2015-05-21 17:40 GMT+02:00 singh.janmejay <[email protected]>: > Are $/ variable manipulations supposed to be atomic?
It depends on what you mean with "atomic". The value returned should be consistent, that for sure. But if you use $/var = $/var + 1 and $/var is 16 when this starts, the result can very well be 18 if another thread executed the exact same sequence. I think for this use there was an atomic increment function planned. I guess I never implemented it, though. > > Eg. $/var % 16 should never produce any number greater than 15, but it does. as David said, that's a bug. > > Are they non-atomic by design? If so, is mmsequence the right thing to > use (assuming it has atomic counters, I haven't checked if it really > does)? mmsequence is deprecated. > > There are few options on the table, I guess. before I take a shot at these, let's see if we had the same understanding of "atomic". Rainer > 1. If $/ variables are supposed to be atomic, we just fix the impl. > 2. We use mmsequence, and keep it alive (assuming it has atomic counters) > 3. We fix mmsequence to implement atomic counters. > 4. If $/ is not supposed to be atomic (by design), we implement $@ > which is thread-local, so people can get atomic counters within thread > (evenness in data(for load-balancing or sampling kind of usecase) is > maintained by the fact that a single thread will pump a lot of > messages, so across all threads it'll approximately be as even as it > is in a single-thread. > 5. We implement a random-number construct (which i believe either > mmsequence or mmcount had) which allows acceptable load-balancing or > sampling etc. > > Thoughts? > > On Wed, Dec 3, 2014 at 11:12 PM, David Lang <[email protected]> wrote: >> On Wed, 3 Dec 2014, Brian Knox wrote: >> >>> So two questions then: >>> >>> 1. In the case of using mmjsonparse on messages where we do not know >>> ahead >>> of time what all the. json attributes will be, is there a var for a place >>> in the tree where we can get all attributes that were in the cee message? >> >> >> There are three 'classes' of variables >> >> $! are 'normal' variables, the place that mmjsonparse, etc put the results >> of parsing the cee message by default. >> >> $. are 'local' variables, they are a place you can put stuff that you don't >> want to end up in a message when you output $! >> >> $\ are 'global' variables, unlike the others, they persist from message to >> message. >> >> All of these variables are a tree, where you can have $!foo!bar and >> $!foo!baz. If you just reference $!foo it will output both bar and baz as >> JSON >> >> so to see everything, parse the message and then output $! >> >>> 2. If mmsequence is being deprecated, is there a pointer to how to >>> increment global variables to provide a sequence? >> >> >> set $\var = $\var + 1; >> >>> 3. This morning I remembered the "mmcount" module - is this also being >>> deprecated in favor of global variables? >> >> >> probably. >> >> David Lang >> >> >>> Brian >>> >>> On Wed, Dec 3, 2014 at 3:52 AM, Rainer Gerhards <[email protected]> >>> wrote: >>> >>>> 2014-12-02 21:59 GMT+01:00 Brian Knox <[email protected]>: >>>> >>>>> We have a case where we are receiving messages in @cee: format, and >>>>> would >>>>> like to add a sequence variable generated via mmsequence to the message. >>>>> >>>>> Before I spend too much time digging into this I wanted to ask if, using >>>>> some template hackery and json subtrees, this is something that sounds >>>>> possible - and if maybe someone else was already doing it. >>>>> >>>>> >>>> David has answered the real question, just let me add that mmsequence was >>>> a >>>> work-around for v7 where global variables were not available. It is now >>>> deprecated and will probably removed in a couple of month. >>>> >>>> I'll check the doc if it tells this clearly enough. >>>> >>>> Rainer >>>> >>>>> Thanks! >>>>> Brian >>>>> _______________________________________________ >>>>> 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. 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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.
