Questions tagged as ['high-availability']

I am currently examining the possibilities to make our existing server application highly available. The software handles messages that come via UDP resp. some higher level railway-specific protocols.

Is there a way (a framework or similar) to create an abstraction layer that takes care of redundancy and failover? I am thinking of something equivalent to a RAID controller with mirroring, but not  ...

I have configured a 2 node (VMs) cluster with SUSE High Availability Extension.

The cluster doesn't use shared disk. So Stonith is not really required. But the cluster keeps on asking for Stonith.

So what basic stonith can i create ??

I have one machine (centos7) with Apache, PHP, MariaDB and Nginx, Nodejs, MongoDB installed and being used by many different domains.

I'd like to create a working mirror and can't decide between 2 options:

1. rsync static websites, server and config files + mariadb and mongodb replications
2. cluster made of 2 machines with some proxmox or other free technology (topic new for me)

I want both of them to ser ...

I set up a k8s cluster more or less following this guide. So I have three master and control-plane nodes. I use haproxy as load balancer with following config:

#/etc/haproxy/haproxy.cfg
#---------------------------------------------
# Global settings
#---------------------------------------------
global
    log /dev/log local0 
    log /dev/log local1 info
    daemon

#---------------------------- ...

I am configuring a two nodes cluster Active/passive where the resources of one node is up at a time, so I added two resources IP address and service, The problem is that after configuring the cluster I see the service is up on one node and down on the other which is desired and normal. However, after a random period I see that the service becomes up on the other node which is undesirable behavior and is ...

So I am trying to build a firewall with a primary and secondary, High-Availability structure. I have configured each of these 2 VirtualBox VMs in GNS3 to connect to each other (for a SYNC) interface, as well as connection to other switches in their topology. These PFsense VMs have about 6 network interfaces in use. I took the configuration file of a single node firewall and am testing with a secondary V ...

I am setting up a ubuntu linux HA cluster. I referred to (https://ubuntu.com/server/docs/ubuntu-ha-introduction).

I am also reading through the clusterlabs documentation at https://clusterlabs.org/pacemaker/doc/deprecated/en-US/Pacemaker/2.0/html-single/Pacemaker_Explained/index.html#idm46061171183360.

My cluster has two nodes viz. node_A and node_B.

I need to have three resources that I call  ...

i already use rspamd within my mailserver construct. Currently there is only 1 rspamd instance on 1 server. For HA reasons i'd like to change this and add another rspamd server into my mailconstruct.

I've already searched for information on this topic but couldn't really find good information about it.

Within the rspamD wiki i found the following:

The WebUI supports displaying and aggregating statis ...

I've had experience building simple HA clusters with HAProxy and Keepalived on a single network and have a general idea how to do it when I control all the pieces (or in AWS). But here is my question

We have multi site connected over SD-Wan that basically gives each site something like 192.168.1.x , 192.168.2.x.. each behind a fortigate managed by a service.

If i wanted one server to sit on the .1.x ...

I'm looking for an alternative to the safekit software which handle high availability using active/passive redundant servers with real-time replication and failover.

Actually we have 2 distant servers, when the second server detects that the main servers fails it activates a common virtual IP and takeover if the main server restarts then the second server will deactivate the virtual ip and the main se ...

We have a vendor product, which support only relational databases (Oracle and MS SQL). Due to operational efficiency and cost, we are planning to use MS SQL. However, we have a challenge to deploy the product in Active-Active mode in two different AWS regions (East and West). Since (as per my knowledge) AWS RDS MS SQL or IaaS MS SQL always-on availability group doesn't allow multi-region writes. Also, d ...

I’ve two cluster on different region, I want to deploy an app that doesn’t need service.

How can I deploy this app on one cluster and if something goes wrong on this cluster (region offline, cluster not healthy, etc) redeploy app on other cluster ?

There is a way to manage that case ?

Thanks in advance

this is my first time asking a question here, and I was wondering is it possible to have two different ISP public IPs connected to a single system for high availability?

for example, if our ISP 1 became offline the 2nd ISP will be available, just like google and youtube have different Public addresses, I am just at a loss where to config this.

we are currently using fortinet 300D.

I am running a Spectrum Scale filesystem on RHEL8 that is exported via NFSv3. The HA part is done by ctdb using 4 nodes (active-active), following this configuration guide by the samba/ctdb people: https://wiki.samba.org/index.php/Setting_up_CTDB_for_Clustered_NFS.

In the nfs.conf there's a state-directory path for statd which points to a directory on the shared Spectrum Scale filesystem:

state-dir ...

We have a lot of Linux servers (Red Hat Enterprise Linux Server 7.9 running vmware) and most of the services are in containers docker. We want to implement a policy of updating our systems with minimal disruption of services.

What would be the best approach to update the system (patches, security patches and kernel) either to have no downtime or to have the shortest service downtime?
Thank you

I have a problem in Masakari, when I want to create segment for HA based on Masakari document with this command:

openstack segment create

I get this error:

Request requires an ID but none was found

I am setting up a high availability load balancer. I found this tutorial from Digital Ocean which says that two load balancers can share a common floating IP.

https://docs.digitalocean.com/products/networking/floating-ips/#how-to-implement-an-ha-setup

What is this floating IP and how does it work?

Can one set it up by one's self (without using Digital Ocean)

My team has the task to build a plan in case the AZ that has the NFS instance fails. This NFS instance shares files with others machines (NFS clients) in others AZ (we use North of California).

We have to propose ideas. One we have is that, when the NFS instance AZ fails, disconnect it's hard drive and attach it to another instance in another AZ (all this using lambda) but with this we also have  ...

There's two parts to my question:

1. Does it make sense to hook up a dual PSU server to an ATS to speed up failover to the secondary circuit?
2. If yes, does it make sense to use two separate ATSes to mitigate hardware failure of a single ATS?

I've experienced a situation at the application level, specifically the oVirt hypervisor on some server, which appears to cause the service to crash when power is ...

I need to duplicate/mirror the traffic comming to my server.

I mean, I have N backend servers A1 A2 ... An(n>=2) and a nginx as reverse-proxy&load-balancer.

All the traffic comming to Nginx redirect to both Ax and Ay(x!=y) in parallel, if one of the server is down(timeout or 5xx), then the other server's response can be used immediately and return the result to the client.

By mirroring the traffic( ...

I have two instances that can interact using internal IPs (ens192), for ex:

• <server_1_internal>
• <server_2_internal>

When I use ens192 as the interface, keepalived works as expected by assigning.
I checked the communication using

sudo tcpdump -i ens192 vrrp

but the specified virtual IP is added inside ens192, but I want the virtual IP to be added as ens224 (as public IP)

Is there any way  ...

I have an AlwaysOn cluster of SQL Server 2019, containing an Availability Group of 3 replicas in Synchronous mode. According to Microsoft documentation:

3. The secondary replica hardens the log and returns an acknowledgement to the primary replica.
4. On receiving the confirmation from the secondary replica, the primary replica finishes the commit processing and sends a confirmation message to the client.

I have a set of apache 2.4 backend (Ubuntu server) with the same virtualhost and same configurations (the content is accessible through an HTTPS balancer) how could I easily replicate this configuration between all apaches (Ubuntu Server)?

FrontEnd LB (HTTPS) -> backend (HTTP) multiples ubuntu servers LTS apache 2.4

Thanks! , a greeting

I am looking for the simplest way to share a single file in a high availability way between a pair of linux servers. (Version and distribution are unimportant, I'm looking for a generic solution.)

I have two servers, each with their own local disks and NFS shares and other services between them. I have a file that both servers need to access, but nothing other than those servers needs to access ...