Cool! Thanks for the answers! Norbert mentions something interesting about references. I have found that even though on each query mongo get the up-to-date version of the objects, it does not install the proxies to look for the up-to-date versions of the references of the queried object.
I made the following experiment: Having two images 1 and 2 and two classes A and B, each of them having one instance variable. ————————— Image 1 (Create two objects, “a” referencing “b”) [ |a b| a := A new. b := B new a setInstVar: b. b setInstVar: ‘foo'. b save. a save. ] Image 2 (Mutates the second object, but the first is not changed) [ b := (repository selectAll: A) first instVar. b setInstVar: ‘bar’. b save. ] Image 1 (Query the first object and access to the referenced object) [ b := (repository selectAll: A) first instVar. b instVar. “-> foo” b := (repository selectAll: B) first. b instVar. “-> bar" ] This little experiment showed me that I cannot trust on the state of other objects that I have not explicitly queried for. Is there any way of solving this without creating new instances of voyage repositories for each request? Thanks! Alejandro > On Jan 25, 2017, at 7:27 AM, Esteban Lorenzano <esteba...@gmail.com> wrote: > >> >> On 25 Jan 2017, at 01:30, Alejandro Infante <alejandroinfant...@gmail.com> >> wrote: >> >> Hi! >> >> I’m close to deploy a web service using Pharo with Voyage and MongoDB. I >> have been playing with it and everything works ok with a single Pharo image. >> >> Couple of days ago I started questioning myself about how voyage behaves >> when you have multiple pharo images using the same mongo database >> (horizontal scaling). I want to know how the cache of voyage behaves in a >> scenario with object updates. >> >> Example: —————————————— >> Imagine I have two images A and B. >> >> - Image A query for object o and voyage put it in the cache. >> - Image B query for object o and voyage put it in the cache. >> - Image A updates object o and push it into the database calling #save. >> - Image B query for object o that should be already in the cache. >> >> In this case, does Image B see the changes performed by image A? >> —————————————— > > yes. > Voyage will always verify the version on the mongodb, no matter the cache, > because in fact, the cache of Voyage is meant just to keep object identity > (there has been discussions on if this is a real cache… I think it is, but > with a different purpose than usual). > Recently Martin enhanced that part by adding > VMMongoRepository>>saveEnsuringCurrent: protocol who will also check your > version is correct when writing (to avoid overwrite before update). > > So, this should be Ok :) > > Esteban > >> >> All ideas are welcome :) >> >> Thanks and cheers! >> Alejandro
