The Object Request Broker (ORB) communications trace, typically referred to as CommTrace, contains the sequence of General InterORB Protocol (GIOP) messages sent and received by the ORB during application execution. It might be necessary to understand the low-level sequence of client-to-server or server-to-server interactions during problem determination. This article uses trace entries from log examples to explain the contents of the log and help you understand the interaction sequence. It focuses only in the GIOP messages and does not discuss in detail additional trace information that appears when intervening with the GIOP-message boundaries.
Location
When ORB tracing is enabled, this information is placed in install_root/logs/trace.
Usage notes
Yes
This file is updated by the administrative function.
You use this file to localize and resolve ORB-related problems.
How to interpret the output
The following sections refer to sample log output found later in this topic.
Following the identifying line entry is a series of items, formatted for convenience, with information extracted from the raw message that identify the endpoints in this particular message interaction. See lines 3-13 in both examples. The formatted items include the following:
Lines 22-41 in the request example illustrate typical service context entries. There are three service contexts in the request message, as shown in line 22. The ID, length of data, and raw data for each service context is printed next. Lines 23-25 show an IBM-proprietary context, as indicated by the ID 0x49424D12. Lines 26-41 show two standard service contexts, identified by ID 0x6 (line 26) and 0x1 (line 39).
Lines 16-32 in the the reply example illustrate two service contexts, one IBM-proprietary (line 17) and one standardized (line 20).
For the definition of the standardized service contexts, see the CORBA specification. Service context 0x1 (CORBA::IOP::CodeSets) is used to publish the character codesets supported by the ORB in order to negotiate and determine the codeset used to transmit character data. Service context 0x6 (CORBA::IOP::SendingContextRunTime) is used by RMI-IIOP to provide the receiving endpoint with the IOR for the SendingContextRuntime object. IBM service context 0x49424D12 is used to publish ORB PartnerVersion information in order to support release-to-release interoperability between sending and receiving ORBs.
Sample Log Entry - GIOP Request
1. OUT GOING: 3. Request Message 4. Date: April 17, 2002 10:00:43 PM CDT 5. Thread Info: P=842115:O=1:CT 6. Local Port: 1243 (0x4DB) 7. Local IP: jdoe.austin.ibm.com/192.168.1.101 8. Remote Port: 1242 (0x4DA) 9. Remote IP: jdoe.austin.ibm.com/192.168.1.101 10. GIOP Version: 1.2 11. Byte order: big endian 12. Fragment to follow: No 13. Message size: 268 (0x10C) -- 15. Request ID: 5 16. Response Flag: WITH_TARGET 17. Target Address: 0 18. Object Key: length = 24 (0x18) 4B4D4249 00000010 BA4D6D34 000E0008 00000000 00000000 21. Operation: _get_value 22. Service Context: length = 3 (0x3) 23. Context ID: 1229081874 (0x49424D12) 24. Context data: length = 8 (0x8) 00000000 13100003 26. Context ID: 6 (0x6) 27. Context data: length = 164 (0xA4) 00000000 00000028 49444C3A 6F6D672E 6F72672F 53656E64 696E6743 6F6E7465 78742F43 6F646542 6173653A 312E3000 00000001 00000000 00000068 00010200 0000000E 3139322E 3136382E 312E3130 310004DC 00000018 4B4D4249 00000010 BA4D6D69 000E0008 00000000 00000000 00000002 00000001 00000018 00000000 00010001 00000001 00010020 00010100 00000000 49424D0A 00000008 00000000 13100003 39. Context ID: 1 (0x1) 40. Context data: length = 12 (0xC) 00000000 00010001 00010100 42. Data Offset: 118 45. 0000: 47494F50 01020000 0000010C 00000005 GIOP............ 46. 0010: 03000000 00000000 00000018 4B4D4249 ............KMBI 47. 0020: [remainder of message body deleted for brevity]
Sample Log Entry - GIOP Reply
1. IN COMING: 3. Reply Message 4. Date: April 17, 2002 10:00:47 PM CDT 5. Thread Info: RT=0:P=842115:O=1:com.ibm.rmi.transport.TCPTransportConnection 5a. remoteHost=192.168.1.101 remotePort=1242 localPort=1243 6. Local Port: 1243 (0x4DB) 7. Local IP: jdoe.austin.ibm.com/192.168.1.101 8. Remote Port: 1242 (0x4DA) 9. Remote IP: jdoe.austin.ibm.com/192.168.1.101 10. GIOP Version: 1.2 11. Byte order: big endian 12. Fragment to follow: No 13. Message size: 208 (0xD0) -- 15. Request ID: 5 16. Service Context: length = 2 (0x2) 17. Context ID: 1229081874 (0x49424D12) 18. Context data: length = 8 (0x8) 00000000 13100003 20. Context ID: 6 (0x6) 21. Context data: length = 164 (0xA4) 00000000 00000028 49444C3A 6F6D672E 6F72672F 53656E64 696E6743 6F6E7465 78742F43 6F646542 6173653A 312E3000 00000001 00000000 00000068 00010200 0000000E 3139322E 3136382E 312E3130 310004DA 00000018 4B4D4249 00000010 BA4D6D34 000E0008 00000001 00000000 00000002 00000001 00000018 00000000 00010001 00000001 00010020 00010100 00000000 49424D0A 00000008 00000000 13100003 33. Reply Status: NO_EXCEPTION 36. 0000: 47494F50 01020001 000000D0 00000005 GIOP............ 37. 0010: 00000000 00000002 49424D12 00000008 ........IBM..... 38. 0020: [remainder of message body deleted for brevity]