Questions tagged [failover]
Failover is the concept of moving services from one host or node to another in order to provide high availability in a computing system.
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What is the best way to simulate split-brain?
I have a Windows failover cluster and would like to test if it works in a split-brain scenario. The cluster consists of virtual machine in hyper-V. How would one go about doing this?
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MySQL Master Slave Asynchronous GTID Replication Failover over ProxySQL with little downtime
This is a production setup and I have to perform a failover from Master A to new potential master B.
MySQL Version is 5.7 and CentOS 7 is the OS.
I have a simple master slave setup with A as Master ...
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Prevent Sql Server sending Failover partner to connecting clients
I have 2 Sql Server 2008R2, enterprise edition servers setup in an asynchronous (High Peformance) mirror setup. There is no witness.
Intermittently I find that a client will attempt to connect to the ...
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It's possible switchover a innodb cluster instance as primary?
If I am in topologyMode Single-Primary, it's possible to switchover the primary instance between machines in the cluster? I did not find anything in the documentation.
Ie: in my lab I have:
topology&...
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Whenever a failover occurs, either manually or automatically Immediately blocking problem occurs
I have a table log_table, and I have two stored procedures: insert_sp for inserting log entries into the table, and update_sp for performing update operations.
I have a SQL Server failover cluster ...
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Can a domain-independent SQL Server Failover Cluster Instance be created
I know that Always on Availability Groups can be set up on a windows server failover cluster without active directory integration.
But can a SQL Server Failover Cluster Instance high availability ...
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Is there support for distributor server failover?
I have done googling for this question. The answer is no. But the answer is on year 2015. How about now? Is the distributor server have failover support capibility?
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How to monitor mysql master - slave replication in windows os and failover in event of failure of master
I have a master and 3 slave all on windows OS.
I need a tool I can use to monitor replication and failover to a slave incase the master is goes down. What tool do you recommend.
I prefer open source ...
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Can I fail back from Node2 to Node1 when my SQL Server database is in recovery?
I recently failed over my SQL Server instance from Node1 to Node2 and noticed below informational message:
Recovery of database 'huge_database' (22) is 24% complete (approximately 399 seconds remain)....
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Promoting MySQL replica to primary during failover
The MySQL primary fails and I'm trying to promote the replica to primary.
Following the official documentation, I've already:
disabled the failed primary server on all load balancers
waited for the ...
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Failover time after SQL Server patch
We have two node Windows Server cluster with installed SQL Server (2019 Standard Edition) Clustered instances on each node
There are 500 active databases
There are no any Availability Groups or any ...
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Is having a backup database system ready for when my database cluster fails a good idea?
We have a MySQL database cluster using NDB with four nodes, two in each datacenter.
The database uptime is very important, it must be up 24x7 and we cannot affort downtime.
Is the following a good ...
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Split brain scenario
We have a 4 node availability group with 3 nodes at primary site and 1 node at the DR. Suppose the Primary site entirely goes down and we have to do a forced failover at the DR.
Now if there is no ...
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Distributed Availability group with witness server for quorum
I have experience in setting up availability group and have used witness server when the nodes are even to achieve quorum.
One of the vendor provided a layout which will have two availability group ...
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What owner node should the quorum drive belong to
Using windows fail over clustering on a two or three node cluster. What owner node should the quorum drive be owned by?
During my fail over testing, i can jump from node 1 to 2 and 2 to 1, but the ...
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How to reliably restore slave to master in MySQL Multi Source Replication?
I have multi source mysql replication setup configured, so I have this big server which act as a slave to other smaller server. The setup looks similar to below.
Everything is working fine— until one ...
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Is it possible to have a failover sql server with same instance name and same database name?
We have an application that is licensed on MS sql server instance name and database name. It is not possible to add a second instance/database. Is it possible to have active mirroring and let the ...
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Should the quorum drive always be at the same node with the SQL Server role in a SQL Server failover cluster environment?
