Hi Swapnil, There were few factors we considered before going with just invalidating the index rather than destroying the index. 1. Debugging reasons : If the indexes were destroyed and logs roll over, and suddenly we see that indexes have disappeared, it will be tough to differentiate between whether the indexes were created improperly in the first place [/ restarts] or if a put corrupted it hence it was destroyed. In case of marking it invalid, we know for sure that a put has corrupted the index and prevent confusion for the user.
2. Performance perspective : We were worried that if a put corrupts multiple indexes and then that put is also responsible for destroying those indexes may slow down the execution as it will have to acquire/release locks to destroy indexes [especially in case of PR indexes]. We were also worried about race conditions arising in that case. Regards Nabarun On Wed, Sep 20, 2017 at 2:59 PM Swapnil Bawaskar <sbawas...@pivotal.io> wrote: > Sorry for not reading this thread earlier, but I was wondering what is the > point of just invalidating the index and having it lie around if it is not > going to be used? > Can we just drop the index instead, and log a warning message to that > effect? This will free up the memory used by the index and will proactively > let the admin/user know what happened. > > On Wed, Sep 20, 2017 at 9:59 AM Nabarun Nag <n...@apache.org> wrote: > > > The PR #768 has been created for this issue and also GEODE-3520 has been > > changed to reflect this requirement. > > > > Regards > > Nabarun > > > > On Thu, Sep 14, 2017 at 5:29 PM Nabarun Nag <n...@apache.org> wrote: > > > > > Thanks you guys for the review. I will revert the GEODE-3520 ticket to > > > reflect that invalidate should happen for both synchronous and > > asynchronous > > > index maintenance. > > > Also, I will resend the PR which reflects the changes mentioned in the > > > ticket > > > > > > Regards > > > Nabarun Nag > > > > > > > > > > > > > > > > > > On Thu, Sep 14, 2017 at 5:55 PM Anilkumar Gingade <aging...@pivotal.io > > > > > wrote: > > > > > >> Dan, you are right...Thanks to Jason, myself and Jason looked into the > > >> code > > >> to see if index is updated before the event/change is saved/injected > > into > > >> the region...It looks like the index update are happening after the > > region > > >> change/update is saved. Moving the index update before that is not an > > easy > > >> task... > > >> > > >> For time, when there is any problem with index update, we can proceed > > with > > >> invalidating the indexes...But we really need to look at making region > > and > > >> index updates in a transactional way, silently invalidating indexes > may > > >> not > > >> be acceptable... > > >> > > >> -Anil. > > >> > > >> > > >> > > >> > > >> On Thu, Sep 14, 2017 at 1:12 PM, Dan Smith <dsm...@pivotal.io> wrote: > > >> > > >> > I'm still going to push that we stick with Naba's original proposal. > > >> > > > >> > The current behavior is clearly broken. If one index update fails, > an > > >> > exception gets thrown to the user (nice!) but it leaves the put in a > > >> > partially completed state - some other indexes may not have been > > >> updated, > > >> > WAN/AEQs may not have been notified, etc. > > >> > > > >> > We should never leave the system in this corrupted state. It would > be > > >> nice > > >> > to be able to cleanly rollback the put, but we don't have that > > >> capability > > >> > especially considering that cache writers have already been invoked. > > So > > >> the > > >> > next best thing is to invalidate the index that failed to update. > > >> > > > >> > Logging an error an allowing the put to succeed does match what we > do > > >> with > > >> > CacheListeners. Exceptions from CacheListeners do not fail the put. > > >> > > > >> > -Dan > > >> > > > >> > On Mon, Sep 11, 2017 at 3:29 PM, Jason Huynh <jhu...