System::beginObjectTracking Method
Signature beginObjectTracking(fileName: String);
The
The information is recorded in a file on the database server node specified by the fileName parameter.
The recorded information distinguishes between read, lock, create, update, delete, and unlock operations.
This does not necessarily record every time an application uses an object, because if the object resides in the persistent object cache, it may not have to be fetched from the database.
Object tracking is terminated by calling the
The file is a standard text (.txt) file. The first line is a header record and the last line is a trailer record. The lines in-between represent individual object accesses. In each line, fields are separated by spaces.
The format of the three types of records is similar to that used for node sampling files, documented under "Statistics File Format", later in this chapter.
The format of the header record is shown in the following table.
| Field | Description |
|---|---|
| Record type | 21 (object tracking header record) |
| Node instance id | Instance id of the database server node |
| Node type | 1 for the database server, 3 for the application server in single user mode, and 5 for standard client in single user mode |
| Computer name | The name of the machine on which the database server node is running |
| JADE version number | In the format major-release-num.minor-release-num.build-num.patch-num; for example, 7.1.03.3 |
| Current date | Current date in Julian day format |
| Current time | Current time in milliseconds from midnight UTC |
| Current UTC bias | UTC bias for the location in which the database server node is executing, in minutes |
| Current date and time | Text representation of the date and time |
| Clock ticks | Microseconds elapsed since the database server node was started |
The format of the trailer record is shown in the following table.
| Field | Description |
|---|---|
| Record type | 23 (object tracking trailer record) |
| Node instance id | Instance id of the database server node |
| Current date | Current date in Julian day format |
| Current time | Current time in milliseconds from midnight UTC |
| Current date and time | Text representation of the date and time |
| Current UTC bias | UTC bias for the location in which the database server node is executing, in minutes |
| Clock ticks | Microseconds elapsed since the database server node was started |
The format of the data records is shown in the following table.
| Field | Description |
|---|---|
| Record type | 22 (object tracking data record) |
| Node instance id | Instance id of the node from which the access request initiated |
| Process number | The identifying number of the process making the request |
| Clock ticks | Microseconds elapsed since the database server node was started |
| Request type | 1 for get object, 2 for lock object, 3 for unlock object, 20 for create object, 21 for update object, and 22 for delete object |
| Class id | Class id of the object being accessed |
| Instance id | Instance id of the object being accessed |
| Parent class id | Parent class id of the object being accessed |
| Sub level | Sub-level of the object being accessed |
| Sub id | Sub-id of the object being accessed |
| Edition | Edition of the object being accessed |
| Process instance id | Instance id of the process making the request |
| Lock type | The lock type, which is 1 for shared, 2 for reserved, and 3 for exclusive |
| Duration | The lock duration, which is zero (0) for transaction and 1 for session |
| Kind | The lock kind (transaction or session), which is zero (0) for normal and 2 for a node lock |
| Millisecond | The length of time the lock was held |
The following is an example of the data record for the unlocking of a shared lock, transaction duration on object 127.206.5.4.14:2 held by process 187.3 running on node 186.2. The lock was held for at least 15 milliseconds.
22 2 2 169691499 3 127 206 5 4 14 2 3 1 0 0 15
For node locks, the process instance id is that of the background process of the associated node. When a server application unlocks a shared lock on a stable object, the unlock request does not normally appear in the file because only the release of node locks is recorded for stable objects.
The type, duration, kind, and millisecond values are present only for unlock object requests (that is, request type 3).
Only one object tracking session can be active at a time. If the beginObjectTracking method is called when object tracking is already active, exception 1138 (
Use the
