Re: [Lustre-devel] Lustre-devel Digest, Vol 72, Issue 17
Chris Gearing
> Problem 1
>
> Currently Lustre and test are living in one code space and build in one
> time,and often have specific dependencies between test and code.
>
> This situation directly affect
>
> 1) interoperability testing between different version. (because testing
> is started from client which have different test framework then server
> and client remotely execute test framework as their own. just copying
> tests for equalization could not work with big difference between versions)
>
> 2) it is not simple execute(especially in automation) testing for test.
> F.e. a bug is fixed, the test on it added. Executing the test on an old
> revision(probably on a previous release) should show failed test result.
> But with big difference between versions where fixed and where execute
> test-framework can fail to start.
>
> Possible solution: split Lustre and lustre tests in code and build
> levels. It means that lustre and tests will not be connected on code
> revision, only by logic, f.e. via keywords. Also should be added in same
> time an abstraction level in test framework which allows to execute
> lustre utils from different version of lustre.
The situation here is exactly the same as exists with the source code.
When we run interop tests the test system runs test scripts belonging to
the server version against those belonging to the client version. So we
might use 1.8.7 client scripts against 2.2 server scripts. These scripts
need to inter-operate in exactly the same way that the Lustre source
code itself needs to interoperate.
If people find cases where this does not happen then they raise bugs
against Lustre and these are fixed using the same processes as any other
Lustre bug. This means people across the community investing effort to
rectify the incompatibilities and then posting patches for review, test
and inclusion in the product. Of course in a perfect world we would be
back at the point where 1.8.7 and 2.x forked and never allow the
interoperability issues in the test scripts to creep in, but the reality
is the issues do exist and effort does needs to be spent resolving them.
I am 100% sure that the resolution of the relatively few
incompatibilities is infinitely easier than attempting to take the 1.8,
2.1 and 2.2 test scripts and produce an independent one size fits all
solution.
We currently track each failing test in Jira, see here
http://jira.whamcloud.com/browse/LU-1193 for an example. If others find
issues in their testing then they should create Jira issues to track
them and if possible post patches to resolve them.
>
>
> Problem 2
>
> (to avoid term problems, I call there: sanity = test suite, 130 = test,
> 130c and 130a = test cases)
>
> Different test cases, ended with letter(f.e. 130c), have an different
> idea of dependencies. Some test cases have dependences to previous test
> cases, some don't have.
>
> All they now can be executed with "ONLY" parameter and all they have
> separated item in result yaml file as just separated tests( which
> doesn't have test cases ended with letter, f.e. sanity 129). Also, tests
> which have testcases and don't have their own body can be execute with
> ONLY parameter( but doesn't have their special result).
>
> So, logically, all test which can be execute via using ONLY must be not
> depended to other tests. But we have test which depended. Moreover, some
> developers prefer to consider testcases as step of full one test.
>
> What is entities which I call "testcases" and "test" from your point of
> view?
>
> Answer of this question affect automated test execution and test
> development, and maybe ask some test-framework changes.
>
I think you highlight a very good point here that we don't really know
enough about the test contents, their prerequisites or other
dependencies. I would suggest that many attempts have been made over the
years to use naming conventions, numeric ordering or other similar
mechanisms to track such behaviour.
What we need to make sense of the 1000+ test cases we have is an
extensible knowledge-base of information that can grow overtime to
become a rich source of information that can be used to allow automated
systems as well as developers to confidently use the tests in the most
flexible way possible.
Because of the nature of Lustre we need to find a way that keeps this
knowledge within the public domain, provides for use to expand the range
of things we store about each test and provides for both people and
machines to access it with equal ease.
One reasonable proposal is to add a comment block at the start of each
test script and subtest within that script that lists the test name,
short and long description that includes what the test is supposed to be
doing, what bug (if any) it was originally added for, what part of the
code it is intended to cover, prerequisites (filesystem initialization,
min/max number of clients, OSTs, MDTs it can test with, etc) in a
machine readable format that it not only documents the test today but
that can be expanded in the future.
Once we have an agreement on an initial format for this comment block,
the development community can work to populate it for each subtest and
improve the understanding and usefulness of all existing tests.
Thanks
Chris Gearing
Sr. Software Engineer
Quality Engineering
Whamcloud Inc
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Roman Grigoryev
Thank you for answer ( I have cut part of my original message):
>> Problem 1
>>
>> Currently Lustre and test are living in one code space and build in one
>> time,and often have specific dependencies between test and code.
......
