Where "./path/to/data/file.dat" is the path to the data file, 1.0 is the speedup factor for the data generation, localhost is the name or the IP address of the destination host, and 8080 is the port number on the destination host. One feature of the generator is that it outputs events preserving their relative occurrence time. This means that the input file is replayed at (almost) the same speed at which the original data was recorded. The replay speed can be influenced by modifying the speedup factor. Specifying a value greater than 1.0 implies a replay speed which is higher than the original data rate while specifying a values below 1.0 implies a replay speed lower than the original data rate.
Within this section we describe the queries which are part of the DEBS 2012 Grand Challenge. In our description we assume that all queries operate on the same event schema as defined above. We describe every query using a block data flow diagram with white rectangles representing operators and gray rectangles representing event streams.
The goal of the first query is to monitor the behavior of Chem Additive sensors which themselves are responsible for the monitoring of Chem Additive Release valves - see Figure above. As all input data in this task is boolean the first operation performed by the operators 1 till 6 is to detect the change of state of each input fields (bm05 till bm10) and emit those along with time stamps of the state change occurrence. The second set of operators (7 till 9) correlates the change of state of the sensor and the change of state of the valve by calculating the time difference between the occurrence of the state changes. Whenever, the time difference increases by more than 1% within a 24hour period an alarm has to be raised. Moreover, a constant monitoring of the trend for the time difference using the least squares method for the period of 24 hours has to be performed. The trend monitoring can be either visualized or returned as a stream of plot parameters.
The goal of the second query is to monitor the energy consumption of the manufacturing equipment. The energy consumption is recorded by the sensors mf01, mf02, and mf03. The first set of operators (operator 1 till 3) calculates the average values for each of the sensors (s1.avg-mf01 till s1.avg-mf03) as well as the relative variation (s1.rng-mf01 till s1.rng-mf03) in each of the sensors readings. Both average and variation values are calculated over the period of 1 second and are output every second.
The relative variation is used to trigger the recording of the raw values of the sensor readings -- see operator 4. Whenever the relative variation on any of the energy measuring sensors exceeds the threshold of 30%, the raw data from each of the sensors (mf01-mf03) needs to be recorded starting 20 seconds before the occurrence of the threshold violation and ending 70 seconds afterwards. If multiple violations occur with the 90 second interval, it needs to be extended so that it always captures 70 seconds of raw data after the occurrence of the last violation and 20 seconds before the occurrence of the first violation.
Finally, operators 5 till 7 record the power consumption of the manufacturing equipment within a period of one minute.