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escribed in the Components in general section.
In the development environment, this property must be set to TRUE if you are using live editing to build your component.
"Threading issues and component types" in PowerBuilder Application Techniques
Web DataWindow Code Size
If you do not use a feature such as display formatting, validation rules, or client-side scripting, you can enhance performance by preventing the server component from generating code for the unused feature.
You can also cache client-side methods in JavaScript files to reduce the size of the generated code and increase performance on both the server and the client. Without JavaScript caching, each time a Web DataWindow is rendered in a client browser, JavaScript code for DataWindow methods is generated on the server and downloaded to the client. However, there is no performance gain if the client web browser settings prevent caching.
"Controlling the size of generated code" in PowerBuilder DataWindow Programmer's Guide
Web DataWindow Container
Using a customized component instead of the preinstalled HTML generator component allows you to set properties for your component in Jaguar Manager. Setting properties reduces the number of method calls required to configure the component and can result in improved performance, maintainability, and scalability.
Specifically, you can set the source file and DataWindow object on the server so that the DataWindow object is loaded when the component instance is created, resulting in fewer method calls from server-side scripts in the Web page. You can also improve performance by having your custom component maintain its state.
"Web DataWindow Container component" in PowerBuilder Building Internet and Enterprise Applications
Using a custom server component" in PowerBuilder DataWindow Programmer's Guide
Web Target default behavior
By default, the PSJaguarConnection methods for using a Web DataWindow make several trips to the server. You can set the bOneTrip argument to make one trip to the server instead.
"PSJaguarConnection" in the PowerBuilder Web Target Reference
Section 4: Message Service
This section contains suggestions for the EAServer Message Service.
Category
Performance Considerations
More Information
Message Acknowledgment
To optimize the performance of a JMS application, set REQUIRES_ACKNOWLEDGE to false so the message service will not acknowledge messages.
"Configuring a message queue's properties" in EAServer System Administration Guide
Sharing
SHARED_LISTENER Indicates whether multiple clients can simultaneously receive messages from the queue. When a queue is not shared, only one client at a time can receive messages from it
"Configuring a message queue's properties" in EAServer System Administration Guide
Transactions
REQUIRES_TRANSACTION determines whether JMS publish, send, receive, and onMessage calls can participate in a transaction. If you set this to false, it significantly improves performance throughput for transient message bulk processing
"Configuring a message queue's properties" in EAServer System Administration Guide
Permanent Destinations
To provide permanent destinations for JMS client applications, define message queues and message topics using Jaguar Manager. When you create a permanent destination, you can optimize its configuration properties, which benefits every JMS client application that uses the destination.
"Adding and configuring the message service parts" in EAServer System Administration Guide
Thread Pools
By default, the Reader, Writer and Worker Threads are set to 0.
For high-volume client notification with transient messages, you can improve performance by tuning the number of reader and writer threads if it improves throughput.
For component notification, you can prevent or allow parallel message processing by changing the worker threads setting.
"Configuring the message service" in EAServer System Administration Guide
Section 5: Client Applications
Be sure to follow good coding practices for the language you write the client application in. Additionally, follow these suggestions for clients you plan to use with EAServer.
Category
Performance Considerations
More Information
Client Design Issues
In designing your client, plan to optimize network performance by keeping traffic between the client and components on the server to a minimum. To optimize network performance, plan to:
- Cache property changes in client data structures
- Validate field values on the client
- Update only the rows and columns that have changed
- Group data changes into larger sets with fewer method calls
- Compress large blobs before passing them between server and client. Some free data compression tools are available, including zlib.
"Implementing components and clients" in EAServer Programmer's Guide
http://www.gzip.org/zlib/
PowerObjects article: Jaguar Performance Using ZLIB
Client Timeout
The IdleConnectionTimeout property specifies the amount of time a connection is allowed to sit idle. By default, connections do not timeout. Specifying a finite timeout for your client applications can improve server performance. If many instances of the client run simultaneously, a finite client connection timeout limits the number of server connections that are devoted to idle clients. A finite timeout also allows rebalancing of server load in an application that uses a cluster of servers.
For CORBA-Java clients -- If you specify an idle connection timeout, make sure the garbage collection interval (com.sybase.CORBA.GCInterval) is set to an equal or lesser value
For C++ clients, use the ORBRetryCount and ORBRetryDelay options
"Creating EJB Clients", "Creating Java-CORBA Clients", "Creating C++ Clients" in EAServer Programmer's Guide
Sockets
com.sybase.ejb.socketReuseLimit, com.sybase.CORBA.socketReuseLimit, com.sybase.ORBSocketReuseLimit
Specify the number of times that a network connection may be reused to call methods from one server. The default is 0, which indicates no limit. The default is ideal for short-lived clients. The default may not be appropriate for a long-running client program that calls many methods from servers in a cluster. If sockets are reused indefinitely, the client may build an affinity for servers that it has already connected to rather than randomly distributing its server-side processing load among all the servers in the cluster. In these cases, the property should be tuned to best balance client performance against cluster load distribution. In Sybase testing, settings between 10 and 30 proved to be a good starting point. If the reuse limit is too low, client performance degrades.
"Creating EJB Clients", "Creating Java-CORBA Clients", "Creating ActiveX Clients", "Creating CORBA-C++ Clients" in EAServer Programmer's Guide
CORBA C++ or ActiveX Client
Ensure that IIOP protocol tracing is not turned on via the ORBLogIIOP parameter to ORB_init, or via the JAG_LOGIIOP environment variable.
"Configure and initialize the ORB runtime", or "Initializing the ORB" in EAServer Programmer's Guide
Web Proxies (a.k.a. HTTP-connect-based proxies)
Web proxies can be used to improve network performance, by caching the results of frequently executed Web requests. Web proxies typically act as a gateway for outgoing connections from a group of workstations, and are sometimes used to enhance network security, by restricting and/or logging the protocols and servers used in client connections.
By default, the client ORB attempts to open IIOP connections, then attempts an HTTP-tunnelled connection if plain IIOP fails. Since Web proxy connections require HTTP tunneling, set the following property to true to eliminate the performance overhead of trying plain IIOP connections before trying HTTP-tunnelled IIOP.
CORBA property: com.sybase.CORBA.http
EJB property: com.tunnel.ejb.http 上一页 [1] [2] [3] [4] [5] [6] [7] [8] 下一页
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