This modifications allows for narrowing the APITrace very verbose traces, and so to be a viable possibility in some customer sites in production to be able to tackle with complex problems.  Modifications are at three levels:  1) QueueConnectionFactory for client custom programs:  with QCF.setTraceMethodPattern("CONN|QOPE|FGRC.*") QCF.setTraceParameterPattern("HConn|HFile|Options")  This limits tracing to only the three primitives and variations (including FGRC and FGRCN), and optionally limits which parameters are to be traced (HConn allows to see the calls/return themselves)  The jfiletdsp/jfiletacq/jfilelist .java have been modified to show this working when specifying SystemProperties: -DtraceMethodPattern=xxxxx -DtraceParameterPattern=xxxxx  An example of client traces with the following log4j settings:  log4j.logger.com.primeur.spazio=ERROR log4j.logger.com.primeur.spazio.api.Driver=DEBUG  is:  2017-11-29 09:50:43,161 [main ] DEBUG OPEN - [Call]=>OPEN( ) 2017-11-29 09:50:43,162 [main ] DEBUG OPEN - [Ret]<= 0 () 2017-11-29 09:50:43,162 [main ] DEBUG CONN - [Call]=>CONN( QMgrName=(String) "G18N3" 2017-11-29 09:50:43,163 [main ] DEBUG CONN - HConn=(MQHCONN) { value=(Integer) 0 0x0 } 2017-11-29 09:50:43,173 [main ] DEBUG CONN - [Ret]<= 5020 (QMgrName=(String) "G18N3" 2017-11-29 09:50:43,173 [main ] DEBUG CONN - HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 09:50:43,175 [main ] DEBUG DISC - [Call]=>DISC( HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 09:50:43,177 [main ] DEBUG DISC - [Ret]<= 0 (HConn=(MQHCONN) { value=(Integer) 0 0x0 }  which is way shorter than the original TraceApi output.  2) The same level of filtering can be adopted in SpazioRMI server, just add the following in spazio.rmi.properties:  com.primeur.spazio.rmi.server.TraceMethodPattern=CONN|QOPE|FGRC.* com.primeur.spazio.rmi.server.TraceParameterPattern=HConn|HFile|Options  and a possible log4j configuration in spfab.system.properties:  mod-sprmi.enabled=true mod-sprmi.configFile=spazio.rmi.properties  log.override.log4j.logger.com.primeur.spazio.api=INFO, sprmi log.override.log4j.additivity.com.primeur.spazio.api=false  log.override.log4j.logger.com.primeur.spazio.api.Driver=DEBUG, sprmi log.override.log4j.additivity.com.primeur.spazio.api.Driver=false  log.override.log4j.logger.com.primeur.spazio.jms=INFO, sprmi log.override.log4j.additivity.com.primeur.spazio.jms=true  log.override.log4j.logger.com.primeur.spazio.rmi=INFO, sprmi log.override.log4j.additivity.com.primeur.spazio.rmi=true   # SPRMI appender log.override.log4j.appender.sprmi=org.apache.log4j.RollingFileAppender log.override.log4j.appender.sprmi.layout=org.apache.log4j.PatternLayout log.override.log4j.appender.sprmi.layout.ConversionPattern=%d | %-5.5p | %-16.16t | %-32.32c{1} | %X{bundle.id} - %X{bundle.name} - %X{bundle.version} | %m%n log.override.log4j.appender.sprmi.file=${SPFAB_TRACE}/sprmi.trace log.override.log4j.appender.sprmi.append=true log.override.log4j.appender.sprmi.maxFileSize=100MB log.override.log4j.appender.sprmi.maxBackupIndex=10  which produces the following tracing:  2017-11-29 10:02:02,584 | INFO | guration Updater | SpRMIConfigurationExtension | 42 - spfab-core - 1.0.15.017 | Updating server status: enabled=true 2017-11-29 10:02:02,584 | INFO | guration Updater | SpRMIServer | 42 - spfab-core - 1.0.15.017 | start() 2017-11-29 10:02:02,596 | INFO | Thread-17 | RemoteServer | 42 - spfab-core - 1.0.15.017 | Start '/home/pakkio/spazio/spazio/cfg/spazio.rmi.properties' 2017-11-29 10:02:02,609 | INFO | Thread-17 | RemoteServer | 42 - spfab-core - 1.0.15.017 | RMI Registry created at port 1099 2017-11-29 10:02:02,625 | INFO | Thread-17 | RemoteDriverFactory | 106 - spjsrv-7.0.7 - 7.0.24 | Created new driver factory 2017-11-29 10:02:02,626 | INFO | Thread-17 | RemoteServer | 42 - spfab-core - 1.0.15.017 | Binding DriverFactory to 'rmi://127.0.0.1:1099/com/primeur/spazio/rmi/server/DriverFactory' 2017-11-29 10:02:02,691 | INFO | Thread-17 | RemoteServer | 42 - spfab-core - 1.0.15.017 | Spazio/RMI Server started 2017-11-29 10:02:02,692 | INFO | Thread-17 | RemoteServer | 42 - spfab-core - 1.0.15.017 | Spazio/RMI Server - Ver. 7.0.24 2017-11-29 10:02:02,692 | INFO | guration Updater | SpRMIConfigurationExtension | 42 - spfab-core - 1.0.15.017 | RMI server started 2017-11-29 10:02:02,693 | INFO | guration Updater | SpRMIConfigurationExtension | 42 - spfab-core - 1.0.15.017 | RMI server ready 2017-11-29 10:02:27,335 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Call]=>CONN( Options=(Integer) 0 0x0 2017-11-29 10:02:27,335 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Call]=>CONN( HConn=(MQHCONN) { value=(Integer) 0 0x0 } 2017-11-29 10:02:27,343 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Ret]<= 5020 (Options=(Integer) 0 0x0 2017-11-29 10:02:27,344 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Ret]<= 5020 (HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 10:02:27,369 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Call]=>CONN( Options=(Integer) 0 0x0 2017-11-29 10:02:27,369 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Call]=>CONN( HConn=(MQHCONN) { value=(Integer) 0 0x0 } 2017-11-29 10:02:27,378 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Ret]<= 5020 (Options=(Integer) 0 0x0 2017-11-29 10:02:27,378 | DEBUG | pool-7-thread-1 | CONN | 106 - spjsrv-7.0.7 - 7.0.24 | [Ret]<= 5020 (HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 10:02:27,391 | DEBUG | pool-7-thread-1 | QOPE | 106 - spjsrv-7.0.7 - 7.0.24 | [Call]=>QOPE( HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 10:02:27,391 | DEBUG | pool-7-thread-1 | QOPE | 106 - spjsrv-7.0.7 - 7.0.24 | Options=(Integer) 9 0x9 2017-11-29 10:02:27,394 | DEBUG | pool-7-thread-1 | QOPE | 106 - spjsrv-7.0.7 - 7.0.24 | [Ret]<= 0 (HConn=(MQHCONN) { value=(Integer) 2 0x2 } 2017-11-29 10:02:27,394 | DEBUG | pool-7-thread-1 | QOPE | 106 - spjsrv-7.0.7 - 7.0.24 | Options=(Integer) 9 0x9  which is 23 lines instead of the ~1k lines produced by standard tracing. (Or in disk space ~3K vs ~250K) which is ~100 times less.  3) spxp.xxxx.properties now supporting the SpazioConn.TraceApi=true SpazioConn.TraceMethodPattern=xxxx SpazioConn.TraceParameterPattern=yyyyy