>> Possible solution: split Lustre and lustre tests in code and build
>> levels. It means that lustre and tests will not be connected on code
>> revision, only by logic, f.e. via keywords. Also should be added in same
>> time an abstraction level in test framework which allows to execute
>> lustre utils from different version of lustre.
> The situation here is exactly the same as exists with the source code.
> When we run interop tests the test system runs test scripts belonging to
> the server version against those belonging to the client version. So we
> might use 1.8.7 client scripts against 2.2 server scripts. These scripts
> need to inter-operate in exactly the same way that the Lustre source
> code itself needs to interoperate.
Yes, it is. But I don't see why we should use old test base for
interoperability testing? Between 1.8.7 and 2.x tests was fixed and also
as test framework was changed. For getting same test coverage for old
features we should backport new fixes in test to old (maybe already
frozen) code.
Also, as results, we have different tests sets for compatibility
testing. For 1.8.7 it will one, for 2.1 - other. Only a part of
differences shows difference between code base for one feature set.
(F.e. we see on special 1.8.7 branch failures which already fixed in 2.x
code.)
>
> If people find cases where this does not happen then they raise bugs
> against Lustre and these are fixed using the same processes as any other
> Lustre bug. This means people across the community investing effort to
> rectify the incompatibilities and then posting patches for review, test
> and inclusion in the product. Of course in a perfect world we would be
> back at the point where 1.8.7 and 2.x forked and never allow the
> interoperability issues in the test scripts to creep in, but the reality
> is the issues do exist and effort does needs to be spent resolving them.
> I am 100% sure that the resolution of the relatively few
> incompatibilities is infinitely easier than attempting to take the 1.8,
> 2.1 and 2.2 test scripts and produce an independent one size fits all
> solution.
>
I agree that there is a lot of work on test framework abstraction layer
also on adding simple filtering procedure and setting keywords.
But having one test base give us good possibility just setup an actual
test package on all nodes and have somehow predict executed test set.
Also, in this letter below, we discuss test/test framework changes. If
we will have separated tests between version package then benefits from
new tests descriptors we be accessible for all previous system too. In
other case we could create incompatible improvements.
> We currently track each failing test in Jira, see here
> http://jira.whamcloud.com/browse/LU-1193 for an example. If others find
> issues in their testing then they should create Jira issues to track
> them and if possible post patches to resolve them.
Thanks for this link. Do you have any keyword or attribute for
interoperability failures?
>
>>
>>
>> Problem 2
>>
>> (to avoid term problems, I call there: sanity = test suite, 130 = test,
>> 130c and 130a = test cases)
>>
...
>> Answer of this question affect automated test execution and test
>> development, and maybe ask some test-framework changes.
>>
> I think you highlight a very good point here that we don't really know
> enough about the test contents, their prerequisites or other
> dependencies. I would suggest that many attempts have been made over the
> years to use naming conventions, numeric ordering or other similar
> mechanisms to track such behaviour.
>
> What we need to make sense of the 1000+ test cases we have is an
> extensible knowledge-base of information that can grow overtime to
> become a rich source of information that can be used to allow automated
> systems as well as developers to confidently use the tests in the most
> flexible way possible.
>
> Because of the nature of Lustre we need to find a way that keeps this
> knowledge within the public domain, provides for use to expand the range
> of things we store about each test and provides for both people and
> machines to access it with equal ease.
>
> One reasonable proposal is to add a comment block at the start of each
> test script and subtest within that script that lists the test name,
> short and long description that includes what the test is supposed to be
> doing, what bug (if any) it was originally added for, what part of the
> code it is intended to cover, prerequisites (filesystem initialization,
> min/max number of clients, OSTs, MDTs it can test with, etc) in a
> machine readable format that it not only documents the test today but
> that can be expanded in the future.
I agree, it is very important to separating meta information and test body.
Internally in Xyratex, we use external scripts and descriptors which
somehow add same possibility(per-test timeouts, keywords...).
>
> Once we have an agreement on an initial format for this comment block,
> the development community can work to populate it for each subtest and
> improve the understanding and usefulness of all existing tests.
I absolutely agree that we need agreement to start any work on test
improvements. How can we initiate this process? Maybe good first step is
creating glossary to use and terms and based on these terms fix tests?
Also, what do you think about a possible simple solutions for decreasing
dependence problem which is currently pretty painful for us:
1) test(test scenario) must have only number name (1,2,3..110...999)
2) test cases (test step) must have number+char index (1f,2,b...99c)
Only Test can be executed via ONLY.
