2016-03-23 10:41 GMT+01:00 David Lang <[email protected]>: > On Wed, 23 Mar 2016, Rainer Gerhards wrote: > >> 2016-03-22 20:34 GMT+01:00 singh.janmejay <[email protected]>: >>> >>> What about wrapDynamicObjects="on|off"? That is required regardless, >>> right? (if we want to preserve backward compatibility). Unless we >>> choose to change it anyway (which im fine with). >>> >>> @Rainer: what do you think about foreach handling object? >> >> >> so far I could only manage to have a glimpse at the conversation. I >> admit that I am really concerned about all the extra complexity we >> introduce. And do so for what I think is a border-use case at best. >> There is a lot of work that should really be done in regard to >> variables and performance and I am unsure if this is the right time to >> do large extensions... >> >> I was happy with the dynstats as it looked like a very contained >> solution that did not affect much else. But now it looks we need to >> touch a big deal of code ... code that's not really ready for that... > > > We are talking about two changes. > > 1. format change to make the bucket elements be at a different level than > the name/origin parameters to avoid conflicts. > > 2. an enhancement to foreach to allow for processing multiple items on a > list, not just elements in an array. > > I think we need to do #1 right away,
full ack, was commenting on the new loop construct > even if we don't do #2, just to > minimize the window that rsyslog is generating the format that could be > abused. > > I think #2 is still going to be contained to a corner of the codebase, the > foreach code. So it shouldn't have any effect on other areas. > Let me give my concerns a bit more precise: we need to change the variable implementation, most probably via libfastjson. Changes to libfastjson *will* affect the internal representation. I fear that if we extend the looping construct, we may get into many more constraints on what I can change with variables. Also I need to test, etc and given the already long list of *important* things I need to go through (your performance/mem leak issue, tx processing, vars,...) I really do not want to spent much time some place else. If that's a compromise, we can extend the loop, as long as we say "this is an extremely experimental feature which can go away at any time" ... and which we do not argue once it is removed. I am probably so concerend because of my experience with liblognorm. Some of those extensions really hurt the new design, and that's also why I really dropped some. I don't want the same happen in rsyslog again. Rainer > Maybe I get a different view when I find time to read all this more >> in-depth.... >> >> Rainer >>> >>> >>> On Wed, Mar 23, 2016 at 1:01 AM, David Lang <[email protected]> wrote: >>>> >>>> On Wed, 23 Mar 2016, singh.janmejay wrote: >>>> >>>>> Foreach can only work with arrays as of now. It can't work with >>>>> objects (key-value pairs). So [{name: ... value: ...}, {..},...] is >>>>> the only format that will work as of now. >>>>> >>>>> We can enhance foreach to work with objects. >>>>> >>>>> I can make a flag available at dyn-stats bucket level, which can >>>>> control serialization format, but that would really be a hack. >>>>> >>>>> From single-responsibility pattern pov, impstats should be the only >>>>> component that decides how to layout data for user to see. >>>>> >>>>> How about this: >>>>> >>>>> impstats(format="json" wrapDynamicObjects="on"...)? >>>>> >>>>> It defaults to off, which keeps backward compatibility. >>>>> >>>>> So what do you guys think about: >>>>> - wrapDynamicObjects="on|off" >>>>> - generating [{name: a, value: 10}, {...} ...] vs. {a: 10, ...} >>>>> (foreach will handle the former out of the box, but later is concise, >>>>> readable and light-weight in addition to being more json-y. >>>>> - enhancing foreach to work with {a: 10, b: 20...} >>>> >>>> >>>> >>>> If we can enhance foreach to work with the concise format, I would >>>> rather >>>> wait for it instead of introducing the wrapping version. >>>> >>>> I'm thinking that foreach walks through arrays, rather than mixing >>>> concepts, >>>> a foreachobject that gives us a name and contents for a {} list of >>>> objects >>>> may be the right thing to do? >>>> >>>> foreach just returns a single object while foreachobject needs to return >>>> the >>>> object and name. >>>> >>>> although, if we ever get the ability to address arrays directly, being >>>> able >>>> to look at the array position would be the equivalent of the name. >>>> >>>> David Lang >>>> >>>> >>>> >>>>> On Wed, Mar 23, 2016 at 12:26 AM, David Lang <[email protected]> wrote: >>>>>> >>>>>> >>>>>> On Tue, 22 Mar 2016, singh.janmejay wrote: >>>>>> >>>>>>> How about this: we support a new flag in impstats which allows >>>>>>> json-formatted stats-line to optionally use >>>>>>> encapsulated/wrapped-layout? >>>>>>> >>>>>>> impstats(format="json" ...) generates >>>>>>> >>>>>>> >>>>>>> >>>>>>> {"name":"msg_per_host","origin":"dynstats.bucket","z-scribe1r-b":80,"SWEB10":67} >>>>>>> >>>>>>> however, >>>>>>> >>>>>>> impstats(format="json/w" ...) generates {"header": >>>>>>> {"name":"msg_per_host","origin":"dynstats.bucket"}, "counters" : >>>>>>> {"z-scribe1r-b":80,"SWEB10":67}} >>>>>>> >>>>>>> This is relevant, the serilization format we use right now mixes >>>>>>> pre-defined keys with counter-names and it can affect regular static >>>>>>> counters too. