High availability is an architectural consideration often involving degrees of redundancy to insure availability in case of system or component failure.

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Keepalived - Keep VIP after stop in both nodes

There's any way to keep the last VIP configuration in the case of a daemon stop in all the nodes of Keepalived? Thanks in advance.
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8 views

Scaling and HA LEMP coming from a single server setup

here is the current configuration 1 Server: nginx php-fpm memcached mariadb 10 The project is growing fast and in the midterm we need to scale. When I have to setup multiple machines I want to ...
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11 views

keepalived should vote more relaxed, is raising garp_master_delay and/or advert_int the solution?

Im using keepalived on two machines. The one being the master establishes an ipsec tunnel. Sometimes (once a month or less) the vrrp packet was missed, and the backup takes over, establishes the ipsec ...
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1answer
84 views

Multi-state MySQL master/slave pacemaker resource fails to launch on cluster nodes

Setup I'm setting up an HA cluster for a web application using two physical servers in a Corosync/Pacemaker managed cluster. After finding out I was heading the wrong way, I decided to use ...
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1answer
33 views

Get IP of node running a specific resource when demoting master nodes to slaves

Setup I am setting up a HA cluster for a web application with 2 nodes (2 physical servers): node1 (current master node) node2 (current slave node) Using Corosync & Pacemaker I was able to ...
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0answers
18 views

What is the most straightforward method in linux to replicate data? [closed]

I'm looking into methods by which one might make generic applications on a basic linux server which don't have replication/distribution features themselves, redundant/highly available from the ...
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2answers
26 views

Keepalived heartbeats not being sent/received on EC2 VPC

I'm trying to setup keepalived + HAProxy as a redundant load balancer on an EC2 VPC (yes, I know that ELB is an option). I believe we have things configured correctly, but killing the master server ...
3
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1answer
108 views

Two-node VMware HA cluster - admission control policy?

I normally setup larger clusters than a 2-node cluster with shared storage, but we have built a cluster specifically for hardware based GPU's for a few VMs and thus new hardware and just a 2-node ...
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1answer
26 views

How to make node join the cluster (Pacemaker, Corosync 2 node setup) automatically after disconnection / unplugging?

I have a 2 node cluster running Corosync and Pacemaker. If I physically unplug the network cable on one node, the other one becomes standalone. But when I plug the network cable back in, I want it ...
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1answer
18 views

SQL Server Failover Clustering (4 nodes)

I think I was able to convince my cow-erkers that jamming all the databases on one server is a good idea. So, our setup will be something like this: Production - SQL 2014 Enterprise Standby - SQL ...
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1answer
17 views

SQL Server: One Production server be Failover for other

I'm surely using the wrong terminology, but I have the following: SQL Server A (SAN1) - DB1, DB2, DB3 SQL Server B (SAN2) - DB4, DB5, DB6 It's currently SQL 2008 and we're looking to move to SQL ...
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0answers
21 views

Which will be better for php application: apache cluster, or virtualized cluster

Company where i'm a sysadmin growth a lot last year, and in this year we expect even more. So we need to rebuild the infrastructure. Our PHP CRM works on apache and mysql. Production environment has ...
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2answers
91 views

nginx multiple frontend servers with SSL DNS setup?

I have my backend app server setup and working with a single reverse proxy nginx setup on the west coast. It also does caching. Now I want to include another frontend server in a east coast region ...
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0answers
117 views

Docker Swarm and Consul production setup recommendation

I'd like to set up a production HA Docker Swarm cluster. Docker Swarm needs a Key Value store as a precondition, consul in this case. Now I'm asking what a clever setup would be: Consul should run ...
3
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0answers
103 views

How to Reduce Failover Interval in HAProxy?

I have setup HAProxy and it is working fine. I observed that when one of the node goes down HAProxy detects that immediately, but switch-over / redirect existing traffic to the rest of working nodes ...
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1answer
40 views

How to make Remote Desktop Services Deployment visible in Windows 2012R2 server manager when logging with a different user?