@pivotal.io> > > wrote: > > >> > > > >> > > Anil, we actually do have a case where the index is out of sync > with > > >> the > > >> > > region currently. It's just not likely to happen but if there is > an > > >> > > exception from an index, the end result is that certain indexes > get > > >> > updated > > >> > > and the region has already been updated. > > >> > > However the exception is thrown back to the putter, so it becomes > > very > > >> > > obvious something is wrong but I believe Naba has updated the > ticket > > >> to > > >> > > show a test that reproduces the problem... > > >> > > > > >> > > > > >> > > On Mon, Sep 11, 2017 at 2:50 PM Anilkumar Gingade < > > >> aging...@pivotal.io> > > >> > > wrote: > > >> > > > > >> > > > The other way to look at it is; what happens to a cache op; when > > >> there > > >> > is > > >> > > > an exception after Region.Entry is created? can it happen? In > that > > >> > case, > > >> > > do > > >> > > > we stick the entry into the Cache or not? If an exception is > > >> handled, > > >> > how > > >> > > > is it done, can we look at using the same for Index... > > >> > > > > > >> > > > Also previously, once the valid index is created (verified > during > > >> > create > > >> > > or > > >> > > > first put into the cache); we never had any issue where index is > > >> out of > > >> > > > sync with cache...If that changes with new futures (security?) > > then > > >> we > > >> > > may > > >> > > > have to change the expectation with indexing... > > >> > > > > > >> > > > -Anil. > > >> > > > > > >> > > > > > >> > > > > > >> > > > On Mon, Sep 11, 2017 at 2:16 PM, Anthony Baker < > aba...@pivotal.io > > > > > >> > > wrote: > > >> > > > > > >> > > > > I’m confused. Once a cache update has been distributed to > other > > >> > > members > > >> > > > > it can’t be undone. That update could have triggered myriad > > other > > >> > > > > application behaviors. > > >> > > > > > > >> > > > > Anthony > > >> > > > > > > >> > > > > > On Sep 11, 2017, at 2:04 PM, Michael Stolz < > mst...@pivotal.io > > > > > >> > > wrote: > > >> > > > > > > > >> > > > > > Great, that's exactly the behavior I would expect. > > >> > > > > > > > >> > > > > > Thanks. > > >> > > > > > > > >> > > > > > -- > > >> > > > > > Mike Stolz > > >> > > > > > Principal Engineer, GemFire Product Manager > > >> > > > > > Mobile: +1-631-835-4771 <(631)%20835-4771> > <(631)%20835-4771> > > <(631)%20835-4771> <(631)%20835-4771> > > >> > > > > > > > >> > > > > > On Mon, Sep 11, 2017 at 4:34 PM, Jason Huynh < > > jhu...@pivotal.io > > >> > > > >> > > > wrote: > > >> > > > > > > > >> > > > > >> Hi Mike, I think the concern was less about the security > > >> portion > > >> > but > > >> > > > > rather > > >> > > > > >> if any exception occurs during index update, right now, the > > >> region > > >> > > > gets > > >> > > > > >> updated and the rest of the system (index/wan/callbacks) > may > > or > > >> > may > > >> > > > not > > >> > > > > be > > >> > > > > >> updated. I think Naba just tried to provide an example > where > > >> this > > >> > > > might > > >> > > > > >> occur, but that specific scenario is invalid. > > >> > > > > >> > > >> > > > > >> I believe Nabarun has opened a ticket for rolling back the > > put > > >> > > > operation > > >> > > > > >> when an index exception occurs. GEODE-3589. It can > probably > > be > > >> > > > > modified to > > >> > > > > >> state any exception instead of index exceptions. > > >> > > > > >> > > >> > > > > >> To summarize my understanding: > > >> > > > > >> -Someone will need to implement the rollback for > GEODE-3589. > > >> This > > >> > > > means > > >> > > > > >> that if any exception occurs during a put, geode it will > > >> propagate > > >> > > > back > > >> > > > > to > > >> > > > > >> the user and it is expected the rollback mechanism will > clean > > >> up > > >> > any > > >> > > > > >> partial put. > > >> > > > > >> > > >> > > > > >> GEODE-3520 should be modified to: > > >> > > > > >> -Add the isValid() api to index interface > > >> > > > > >> -Mark an index as invalid during async index updates but > not > > >> for > > >> > > > > >> synchronous index updates. The synchronous index updates > > will > > >> > rely > > >> > > > on a > > >> > > > > >> rollback mechanism > > >> > > > > >> > > >> > > > > >> > > >> > > > > >> > > >> > > > > >> > > >> > > > > >> On Mon, Sep 11, 2017 at 1:23 PM Michael Stolz < > > >> mst...@pivotal.io> > > >> > > > > wrote: > > >> > > > > >> > > >> > > > > >>> I think there was an intention of having CREATION of an > > index > > >> > > > require a > > >> > > > > >>> higher privilege than DATA:WRITE, but it shouldn't affect > > >> > applying > > >> > > > the > > >> > > > > >>> index on either of put or get operations. > > >> > > > > >>> > > >> > > > > >>> If we are requiring something like CLUSTER:MANAGE for put > on > > >> an > > >> > > > indexed > > >> > > > > >>> region, that is an incorrect requirement. Only DATA:WRITE > > >> should > > >> > be > > >> > > > > >>> required to put an entry and have it be indexed if an > index > > is > > >> > > > present. > > >> > > > > >>> > > >> > > > > >>> -- > > >> > > > > >>> Mike Stolz > > >> > > > > >>> Principal Engineer, GemFire Product Manager > > >> > > > > >>> Mobile: +1-631-835-4771 <(631)%20835-4771> > <(631)%20835-4771> > > <(631)%20835-4771> > > >> <(631)%20835-4771> <(631)%20835-4771> > > >> > > > > >>> > > >> > > > > >>> On Fri, Sep 8, 2017 at 6:04 PM, Anilkumar Gingade < > > >> > > > aging...@pivotal.io > > >> > > > > > > > >> > > > > >>> wrote: > > >> > > > > >>> > > >> > > > > >>>> Indexes are critical for querying; most of the databases > > >> doesn't > > >> > > > allow > > >> > > > > >>>> insert/update if there is any failure with index > > >> maintenance... > > >> > > > > >>>> > > >> > > > > >>>> As Geode OQL supports two ways (sync and async) to > maintain > > >> the > > >> > > > > >> indexes, > > >> > > > > >>> we > > >> > > > > >>>> need be careful about the error handling in both cases... > > >> > > > > >>>> > > >> > > > > >>>> My take is: > > >> > > > > >>>> 1. For synchronous index maintenance: > > >> > > > > >>>> If there is any failure in updating any index > > (security/auth > > >> or > > >> > > > > logical > > >> > > > > >>>> error) on the region; throw an exception and rollback the > > >> cache > > >> > > > > >> update/op > > >> > > > > >>>> (index management id done under region.entry lock - we > > >> should be > > >> > > > able > > >> > > > > >> to > > >> > > > > >>>> revert the op). If index or cache is left in bad state, > > then > > >> > its a > > >> > > > bug > > >> > > > > >>> that > > >> > > > > >>>> needs to be addressed. > > >> > > > > >>>> > > >> > > > > >>>> Most of the time, If there is any logical error in index, > > it > > >> > will > > >> > > be > > >> > > > > >>>> detected as soon as index is created (on existing data) > or > > >> when > > >> > > > first > > >> > > > > >>>> update is done to the cache. > > >> > > > > >>>> > > >> > > > > >>>> 2. For Asynchronous index maintenance: > > >> > > > > >>>> As this is async (assuming) user has good understanding > of > > >> the > > >> > > risk > > >> > > > > >>>> involved with async, any error with index maintenance, > the > > >> index > > >> > > > > should > > >> > > > > >>> be > > >> > > > > >>>> invalidated... > > >> > > > > >>>> > > >> > > > > >>>> About the security/auth, the user permission with region > > >> > > read/write > > >> > > > > >>> needs > > >> > > > > >>>> to be applied for index updates, there should not be > > >> different > > >> > > > > >> permission > > >> > > > > >>>> on index. > > >> > > > > >>>> > > >> > > > > >>>> -Anil. > > >> > > > > >>>> > > >> > > > > >>>> > > >> > > > > >>>> > > >> > > > > >>>> On Fri, Sep 8, 2017 at 2:01 PM, Nabarun Nag < > > n...