What is active/active clustering?
Also known as Dual Active Clustering, Active/Active clustering means that independent nodes in a networked server cluster have access to their own replicated database server.
What is an active-active SQL Server?
When the terminology is used correctly this simply means that either all nodes (servers) participating in a Microsoft SQL Server cluster are dedicated to running at least a single SQL instance (Active-Active) or at least one of these nodes is reserved as a standby to accept failover of a SQL instance if one occurs.
What is active-passive failover failover cluster in SQL Server?
Simple two-node, for Active-Passive cluster, only a single SQL Server instance is running. For Active-Active cluster, both SQL Server instances are running on each physical node of the cluster. Generally, we can use one of the following options to identify the active node in a SQL Active-Passive Failover Cluster.
What is the difference between simple two-node and active-passive clusters?
Simple two-node, for Active-Passive cluster, only a single SQL Server instance is running. For Active-Active cluster, both SQL Server instances are running on each physical node of the cluster.
What is the difference between active-active and active/passive cluster in SQL Server?
Like the active-active cluster configuration, an active-passive cluster also consists of at least two nodes. However, as the name "active-passive" implies, not all nodes are going to be active. In the case of two nodes, for example, if the first node is already active, the second node must be passive or on standby.
What is active-active and active/passive cluster?
Introduction. Active/passive clustering is a concept that uses clustering software and special purpose hardware to minimize system downtime. Active/passive clusters are groups of computing resources that are implemented to provide high availability of software and hardware computing services.
How do active/active clusters work?
In an active/active cluster, multiple servers are active and working together to publish and subscribe messages. Universal Messaging clients automatically move from one server to another server in a cluster as required or when specific servers within the cluster become unavailable to the client for any reason.
What is active clustering?
What is Active/Active Clustering? Also known as Dual Active Clustering, Active/Active clustering means that independent nodes in a networked server cluster have access to their own replicated database server.
What is active-active and active standby?
In Active/Standby Configuration, only one node is in active mode while the other is in standby mode. When an issue is identified on the Active system, the standby node will take the place of the active node without any changes on the last state until such time the issue is resolved.
What is a benefit of the active/active cluster implementation?
Advantages of Active-Active Clustering It provides high availability data architecture to annihilate a single point of failure, ensuring the full-time response of mission-critical applications, solutions, systems, and databases. It continuously maintains uptime longer than usual time.
How do you set up active/active clusters?
If a license server needs to be configured on both the nodes of a cluster, then perform the following steps:Navigate to Configuration > Licensing > Configure Server.Select the setting for Entire cluster.Configure the License server IP and preferred network.Click Save Changes.More items...
What is an active-active database?
Active-active databases: Where a database has active nodes that shard data and perform writes to the database. Multi-active databases: Where a database has at least three active nodes, each of which can perform reads and writes for any data in the cluster without generating conflicts.
What are active-active systems?
An active/active system is a network of independent processing nodes, each having access to a common replicated database such that all nodes can participate in a common application. The application network comprises two or more processing nodes connected to a redundant communications network.
What is active active failover cluster?
In an active/active failover configuration, two or more database nodes are clustered together to provide a common service to applications. Unlike active/passive failover configurations, all nodes of an active/active failover configuration are actively processing transactions.
How many nodes are in a cluster?
It's best practice to create clusters with at least three nodes to guarantee reliability and efficiency. Every cluster has one master node, which is a unified endpoint within the cluster, and at least two worker nodes. All of these nodes communicate with each other through a shared network to perform operations.
What is active active load balancing?
In an active-active configuration, the load balancer spreads out the workload's traffic among multiple nodes. Distribution may be equal, called symmetrical distribution, or uneven –asymmetrical -- depending on the computing power of each node or how an administrator prefers for the active-active cluster to behave.
What is active and passive mean?
Active and passive voice FAQs In the active voice, the sentence's subject performs the action on the action's target. In the passive voice, the target of the action is the main focus, and the verb acts upon the subject.
What is active and passive database?
The active database is the one that is currently being used by the clients that have mailboxes in that database. All the transactions for that database are being generated by the server it's on. The passive database is not being used by clients, or generating transactions.
What is the difference between HA and cluster?
GitHub Enterprise Server High Availability Configuration (HA) is a primary/secondary failover configuration that provides redundancy while Clustering provides redundancy and scalability by distributing read and write load across multiple nodes.
Overview of Windows Server Failover Clustering
Windows Server Failover Clustering provides infrastructure features that support the high-availability and disaster recovery scenarios of hosted se...
SQL Server Always on Technologies and WSFC
SQL Server 2017 Always On is a high availability and disaster recovery solution that takes advantage of WSFC. The Always On features provide integr...
WSFC Health Monitoring and Failover
High availability for an Always On solution is accomplished though proactive health monitoring of physical and logical WSFC cluster resources, toge...
