6.3.4 Details of tuple logs

Tuple logs are log files to which information about input and output tuples is output. A tuple log is output for each stream queue. You can use tuple logs for the following purposes:

For details about re-execution of queries, see 4.3.1 Re-executing queries.

The following figure shows a flow of output and display of tuple logs.

Figure 6-2 Flow of output and display of tuple logs

[Figure]

Organization of this subsection
(1) Outputting tuple logs
(2) Names of tuple logs
(3) Displaying tuple logs

(1) Outputting tuple logs

You specify whether or not tuple logs are to be output by using parameters that begin with tpl. in the files listed below:

For details about each file, see 8. SDP Server Definition Files.

Tuple logs are placed in a tuple buffer provided for each stream queue and then are output to file. The table below describes the tuple log output timing.

Table 6-9 Tuple log output timing

No.Tuple log output timingTuple log that is output to file
1When the specified tpl.bufferSize parameter value is exceededTuple log in the buffer
2When the putEnd method is executed on an input stream queueAll tuple logs in the buffer for the input stream queue
3When the putEnd method is executed on all input stream queues in a query groupAll tuple logs in the buffer for the output stream queue in the query group
4When a query group is terminatedAll tuple logs in the buffers for the stream queues in the query group
5When the SDP server is shut downAll tuple logs in the buffers for the stream queues on the SDP server

Tuple logs are output in the wraparound mode to as many files as the value specified in the tpl.fileCount parameter. The following table describes the timing of switching tuple log files.

Table 6-10 Timing of switching tuple log files

No.Timing of tuple log file switchingTuple log file to be switched
1When the specified tpl.fileSize parameter value is exceededTuple log file that has become full
2When the putEnd method is executed on all input stream queues in a query groupTuple log files for the stream queues in the query group

Tuple logs are not output in the following cases:

(2) Names of tuple logs

The files listed below are output to the tuple log output destination directory. Note that the file access permissions depend on the user permissions used to execute the sdpstart command.

These files are output under the following names:

Tuple log files:

tpl_query-group-name-stream-name_file-serial-number

Backup files of tuple log files:

tpl_query-group-name-stream-name_file-serial-number.bkbackup-generation-number

The following describes each component of the file names:

(3) Displaying tuple logs

You can check the output tuple log information by executing the sdptplls command.

For details about the sdptplls command, see sdptplls (displays tuple information) in 7. Commands.