Configuring the SAP Event Stream Processor WebSocket Provider

Use the wsp.xml configuration file to configure the ESP WebSocket Provider.

SslContextFactory sslContextFactory = new SslContextFactory(); 
//other SSL settings 
//… 
sslContextFactory.setProtocol("TLSv1.2"); 
try { 
sslContextFactory.start(); 
} catch (Exception e) { 
} 

1. Enable the ESP Web Services Providers by setting <webService enabled ="true">.
2. In the <protocol> property, set the protocol for the WebSocket client to which you are connecting the ESP WebSocket Provider.
3. Enable the ESP WebSocket Provider by setting <webSocket enabled="true">.
4. Set properties for the WebSocket Provider within the <webSocket> section:

   Property	Description
   <webSocketPort>	(Required) Specify the port of the WebSocket provider.
   <secured>	(Required) Specify whether to use HTTP or HTTPS as the protocol. If set to true, the protocol is HTTPS.
   <publishSocketLoading>	(Required) Specify the maximum number of remote connections that can publish data over a single connection to ESP.
   <subscribeSocketLoading>	(Required) Specify the maximum number of remote connections that can subscribe to data over a single connection from ESP.

5. (Optional) Edit the cluster information in the <DefaultCluster> section to avoid having to specify full connection details for the cluster each time you send a request. If you do not edit this section, the information for the cluster you created during the installation process is specified by default.
   Note You cannot use a WebSocket request with a fully-specified URI to publish or subscribe to a different cluster than the one specified in the <DefaultCluster> section.

   Property	Description
   <Hostname>	(Required) Specify the name of the host on which the cluster resides.
   <Port>	(Required) Specify the cluster's port number.
   <Workspace>	(Required) Specify the workspace associated with the cluster. The default value is default.
   <Authtype>	(Required) Specify the authentication type.Valid values are user, rsa, and kerberos.
   <SslEnabled>	(Required) Specify whether SSL is enabled. Valid values are true or false.
   <projectLoading>	(Required) Specify the maximum number of socket connections (either publish or subscribe) to ESP to create for each project instance.

6. Edit the thread pool configuration that Jetty uses by editing the values in the <threadPool> section:
   1. In the <minThreads> parameter, specify the minimum number of threads you want Jetty to spawn. The default value is 20.
   2. In the <maxThreads> parameter, specify the maximum number of threads that Jetty may spawn to service incoming connections. The default value is 500.
   3. In the <idleTimeout> parameter, specify the amount of time, in milliseconds, that a threads needs to idle before becoming eligible to be stopped. The default value is 30000.
7. (Optional) To edit advanced publisher options for the WebSocket Provider, set the enabled attribute to true in the <publishOptions> section. For example, <publishOptions enabled="true">.

   Property	Description
   <publishBlockMode>	(Required if the enabled attribute is set to true) When publishing is buffered, use this property to specify the publishing block mode. Valid values are none, explicit, and auto. Explicit lets you control the batches by using start transaction and end block calls, and auto ignores these calls and batches rows internally. The default mode is auto (autoblocking).
   <publishBuffersize>	(Required if the enabled attribute is set to true) Specify a positive number to enable buffered publishing. When publishing is buffered, the data is first written to an internal queue. This is picked up by a publishing thread and then written to theESP project. This is the default operating mode.
   <publishBlockSize>	(Required if the enabled attribute is set to true) This value is only used if the value of <publishBlockMode> is set to explit. Specifies the number of rows inside a message block. Recommended values are 64 to 1024.
   <publishUseTransactions>	(Required if the enabled attribute is set to true) If set to true, the WebSocket Provider uses transaction blocks instead of envelopes. The default value is false.

8. (Optional) To edit advanced subscriber options for the WebSocket Provider, set the enabled attribute to true in the <subscribeOptions> section. For example, <subscribeOptions enabled="true">.

   Property	Description
   <baseDrainTimeout>	(Required if the enabled attribute is set to true) Specify how long, in milliseconds, ESP waits for a subscriber to read all base data. If there are multiple client connections sharing a subscription to ESP, all connections are dropped if the web service client is slow.
   <droppable>	(Required if the enabled attribute is set to true) Specify whether ESP should drop a subscriber that is reading data slowly. If there are multiple client connections sharing a subscription to ESP, all connections are dropped if the web service client is slow
   <queueSize>	(Required if the enabled attribute is set to true) Specify the internal subscription queue size (number of rows) for ESP to create. Larger values result in more rows being buffered internally. Note that though this can help with slower clients, it also increases memory requirements.

9. If you are using HTTPS protocol, specify the keystore type, file, and password in the <Security> section. If you are using HTTP protocol, this section is ignored.
10. (If Kerberos authentication is enabled on the ESP Server) In the %STREAMING_HOME%\wsp\wsp.bat or $STREAMING_HOME/wsp/wsp.sh script, add:

    -Djava.security.krb5.realm=<RealmName> -Djava.security.krb5.kdc=<ServerName>