Test cases can be execute only as part of test.
Thanks,
Roman
Chris Gearing
> Hi Chris,
> Thank you for answer ( I have cut part of my original message):
>> the server version against those belonging to the client version. So we
>> might use 1.8.7 client scripts against 2.2 server scripts. These scripts
>> need to inter-operate in exactly the same way that the Lustre source
>> code itself needs to interoperate.
> Yes, it is. But I don't see why we should use old test base for
> interoperability testing? Between 1.8.7 and 2.x tests was fixed and also
> as test framework was changed. For getting same test coverage for old
> features we should backport new fixes in test to old (maybe already
> frozen) code.
> Also, as results, we have different tests sets for compatibility
> testing. For 1.8.7 it will one, for 2.1 - other. Only a part of
> differences shows difference between code base for one feature set.
> (F.e. we see on special 1.8.7 branch failures which already fixed in 2.x
> code.)
>
tightly coupled to the Lustre version. There were a lot of changes
between 1.8.x and 2.x and a lot of corresponding changes to the test
scripts. Where the tests are the same and bugs were found in the 2.x
test scripts these should have been backported to the 1.8.x test scripts
if this was not done then we should do it for inclusion into the 1.8.8
release.
The notion of making 'master' scripts work with with all versions is
obviously possible but it is a very significant task and given that the
scripts themselves are written in a language (sic) that does not provide
structure a single script strategy is likely to create many more
'interoperability issues' than it fixes.
Also it's worth considering that we have best part of a 1000 discrete
changes, whenever a test is re-engineered the test itself must be proven
to detect failure as well as success. i.e. If someone produced a version
independent test set that passed all versions we would not know that the
process was a success, we would need to check that each re-engineered
test 'failed' appropriately for each Lustre version, this is a big task
that I doubt can be properly achieved in bash.
So in summary the best solution given what we have today is to back port
fixes to the test scripts as we back port fixes to the code. This is an
investment in time and requires the same discipline to test as we have
for coding. A single set of scripts that caters for all versions appears
I believe like an easy solution but actually would require huge
investment that would be better spent developing a modern test framework
and infrastructure that can support Lustre for the next ten years.
>
>>>
>>> Problem 2
>>>
>>> (to avoid term problems, I call there: sanity = test suite, 130 = test,
>>> 130c and 130a = test cases)
>>>
> ...
>
>>> Answer of this question affect automated test execution and test
>>> development, and maybe ask some test-framework changes.
>>>
>> I think you highlight a very good point here that we don't really know
>> enough about the test contents, their prerequisites or other
>> dependencies. I would suggest that many attempts have been made over the
>> years to use naming conventions, numeric ordering or other similar
>> mechanisms to track such behaviour.
>> ...
>> One reasonable proposal is to add a comment block at the start of each
>> test script and subtest within that script that lists the test name,
>> short and long description that includes what the test is supposed to be
>> doing, what bug (if any) it was originally added for, what part of the
>> code it is intended to cover, prerequisites (filesystem initialization,
>> min/max number of clients, OSTs, MDTs it can test with, etc) in a
>> machine readable format that it not only documents the test today but
>> that can be expanded in the future.
> I agree, it is very important to separating meta information and test body.
> Internally in Xyratex, we use external scripts and descriptors which
> somehow add same possibility(per-test timeouts, keywords...).
>
>> Once we have an agreement on an initial format for this comment block,
>> the development community can work to populate it for each subtest and
>> improve the understanding and usefulness of all existing tests.
> I absolutely agree that we need agreement to start any work on test
> improvements. How can we initiate this process? Maybe good first step is
> creating glossary to use and terms and based on these terms fix tests?
>
> Also, what do you think about a possible simple solutions for decreasing
> dependence problem which is currently pretty painful for us:
>
> 1) test(test scenario) must have only number name (1,2,3..110...999)
> 2) test cases (test step) must have number+char index (1f,2,b...99c)
>
> Only Test can be executed via ONLY.
> Test cases can be execute only as part of test.
I don't think there is a problem with this simple solution in that it
does no harm as long as you applied any changes to all the branches that
are applicable. At the same time I will draft a possible meta data
format that includes the extensible metadata within the source in a way
that maximizes its value both today and in the future, we can then
review, revise and then agree that format on Lustre-Devel, although I'll
mail you privately so you can have input before that. It may actually be
the case that some work has occurred on this topic previously and if so
we can leverage that.
Thanks
Chris Gearing
Sr. Software Engineer
Quality Engineering
Whamcloud Inc