How to achieve synchronization in DB update when application is running on multiple nodes?
java,database,multithreading,synchronization,high-availability
It depends on the RDMS you are using if it is Transnational or not and the level of Isolation. According to Wikipedia, Transactions in a database environment have two main purposes: 1- To provide reliable units of work that allow correct recovery from failures and keep a database consistent even...
Google Cloud Bigtable Durability/Availability Guarantees
high-availability,google-cloud-platform,google-cloud-bigtable
On replication: The answer you referenced is referring to replication of data across Bigtable Clusters, which is not supported at this time. (For example, a Bigtable Cluster in the United States replicating its writes to a second Cluster in Europe) This concept is separate from replication of data within a...
Shared IP in CoreOS
cluster-computing,docker,high-availability,coreos,hipache
There are a few different methods of taking care of this. If you're using a cloud provider (EC2 / OpenStack / Google Compute Engine) there is the concept of a floating IP which can be moved via an API call. This gets rid of having to use things like VRRP...
Load Balancer with Healt Check for JBoss 7.1 or Apache
java,apache,jboss7.x,load-balancing,high-availability
The answer is mod_cluster. Currently 1.3.1.Final. loadbalancing with load calculated on the worker nodes High-Availablity in conjunction with worker clustering before the worker is contacted, either AJP cping/cpong logic takes place or OPTIONS method is sent (in case of HTTP(S)) in order to assert worker's availability seamless failover sticky sessions...
Two node ZooKeeper ensemble
java,deployment,zookeeper,high-availability
No. In case of Zookeeper 2 nodes is not enough. Even if one of your nodes went out, the remaining one couldn't tell if it was down or just partitioned. This would cause inconsistency, a split brain scenario, because both of them would continue serving their clients. I am not...
High Availability Error “An error occurred while receiving data: '10054(An existing connection was forcibly closed by the remote host.)'.”
high-availability,sql-server-2014
I found it. my problem was installed same instance name.
Using couchbase as memcache in a cluster configuration
python,django,memcached,couchbase,high-availability
A better solution would be to use Couchbase's MOXI server to proxy memcached. You install it on your application server and it will do the connections to the Couchbase cluster for you. In Moxi's configs you want to make sure that you are using at least 3 of the Couchbase...
RabbitMQ clustering and mirror queues behavior behind the scenes
rabbitmq,haproxy,high-availability
Can someone please explain what is going on behind the scenes in a RabbitMQ cluster with multiple nodes and queues in mirrored fashion when publishing to a slave node? This blog outlines exactly what happens. But what happens when I publish to a slave node? Will this node do...
Node.js & Socket.io with High Availibility
node.js,socket.io,high-availability
There is no way to have a webSocket auto fail-over without any interruption to a new server when the one it is currently connected to goes down. The webSockets that were connected to the server that went down will die. That's just how TCP sockets work. Fortunately with socket.io, the...
Upgrade Node.JS web app without restarting
Yes, it's possible with the cluster module. Basically, you will start several slave instances of your app sharing the same port through a master process. The master will distribute incoming connections to the slaves. When you want to restart, the master will, in sequence: stop passing connections to a slave...
Logstash cluster output to Elasticseach cluster without multicast
elasticsearch,multicast,high-availability,logstash,discovery
You could potentially run a separate (non-embedded) Elasticsearch instance within the Logstash container, but configure Elasticsearch not to store data, maybe set these as the master nodes. node.data: false node.master: true You could then add your Zookeeper plugin to all Elasticsearch instances so they form the cluster. Logstash then logs...
LMAX Replicator Design - How to support high availability?
replication,high-availability,disruptor-pattern,lmax,raft
Your intuition is correct about folding the replication and journalling into the Raft component. But, the Raft protocol dictates exactly when things need to be stored on disk. Here are two different ways to look at it. I'm assuming there is no is hefty computation, such as a transaction processing,...
Unable to Form the HA Hadoop cluster in multihomed Network
java,hadoop,hdfs,zookeeper,high-availability
issues.apache.org/jira/browse/HDFS-4210 this could help
Recognize RabbitMQ master node in high-availability cluster
RabbitMQ will take care of that. The idea of HA queues is that you publish and consume from either node, and RabbitMQ will try to keep a consistent state.
For Oracle high availability on Azure Is Oracle Data Guard sufficient or is Active Data Guard (or Golden Gate) needed?
oracle,azure,high-availability,dataguard
Oracle Active Data Guard is a licensed option introduced in version 11g. With Oracle Data Guard, you will have the same functionality in terms high availability. Switchover and failover will work the same way. So the answer is yes. ...
Frame works for distributed scheduling task queue for a high scale
rabbitmq,akka,scalability,high-availability,task-queue
If you are worried about the accuracy of the Akka scheduler, once I found myself in the same situation and I will tell you my solution. Maybe there are better practices for this kind of scenario, but this one worked nicely for me. I would appreciate any improvements and suggestions....
corosync-objctl: command not found
member,high-availability,totem
corosync-objctl has been replaced with corosync-cmapctl in Corosync 2.x.x.
Behaviour of SAML when HTTP Server used for high availability
saml,high-availability,httpserver,spring-saml,ibmhttpserver
When deploying same instance of application in a clustered mode behind a load balancer you need to instruct the back-end applications about the public URL on the HTTP server (https://httpserver.com/myapp/) which they are deployed behind. You can do this using the SAMLContextProviderLB (see more in the manual). But you seem...
How to configure ha-jdbc with sql server 2008
sql-server-2008,jdbc,high-availability
com.microsoft.sqlserver.jdbc.SQLServerDataSource worked for me.
Cluster node fails to start
neo4j,installation,cluster-computing,high-availability
A cluster needs to have at least 3 instances since a master election requires a quorum (more than half). Try to setup a third instance to solve this and amend the 3rd instance to initial_hosts. Be sure to have the 3 instances on the same network or use a vpn...
How do I design an API such that code updates don't cause interruptions?
python,api,design,high-availability
actually there is no silver bullet. you mention two different things. one is availability. it depends on how many nines you want to have in your 9,999... availability. second thing is api change. so: availability: some technologies allows you to do hot changes/deloyments. which means pending requests goes the old...