@pivotal.io > > >> > > > >> > > > wrote: > > >> > > > > >>>> > > >> > > > > >>>>> Hi Mike, > > >> > > > > >>>>> > > >> > > > > >>>>> Please do find our answers below: > > >> > > > > >>>>> *Question:* What if there were multiple indices that > were > > in > > >> > > flight > > >> > > > > >> and > > >> > > > > >>>>> only the third > > >> > > > > >>>>> one errors out, will they all be marked invalid? > > >> > > > > >>>>> > > >> > > > > >>>>> *Answer:* Only the third will be marked invalid and only > > the > > >> > > third > > >> > > > > >> one > > >> > > > > >>>> will > > >> > > > > >>>>> not be used for query execution. > > >> > > > > >>>>> > > >> > > > > >>>>> *Question/Statement:* If anything goes wrong with the > put > > it > > >> > > should > > >> > > > > >>>>> probably still throw back to > > >> > > > > >>>>> the caller. Silent invalidation of the index is probably > > not > > >> > > > > >> desirable. > > >> > > > > >>>>> > > >> > > > > >>>>> *Answer: * > > >> > > > > >>>>> In our current design this the flow of execution of a > put > > >> > > > operation: > > >> > > > > >>>>> entry put into region -> update index -> other wan > related > > >> > > > > >> executions / > > >> > > > > >>>>> callbacks etc. > > >> > > > > >>>>> > > >> > > > > >>>>> If an exception happens while updating the index, the > > cache > > >> > gets > > >> > > > > >> into a > > >> > > > > >>>> bad > > >> > > > > >>>>> state, and we may end up getting different results > > >> depending on > > >> > > the > > >> > > > > >>> index > > >> > > > > >>>>> we are using. As the failure happens half way in a put > > >> > operation, > > >> > > > the > > >> > > > > >>>>> regions / cache are now in a bad state. > > >> > > > > >>>>> -------------------------- > > >> > > > > >>>>> We are thinking that if index is created over a method > > >> > > invocation > > >> > > > in > > >> > > > > >>> an > > >> > > > > >>>>> empty region and then we do puts, but method invocation > is > > >> not > > >> > > > > >> allowed > > >> > > > > >>> as > > >> > > > > >>>>> per security policies. The puts will now be successful > but > > >> the > > >> > > > index > > >> > > > > >>> will > > >> > > > > >>>>> be rendered invalid. Previously the puts will fail with > > >> > exception > > >> > > > and > > >> > > > > >>> put > > >> > > > > >>>>> the entire cache in a bad state. > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> Regards > > >> > > > > >>>>> Nabarun > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> > > >> > > > > >>>>> On Fri, Sep 8, 2017 at 10:43 AM Michael Stolz < > > >> > mst...@pivotal.io > > >> > > > > > >> > > > > >>> wrote: > > >> > > > > >>>>> > > >> > > > > >>>>>> Just to help me understand, the index is corrupted in a > > way > > >> > > beyond > > >> > > > > >>> just > > >> > > > > >>>>> the > > >> > > > > >>>>>> field that errors out? > > >> > > > > >>>>>> What if there were multiple indices that were in flight > > and > > >> > only > > >> > > > > >> the > > >> > > > > >>>>> third > > >> > > > > >>>>>> one errors out, will they all be marked invalid? > > >> > > > > >>>>>> If anything goes wrong with the put it should probably > > >> still > > >> > > throw > > >> > > > > >>> back > > >> > > > > >>>>> to > > >> > > > > >>>>>> the caller. Silent invalidation of the index is > probably > > >> not > > >> > > > > >>> desirable. > > >> > > > > >>>>>> > > >> > > > > >>>>>> -- > > >> > > > > >>>>>> Mike Stolz > > >> > > > > >>>>>> Principal Engineer, GemFire Product Manager > > >> > > > > >>>>>> Mobile: +1-631-835-4771 <(631)%20835-4771> > <(631)%20835-4771> > > <(631)%20835-4771> > > >> <(631)%20835-4771> <(631)%20835-4771> > > >> > > > <(631)%20835-4771> > > >> > > > > >>>>>> > > >> > > > > >>>>>> On Fri, Sep 8, 2017 at 12:34 PM, Dan Smith < > > >> dsm...