I wonder whether there's a way to program a resource DLL for Windows Clusters in Delphi. I want to write a program that observes cluster state changes. Judging from the MSDN API reference, all relevant functions are located in the ClusAPI.h and ResAPI.h headers, but unfortunately it seems as if they haven't been ported yet and HeaderCon...
I have a Cherokee virtual host configured as follows: 1st rule: "Directory /" -> HTTP Reverse Proxy 2nd rule: "Directory /" -> uWSGI I know the second rule is useless because it's never triggered. However, the first rule seldom returns a 504 Gateway Timeout error so I was thinking of failing over the second rule, yet I don't know how...
Hi, I have a question regarding Clustering (session replication/failover) in tomcat 6 using BackupManager. Reason I chose BackupManager, is because it replicates the session to only one other server. I am going to run through the example below to try and explain my question. I have 6 nodes setup in a tomcat 6 cluster with BackupMana...
Cassandra offers controlled consistency like "write to 2 nodes and tell me it's done". Two "master" nodes and some slaves makes system good failover. MongoDB offers replication pairs - simmilar failover force like cassandra? Is there any other database with this form-box functionality? ...
I've noticed that google app engine seems to have a fair amount of downtime where they place the datastore into read-only mode. Frequently this downtime is in the middle of the day. Is this something that is happening only during early development, or is this something that I can expect to be always be occurring? I'm developing an app...
Hi everybody, Redis really seems like a great product with the built in replication and the amazing speed. After testing it out, it feels definitely like the 2010 replacement of memcached. However, since when normally using memcached, a consistent hashing is being used to evenly spread out the data across the servers in a pool. If one ...
I have a php curl script which crawls different websites . The problem is that after a while I think the websites place a kind of temporary ban on my IP and the script is unable to connect to the host anymore(as I'm getting "couldn't connect to host" error) . I would like to set a condition/function to make the script stop for a while (e...
We have a server that uses NHibernate, and we would like to load balance multiple instances of this server. Our database is big, ~100 GB. If we use a distributed second level cache like memcached or sharedcache, are there still potential data integrity issues? And, why doesn't the first level cache need to be distributed? Also, how ...
I have an application that I would like to have support SQL Server Mirroring. However, the architecture is currently such that multiple WCF services and DB connections will be enlisted in a single MSDTC transactions, and Microsoft states that MSDTC is not supported when using Mirroring. Their explanation is not terribly informative: ...
** Before you comment and say this should be on serverfault.com - it IS on serverfault.com and I've only had one comment so far over 48 hours - I desperately need to get this sorted and stackoverflow always has prompt responses, so I thought I'd try my luck here! ** Hi, I have two servers, both with Windows Network Load Balancing insta...
RabbitMQ supports clustering by default, but queues aren't replicated and are bound to the node on which they're created. I'm now looking for ways to make RabbitMQ highly available other than the DRBD solution that they've documented, because it seems like a waste of resources to reserve an entire server that's doing nothing but waiting ...
Hi everybody, We have thought a bit about running a noSQL database for our next project. However, we're not sure about which platform that will give us the best possible availability and has the best built-in replication features/functions to provide this - with the least headache. Right now, Cassandra appears as the best candidate, bu...
Hi everybody, Let's say that we are about to build an web application where high availability is top focus. Our customers are companies, so downtime are equal to loss of revenue for everyone involved. To sum it up, we need to be online at all times to keep everyone happy. So, from a very basic perspective, what techniques should we be...
I would like to setup a free/custom solution to perform failover for VMware ESXi. The setup is as follows: 2x Physical servers each with independent storage. For each physical server there are 2x Win2k8 Enterprise servers. In the case a physical server completely fails, we want the other (for convenience sake we can assign it with a s...
I've currently got heartbeat set up nicely on ubuntu linux server so that if the heartbeat service is not detected (either because the server is down or just the heartbeat service is down) it fallsover to the secondary server as described in a blog post on my site. Having less than 10 reputation I can't post images, so here is a link in...
I need to build Identity server like Microsoft's http://login.live.com. To handle failover I will have multiple web servers nodes. The plan is that all database write operations are done by sending messages to the database server. Database will be mirrored or replicated. The idea is that database subscribes to the write operations but t...
Hello, We're trying to find a way to change the sessionState's sqlConnectionString (in SQLServer mode) at runtime. We're implementing a fail over for our SQL server and we want to catch when the sessionState fails to have access to my SQL server and tell it to fail over to my secondary server and initialize the site-wide fail over at th...
Hi, I'm looking for a bit of advice setting up a SQL cluster to be accessed via an alias. At present, say my cluster is called 'SQLCLUSTER' and I want to set up an alias to redirect to it. Ideally, I'd like any attempt to connect to '(local)' on either of the machines in the cluster to redirect to 'SQLCLUSTER'. I'm using SQL server 200...