This whole issue was caused by inconsistent equals/hashCode on a cache
key, which appearantly has the capability of stopping replication dead
in its tracks. Nailing this one after 3-4 days of a very nagging
"select is broken" feeling was great. You guys helping us here might
want to be particularly aware of this, since it undeniably gives a newbie an
impression that ignite is broken while it's my code :)

Thanks for the help !

Kristian


2016-06-17 20:00 GMT+02:00 Alexey Goncharuk <[email protected]>:
> Kristian,
>
> Are you sure you are using the latest 1.7-SNAPSHOT for your production data?
> Did you build binaries yourself? Can you confirm the commit# of the binaries
> you are using? The issue you are reporting seems to be the same as
> IGNITE-3305 and, since the fix was committed only a couple of days ago, it
> might not get to nightly snapshot.
>
> 2016-06-17 9:06 GMT-07:00 Kristian Rosenvold <[email protected]>:
>>
>> Sigh, this has all the hallmarks of a thread safety issue or race
>> condition.
>>
>> I had a perfect testcase that replicated the problem 100% of the time,
>> but only when running on distinct nodes (never occurs on same box)
>> with 2 distinct caches and with ignite 1.5; I just expanded the
>> testcase I posted initially . Typically I'd be missing the last 10-20
>> elements in the cache. I was about 2 seconds from reporting an issue
>> and then I switched to yesterday's 1.7-SNAPSHOT version and it went
>> away. Unfortunately 1.7-SNAPSHOT exhibits the same behaviour with my
>> production data, it just broke my testcase :( Assumably I just need to
>> tweak the cache sizes or element counts to hit some kind of non-sweet
>> spot, and then it probably fails on my machine.
>>
>> The testcase always worked on a single box, which lead me to think
>> about socket-related issues. But it also required 2 caches to fail,
>> which lead me to think about race conditions like the rebalance
>> terminating once the first node finishes.
>>
>> I'm no stranger to reading bug reports like this myself, and I must
>> admit this seems pretty tough to diagnose.
>>
>> Kristian
>>
>>
>> 2016-06-17 14:57 GMT+02:00 Denis Magda <[email protected]>:
>> > Hi Kristian,
>> >
>> > Your test looks absolutely correct for me. However I didn’t manage to
>> > reproduce this issue on my side as well.
>> >
>> > Alex G., do you have any ideas on what can be a reason of that? Can you
>> > recommend Kristian enabling of DEBUG/TRACE log levels for particular
>> > modules? Probably advanced logging will let us to pin point the issue
>> > that
>> > happens in Kristian’s environment.
>> >
>> > —
>> > Denis
>> >
>> > On Jun 17, 2016, at 10:02 AM, Kristian Rosenvold <[email protected]>
>> > wrote:
>> >
>> > For ignite 1.5, 1.6 and 1.7-SNAPSHOT, I see the same behaviour. Since
>> > REPLICATED caches seem to be broken on 1.6 and beyond, I am testing
>> > this on 1.5:
>> >
>> > I can reliably start two nodes and get consistent correct results,
>> > lets say each node has 1.5 million elements in a given cache.
>> >
>> > Once I start a third or fourth node in the same cluster, it
>> > consistently gets a random incorrect number of elements in the same
>> > cache, typically 1.1 million or so.
>> >
>> > I tried to create a testcase to reproduce this on my local machine
>> >
>> > (https://github.com/krosenvold/ignite/commit/4fb3f20f51280d8381e331b7bcdb2bae95b76b95),
>> > but this fails to reproduce the problem.
>> >
>> > I have two nodes in 2 different datacenters, so there will invariably
>> > be some differences in latencies/response times between the existing 2
>> > nodes and the newly started node.
>> >
>> > This sounds like some kind of timing related bug, any tips ? Is there
>> > any way I kan skew the timing in the testcase ?
>> >
>> >
>> > Kristian
>> >
>> >
>
>

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