your primary for creating the standby instance and then configure both in cold standby topology. This ensures that the initial synchronization between primary and standby is not time and resource consuming.

If you install a fresh instance then the standby instance will have to synchronize lots of data from the primary which can take lot of time depending on the differences between your primary and fresh standby instance.

Also, if you have binary files to synchronize then make sure to configure the time out settings of the synchronization appropriately depending on the network latency between primary and standby. And notice in the documentation [1] the Tar MK compaction process for standby. There is a difference in the compaction process in standby. 

[1] https://docs.adobe.com/docs/en/aem/6-1/deploy/recommended-deploys/tarmk-cold-standby.html

[francisco_ribei]

Hi @bsloki and @kunal23,

I've setup my primary machine with all the settings we need like: LDAP Connection, FileDataStore, Email Notifications.

Then I'd like to setup a secondary one, I tried both ways using a fresh install and copying the crx-quickstart folder from the primary but in both cases I got the same problem,

When copying the installation folder should I also copy the FileDataStore contents to the secondary machine?

I'll try to set a different timeout to see if it is the problem. I don´t think that´s the problem because in the primary one the error message is that the segment is not found.

Thanks

[francisco_ribei]

That is the error message I am getting on the primary one:

10.12.2015 15:37:31.269 *DEBUG* [nioEventLoopGroup-3-13] org.apache.jackrabbit.oak.plugins.segment.standby.server.StandbyServerHandler waiting for segment. Got exception: Segment 14b8ef13-9b51-4a88-b054-79e45f2424ec not found

[francisco_ribei]

Hi,

I was able to make it work.

This time, I copied the crx-quickstart folder and also the DataStore folder content to the secondary. 

Then I changed the config to make it the secondary one, and now the copy of the files is working.

I have other questions but I´ll ask them in other topics.

Thanks for all your help.