Hazelcast cluster with 3 nodes

[karim slaimi]

Hello,

I have installed hazelcast (4.0). I am using it as a tomcat session manager. And also storing some data into IMap. I am using 1 node only.

Now I would like to add more nodes in order to make data replicated in case of 1 node failure.

So I have 2 questions:

1- How many nodes should I use to start having a real cluster. Because it seems a cluster with nodes number less than 3 will not work well. So, is the Hazelcast cluster well working with 2 nodes or 3 nodes required or how many nodes exactly?  

2- Is it possible to make a cluster with 3 nodes (or more) using the free Hazelcast version or is it available with the enterprise version only?

Thank you in advance for your help.

Best 

Karim SLAIMI

[Bence Eros]

Hello Karim,

3 nodes is a recommended minimum.

You can have as many Hazelcast nodes as you need, but if you want to use Management Center to manage and monitor them, then it is license-free only up to 3 nodes.

Kind regards,

--
You received this message because you are subscribed to the Google Groups "Hazelcast" group.
To unsubscribe from this group and stop receiving emails from it, send an email to hazelcast+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/hazelcast/CAHSeLL2Z780ei5qXJYy5%2BRR%2BwNbG%3DkwpfMu5YZ6fAVSOXNxUpA%40mail.gmail.com.

This message contains confidential information and is intended only for the individuals named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message, which arise as a result of e-mail transmission. If verification is required, please request a hard-copy version. -Hazelcast

[Nick Pratt]

1. HZ will run with 1 node, but if you want data redundancy / fault tolerance a minimum of 2 nodes (with 1 backup) is needed.  I believe the recommendation for production usage is 4 nodes (so you can tolerate a failure).  Running with 3 nodes with 2 backups (so every node has a copy of the data) would work, but any failures will leave you data susceptible to another failure.  The more nodes you have the higher the changes of network/disk/psu failure - that's just a purely numeric calculation/fact.

2. You can run as many nodes as you want with the free version.

--