MSSQL Load Balancer (Moebius)

For the long-term development of. NET programmer, MSSQLServer is no longer familiar, for large traffic, Microsoft itself has not come up with a good solution, we usually rely on third-party solutions (the program is paid): Moebius ( For SQL), this thing is still relatively professional, can achieve the database load balancing, read and write separation, dual standby, disaster preparedness, cluster synchronization can also have real-time synchronization and quasi-real-time synchronization.

Moebius Concept

Database clustering technology can effectively integrate and utilize existing IT resources to provide efficient and reliable data services. Moebius®for SQL Server is a comprehensive clustered platform dedicated to the Microsoft SQL Server database that makes it easy for any enterprise to build a database cluster for its business to meet user load balancing, availability, The need for data security and extensibility. Moebius®for SQL Server-based kernel implementation, the core program hosted in the SQL Server kernel, Moebius cluster powerful SQL parsing engine combined with a variety of load balancing policies, can achieve SQL statement-level load balancing; The automatic fault monitoring, virtual IP and failover technology are integrated to meet the requirements of high-availability system construction. When data is replicated, synchronous and asynchronous replication modes are used to realize real-time synchronization of data between multiple servers, ensuring transactional consistency and integrity, and supporting long-distance replication. Moebius The cluster has the characteristics of low bandwidth consumption, high synchronization efficiency, high real-time data, and good data consistency.

Composition of the Moebius cluster

The Moebius cluster platform software consists of 3 parts: Moebius cluster Configuration Manager, Moebius for SQL Server Agent, Moebius Core

Moebius Cluster architecture diagram

VIP will automatically drift through the quorum file when a problem occurs on the server where the VIP is located

Architecture Principles

The load Balancing cluster is composed of a set of independent computer systems, which are connected by a regular network or a private network, the routers converge together, each node cooperates, the common load, and the equilibrium pressure, for the client, the whole cluster can be regarded as a stand-alone server with super high performance.

1. Principle of realization
To realize the load balancing technology of the database, we must first have a control side that can control the connection database. Here, it truncates the direct connection between the database and the program, which is accessed by all programs, and then by the middle tier to access the database. This allows us to control access to a particular database, and then we can take an effective equalization strategy based on the current load of the database to adjust each connection to which database.

2. Realize data synchronization of multi-database
For load balancing, the most important thing is that all server data is synchronized in real time. This is necessary for a cluster, because, if the number is not real-time, out-of-sync, then the user from one server read the data, it is different from the other server read the data, this is not allowed. Therefore, data synchronization of the database must be implemented. In this way, the query can have multiple resources, to achieve a balanced. A more common approach is Moebius for SQL Server clusters, where the Moebius for SQL Server cluster takes the approach of hosting the core program in a database of each machine, called the Moebius for SQL Server middleware, The primary role is to monitor changes in the data in the database and synchronize the changed data to other databases. After the data synchronization is completed, the client will get a response, the synchronization process is completed concurrently, so synchronization to multiple databases and synchronization to a database is basically the same time, and the synchronization process is done in the context of the transaction, to ensure that the data at any time of multiple data consistency. Because of the innovation of Moebius middleware hosting in database, the middleware can not only know the change of data, but also know the SQL statement which causes the data change, and adopt different data synchronization strategy according to the type of SQL statement to ensure the minimization of the data synchronization cost.

3. Advantages and Disadvantages

Advantages:
(1) Strong extensibility: When the system to higher database processing speed, as long as simply increase the database server can be extended.
(2) Maintainability: When a node fails, the system will automatically detect the failure and transfer the application of the fault node to ensure the continuous work of the database.
(3) Security: Because the data will be synchronized on multiple servers, you can achieve the redundancy of the data set, through multiple copies of data to ensure security.

In addition, it successfully put the database into the intranet to better protect the security of the database.
(4) Ease of use: completely transparent to the application, the cluster exposes an IP

Disadvantages:

(1) The load cannot be allocated according to the processing capacity of the Web server.
(2) The Load Balancer (control side) failure can cause the entire database system to be paralyzed.

Second, installation and configuration

The installation of the Moebius is very simple, click on the installation package directly on the server with the SQL Server engine installed, the next step in the installation process (such as).

The configuration environment looks like this:

Third, test results

With a simple test of Moebius, Moebius does realize load balancing, high availability, and secure data for SQL Server.

It is excellent for a domestic company to have a load balancing scheme like Oracle RAC, due to the limited environment, not in the complex environment

Under the test, if it can be in the big Data Environment and multi-machine cluster environment can also be stable operation, it should be considered a good solution.

Attached Moebius Detailed document connection, there is a need to refer to:

Http://wenku.baidu.com/view/383b2f83b9d528ea81c7797d.html?re=view

MSSQL Load Balancer (Moebius)