Alfresco Community 5 Share Clustering

Question

I'm seeing a lot of conflicting information on the internet about Alfresco Share clustering . From what I can find, it looks like clustering was removed completely from Alfresco Community in versions 4.2 and above .

I did find some documentation showing that Alfresco One 5 has Share clustering and I noticed that I can enable hazelcast in Alfresco Community 5 but the clustering doesn't work at all.

Is there a way to have more than 1 instance of Alfresco Community 5 behind a load balancer and have proper synchronization/replication/clustering occur between the share instances?

Answer 1

Short answer

There is no cluster and no load balancer support for the Alfresco Community version (I know of). Alfresco removed that feature from the community version starting with 4.2 when they refactored the whole cluster thing.

Long answer

What are you trying to archive?

If scalability is your goal you should focus on the bottlenecks in the Alfresco architecture which will not be solved by clustering / load balancing. I haven't seen a system where Share tier was the bottleneck.

quite the contrary: If load from share against the repository tier is too high you will fall into a timeout and thread escalation since Alfresco follows the "retrying transaction" principle: If errors occur, share will retry - which means: if repositry is answering too slow share will create new requests/threads until the OS reaches kernel or process limits without any result.

So instead you should focus on optimizing the repository tier to become as fast as possible to avoid thread escalations in share (This also can't be achived by clustering):

• transformation --> understand, replace or disable sync transfomation stuff running on repository tier
• search --> understand, optimize tracking and run SOLR on separate host(s), but tracking will rely on the transformation performance of the repository tier
• caching --> use smart reverse proxys to cache Share stuff on client and proxy side to minimize traffic
• very fast/smart storage concepts on db and index tier

If availability is your concern you may get better results by using HA features from virtualisation platforms like VMWare ESX and your support efforts will be a fraction compared to clustered Alfresco.