補償服務設定

請利用這個頁面來管理補償服務。補償服務支援補償啟用和記載的伺服器層次配置。

To view this administrative console page, click Servers > Server Types > WebSphere application servers > server_name > [Container Settings] Container services > Compensation service.

「配置」標籤

在伺服器啟動時啟用服務

Specifies whether the application server attempts to start the compensation service when the server next starts up.

Default Selected
Range
Selected
When the application server starts, it attempts to start the compensation service automatically.
Cleared
The server does not try to start the compensation service. If compensation is used in applications that run on this server, the system administrator must start the service manually or select this property and then restart the server.
回復日誌目錄

指定目錄路徑,如果設定,其會置換補償服務用來儲存這個伺服器之回復日誌檔的位置。

A blank value in the server configuration is expanded by the compensation service at startup as the directory profile_root/recoveryLogs/cell_name/node_name/server_name/compensation. The variable profile_root is the home directory for the WebSphere Application Server profile used for the server.

When compensation is used, the WebSphere product stores information that is needed to perform compensation after a system failure on a physical storage device. In a higher application load, this persistence slows down performance of the application server because the application server is dependent on the operating system and the underlying storage systems.

To achieve better performance, move the compensation log files to a storage device with more physical disk drives, or preferably Redundant Array of Independent Disks (RAID) disk drives. When the log files are moved to the file systems on the RAID disks, the task of writing data to the physical media is shared across the multiple disk drives. This sharing provides more concurrent access to make compensation information persistent and provides faster access to that data from the logs. Depending upon the design of the application and storage subsystem, typical performance gains can be 10% to 100% or greater.

This change applies only to the configuration where the application has compensation configured. Consider setting this property when the application server shows one or more of following signs:

  • CPU use remains low despite an increase in requests that can be compensated
  • Transactions fail with several time outs
  • The server stops and needs to be restarted
  • The disk on which the server is running shows higher use
Data type String
Default profile_root/recoveryLogs/cell_name/node_name/server_name/compensation

Where profile_root is the home directory for the WebSphere Application Server profile used for the server.

Recommended Create a file system with at least 3 to 4 disk drives grouped together in a RAID-0 configuration. Create the compensation log on this file system with the default size. When the server is running under load, check the disk input and output. If the disk input and output time is more then 5%, consider adding more physical disks to lower the value. If the disk input and output is low, but the server load is still high, consider increasing the size of the log files.
回復日誌檔大小

指定補償服務用來回復資料的回復日誌檔大小上限 (MB)。 預設值是 5 MB。

The amount of data logged by the compensation service is influenced by the number of concurrently-active applications that use compensation, and the size of the application data that is provided as input to the compensation logic.

The compensation service reserves space on a physical storage device at server start for compensation recovery data. If this size is not enough for active compensation data, the log files grow dynamically until they reach the maximum size that this value specifies.

Data type Integer
Units Megabytes
Default 5
Range 1 through 2147483647 megabytes

Although the allowed range for Recovery Log File Size is 1 through 2147483647, the maximum size that is actually possible depends on the maximum size allowed by the operating system for a mapped file.

補償處理程式重試限制

指定補償服務重試補償處理常式的次數上限。

This value specifies the number of times that the compensation service calls the CompensationHandler methods compensate() and close(). Each time that the compensation handler is retried, the Compensation handler retry interval doubles.

Set this value to -1 to retry the compensate() and close() methods indefinitely. Set the value to 0 to never retry either method.

Data type Integer
Default -1
Range -1 or above
補償處理程式重試間隔

指定補償服務在重試補償處理常式之前,所等待的時間間隔(秒)。 Each time that the compensation handler is retried, the interval doubles.

The compensation service retries a compensation handler by recalling the CompensationHandler methods compensate() and close() if either throws a RetryCompensationHanderException.

Data type Integer
Units Seconds
Default 30
Range 0 or above



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相關工作
相關參考


檔名: ueac_cmpsettings.html