Questions tagged [high-availability]
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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Highly available ZFS SAN/NAS with SMB and NFS
I've currently got a storage server running Oracle Solaris Express 11 with 12x1tb disks. It currently provides two functions: 1) Providing a datastore for a small vSphere 4.1 farm over NFS and 2) ...
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Windows Server Appfabric caching and high availability
We are in the process of converting a solution to use Windows Server Appfabric Caching.
We are wondering:
How do you turn on the high availability option? Such that the cache is stored on more than ...
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Exchange 2010 mailbox server role on a secondary dc - what is your opinion
I'm looking at the database availability groups in regards to creating a constant replication of the mailbox database.
Here are three options I'm thinking of (and sorry if I'm wrong with my ...
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Addressing SQL 2008 mirror cluster
Hallo SQL jedis,
I want my database to be always available. So I've set up database mirroring, which is working peachy.
My question though, is how can I consistently address the database? I want ...
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Low cost solution to http loadbalancer single point of failure?
I have many low end atom servers for a startup project, each server have a few public ip addresses (no private network).
I'm currently in the process of making it failsafe. There now is a load ...
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Advantages of MySQL Server Enterprise
We build for a customer a social network site, where we will have on beginning 1 Master and 2 Slave MySQL Server.
I'm not sure if we need to go with the Enterprise or use the GA Version. The only ...
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Exchange 2010 High Availability two sites mx records
I currently have two sites where one is just a spoke that talks back the exchange server at the main site. Luckily I'm finally getting some bandwidth between the two and I'm trying to figure out a ...
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What configuration would allow me to keep my MySQL server(s) updated while keeping the service consistently available?
I have several Centos 5 web hosting servers with local instances of MySQL that I am looking to segment so that all servers connect to a central MySQL instance. These are web applications doing more ...
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DNS Round Robin: Multiple Nameservers VS Multiple A Records?
Note: This is a follow-up to my previous question regarding DNS Failover.
The Goal: to make the client's web browser select the next available server if one is down instantly.
I've read somewhere ...
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High Availability Mysql without virtual IP
I am trying to design a simple high availability system for our production system at the mysql level. From what I have read so far, the best solution is to set up master-master replication. ...
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Can I have a list of software to run a two nodes HA Ubuntu (server) cluster?
This is only for experimental purpose :-) I want to learn how to create a High-Availability Ubuntu (server) cluster. What are the basic software requirements? I heard about Beowoulf, heartbeat and ...
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Varnish & Heartbeat as loadbalancers
Here is the set up I am trying to accomplish
So, what I'm trying to accomplish is: a user goes to 10.0.0.1 it passes it to whichever loadbalancer is managing the requests. I then want varnish ...
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Real HA/FT SAN for VMware?
I'm planning a redundant set-up for VMware. Two locations (about 8-12km distance) are to be connected with dark fibre for SAN connectivity. I am looking for a FC-SAN product that allows transparent ...
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How do cluster file systems avoid race conditions?
How do cluster file systems avoid the myriad of possible race conditions?
I'm trying to get a grip on using a cluster file system in a Master-Master architecture. I'm thinking specifically about ...
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Load balancing Apache on a budget?
I am trying to get my head around the concept of load balancing to ensure availability and redundancy to keep users happy when things go wrong, rather than load balancing for the sake of offering ...
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Replacement command for hb_takeover
I recently installed the latest DRBD on Ubuntu 10.04 and would like to issue a one-step command to test failover to demonstrate to the powers that be the simplicity of failing over. In previous ...
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Heartbeat not taking its resource
So I have heartbeat installed, I followed a config guide where I literally changed the IP's of the guide and it's not working as it should :(.
The reason the eth numbers are obviously different. I ...
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Xen Remus setup
Currently, I'm running the IT for a small organization, and we just purchased a new server to replace our aging Dell poweredge. As the Dell isn't so bad as to be junk, I was hoping to set up Xen on ...
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Biztalk 2009 logshipping with SQL 2008
I am setting up biztalk logshipping for Biztalk 2009 database. Following http://msdn.microsoft.com/en-us/library/aa560961.aspx article, I am doing the following to setup biztalk logshipping on ...
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Datacenter firewall - considering Sonicwall nsa 240, looking for suggestions [closed]
We are looking into putting a hardware firewall into a data center to protect our rack of servers.
We are using the servers for terminal services and we have 2 x 1GB connections to the Internet.
We ...
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SonicWall "gotchas"?
We're looking to move away from PFSense and CARP to a pair of SonicWall NSA 24001 configured in Active/Passive for High Availability.
I've never dealt with SonicWall before, so is there anything I ...
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HA suggestions for geographically separated sites
I have 6 instances of sql server that I need to be highly available by being hosted on two sites (one as principal, one as DR). Transparent automatic failover is required. Most are fairly boring and ...
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Stability, x86 Vs Sparc
Our project are plan to migrate from Sparc to x86, and our HA requirement is 99.99%, previous on Sparc, we assume the hardware stability would like, hardware failure every 4 month or even one year, ...
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What are the differences among Windows Network load balancing ,Hardware load balancing and Failover clustering?
I am new to the IT pro world ,can anyone shine some light on :
What are the differences among Windows Network load balancing ,Hardware load balancing and Failover clustering?
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DRBD Replication failure
A couple of weeks ago I setup a 2 nodes CRM system with one of the resources managed being MySQL over DRBD. Today for maintenance reasons I restarted both nodes but now they can't connect to each ...
