Overview

This topic contains the following sections:

•	Caching Strategies

•	Components and Deployment

•	Administrator Tasks

•	Programmer Tasks

Caching Strategies

Oracle Tuxedo Distributed Caching (TDC) leverages Oracle Coherence and uses Oracle Tuxedo Caching Server Module (configured in Oracle Tuxedo Java server, which is working as a client of Oracle Coherence). This assures you taking all advantages that Oracle Coherence has for caching.

This feature supports the following caching strategies.

•	Data Caching for Clients and Servers

•	Result Caching for Oracle Tuxedo Services

Data Caching for Clients and Servers

When you enable data caching, you can store data in cache, and clients on other machines can retrieve the data from the cache. This offers you a new way of sharing data between clients and servers, especially sharing data for or from other servers.

This feature provides you

•	High performance

Storing and retrieving through cache is faster and lighter than before.

Oracle Tuxedo also adopts other ways to achieve high performance, such as minimizing local buffer copies (ideally providing some zero copy use cases) and focusing on primarily read intensive operations (for example, make 2:1 read/write ratio or higher).

•	Various buffer types support

This feature supports many Oracle Tuxedo buffer types so that you do not need to manage to match your data with the data types that Oracle Tuxedo supports. The supported Tuxedo buffer types are CARRAY, FML, FML32, MBSTRING, STRING, VIEW, VIEW32, XML, RECORD, X_C_TYPE, X_OCTET, and X_COMMON.

Result Caching for Oracle Tuxedo Services

When you enable result caching, Oracle Tuxedo first reaches the result from the cache entry instead of reaching the backend service; if it fails to reach it or if the cache or cache entry is expired, Oracle Tuxedo reaches the backend service and the result is stored in the cache for Oracle Tuxedo to reach it next time.

This feature provides you

•	High performance

Synchronous services that return results that do not change often are good candidates to have their results cached by Oracle Tuxedo. This can improve performance by reducing network overhead to access the backend service.

Oracle Tuxedo also adopts other ways to achieve high performance, such as minimizing local buffer copies (ideally providing some zero copy use cases) and focusing on primarily read intensive operations (for example, make 2:1 read/write ratio or higher).

•	High availability and scalability

By integrating with Oracle Coherence, Oracle Tuxedo takes advantage of its specialized scalable protocol and its creation of a cluster. A cluster can be seamlessly expanded to add more memory, processing power or both, and can avoid single point of failure as it transparently fails over if a cluster member fails. As a result this feature provides you a highly availability and scalability.

Also, taking advantage of Oracle Coherence, any cache entry can be replicated across two or more machines, and the data processing can be farmed out to where the data is and return results to you. This assures your data to be scalable.

•	Various buffer types support

This feature supports many Oracle Tuxedo buffer types so that you do not need to manage to match your data with the data types that Oracle Tuxedo supports. The supported Tuxedo buffer types are CARRAY, FML, FML32, MBSTRING, STRING, VIEW, VIEW32, XML, RECORD, and X_COMMON.

•	Easy approach

This feature can be transparent for you so you can use it without making any code changes, providing you an easy approach. Oracle Tuxedo encapsulates Oracle Coherence functions in Oracle Tuxedo Caching Server Module (in Oracle Tuxedo Java server container) so that you can just use Oracle Tuxedo Caching Server Module to implement all functions that pertain to this feature.

Components and Deployment

Figure 1‑1 illustrates a typical deployment in an Oracle Tuxedo MP domain to use TDC based on Oracle Coherence.

Figure 1‑1 Oracle Tuxedo Distributed Caching Components and Deployment

As you can see from this figure, TMJAVASVR, where Oracle Tuxedo Caching Server Module is configured, is taken as Oracle Coherence's client (member). You can directly use TMJAVASVR to cache results from multiple machines without worrying about how cluster members located in different machines communicate with each other.

Administrator Tasks

As Oracle Coherence and Oracle Tuxedo Caching Server Module are used, it requires you to configure them both before actually using TDC.

•	Configuring Oracle Coherence

•	Configuring Oracle Tuxedo Caching Server Module

•	Configuring Data Caching for Clients and Servers

•	Configuring Result Caching for Oracle Tuxedo Services

Programmer Tasks

•	Use Oracle Tuxedo Distributed Caching (TDC) Related ATMI APIs

•	Put An Oracle Tuxedo Buffer to Cache

•	Get An Oracle Tuxedo Buffer from Cache

•	Remove Oracle Tuxedo Buffer(s) from Cache