We have an high availability setup for Remote Desktop Services (Windows 2012R2 datacenter edition) all servers are member of "Domain A": 2 Domain controllers : DCA01, DCA02 1 Gateway ...
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1answer
32 views

How do I setup bonding on Centos 6.x for High Availability? [closed]

My server has two Ethernet ports. With Bonding I setup two different IP addresses for both. The hardware is not very new, so I wouldn't expect that the newest versions of these features to work. ...
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0answers
29 views

Linux Heartbeat error

I'm getting the below error while heartbeat is running. I have checked authkey files and they have the same details on both servers. The hostname is also correct. These 2 servers are also on their own ...
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1answer
46 views

Neo4j HA in Azure Iaas VMs and availability set

I am about to setup Neo4j HA on Azure VMs, what is the best arrangement of the VMs in azure availability set to provide HA for Neo4j. I think if i put all the VMs in one availability set there could ...
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0answers
28 views

Neo4j HA scale out scenario

Is it possible or even feasible to start Neo4j HA with one master and add slave in high traffic time with some sort of load balancing? From Neo4j Doc : Neo4j HA requires a quorum in order to ...
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1answer
30 views

One big server or multiple small? [duplicate]

I run an ad network with about 10 million visits per month. It is very likely that this rate will increase to 50 million in the next 6 months. What is the best way wo scale hardware? Currently I am ...
3
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0answers
15 views

Dell switches, LAG config, ports stay lit when device powered off

I have two Dell switches configured in a stack (with stacking cables). I have four ports on each unit in the stack configured in two separate LAGs as follows: Unit 1/P1: LAG1 Unit 1/P2: LAG1 Unit ...
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1answer
52 views

What is the best practice for deploying dev database to live system?

My developers in a project want to have the dev db on dev server synced with live db on live servers, which I think is a bad idea. Despite that, what is the best way to deploy a codebase+db to live? ...
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1answer
112 views

How to set up an automatic failover reverse proxy for two identical Icecast master servers?

I'm trying to do simple everything double with a reverse proxy in the front high availability for an Icecast master streaming server (i.e. I'm not talking about Icecast relays here). So, three VMs: ...
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1answer
25 views

how to prevent Innob db spiking at 97% Disk I/O Utilization

Our database(InnobDb) is spiking at 99% I/O at random times. After the spike it goes down to about 2% until it spikes agian. There are not some "super" queries that are running in these intervals. We ...
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2answers
66 views

server crashes under high load

We are running a setup that has gotten a lot of media attention these days and we expect the traffic to continue. We have 1 haproxy loadbalancer, 3 application servers(2 image, 1 general) and one ...
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1answer
52 views

2 Node Failover Cluster

Hi fellow tech geniuses! I got a task from my boss to build a 2 node Hyper-V failover cluster, that's dead simple right? The problem is that the hardware is already bought. Both servers are ...
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1answer
57 views

IP configuration of cluster application to database server

I need to setup the IP of a cluster of applications servers to connect to a cluster of database servers. For 1 to 1, application server to database server is quite easy, but when comes to a cluster ...
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0answers
43 views

HAProxy failing at random times (backend has no server available!)

I have a CentOS 7.1 (x64) droplet configured to load balance between 2 apache/php servers. I have it working perfectly, but randomly throughout the day it reports the following: haproxy[12947]: ...
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20 views

Minimal Rails server OS for use with High Availability (XenServer)

I have multiple XenServers configured with High Availability. I have multiple simple Rails apps that talk to each other and form a higher purpose. I have a postgresql database. Is there any distro ...
0
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1answer
45 views

Use Azure availability set or deploy to single instances to paired region for HA

Considering that Azure will not roll out an update on paired regions simultaneously during a planned maintenance of virtual machines with single-instance configurations, is it a good strategy to have ...
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1answer
41 views

Looking for Failover Cluster for Scientific Linux and nginx [closed]

here is what I'm trying: two instances of SL7.1 with nginx as reverseproxy no shared filesystem shared resources: virtual IP running nginx service I already tried keepalived and corosync + ...
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52 views

pgpool: ip addresses conflict after master failed

I have two servers with pgpool in master-slave architecture. Virtual IP | | ------------- ------------- ...
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1answer
95 views

