Looking specifically at China,

CN on Jan 3rd: 9103 in log file, 9415 in DB
CN on Jan 20th: 13816 in log file, 13586 in DB

This is further confirmation that EL seems to be fine. Thanks for pointing
me in the direction of the raw logs, I didn't know where they were. I'll
post an update when we've found the source of this issue.

On Wed, Jan 28, 2015 at 6:20 PM, Gilles Dubuc <[email protected]> wrote:

> Does this throughput rate match what you see on the database?
>>
>
> It's hard to tell, because I can't infer how many events per day are
> generated based on what you're showing me. It depends on the granularity of
> the curve's rendering. Even if I knew what the numbers going up to 6.2 on
> the left represent, it still wouldn't tell me how many per hour/per day are
> recorded there.
>
> Are there a bigger number of events that might not be validating for other
>> wikis versus China?
>>
>
> Are you talking about syntactically incorrect events that don't pass the
> schema check?
>
> Wouldn't this happen if your product is "more used" in china than
>> elsewhere?
>>
>
> Sure, but that doesn't really matter, because global trends would evolve
> slowly. The point of tracking the network performance statistics worldwide,
> despite their very uneven distribution, is to immediately spot when
> something very wrong happens. We also track the same stats per wiki, and
> per country (albeit not on a timeline at this point for the per-country
> ones). The bottom line is that the per-country share of recorded EL events
> shouldn't vary wildly like that.
>
> Logs are at: stat1002:/a/eventlogging/
>>
>
> gilles@stat1003:~/20150120$ cat all-events.log-20150120 | grep
> "\"clientValidated\": true" | grep -c "\"schema\":
> \"MultimediaViewerNetworkPerformance\""
> 330061
>
> And in the DB across the tables that have "active" versions, I get a total
> of 31 + 327867 = 327898 events recorded
>
> A difference of 2000ish events, might not be a real difference since the
> date cutoff probably differs between the log file and the timestamp
> contained in its entries.
>
> Now, looking at an earlier date, when things seemed to be stable in terms
> of country-based sampling:
>
> gilles@stat1003:~/20150103$ cat all-events.log-20150103  | grep
> "\"clientValidated\": true" | grep -c "\"schema\":
> \"MultimediaViewerNetworkPerformance\""
> 287712
>
> And in the DB, a total of  5 + 289461 = 289466
>
> So far it does look like everything is making it to the DB, I'll keep
> investigating tomorrow.
>
> On Wed, Jan 28, 2015 at 5:43 PM, Nuria Ruiz <[email protected]> wrote:
>
>> Gilles:
>>
>> This event has a "pretty" constant rate of input:
>> http://graphite.wikimedia.org/render/?width=588&height=311&_salt=1422494956.516&from=00%3A00_20141201&until=23%3A59_20150128&target=eventlogging.schema.MultimediaViewerNetworkPerformance.rate
>>
>> And as far as I can see it has not changed (greatly) before and after the
>> 7th. Does this throughput rate match what you see on the database? If so, I
>> would say db matches incoming stream. Now, if it doesn't (somehow the db
>> has less data) we might have a problem. However, dropped events when
>> inserting on the db will affect all countries equally so I doubt these will
>> be the source of the discrepancy.
>>
>> Are there a bigger number of events that might not be validating for
>> other wikis versus China?
>> Logs are at: stat1002:/a/eventlogging/archive and the all-events log will
>> have every single one of your events received. Please note that events are
>> not inserted right away when received, there is a buffer of couple minutes.
>>
>> >This balance shifting over time is really problematic for tracking
>> Media Viewer client-side network performance, because Chinese >traffic
>> suddenly accounting for a bigger or smaller share of the overall recorded
>> events creates big swings in the global >averages/percentiles (since
>> network performance in China is bad).
>>
>> Wouldn't this happen if your product is "more used" in china than
>> elsewhere? If you are counting "absolute" values you will be always skewed
>> to the biggest dataset unless you are doing some kind of scaling.
>>
>>
>> Thanks,
>>
>> Nuria
>>
>> On Wed, Jan 28, 2015 at 4:09 PM, Gilles Dubuc <[email protected]>
>> wrote:
>>
>>> Hi all,
>>>
>>> I've tracked down an unexplained EL phenomenon that surfaced in our
>>> stats as a false trend in our global stats.
>>>
>>> The data I'm looking at specifically is coming from Media Viewer's
>>> MultimediaViewerNetworkPerformance_* tables.
>>>
>>> Have a look at this graph:
>>> https://docs.google.com/spreadsheets/d/1PJsyzAyj74dctGCl4-09L7LS4AMZRh57G56Xc2qZv6w/edit?usp=sharing
>>> the big change is on Jan 7th/8th
>>>
>>> It shows how many EL events we've recorded, per client-reported country,
>>> over the last 90 days. The sampling factor we use has been constant for
>>> each wiki over that period. Thus, the distribution shouldn't evolve
>>> drastically, aside from seasonal/local trends. Besides the Ukraine spike on
>>> a particular date (probably related to world events), the graph before Jan
>>> 7th looks like what you would expect. Then, following the outage that
>>> happened on Jan 7th, not only the balance is completely changed, but it
>>> evolves over time (the US and China are keeping "higher than normal"
>>> levels, while the rest seems to slide down lower than pre-7th quantities),
>>> showing me that something strange is happening and is probably unresolved.
>>>
>>> This balance shifting over time is really problematic for tracking Media
>>> Viewer client-side network performance, because Chinese traffic suddenly
>>> accounting for a bigger or smaller share of the overall recorded events
>>> creates big swings in the global averages/percentiles (since network
>>> performance in China is bad).
>>>
>>> _______________________________________________
>>> Analytics mailing list
>>> [email protected]
>>> https://lists.wikimedia.org/mailman/listinfo/analytics
>>>
>>>
>>
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>>
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