Relationship of SQL Server AlwaysOn Components to WSFC
Several layers of relationships exist between SQL Server Always On and WSFC features and components. Always On availability groups are hosted on SQ...
What does "active active" mean in SQL?
Essentially, it means you've not spent your money efficiently (unless this was your intention.) Most organizations end up with Active-Active SQL Server clusters not out of design, but out of circumstance.
What is SQL Server Cluster?
SQL Server clusters are often referred to as either being Active/Active or Active/Passive. When the terminology is used correctly this simply means that either all nodes (servers) participating in a Microsoft SQL Server cluster are dedicated to running at least a single SQL instance (Active-Active) or at least one of these nodes is reserved as ...
What does high availability mean in SQL?
This means that your cluster failover process needs to allow for consistency in hardware between the nodes in your cluster.
Can you install SQL Server after the fact?
Since this set of components is a child of the Database Services product you can not install it after the fact. SQL Server will check for installed components, see that Database Services are already installed, and will then not allow you to install Replication Components afterwards.
Can a clustered server host multiple SQL Server instances?
I think this is the right time to make an important note that has not been discussed to this point: just because a node in a clustered environment is already hosting a SQL instance (acting as an Active node, in other words) does not preclude it from hosting another SQL instance. In fact, the server behaves no differently in this respect as it does in a non-clustered environment. A server can host multiple instances of SQL Server: a single default instance, and multiple additional named instances. Your only limits are the edition of Microsoft SQL Server, and of course, system resources.
What is always on failover cluster?
An Always On Failover Cluster Instance (FCI) is a SQL Server instance that is installed across nodes in a WSFC. This type of instance depends on resources for storage and virtual network name. The storage can use Fibre Channel, iSCSI, FCoE, or SAS for shared disk storage, or use locally attached storage with Storage Spaces Direct (S2D). The virtual network name resource depends on one or more virtual IP addresses, each in a different subnet. The SQL Server service and the SQL Server Agent service are also resources, and both are dependent upon the storage and virtual network name resources.
What is SQL Server Always On?
SQL Server Always On is a high availability and disaster recovery solution that takes advantage of WSFC. The Always On features provide integrated, flexible solutions that increase application availability, provide better returns on hardware investments, and simplify high availability deployment and management.
What is availability group listener?
An availability group listener on the primary replica's node responds to incoming client requests to connect to the virtual network name, and based on attributes in the connection string, it redirects each request to the appropriate SQL Server instance.
What is an AG in SQL Server?
An Always On Availability Group (AG) is a one or more user databases that fail over together. An availability group consists of a primary availability replica and one to four secondary replicas that are maintained through SQL Server log-based data movement for data protection without the need for shared storage. Each replica is hosted by an instance of SQL Server on a different node of the WSFC. The availability group and a corresponding virtual network name are registered as resources in the WSFC cluster.
What happens when a SQL Server instance is re-started?
In the event of a failover, the WSFC service transfers ownership of instance's resources to a designated failover node. The SQL Server instance is then re-started on the failover node, and databases are recovered as usual. At any given moment, only a single node in the cluster can host the FCI and underlying resources.
What is failover clustering?
Windows Server Failover Clustering provides infrastructure features that support the high-availability and disaster recovery scenarios of hosted server applications such as Microsoft SQL Server and Microsoft Exchange. If a cluster node or service fails, the services that were hosted on that node can be automatically or manually transferred to another available node in a process known as failover.
What is cluster resource?
A cluster resource can be owned by only a single node at any point in time. Role. A collection of cluster resources managed as a single cluster object to provide specific functionality. For SQL Server, a role will be either an Always On Availability Group (AG) or Always On Failover Cluster Instance (FCI).
What is Active/Active Clustering?
Also known as Dual Active Clustering, Active/Active clustering means that independent nodes in a networked server cluster have access to their own replicated database server. Essentially, multiple copies of the same application have their own server environment for the purpose of load balancing and redundant backup, which keep applications running at peak performance.
What is an active cluster?
In Active/Active Clustering, a set of companion nodes, a primary and a secondary, function in a relationship with their database. If the primary node fails, then the secondary picks up where it left off, and there are no outages. It handles the traffic until the primary node comes back online and resumes its responsibilities from the secondary node, in a procedure called a failback. Any unissued transactions are held and then resubmitted to the currently active server node during failover and failback so that no duplication occurs and the data is cleanly maintained.
What is an active passive server?
In an Active/Passive scenario, a single server runs on either the primary or secondary node. The server runs on the primary node until a failover occurs, then the single primary server is restarted and relocated to the secondary node. The failback to the primary node is not necessary since the environment is already running on the secondary node. Client connections must then reconnect to the active node and resubmit their transactions when it comes back online in the failover and failback scenarios.
