Calculating the Health Score

For each Managed Server in a cluster, WebLogic Server provides a default health score calculation. The default health score calculation is based on CPU load, heap usage, Work Manager stuck threads count, and data source pending connection request counts. This health score is calculated individually, by each Managed Server, and then returned to the proxy plug-in when requested. For more information on how the health score is calculated in WebLogic Server, see Health Score-Based Intelligent Routing in Administering Server Environments for Oracle WebLogic Server.

WLS proxy plug-ins request the health scores of Managed Servers through the request header X-WebLogic-Request-Server-Health-Score.

WebLogic Server sends the health score of each Managed Server through the predefined response header X-WebLogic-Server-Health-Score.

<Location /sampleApp>
    WLSRequest On
    WebLogicCluster host1:port1,host2:port2,host3:port3
    RoutingAlgorithm Weighted-Least-Connection
    WeightUpdateInterval 7
</Location>

Selecting a Managed Server

In addition to the health score, WLS proxy plug-ins also use the active connection count parameter to select which Managed Server from the cluster to route the request.

The active connection count is stored at the proxy plug-in level. The active connection count represents how many requests from the proxy plug-in side are currently being served by a Managed Server.

WLS proxy plug-ins use the weighted least connection routing algorithm to select the next server from cluster. The algorithm selects the Managed Server with the lowest ratio of active connection count and Managed Server health score. This ensures that Managed Servers with higher capacities receive a proportionally larger share of the workload, while preventing overloading of less capable servers.

Configuring Intelligent Load Balancing

To enable intelligent load balancing, you must configure settings in both the WLS proxy plug-ins and WebLogic Server. If you do not configure intelligent load balancing, the round-robin routing algorithm is used by default.

In the proxy plug-in, set the RoutingAlgorithm directive to Weighted-Least-Connection. For more information, see RoutingAlgorithm.

By default, WLS proxy plug-ins request the health score of a Managed Server in one second intervals, when the request is selected to be served by a Managed Server. To reduce the frequency, configure the WeightUpdateInterval directive.

The following module needs to be loaded.

LoadModule socache_shmcb_module "${PRODUCT_HOME}/modules/mod_socache_shmcb.so"

<Location /sampleApp>
    WLSRequest On
    WebLogicCluster host1:port1,host2:port2,host3:port3
    RoutingAlgorithm Weighted-Least-Connection
    WeightUpdateInterval 7
</Location>

For instructions for configuring WebLogic Server, see Configuring the Health Score in Administering Server Environments for Oracle WebLogic Server.

Support for TLSv1.3 Protocol

WLS proxy plug-ins support the TLSv1.3 protocol.

Use the WebLogicSSLVersion directive to specify the SSL protocol version to be used for communication between the proxy plug-in and Oracle WebLogic Server.

The support for TLSv1.3 protocol includes the following features:

• Support for new TLSv1.3 cipher suites. See WebLogicSSLCiphers.
• Support for certificates signed with the RSASSA-PSS signature algorithm. See Using Certificates Signed with RSASSA-PSS Signature Algorithm.

TLS Ciphers

A few ciphers were deprecated in previous releases and are removed from the list of supported ciphers. If you want to use the deprecated ciphers for a handshake between the web server and the Oracle WebLogic Server, you must explicitly add them to the configuration using the WebLogicSSLCiphers directive. A warning message is generated if any cipher from the deprecated list is used.

• Default list of ciphers for TLSv1.3:
  • TLS_AES_256_GCM_SHA384
  • TLS_AES_128_GCM_SHA256
  • TLS_CHACHA20_POLY1305_SHA256
• Default list of ciphers for TLSv1.2:
  • ECDHE-RSA-AES256-GCM-SHA384
  • ECDHE-RSA-AES128-GCM-SHA256
  • ECDHE-ECDSA-AES256-GCM-SHA384
  • ECDHE-ECDSA-AES128-GCM-SHA256
• Deprecated list of ciphers in 14.1.2.0.0:
  • AES128-GCM-SHA256
  • AES256-GCM-SHA384
  • AES128-SHA256
  • AES256-SHA256
  • AES256-SHA
  • AES128-SHA