#high-availability

High-availability systems/servers are any systems capable of working continuously for a long time without any breakdown. These are the systems capable of storing critical and large amount of data and offer higher stability, flexibility, reliability, and speed along with almost zero probability of system failure for the industries generating large amount of data. Rapidly changing BFSI industry is the prime growth driver for these types of servers as this industry executes large number of transaction with large pool of data which is critical for daily functioning of this industry. 

How We Ensure High Availability | Virtuoso QA Blog

Keeping your site up and running is our highest priority. How do we make sure it stays working? Here’s a detailed snapshot of how

Visit here,

https://www.virtuoso.qa/post/high-availability

Handy list of rabbit and pacemaker links

https://www.rabbitmq.com/pacemaker.html

https://www.rabbitmq.com/management-cli.html

http://www.rabbitmq.com/admin-guide.html

https://ask.openstack.org/en/question/83391/rabbitmq-failover-issue-kilo/

https://ask.openstack.org/en/question/78519/cinder-rabbitmq-timeout-problem-with-multiple-rabbit-hosts/

http://docs.openstack.org/ha-guide/intro-ha-concepts.html

http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html/Clusters_from_Scratch/_add_a_resource.html

http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html/Clusters_from_Scratch/_what_is_emphasis_pacemaker_emphasis.html

http://clusterlabs.org/doc/en-US/Pacemaker/1.1/html/Pacemaker_Explained/ap-ocf.html

http://clusterlabs.org/doc/en-US/Pacemaker/1.0/html/Pacemaker_Explained/s-resource-clone.html

http://docs.openstack.org/ha-guide/controller-ha-haproxy.html

https://enekumvenamorublog.wordpress.com/2014/07/21/neutron-pacemaker-for-ha-gives-error/

https://www.youtube.com/watch?v=Ow5rhYTbT34

http://clusterlabs.org/doc/en-US/Pacemaker/1.0/pdf/Clusters_from_Scratch/Pacemaker-1.0-Clusters_from_Scratch-en-US.pdf

We’re working for more than a day to solve this out, until we’ve found how to work around it.

We have Ambari 1.6.1 running HDP 2.1 (quiet old, but this is what our customer has).

Issue: When one tries to enable HA for namenode, the is a nice wizard telling you to do this and that. On step 4 we should do:

hdfs dfsadmin -safemode enter hdfs dfsadmin -saveNamespace

and then wait till the checkpoint…

Fixed: Seeking distributed, fault-tolerant, networked block storage #development #it #dev

Seeking distributed, fault-tolerant, networked block storage

I’m looking for a distributed, fault-tolerant network storage system which exposes block devices (not filesystems) on the clients.

A client’s block device should write simultaneously to several storage nodes

A client’s block device should not fail as long as not all storage nodes backing it went down

The master should automatically…