A multi data source is an abstraction around a group of data sources that provides load balancing or failover processing between the data sources associated with the multi data source.

What is the use of datasource in WebLogic?

In WebLogic Server, you configure database connectivity by adding data sources to your WebLogic domain. WebLogic JDBC data sources provide database access and database connection management. Each data source contains a pool of database connections that are created when the data source is created and at server startup.

What is JDBC in WebLogic?

JDBC is a low-level interface, which means that you use it to invoke (or call) SQL commands directly. In addition, JDBC is a base upon which to build higher-level interfaces and tools, such as Java Message Service (JMS) and Enterprise Java Beans (EJBs). Using JDBC Drivers with WebLogic Server.

What is proxy datasource?

datasource-proxy provides simple API to intercept JDBC interactions and allows user to perform own logic before/after query or method executions. The proxy works as a javax. sql. DataSource and takes listeners.

How do I check datasource in WebLogic?

In order to see a Server/State and Test Data Source action listed under Services -> Data Sources -> <your datasource> -> Monitoring (Tab) -> Testing (Tab) , all of the following need to be true: At least one server targeted by the Data Source needs to be running.

What are different types of data sources in WebLogic?

Oracle WebLogic Server provides three types of data sources: Generic Data Sources—Generic data sources and their connection pools provide connection management processes that help keep your system running efficiently. You can set options in the data source to suit your applications and your environment.

What is proxy data source in WebLogic?

In a WebLogic Server Multitenant environment, resources, including data sources, are replicated for each partition. The Proxy data source simplifies the administration of multiple data sources by providing a light-weight mechanism for accessing a data source associated with a partition or tenant.

What is connection pool in WebLogic?

A connection pool is a named group of identical JDBC connections to a database that are created when the connection pool is deployed, either at WebLogic Server startup or dynamically during run time. Your application “borrows” a connection from the pool, uses it, then returns it to the pool by closing it.

What is shrink frequency in WebLogic?

Shrink Frequency

The WebLogic Server periodically shrinks the connection pool to its initial capacity based on usage. – The Shrink Frequency parameter is used to specify the number of seconds to wait before shrinking a connection pool.

How does WebLogic connect to database?

In WebLogic Server, you configure database connectivity through JDBC data sources, either in your WebLogic domain configuration or in your enterprise application. A data source is a Java EE standard method of configuring connectivity to a database. Each WebLogic data source contains a pool of database connections.

What is JNDI name in WebLogic?

JNDI provides a common-denominator interface to many existing naming services, such as LDAP (Lightweight Directory Access Protocol) and DNS (Domain Name System). These naming services maintain a set of bindings, which relate names to objects and provide the ability to look up objects by name.

How do I change data source in WebLogic?

In the Change Center of the Administration Console, click Lock & Edit. In the Domain Structure tree, expand Services > JDBC and select Data Sources. Select the name of the data source that you want to restart and select the Targets tab.

How do I create a non XA datasource in WebLogic?

1) Login to Weblogic server console using http://<hostname>:7001/console. 3) You will view the below screen. 4) In order to enable the ‘New’ button click on the ‘Lock & Edit’ button under ‘Change Center’ on the top left corner. 8) Now you need to add this Data source (jamesxedb) in the DBAdapter connection pool.

What is difference between XA and non-XA datasource?

In terms of datasources, an XA datasource is a data source that can participate in an XA global transaction. A non-XA datasource generally can’t participate in a global transaction (sort of – some people implement what’s called a “last participant” optimization that can let you do this for exactly one non-XA item).

What is XA and non-XA in WebLogic?

An XA transaction involves a coordinating transaction manager, with one or more resources (databases\JMS) all involved in a single global transaction. Non-XA transactions have no transaction coordinator, and a single resource is doing all its transaction work itself (also called local transactions).

What is two phase commit in WebLogic?

WebLogic Server coordinates the transaction using the two-phase commit protocol, which guarantees that all or none of the transaction will be completed.

What is multi phase commit?

A two-phase commit protocol ensures that transactions are uniformly committed or rolled back across multiple database servers. You can use IBM® Informix® database servers with IBM Informix Enterprise Gateway products or transaction managers to manipulate data in non-Informix databases.

What is an XA resource?

The XAResource interface is a Java mapping of the industry standard XA interface based on the X/Open CAE Specification (Distributed Transaction Processing: The XA Specification).

Why is 2PC needed?

2PC ensures that each system accessed by a transaction durably stores its portion of the transaction’s updates before the transaction commits anywhere. 2PC is usually implemented by a transaction manager. The transaction manager tracks which resource managers are accessed by each transaction and runs the 2PC protocol.

Where is 2PC used?

The two-phase commit protocol (2PC) has been used in enterprise software systems for over three decades. It has been an an incredibly impactful protocol for ensuring atomicity and durability of transactions that access data in multiple partitions or shards.

What is 2PC in database?

A two-phase commit is a standardized protocol that ensures that a database commit is implementing in the situation where a commit operation must be broken into two separate parts. In database management, saving data changes is known as a commit and undoing changes is known as a rollback.

Can 2PC fail?

The solution is a protocol called two-phase commit (2PC), which is executed by a module called the transaction manager. The crux of the problem is that a transaction can commit its updates on one database system, but a second database system can fail before the transaction commits there too.

Why is 2 phase commit slow in the cloud?

Two-phase commits are slow by design due to their dependence on the transaction coordinator. This can cause scalability issues, particularly in a microservices-based application and in a roll-back scenario involving many services.

What is 2 phase commit in Oracle?

The Oracle Two Phase Commit

Recovery in a distributed database environment involves ensuring that the entire transaction has completed successfully before issuing a commit to each of the subcomponents in the overall transaction. This can often be a cumbersome chore, and it is the idea behind the two-phase commit.

How is concurrency performed?

Concurrent Execution in DBMS

In a multi-user system, multiple users can access and use the same database at one time, which is known as the concurrent execution of the database. It means that the same database is executed simultaneously on a multi-user system by different users.

What concurrency means?

Definition of concurrent

1 : operating or occurring at the same time. 2a : running parallel. b : convergent specifically : meeting or intersecting in a point.

How do you control concurrency?

Concurrency Control Techniques

  1. (i) enforce isolation among transactions.
  2. (ii) preserve database consistency through consistency preserving execution of transactions.
  3. (iii) resolve read-write and write-read conflicts.