@pivotal.io > > >> > > > > >> > > > > >>> wrote: > > >> > > > > >>>>>> > > >> > > > > >>>>>>> +1 > > >> > > > > >>>>>>> > > >> > > > > >>>>>>> -Dan > > >> > > > > >>>>>>> > > >> > > > > >>>>>>> On Thu, Sep 7, 2017 at 9:14 PM, Nabarun Nag < > > >> n...@apache.org > > >> > > > > >> > > > > >>> wrote: > > >> > > > > >>>>>>> > > >> > > > > >>>>>>>> *Proposal:* > > >> > > > > >>>>>>>> * Index interface will include an API - isValid() > which > > >> will > > >> > > > > >>> return > > >> > > > > >>>>>> true > > >> > > > > >>>>>>> if > > >> > > > > >>>>>>>> the index is still valid / uncorrupted, else will > > return > > >> > false > > >> > > > > >> if > > >> > > > > >>>> it > > >> > > > > >>>>>>>> corrupted / invalid. > > >> > > > > >>>>>>>> * gfsh command "list index" will have one more column > > "Is > > >> > > > > >> Valid" > > >> > > > > >>>>> which > > >> > > > > >>>>>>> will > > >> > > > > >>>>>>>> state the status as "true" or "false". > > >> > > > > >>>>>>>> * Invalid indexes will not be used during query > > >> executions. > > >> > > > > >>>>>>>> * In case the index is found to be invalid, the user > > >> will be > > >> > > > > >> able > > >> > > > > >>>> to > > >> > > > > >>>>>>>> remove/destroy the index. > > >> > > > > >>>>>>>> * When a put operation corrupts an index, it will be > > >> logged. > > >> > > > > >>>>>>>> > > >> > > > > >>>>>>>> *Reasoning:* > > >> > > > > >>>>>>>> * Currently if a put operation raises an exception > > while > > >> > > > > >> updating > > >> > > > > >>>> the > > >> > > > > >>>>>>>> index, the put operation fails with an exception to > the > > >> > > putter. > > >> > > > > >>>>>>>> * For example, if an index is created on an object > > >> method, > > >> > and > > >> > > > > >>> that > > >> > > > > >>>>>>> method > > >> > > > > >>>>>>>> causes an exception while updating the index as a > part > > >> of a > > >> > > put > > >> > > > > >>>>>>> operation, > > >> > > > > >>>>>>>> then the put operation fails for that particular > entry > > >> and > > >> > the > > >> > > > > >>>> index > > >> > > > > >>>>> is > > >> > > > > >>>>>>>> left in a bad state. > > >> > > > > >>>>>>>> * This may occur also due to lack of permission to > > update > > >> > > index > > >> > > > > >>> but > > >> > > > > >>>>>> have > > >> > > > > >>>>>>>> permission to do puts. > > >> > > > > >>>>>>>> * We are proposing that in the above mentioned > > scenarios, > > >> > the > > >> > > > > >> put > > >> > > > > >>>>>>> succeeds > > >> > > > > >>>>>>>> in putting the entry in the region but the index > which > > it > > >> > was > > >> > > > > >>>> trying > > >> > > > > >>>>> to > > >> > > > > >>>>>>>> update will be marked invalid and will not be used > for > > >> query > > >> > > > > >>>>>> executions. > > >> > > > > >>>>>>>> * This can be justified because the corrupted index > > will > > >> not > > >> > > > > >>>>> correctly > > >> > > > > >>>>>>>> represent the region entries. > > >> > > > > >>>>>>>> > > >> > > > > >>>>>>>> *Status Quo:* > > >> > > > > >>>>>>>> * Index creation will still fail if we are trying to > > >> create > > >> > an > > >> > > > > >>>> index > > >> > > > > >>>>>>> over a > > >> > > > > >>>>>>>> region containing an entry/entries which will cause > an > > >> > > > > >> exception > > >> > > > > >>>>> while > > >> > > > > >>>>>>>> loading the entry into the index. > > >> > > > > >>>>>>>> > > >> > > > > >>>>>>>> Regards > > >> > > > > >>>>>>>> Nabarun Nag > > >> > > > > >>>>>>>> > > >> > > > > >>>>>>> > > >> > > > > >>>>>> > > >> > > > > >>>>> > > >> > > > > >>>> > > >> > > > > >>> > > >> > > > > >> > > >> > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > > > > >