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SAN/NAS with high availability?
I have two servers that I plan to use for storage. Each of them has a few SATA disks directly attached. I want the storage to be available even if one of the storage servers is down (preferably the ...
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How to make cronjobs high available?
What would be a good solution to make a failover pair that has multiple cronjobs running avoid running the processes twice?
Either in failover, or by dividing the jobs between them, and of course ...
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How are you supposed to setup UCARP in CentOS?
I have UCARP working but the documentation is confusing and I've found at least 3 different ways suggested in blogs (these are old and don't all seem to work). I currently have ucarp- lines added to /...
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Can I replace a router and DHCP server without disrupting traffic?
I have a device which acts as a router and DHCP server. I'm replacing it, and would like to minimize down time.
If I unplug it, and plug in a different device with the same IP, will all the PCs with ...
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Best solution for High Availability and SSRS on SQL Server 2008 R2?
I have 2 Physical Servers with SQL Server 2008 R2. – SQL Server 1(Active) & SQL Server 2 (Passive)
Web Application is developed using .Net 4.0 Framework.
I want to know the best solution to have ...
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Prevent HAProxy from toggling back from fallback to master
We have Redis master-slave setup, and we want to fallback to the slave once the master failed. But if it has failed it should never toggle back, even if the master is online again.
Is this possible?
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When to use MySQL replication or DRBD for HA on Xen VM?
I'm setting up a database which needs to be needs to provide High Availabilty.
My primary concern is high performance and robustness (I don't want something that will fail fast and badly). The ...
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Avoiding DNS timeouts when a DNSserver fails
We have a small datacenter with about a hundred hosts pointing to 3 internal DNS servers (bind 9). Our problem comes when one of the internal DNS servers becomes unavailable.
At that point all the ...
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My DAG has failed over, but Outlook clients won't connect
My company have two exchange 2010 server(Mail1 & Mail2) with DAG configuration. One day my Mail1 server down and the Mail2 auto take over! My question is now the end user can't access the mail2 ...
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OpenVPN multiple servers on the same subnet, high availability
Hey everyone. Let me start by saying that my Linux experience isn't super awesome but I can usually find my way around things easily.
Over at work we have an OpenVPN setup that's been due for some ...
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High availability open source SQL database solution for Rails application
I'm researching a topic of high availability database for a Rails application. I'm looking for Open Source based solutions.
At the moment our system is running on one application host + one db host, ...
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Exchange 2010 High Avaibility Solution planning architecture
I'm planning to deploy Exchange 2010 in organization. This organization consists of 2 sites.
The plan for 1st location (holding most of the employees) is:
- 2 x Windows Server 2008 R2 Enterprise - ...
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IP migration by filtering
I'm looking for a solution to use virtual IPs between 2 hosts, but in a specific way. I would like to have the addresses bound to both hosts at once, but filtered out on the inactive one (arp ...
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Linux heartbeat: which one becomes master?
Suppose I confiugred 2 machines to be active/passive with the linux heartbeat and pacemaker, then I create a resource group in node1, commit it. If I am correct the configuration will be propagated to ...
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High Availability and Load Balancing with Debian 5.0 (Lenny)
Suppose I have two Debian 5.0 servers and a generic session-based DB-driven website is running on them.
Assume that the two DB instances are already clustered.
Each server has its own internal IP ...
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Firewall that supports HighAvailability and Spanning Tree
I'm looking for a firewall appliance that supports high availability and spanning tree.
I have two ha-cluster nodes and I'd like to protect them with a firewall. To avoid a single point of failure, I'...
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Swapping db's to increase availability during database update
I have a SQL server database with data supplied from a 3rd party. They supply a tool to update the database data weekly. The tool is pretty old and uses ODBC. The update can take several hours. In ...
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High Availability on a Budget using EC2 for Fail-Over?
I am doing some research to determine how to best create a high availability solution for deployment of a rails/mysql web application for the minimum cost.
I've come up with a possibility, and am ...
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Using Windows Network Load Balancing for one IP only?
When configuring NLB, you choose the cluster IP. This removes any other secondary IP addresses for the network adapter.
How can I have one cluster IP shared by NLB while still having multiple ...
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Moving from a single IIS to a webfarm using NLB with minimal downtime?
Say the IP of our website is 1.1.1.1, and we want to set up NLB, is it best to set 1.1.1.1 as the virtual IP - could mess this up and cause downtime...
Better to set the virtual IP as 1.1.1.2, then ...
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Installing two versions of MSSQL on a production server?
We've just provisioned a second dedicated server so we can use database mirroring for high availability.
The existing server uses MSSQL Express 2005. We have MSSQL Web 2008 and want to minimise the ...
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mysql redundancy with mixed storage types
Looking at building redundancy into our system, as we are currently, um, exposed should anything blow up.
We have a large-ish DB (150G), consisting of a mix of innoDB and myISAM table types. We want ...
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How do I implement a transparent high availability database fail-over solution? [closed]
How do I implement a transparent high availability database fail-over solution for my website?
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vSphere HA - Dealing with storage hba/link failure?
I'm looking at putting in a small cluster spanning two locations on the same campus.
The vSphere hosts in each location would have a vSwitch connected to the production LAN, and I'd also be using a ...
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High Availability. HAProxy Nginx application server
Does it make sense to have this architecture where users connect to https://a.com then HAProxy does TCP redirection to one of the servers defined in the cluster, then once that server gets the data (...
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