In a SQL Server failover cluster environment, I can move the SQL Server role to node a and the quorum drive at node b. Although it's possible, is this a correct configuration? While I was Googling ...
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How to failover in a database mirroring session when the safety mode is off and no witness
I'm testing SQL Server database mirroring and below is my topology.
node2, principal
node1, mirror
+-------------+--------------------------------------+-----------------+----------------------+-----...
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Multi master with some slaves vs single master with some slaves
I need some advice on architecture.
I have a national database that relies on postgres and some architectural design that involves orchestrating several components, very much similar to the picture ...
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Exception code: 0xc0000374 constant failover
I have two clusters setup for failover.
However, from some time ago, I keep getting error Exception code: 0xc0000374
Then SQL SERVER failover happens.
When failover happens, sometimes the secondary ...
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Using logical replication with PostgreSQL 14 & handling failover and failback
I have PostgreSQL 14 on two Linux servers. There is a database on both servers, let’s say database ‘A‘ in server-1 and database ‘B‘ server-2. I have a software that generates some data, and while I ...
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This operation returned because the timeout period expired - unable to add third node to existing Windows Failover Cluster
I have a Windows failover cluster up and running, with two nodes.
I'm now trying to add a third node:
Add-ClusterNode -Name node3
this unfortunately fails with the following error:
The clustered ...
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Does an asynchronous replica in Always On Availability Group need to be part of windows failover cluster?
I have a Windows failover cluster up and running, with a primary and secondary server.
I have also created an Always On Availability Group with the two servers, with both the primary and the secondary ...
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Failover - azure. Connection string
I've got a primary and secondary database that i've just configured a Failover group.
My question is:
Can existing connection still connect directly to the DB, or do i need to change all connection ...
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Slow Database queries when on Secondary Node of Availability Group
Failover happens almost immediately, but an application connecting to several databases on the server runs WAY slower (Queries return in 4 minutes compared to 30 seconds).
The hardware and software on ...
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Split Brain scenario Always on Availability group
Due to maintenance our primary site will be offline for few hours. I have an availability group where there are 2 nodes at the primary site and one node at the DR Site.
Since the Primary site will be ...
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Why automatic failover does not occur when I turn off SQL Service in SQL Server Failover Cluster Instance?
I faced unusual behavior associated with automatic failover so that automatic failover does not work in the case of turning off SQL Server service. It seems that clustered disks are still remaining ...
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3 Node WFCS - How to automatically FO to DR?
I am planning to implement a two-node Windows Server Failover Cluster (WSFC) for SQL Server Always On Availability Group in our main site, and the third node in our DR site.
All application clients ...
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AG failover successful, but old Primary node thinks its still primary after bringing back online
I am doing some testing on SQL 2017 Availability Groups and have the following setup:
1 SQL Clustered instance on a 2-node WSFC in DC1
1 standalone SQL node in DC2
There is 1 AG, containing 3 DBs, ...
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Procedures to safely perform SQL Server Always On database cluster failover during Updates & Patching?
I need some steps and guidance, to perform the Microsoft Cluster Failover (MSCS 2016) for my SQL Server 2017 Enterprise Edition – Always-On 2x nodes.
This is to perform the Windows Server updates that ...
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Always On Failover Cluster Instances (FCI) on existing SQL Server
I have launched three EC2 Windows_Server-2019_SQL_2019_Standard instances. How can I implement Always On Failover Cluster Instances (FCI) on these existing SQL Servers. I can only find details like ...
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SQL Sever Alwayson - Increase the WSFC failover threshold
Im trying to simulate the Failover in my SQL server 2017 alwayson by stopping and starting the SQL server service.
It worked 2 times, but after that, the failover is not happening, It showing an error ...
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How to organize MongoDB replicaset backup and alerting
I have a running MongoDb replicaset consisting of 2 replicas and 1 master nodes. Recently I noticed that my master gone and automatic failover took action and changed master, however I wasn't aware of ...