Does a cluster have a quorum?
No Majority: Disk Only: The cluster has quorum if one node is available and in communication with a specific disk in the cluster storage.
How many nodes are in an active passive cluster?
Like the active-active cluster configuration, an active-passive cluster also consists of at least two nodes. However, as the name "active-passive" implies, not all nodes are going to be active. In the case of two nodes, for example, if the first node is already active, the second node must be passive or on standby.
What is HA clustering?
The two most commonly used high availability (HA) clustering configurations are active-active and active-passive. What's the difference between the two? This article gives a straightforward explanation of active-active vs active-passive cluster nodes.
Do disaster recovery clusters need to be redundant?
In order for the disaster recovery cluster to operate seamlessly, we recommend that the two nodes be configured for redundancy. In other words, their individual configurations/settings must be virtually identical.
Is assigning clients to nodes in a cluster arbitrary?
Assigning clients to the nodes in the cluster isn't an arbitrary process. Rather, it's based on which load balancing algorithm is set on the load balancer. So for example, in a "Round Robin" algorithm, the first client to connect is sent to the first server, the second client goes to the second server, the third client goes back to the first server, the fourth client back to the second server, and so on. We'll elaborate more on these algorithms in a future post.
2. Domain Controller Configurations
1. Open Server Manager 2. Local Server --> Manage --> Add Roles & Features 3. Installation Type --> Role Based Installation 4. Select local server - this is a default option 5. Server Roles --> Select - Active Directory Domain Services 6. Install
5. Installation of iScassi Target
As mentioned in very first video and also in image, DC Server / Node will also act as Storage or SAN. We will create 6 drives there as below
6. Installing & Configuring Windows Server 2019 Cluster
As we discussed in very first video, in order to configure SQL Server 2019 Cluster we should first have Windows Server 2019 cluster. This Windows Cluster 2019 will be between gogate-node-1 & gogate-node-2, as Domain Controller node is not required now.
7. SQL Server 2019 Installation - Prerequisite
1. Open "Active Directory Users and Computers" 2. Create AD Group "SQL PRD ADMIN" for all Admins, and give Domain Admin or Local Admin access to this group. 3. Add individual Domain Accounts to "SQL PROD ADMIN". e.g. Add gogates\magogate or gogates\dgogate to group "SQL PRD ADMIN" 4.
Active/Active Or Active/Passive Clustering
- SQL Server clusters are often referred to as either being Active/Active or Active/Passive. When the terminology is used correctly this simply means that either all nodes (servers)participating in a Microsoft SQL Server cluster are dedicated to running at leasta single SQL instance (Active-Active) or at least one of these nodes is reservedas a stand...
Active-Active Clustering Considerations
- When we created our first Microsoft SQL Server 2005 cluster we did so with twonodes; an instance of SQL Server 2005 Enterprise Edition running on each node. This was also a 64-bit environment and had substantial amounts of RAM (though notnearly enough we would come to find out.) There was a terabyte of SAN dedicatedfor the cluster. This was a pricey consumer of s…
Active-Passive Clustering Considerations
- High-Availability technically means that your SQL instances are available foruser consumption of data. I would prefer to refine this definition and statethat the data should not justbe readily available, but also responding touser requests at a rate that are consistent with regular performance benchmarks. This means that your cluster failover process needs to allow for cons…
Further Considerations
- You must understand that no matter which architectural plan is used in your environment,you still end up with only a single instance of your data and the SQL Server objects(logins, Agent jobs, etc.) on your clustered instance. Unlike other formsof high-availability design afforded to the Microsoft SQL Server DBA, clusteringonly provides the means to ensure you are protected from server har…
What Is Active/Active Clustering?
Active/Active vs Active/Passive
- InActive/Active Clustering, a set of companion nodes, a primary and a secondary, function in a relationship with their database. If the primary node fails, then the secondary picks up where it left off, and there are no outages. It handles the traffic until the primary node comes back online and resumes its responsibilities from the secondary node, in a procedure called a failback. Any uniss…
Benefits of Active/Active Clustering
- Secondary servers are already active and waiting to receive connections, so there is no downtime during failover scenario.
- The environment enjoys improved the processing capacity because two server nodes are actively running instead of one waiting Idly as it does in Active/Passive Clustering.
- No extra hardware is needed since both methodologies use multiple server nodes. In Active/…
- Secondary servers are already active and waiting to receive connections, so there is no downtime during failover scenario.
- The environment enjoys improved the processing capacity because two server nodes are actively running instead of one waiting Idly as it does in Active/Passive Clustering.
- No extra hardware is needed since both methodologies use multiple server nodes. In Active/Active they are utilized to fit the strategy.
- It’s easy to expand capacity as traffic increases. The network staff can easily add new nodes as necessary.