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> with the existing pstats output, there is no ability for user-defined >>>>>> data >>>>>> to become a tag name, so there is no potential for ambiguity. but with >>>>>> dynastats, this is not a possibility, and the format we use should >>>>>> prevent >>>>>> problems. >>>>>> >>>>>> Also, just from a conceptual point of view, why should the bucket >>>>>> contents >>>>>> be at the same level as the bucket name? >>>>>> >>>>>> other than backwards compatibility, what advantage is there of the >>>>>> current >>>>>> version in JSON? the documentation uses the plain text equivalant, >>>>>> which >>>>>> is >>>>>> perfectly legitimate because there is an order to the line, and after >>>>>> you >>>>>> get past the name and origin, everything else on the line is >>>>>> name-value >>>>>> pairs of counters, again, no ambiguity. >>>>>> >>>>>> But with JSON, I don't believe that you can depend on tools >>>>>> maintaining >>>>>> (or >>>>>> even identifying) the order of the elements, and if you have multiple >>>>>> elements with the same name, it's implementation dependent as to which >>>>>> one >>>>>> will be seen. >>>>>> >>>>>> So purely from a correctness and defensive programming point of view, >>>>>> I >>>>>> think the current JSON serialization should be changed, with the old >>>>>> format >>>>>> no longer being an option. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> As to the details of the new format >>>>>> >>>>>> What I'm wanting to do with the counters is something like >>>>>> >>>>>> if $!origin == "dynstats.bucket" then { >>>>>> foreach $.tag $!counters { >>>>>> /var/log/stats;format >>>>>> } >>>>>> } >>>>>> >>>>>> to output one line per counter. >>>>>> >>>>>> I'm very flexible in how to do this, but I would much rather be able >>>>>> to >>>>>> do >>>>>> this inside rsyslog than have to serialize things to an external >>>>>> script, >>>>>> have it parse the json and process it. >>>>>> >>>>>> my initial thinking was just do >>>>>> >>>>>> counters: [ "z-scribe1r-b":80,"SWEB10":67 ] >>>>>> >>>>>> but as I'm typing this, I realize that doesn't work as I don't have a >>>>>> way >>>>>> to >>>>>> break $.tag down to reference the name and the value. >>>>>> >>>>>> I'd hate to have to do something like >>>>>> >>>>>> counters: [{"name":"z-scribe1r-b","value":80 >>>>>> },{"name":"SWEB10","value":67}] >>>>>> >>>>>> this mirrors the misuse of XML that gives it such a horrible >>>>>> reputation. >>>>>> But >>>>>> unless we introduce some new function to rsyslog to break things down, >>>>>> I >>>>>> don't see a better way. If we do need to do something like this, I >>>>>> sure >>>>>> would not want to make it the default JSON, which would result in two >>>>>> different formats. I hate the idea of starting to have different >>>>>> formats >>>>>> because of subtypes of data (what is someone wants the cee version of >>>>>> this >>>>>> for example, you start to have orthoginal format decisions) >>>>>> >>>>>> >>>>>> David Lang >>>>>> _______________________________________________ >>>>>> rsyslog mailing list >>>>>> http://lists.adiscon.net/mailman/listinfo/rsyslog >>>>>> http://www.rsyslog.com/professional-services/ >>>>>> What's up with rsyslog? Follow https://twitter.com/rgerhards >>>>>> NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a >>>>>> myriad >>>>>> of >>>>>> sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you >>>>>> DON'T >>>>>> LIKE THAT. >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>> _______________________________________________ >>>> rsyslog mailing list >>>> http://lists.adiscon.net/mailman/listinfo/rsyslog >>>> http://www.rsyslog.com/professional-services/ >>>> What's up with rsyslog? Follow https://twitter.com/rgerhards >>>> NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad >>>> of >>>> sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you >>>> DON'T >>>> LIKE THAT. >>> >>> >>> >>> >>> -- >>> Regards, >>> Janmejay >>> http://codehunk.wordpress.com >>> _______________________________________________ >>> rsyslog mailing list >>> http://lists.adiscon.net/mailman/listinfo/rsyslog >>> http://www.rsyslog.com/professional-services/ >>> What's up with rsyslog? Follow https://twitter.com/rgerhards >>> NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad >>> of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T >>> LIKE THAT. >> >> _______________________________________________ >> rsyslog mailing list >> http://lists.adiscon.net/mailman/listinfo/rsyslog >> http://www.rsyslog.com/professional-services/ >> What's up with rsyslog? Follow https://twitter.com/rgerhards >> NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad >> of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T >> LIKE THAT. >> > _______________________________________________ > rsyslog mailing list > http://lists.adiscon.net/mailman/listinfo/rsyslog > http://www.rsyslog.com/professional-services/ > What's up with rsyslog? Follow https://twitter.com/rgerhards > NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of > sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T > LIKE THAT. _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com/professional-services/ What's up with rsyslog? Follow https://twitter.com/rgerhards NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT.