Can Azure availability set span 2 regions (Dublin, Amsterdam)

Is it possible for 2 VMs to be provisioned in 2 different regions (West & North Europe) and still keep them in the same availability set? Is region the correct word to refer to the datacenter(s) ...
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1answer
86 views

Xenserver 6.5 High Availability

I'm running xenserver 6.5 and I just configured high availability. I noticed that there is the option for start order. Is there a best practice for start order when it comes to HA? Obviously the more ...
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0answers
127 views

nginx high-availability with corosync and pacemaker

I configured nginx in a failover with corosync and pacemaker. Everything looked until the test of the failover: The VirtualIP is transmitted to the other host, but the resouce reverseproxy fails to ...
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3answers
110 views

AWS Elastic Container Service - Run service in multiple availability zones

I am running long running tasks via ECS. The container instances are spread over multiple availability zones. Is it possible to define in ECS that when having more then 1 instance of a task, each task ...
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1answer
23 views

Negotitate VRRP on a private link between routers (Possible?)

I have a topology similar to this one: R1 and R2 are two physical machines acting as routers. (Running some linux distro with Keepalived) R1 and R2 are connected to one another with a private link. ...
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1answer
36 views

RHEL HA cluster, is it possible to get a notification upon failover

I have configured Linux HA cluster on RHEL 7.1, can i get a notification upon failover or is it possible to start the crashed resource automatically ?
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1answer
221 views

High availability and AWS VPN

I have a question about achieving high availability over an AWS VPN. Context: I have a requirement to establish a site to site VPN connection between my AWS VPC and a big corporate. This VPN link is ...
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0answers
193 views

How to configure Failover IPs for High Availability with Hetzner Online

I have a cluster of 3 Ubuntu nodes running in VMs in the lab and want to take it now to production. Hetzner Online hetzner.de offers some good value dedicated servers, so I rented 3 machines, ...
0
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2answers
153 views

What is the best way to sync 2 identical centos servers in real time

I am operating a centos linux server(A) and I want to create a realtime backup server(B) so whenever server A goes down server B(after the failover kicks in) will take over. I already solved the ...
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1answer
148 views

Icinga2 dependecies of devices on HA

I would like to configure a Host-to-Host dependency on Icinga2, however, one of the Hosts has an HA configuration, so I need the to trigger it only when both HA devices are down. Suppose this ...
3
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1answer
137 views

Distributed mirrored filesystem under FreeBSD

Can someone share their experience in building a distributed mirrored filesystem between multiple FreeBSD machines? I. e. we have two (three, four...) servers and special partition "part1" mounted on ...
3
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1answer
174 views

Can my redundant network setup be made more robust?

With my current design I have a DL380 Gen9 running ESXi. It has redundant NICs cabled to two different switches. Those switches in turn are both cabled to a third switch that allows my workstation to ...
0
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1answer
559 views

Change Xenserver 6.5 Pool Master

I'm looking to change the pool master because my current pool master is having some hardware issues. I've disabled HA and I came across this script to change the pool master to my other server: xe ...
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3answers
62 views

How to design high availability system [closed]

Suppose I have some web applications & also some desktop applications running on a server in production environment. In production environment, even a single minute downtime is not tolerated. ...
2
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0answers
99 views

Loadbalancing and HA with SolrCloud?

I have a LAMP Application running with solr 3.x on one server for several years now. Now I am migrating due to heavy load to a setup with two dedicated machines where all services are loadbalanced via ...
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1answer
149 views

Keepalived failover not working - how to configure master / failover

I have following two server setup running: node1: keepadlived master -> HAProxy -> Apache node2: keepadlived failover -> HAProxy -> Apache The system works perfectly until I shut down keepalived ...
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1answer
73 views

How to configure keepalived - not able to setup VIP

I am trying to setup a comiled keepalived 1.2.19 on ubuntu 14.04 with failover. Somehow the virtual ip never shows up: ip addr show eth0 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 ...