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High availability primary does not automatically take secondary role when back online
Setup:
Basic high availability
2 replicas (1 primary, 1 secondary).
DB01 => initial primary.
DB02 => initial secondary
Synchronous commit on both
Both are in synchronized state
There is no ...
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Automatic Failover for Basic Availability Group
This will be my first project with Basic availability group so I thought would check before implementing .
As per Microsoft documentation below it says we will need to have Software assurance for ...
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Why sql service is still running after uninstalling failover cluster instance?
The installation of sql server failover cluster instance didn't go well.
So I decided to remove whatever was installed and reinstall it again.
To to uninstall sql failover cluster instance went ...
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Turning off Secondary Replica in Always on availability group for maintenance
We are planning to turn off the secondary synchronous replica in our always on availability group for few hours for maintenance . Once we are done with the maintenance then we will need to failover ...
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Testing WSFC failover puts secondary replica in RESOLVING mode
I have 2 locations and each has its own WSFC.
Cluster 1: WSFC,Datacenter1, Node1, Node2. Listener1
Cluster 2: WSFC, Datacenter2, Node3, Node4. Listener2
Created an Availability group as EXTERNAL ...
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Windows Failover Cluster/Availability Groups - Issues because all servers of one site where unreachable
we had some issues because of maintenance and hope someone can explain what happened.
Our cluster looks like this:
Site A:
Node A1 (Quorum vote)
Node A2 (Quorum vote)
Node A3 (Quorum vote)
Node A4 (...
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What happens to application in-flight transactions in an SQL Failover Cluster Instance?
In a SQL Server FCI configuration, what happens to transactions that are in flight when the failover event happens? 1. If the transaction is committed just before the server crashes 2. If the ...
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Is there a SQL Server HA Configuration that is similar to Oracle RAC?
Please is there a SQL server High Availability configuration that is similar to Oracle RAC with respect to scalability? In Oracle RAC, in order to avoid overloaded resources, application requests can ...
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Does Postgres CHECKPOINT process affects streaming replication?
Does Postgres CHECKPOINT process affect async streaming replication in any way?
If checkpoint_timeout is increased from 5min (default) to 30min, then CHECKPOINT processes will be triggered less often (...
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DB_CHAINING lost on on planned Availability Group failover for SQL Server 2019 cumulative update
I'm looking for ideas on how to determine a plausible root cause for DB_CHAINNG problems encountered when we recently performed a planned AG failover.
We're using SQL Server 2019 Standard Edition with ...
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Entity Framework Core for SQL Server Failover Basic Availability Groups does not work
I have set up an SQL Server Standard 2019 with Basic Availability Groups on a Windows Failover cluster. It is not like the Always On AG, but more of a limited version of it where DB operations are on ...
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Migrate from Standalone Instance to Failover Node Instance
I am fairly new to the MS SQL and i am currently working on a project at my company. We have a ERP System built on a SQL Server and we want to create a SQL failover node.
The original configuration is ...
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Failover Cluster Manager > Role > SQL Server (Node1 is owner) > Resources (SQL Server & SQL Agent)
I created 2 separate WFC, one for database (SQLClustr) and one for application (APPCluster). Each cluster has 2 nodes plus one disk witness in quorum. I can easily failover by rebooting the one of the ...
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SQL Server Always On AG – Is a Passive Secondary Required for Automatic Failover?
It is my understanding that for automatic failover to occur in an Always On AG environment, the replicas just need to be configured with "automatic failover," "synchronous commit" ...
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Got fatal error 1236 from master when reading data from binary log
I am trying to do a MySQL failover, in some situations I endup with broken replication. Any idea what could be the cause of it ?
Background
Needed to perform a host updates on master host. Hence ...
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What are the available automatic failover solutions for MariaDB Master-Slave replication on Windows Server?
I am setting up a Master-Slave or Master-Master setup in MariaDB on two seperate servers running Windows Server. I also need to configure an automatic failover solution where client read requests gets ...
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