Description:
Enable more logging to see how BW treats persistent connection differently. Use the following lines to enable a persistent connection and change log4j.properties to log more details:

# Enter the the following lines to use persistent connection manager for HTTPS.
#bw.plugin.http.client.usePersistentConnectionManagerForSSL=true
#bw.plugin.http.client.ResponseThreadPool=100
#bw.plugin.http.client.usePersistentConnectionManager=true
#bw.plugin.http.client.maxConnectionsPerHost=100
#bw.plugin.http.client.checkForStaleConnections=true

How to debug and prove the HTTPS persistent connection manager is used and that the BW treats the connection differently.

Enabled the following in "F:\tibco\bw\5.12\lib\log4j.properties":

log4j.logger.org.apache=DEBUG, tibco_bw_log
log4j.logger.httpclient.wire.header=DEBUG, tibco_bw_log

Attached is a zip and properties file (Filename:debugComparationFor_PersistentConnectionManager.zip, log4j.properties) containing the debug file for comparison regarding if persistence is used or not.

The "httpclient.wire.header" will print the HTTP header "close" if persistence is not used. The "org.apache" log will print the lines below if persistence is used :

2015 Oct 19 16:49:42:412 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.HttpMethodBase] BW-EXT-LOG-300002 Resorting to protocol version default close connection policy
2015 ?? 19 16:49:42 CST   Resorting to protocol version default close connection policy
2015 Oct 19 16:49:42:413 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.HttpMethodBase] BW-EXT-LOG-300002 Should NOT close connection, using HTTP/1.1
2015 ?? 19 16:49:42 CST   Should NOT close connection, using HTTP/1.1
2015 Oct 19 16:49:42:413 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.HttpConnection] BW-EXT-LOG-300002 Releasing connection back to connection manager.
2015 ?? 19 16:49:42 CST   Releasing connection back to connection manager.
2015 Oct 19 16:49:42:414 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.MultiThreadedHttpConnectionManager] BW-EXT-LOG-300002 Freeing connection, hostConfig=HostConfiguration[host=https://localhost:9696]
2015 ?? 19 16:49:42 CST   Freeing connection, hostConfig=HostConfiguration[host=https://localhost:9696]
2015 Oct 19 16:49:42:415 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.util.IdleConnectionHandler] BW-EXT-LOG-300002 Adding connection at: 1445244582414
2015 ?? 19 16:49:42 CST   Adding connection at: 1445244582414
2015 Oct 19 16:49:42:425 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.MultiThreadedHttpConnectionManager] BW-EXT-LOG-300002 Notifying no-one, there are no waiting threads
2015 ?? 19 16:49:42 CST   Notifying no-one, there are no waiting threads
2015 Oct 19 16:49:42:427 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.util.IdleConnectionHandler] BW-EXT-LOG-300002 Checking for connections, idleTimeout: 1445244579427
2015 ?? 19 16:49:42 CST   Checking for connections, idleTimeout: 1445244579427
2015 Oct 19 16:49:43:428 GMT +0800 BW.BW513SSL_TLSv1_issueL3 Debug [org.apache.commons.httpclient.util.IdleConnectionHandler] BW-EXT-LOG-300002 Checking for connections, idleTimeout: 1445244580428
2015 ?? 19 16:49:43 CST   Checking for connections, idleTimeout: 1445244580428