Redis Team has very good documentation on this Core Steps: Setup your new Redis instance as a slave for your current Redis instance. In order to do so you need a different server, or a server that has enough RAM to keep two instances of Redis running at the same time. If you use a … Read more
I used the Raft consensus protocol to replicate my SQLite database. You can find the system here: https://github.com/rqlite/rqlite
I have found this article on the subject: http://www.tenereillo.com/GSLBPageOfShame.htm Basically if you do not require long lasting sticky sessions you can configure your DNS servers to return multiple A records (IP addresses) for your website. Web browsers are smart enough to try all the addresses until they find one that works.
I’ve looked extensively at Zookeeper/Curator, Eureka, etcd, and consul. Zookeeper/Curator and Eureka are in many ways the most polished and easiest to integrate if you are in the Java world. Etcd is pretty cool and very flexible, but It is really just a HA key store so you would have to write a lot of … Read more
Uptime is a slippery thing… If you want to calculate the availability of a service then it is simply amount of time service is available ———————————– x 100 amount of time that has passed If you have a cluster providing the service, then the likelyhood that the service becomes unavailable does down but the availability … Read more
Heartbeat is sort of deprecated and the new “industry standard” will be pacemaker and OpenAIS. They’re very different animals, so be careful to read their roles. Pacemaker is a ‘cluster resource manager’ — the part you asked about in your original question. It can use OpenAIS or Heartbeat as the network layer to manage a … Read more
Assuming your rabbitmq clients can tolerate a dropped connection, you can consider what’s described here. our cluster is behind a VIP. When we want to upgrade a cluster, we spin up an alternate cluster and switch the VIP over to the alternate cluster. Meanwhile, we have tooling that moves messages between clusters. When the ‘master’ … Read more
I like GlusterFS. Actually, I adore GlusterFS. As long as you can give it some dedicated bandwidth everything’s fine. One of the best things about GlusterFS is using it with NFS. One of the surprising things I’ve been working with lately is NFS on Windows 7 and 2k8R2. Here’s what I’d do. Set up 2 … Read more
You can’t, which is why load-balancing has nothing to do with availability.
We recently started researching GlusterFS for our own usage so this question was interesting to me. Gluster uses what are called ‘translators’ on the FUSE client to handle how you store data. There are several types of translators which are outlined here: http://www.gluster.com/community/documentation/index.php/GlusterFS_Translators_v1.3 The one you are asking about specifically is called the Automatic File … Read more