Troubleshooting
Problem
Starting with IBM® WebSphere® 4.0.4, the WebSphere code to prevent "denial of service" attacks might affect some IBM® iSeries® Access for Web functions, such as Copy Files to Server, Copy Data to Table, and Import Client Access Data Transfer.
Resolving The Problem
Starting with IBM® WebSphere® 4.0.4, WebSphere added functionality to help prevent denial of service attacks. This new function might affect the IBM® iSeries® Access for Web Copy Files to Server, Copy Data to Table, and Import Client Access Data Transfer Request functions. The new function limits the amount of data that can be accepted on an HTTP POST. The result is that a 413 Request Entity Too Large error can be returned to the browser for posts involving large amounts of data.
To circumvent this problem, the system administrator must follow the instructions in the WebSphere 4.0.4 (or later) release notes to set a limit that is acceptable for their use. A section of the release notes is included below.
Notes:
| 1 | According to WebSphere development, the Note at the end is not correct. The change must be made only once, and it will be preserved when the plugin-cfg.xml is regenerated. |
| 2 | This also affects WebSphere 5 Base and Express. However, the <ServerCluster> tag should be modified rather than the <ServerGroup>. |
| Servlets and JavaServer Pages (JSP) Files Denial of Service functionality has been added to the WebSphere Application Server HTTP Plugins to limit the amount of Post data that the plugin will accept from a client (browser). The default limit for Post data is 10000000 (10MB) - to adjust the amount, edit the /QIBM/UserData/WebASAdv4/<instance>/config/plugin-cfg.xml file where <instance> is the name of your WebSphere Application Server instance. Add an attribute named PostSizeLimit to the ServerGroup tag to limit the number of bytes of Post data accepted by the WebSphere Plugin. For example, changing: <ServerGroup Name="MY_NODE/Default Server"> to: <ServerGroup Name="MY_NODE/Default Server" PostSizeLimit="30000000"> results in the plugin accepting up to 30 MB of Post data. Note: The change is overwritten each time the plugin-cfg.xml file is regenerated. As a result, each time you regenerate this plugin file, you need to perform this manual step to change the Post size limitation. |
Historical Number
29772646
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Document Information
Modified date:
18 December 2019
UID
nas8N1016621