On Fri, 2018-10-12 at 21:39 -0400, Mark Reynolds wrote: > On 10/10/18 6:57 PM, William Brown wrote: > > On Wed, 2018-10-10 at 16:26 +0200, thierry bordaz wrote: > > > Hi William, > > > > > > Thanks for starting this discussion. > > > Your email raise several aspects (How, for whom,..) and I think a > > > way > > > to > > > start would be to write down what we want. > > > A need is from a given workload to determine where we are > > > spending > > > time > > > as a way to determine where to invest. > > > An other need is to collect metrics at operation level. > > > > Aren't these very similar? The time we invest is generally on > > improving > > a plugin or a small part of an operation, to make the operation as > > a > > whole faster. > > > > So if we can report on an individual operation, we can write a tool > > similar to log-conv.pl, but for performance metrics that displays > > trends of operations that are not performaning well, then we can > > find > > examples of operations and why. > > > > > From the how perspective, we can rely on external tools > > > (stap+scripts), > > > or internal tool (like the plugin you described+scripts). Of > > > course > > > we > > > can also do some enhancements inside DS (like adding probes) to > > > help > > > external tools. I have no strong opinion if an approach is better > > > than > > > the other but I think it also depends what you want to perform. > > > > I think that it would be great if the tools we use internal to the > > team, were accessible outside to admins of ds. That way when we get > > reports for performance concerns, we have a standardised way of > > looking > > at this. It's going to mean our workflow is the same between > > internal > > development and profiling, as for external reports, and it will > > force > > us to have all the information we need in that one place. > > > > I think as a coarse first metric internal event timings is probably > > want we want first. After that we can continue to extend from > > there? > > > > As for the how, perhaps we can put something on the Operation > > struct > > for appending and logging events and turning those into metrics? > > > > As mentioned you could use stap too with defined points for > > tracing, > > but that limits us to linux only? > > Whatever tools we use doesn't really concern me - as long as we get > good > data. Somewhere we have old reports from stap pointing out lock > contention problem areas, but we should really rerun all of those > tests > with the current code base. I think those tests did not properly check atomic usage nor different lock types ... > As for improving performance I think we > should first address the major issues found by the existing tools > (stap > and friends) - specifically the lock contention problems (config, > connections, attr syntax checking, etc). Once these are addressed > then > we can start adding probes/internal structs to fine tune other > aspects > of the server. I think the information we have from current tools isn't complete, and it doesn't help us when people give us reports of the server being slow. We really need to invest in observability into performance, so that long term we get better views into what exactly the issues are. That's why I think we should look at this tooling/logging first. > > Improving performance will be the primary focus for 389-ds-base- > 1.4.1, > and we should be able invest a good amount of time into this > effort. > Getting nunc-stans stable falls into this category as well (it > should > actually be addressed first). There is a patch awaiting review for this topic ... :) > > Mark > > > > > > best regards > > > thierry > > > > > > On 10/08/2018 12:37 PM, William Brown wrote: > > > > Hi there, > > > > > > > > In a ticket Thierry and I mentioned that we should have a quick > > > > discussion about ideas for profiling and what we want it to > > > > look > > > > like and what we need. I think it’s important we improve our > > > > observation into the server so that we can target improvements > > > > correctly, > > > > > > > > I think we should know: > > > > > > > > * Who is the target audience to run our profiling tools? > > > > * What kind of information we do want? > > > > * Potential solution for the above. > > > > > > > > With those in mind I think that Thierry suggested STAP scripts. > > > > > > > > * Target audience - developers (us) and some “highly > > > > experienced” > > > > admins (STAP is not the easiest thing to run). > > > > * Information - STAP would largely tell us timing and possibly > > > > allows some variable/struct extraction. STAP does allow us to > > > > look > > > > at connection info too a bit easier. > > > > > > > > I would suggest an “event” struct, and logging service > > > > > > > > At the start of an operation we create an event struct. As we > > > > enter > > > > - exit a plugin we can append timing information, and the > > > > plugin > > > > itself can add details (for example, backend could add idl > > > > performance metrics or other). At the end of the operation, we > > > > log > > > > the event struct as a json blob to our access log associated to > > > > the > > > > conn/op. > > > > > > > > * Target - anyone, it’s a log level. Really easy to enable > > > > (Think > > > > mailing list or user support, can easily send us diagnostic > > > > logs) > > > > * Information - we need a bit more work to structure the > > > > “event” > > > > struct internally for profiling, but we’d get timings and > > > > possibly > > > > internal variable data as well in the event. > > > > > > > > > > > > I think these are two possible approaches. STAP is less > > > > invasive, > > > > easier to start now, but harder to extend later. Logging is > > > > more > > > > accessible to users/admins, easier to extend later, but more > > > > work > > > > to add now. > > > > > > > > What do we think? > > > > > > > > > > > > — > > > > Sincerely, > > > > > > > > William > > > > > > > > > > > > _______________________________________________ > > > > 389-devel mailing list -- 389-devel@xxxxxxxxxxxxxxxxxxxxxxx > > > > To unsubscribe send an email to > > > > 389-devel-leave@lists.fedoraproject > > > > .org > > > > Fedora Code of Conduct: > > > > https://getfedora.org/code-of-conduct.html > > > > List Guidelines: > > > > https://fedoraproject.org/wiki/Mailing_list_guidel > > > > ines > > > > List Archives: > > > > https://lists.fedoraproject.org/archives/list/389-de > > > > vel@xxxxxxxxxxxxxxxxxxxxxxx > > > > > > _______________________________________________ > > > 389-devel mailing list -- 389-devel@xxxxxxxxxxxxxxxxxxxxxxx > > > To unsubscribe send an email to > > > 389-devel-leave@lists.fedoraproject.o > > > rg > > > Fedora Code of Conduct: > > > https://getfedora.org/code-of-conduct.html > > > List Guidelines: > > > https://fedoraproject.org/wiki/Mailing_list_guidelin > > > es > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-deve > > > l@xxxxxxxxxxxxxxxxxxxxxxx > > > > _______________________________________________ > > 389-devel mailing list -- 389-devel@xxxxxxxxxxxxxxxxxxxxxxx > > To unsubscribe send an email to > > 389-devel-leave@xxxxxxxxxxxxxxxxxxxxxxx > > Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > > https://lists.fedoraproject.org/archives/list/389-devel@xxxxxxxxxxxxxxxxxxxxxxx -- Sincerely, William _______________________________________________ 389-devel mailing list -- 389-devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to 389-devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-devel@xxxxxxxxxxxxxxxxxxxxxxx
