Application Server property settings for a web server plug-in
Use this page to view or change application server settings for a web server plug-in. To view this console page, click Servers > Server Types > WebSphere application servers > server_name, and then, in the Additional Properties section, click Web server plug-in properties.
Server Role
Role this application server is assigned.
Select Primary to add this application server to the list of primary application servers. The plug-in initially attempts to route requests to the application servers on this list.
Select Backup to add this application server to the list of backup application servers. The plug-in does not load balance across the backup application servers. A backup server is only used if a primary server is not available. When the plug-in determines that a backup application server is required, it goes through the list of backup servers, in order, until no servers are left in the list or until a request is successfully sent and a response received from one of the servers on this list.
| Information | Value |
|---|---|
| Default setting | Primary |
Connection timeout
Whether there is a limited amount of time during which the application server maintains a connection with the web server.
This field corresponds to the ConnectTimeout element in the plugin-cfg.xml file.
The setting for this field determines whether the plug-in performs non-blocking connections with the application server. Non-blocking connections are beneficial when the plug-in is unable to contact the destination to determine whether or not the port is available.
If the Use connection timeout setting is not selected, the plug-in performs nonblocking connections with the application server. If the Use connection timeout setting is selected, specify a value in the seconds field:
- If we specify a value greater than 0 in the seconds field, the plug-in waits the specified number for seconds to perform a successful
connection. If a connection does not occur during that time interval, the plug-in marks the server unavailable, and sends the request to another application server in the cluster.
- If we specify a value of 0 in the seconds field, the plug-in performs a blocking connection.
- If we do not specify a value in the seconds field, the plug-in performs a blocking connection where the plug-in sits until the operating system times out, which might be as long as two minutes, depending on the platform, before it marks the server unavailable.
| Information | Value | |
|---|---|---|
| Data type | Integer | |
| Default | Default | 0 for the first application server (server1) of a profile, and 5 for all of the other application servers of a profile. |
Use read/write timeout
Whether there is a time limit for how long the plug-in waits to send a request to or receive a response from the application server.
This field corresponds to the ServerIOTimeout element in the plugin-cfg.xml file.
Select the Use read/write timeout property to set a read/write timeout. When you select this setting, specify the length of time, in seconds that the plug-in waits to send a request or to receive a response. When selecting a value to specify for this field, remember that it might take a couple of minutes for an application server to process a request. Setting the value too low might cause the plug-in to send a false server error response to the client. If the checkbox is not checked, the plug-in uses blocked I/O to write requests to and read responses from the application server until the TCP connection times out.
For transitioning users: The Use read/write timeout setting on the console corresponds to the ServerIOTimeout attribute in the plugin-cfg.xml file. Beginning with Version 8.0, the default value for this setting is different from the default value in previous versions of the product.trns
| Information | Value |
|---|---|
| Data type | Integer |
| Default | 900 seconds |
Use maximum number of connections
Maximum number of pending connections to an Application Server that can be flowing through a web server process at any point in time.
This field corresponds to the ServerMaxConnections element in the plugin-cfg.xml file.
Select the Use maximum number of connections property to set a maximum number of connections. When you select this setting, you, must specify the maximum number of connections that can exist between the web server and the Application Server at any given point in time.
For example, assuming that:
- The application server is fronted by 5 nodes that are running an IHS web server.
- Each node starts 2 processes.
- This property is set to 50.
In this example, the application server could potentially get up to 500 connections. (You take the number of nodes, 5, multiply it by the number of processes, 2, and then multiply that number by the number specified for this property, 50, for a total of 500 connections.
If either zero or -1, there is no limit to the number of pending connections to the Application Servers.
(zos) This attribute is ignored on the z/OS platform. The z/OS controller, working in conjunction with WLM, handles new connections dynamically.
| Information | Value |
|---|---|
| Data type | Integer |
| Default | 0 |
Use extended handshake to check whether application server is running
When selected, the web server plug-in uses an extended handshake to check whether the application server is running.
This field corresponds to the ExtendedHandshake element in the plugin-cfg.xml file.
Select this property if a proxy firewall is between the plug-in and the application server.
The plug-in marks a server as down when the connect() fails. However, when a proxy firewall is in between the plug-in and the application server, the connect() will succeed, even though the back end application server is down. This causes the plug-in to not failover correctly to another application server.
If the plug-in performs some handshaking with the application server to ensure that the application server is started before the plug-in sends a request, the plug-in can failover to another application server if it detects that the application server with which it is attempting to perform a handshake is not available.
By default, this field is not selected. Select this field to use extended handshake to check whether an application server is running.
Send the header "100 Continue" before sending the request content
Whether the web server plug-in sends the header "100 Continue" to the application server before it sends the request content.
This field corresponds to the WaitForContinue element in the plugin-cfg.xml file.
When selected, the web server plug-in sends the header "100 Continue" to the application server before it sends the request content.
By default, this field is not selected. Select this field to enable this function.
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