Introduction [edit section]

The criteria.json file is used to specify the criteria used to determine whether a test has passed or failed.

For the purpose of this explanation, I'll group tests into roughly 3 groups:

I'll come back to these definitions in a moment.

The criteria.json file contains data that allows Fuego to interpret the test results, and indicate overall PASS or FAIL status for a test.

For functional tests, this includes things like counting the number of test_cases in the test that had "PASS" or "FAIL" status, as well as ignoring some specific test results.

For benchmark tests, this includes specifying threshold values for measurements taken by the benchmark, as well as operations (e.g. 'less than' or 'greater than'), to use to determine if a specific measure passed or failed.

Fuego uses the results of the test along with the criteria, to determine the final result of the test.

If no criteria.json file is provided, then a default is constructed based on the test results, consisting of the following:

 'tguid': <test_set_name>
 'max_fail': 0

Types of tests and pass criteria [edit section]

A simple functional test runs a short sequence of tests, and if any one of them fails, then the test is reported as a failure. Since this corresponds to the default criteria.json, then most simple Functional tests do not need to provide a criteria.json file.

A complex functional test (such as LTP or glib) has hundreds or possibly thousands of individual test cases. Such tests often have some number of individual test cases that fail, but which may be safely ignored (either temporarily or permamently). For example, some test cases may fail sporadically due to problems with the test infrastructure or environment. Other tests may fail due to configuration choices for the software on the board. (For example, a choice of kernel config may cause some tests to fail - but this is expected and these fail results should be ignored).

Functional tests that are complex require a criteria.json file, to avoid failing the entire test because of individual test_cases that should be ignored.

Finally, a Benchmark test is one that produces one or more "measurements", which are test results with numeric values. In order to determine whether a result indicates a PASS or a FAIL result, Fuego needs to compare the numeric result with some threshold value. The criteria.json file holds the threshold value and operator used for making this comparison.

Different boards, or boards with different software installations or configurations, may require different pass criteria for the same tests. Therefore, the pass criteria are broken out into a separate file that can be adjusted at each test site, and for each board. Ultimately, we would like testers to be able to share their pass criteria, so that each Fuego user does not have to determine these on their own.

Evaluation criteria [edit section]

The criteria file lists "pass criteria" for test suites, test sets, test cases and measures. A single file may list one or more pass criteria for the test.

The criteria file may include count-based pass criteria, specific testcase lists, and measure reference values (thresholds).

The criteria file specifies the pass criteria for one or more test element results, by specifying the element's test id (or tguid), and the criterion used to evaluate that element. Some results elements, such as test sets, are aggregates of other elements. For these, the criteria specify attributes of their child elements (like required counts, or listing individual children that must pass or fail).

The criteria file consists of a list of criterion objects (JSON objects), each of which specifies the tguid for the result element of the test, and additional data used to evaluate that element. tguids are generated by Fuego during the processing phase, and consist of statically defined strings unique to each test. You should look at a test's run.json file to see the test element names for a test.

Here are the different operations that can be used for criteria:

The operator can be one of the following strings:

In case the reference object has an operator of 'bt', the 'value' field should have a string consisting of two numbers separated by a ','. For example, to indicate that the result value should be between 4 and 5, the 'value' field should have the string "4,5". Note that the comparison for 'between' also succeeds for equality. So in the example case of a reference value of "4,5", the test would pass if the test result was exactly 4, or exactly 5, or any number between 4 and 5.

Note: The equality and inequality operators ('eq' and 'ne') are less likely to be useful for numerical evaluations of most benchmark measures, but are provided for completeness. These are useful if a test reports numerical results from within a small set of numbers (like 0 and 1).

Customizing the criteria.json file for a board [edit section]

A Fuego user can customize the pass criteria for a board, by making a copy of the criteria.json file, manually editing the contents, and putting it in a specific directory with a specific filename, so Fuego can find it.

Using an environment variable [edit section]

A Fuego user can specify their own path to the criteria file to use for a test using the environment variable FUEGO_CRITERIA_JSON_PATH. This can be set in the environment variables block in the Jenkins job for a test, if running the Fuego test from Jenkins, or in the shell environment prior to running a Fuego test using 'ftc'.

For example, the user could do the following:

Using a board-specific directory [edit section]

More commonly, a user can specify a board-specific criteria file, by placing the file under either /fuego-rw/boards or /fuego-ro/boards

When Fuego does test evaluation, it searches for the the criteria file to use, by looking for the following files in the indicated order:

As an example, a user could customize the criteria file as follows:

Examples [edit section]

Here are some example criteria.json files:

Benchmark.dbench [edit section]

The interpretation of this criteria file is that the measured value of dbench.Throughput (the result value) must have a value greater than 100. Also, at least 1 measure under the 'default.dbench' test must pass, for the the entire test to pass.

Simple count [edit section]

The interpretation of this criteria file is that the test may fail up to 2 individual test cases, under the 'default' test set, and still pass.

Child results [edit section]

The interpretation of this criteria file is that, within the 'syscall' test set, a minimum of 1000 testcases must pass, and no more than 5 fail, in order for that set to pass. Also, in the test set 'timers', if the testcase 'leapsec_timer' fails, it will not cause the entire test to fail. However, in the test set 'pty', the testcase 'hangup01' must pass for the entire test to pass.

Schema [edit section]

The schema for the criteria.json file is contained in the fuego-core repository at: engine/scripts/parser/fuego-criteria-schema.json.

Here it is (as of Fuego 1.2):

Compatibility with previous Fuego versions [edit section]

The criteria.json file replaces the reference.log file that was used in versions of Fuego prior to 1.2. If a test is missing a criteria.json file, and has a reference.log file, then Fuego will read the reference.log file and use it's data as the the pass criteria for the test.

Previously, Fuego (and it's predecessor JTA) supported pass criteria functionality in two different ways:

Functional test pass/fail counts [edit section]

For functional tests counts of positive and negative results were either hard-coded into the base scripts for the test, as arguments to the log_compare() in each test's test_processing() function, or they were specified as variables, read from the board file, and applied in the test_processing() function.

For example, the Functional.OpenSSL test used values of 176 pass and 86 fails (see fuego-core/engine/tests/Functional.OpenSSL/ in fuego-1.1) to evaluate the result of this test.

    log_compare "$TESTDIR" "176" "${P_CRIT}" "p"
    log_compare "$TESTDIR" "86" "${N_CRIT}" "n"

But tests in JTA, such as Functional.LTP.Open_Posix expected the variables LTP_OPEN_POSIX_SUBTEST_COUNT_POS and LTP_OPEN_POSIX_SUBTEST_COUNT_NEG to be defined in a the board file for the device under test.

For example, the board file might have lines like the following:


These were used in the log_compare function of the base script of the test like so:


Starting with Fuego version 1.2, these would be replaced with criteria.json files like the following:

For Functional.OpenSSL:

        'tguid': 'OpenSSL',
        'min_pass': 176,
        'max_fail': 86

For Functional.LTP.Open_Posix:

        'tguid': 'LTP.Open_Posix',
        'min_pass': 1232,
        'max_fail': 158

FIXTHIS - should there be 'default' somewhere in the preceding tguids?

Benchmark measure evaluations [edit section]

For Benchmark programs, the pass criteria consists of one or more measurement thresholds that are compared with the results produced by the Benchmark, along with the operator to be used for the comparison.

In JTA and Fuego 1.1 this data was contained in the reference.log file.