[jira] [Updated] (SOLR-6364) _version_ value too big for javascript clients causing reported _version_ never matching internal _version_ ==> suggested resolution: json should communicate _version_ as string!

["Tomas Eduardo Fernandez Lobbe (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/SOLR-6364?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Tomas Eduardo Fernandez Lobbe updated SOLR-6364:
------------------------------------------------
    Component/s:     (was: update)
                 Admin UI

> _version_ value too big for javascript clients causing reported _version_ never matching internal _version_ ==> suggested resolution: json should communicate _version_ as string! 
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: SOLR-6364
>                 URL: https://issues.apache.org/jira/browse/SOLR-6364
>             Project: Solr
>          Issue Type: Bug
>          Components: Admin UI
>    Affects Versions: 4.9
>         Environment: ubuntu 14.04 desktop 32bit
> Oracle Corporation Java HotSpot(TM) Server VM (1.7.0_45 24.45-b08)
> lucene-spec 4.9.0
> lucene-impl 4.9.0 1604085 - rmuir - 2014-06-20 06:22:23
> solr-spec  4.9.0
> solr-impl  4.9.0 1604085 - rmuir - 2014-06-20 06:34:03
>            Reporter: Marc Portier
>            Priority: Major
>
> There seems to be a 100 based rounding active in the output/rendition/return of the _version_ field of added documents.  Internally on the solr side however the real number (non-rounded) is effective and introduces conflicts with the optimistic concurrency logic.
> Apparently this is to be expected in all Javascript clients, since the _version_ numbers used are too big to fit into Javascript Number variables without loss of precision.
> Here is what one can do to see this in action - all steps below with 
> 1/ using the solr4 admin UI on 
>     http://localhost:8983/solr/#/mycore/documents
> 2/ the request-handler box set to 
>     /update?commit=true&versions=true
> 3/ by adding the following into the "documents"  section on the page:
> [1] for create 
> Using:
> { "id": "tst-abcd, "version": 1, "type": "test", "title": ["title"], "_version_": -1 }
> Response:
> {  "responseHeader": {    "status": 0,    "QTime": 1882  },
>   "adds": [    "tst-abcd",    1476172747866374100  ]
> }
> >> see the returned __version__ is a multiple of 100, always!
> [2] update
> Using:
> { "id": "tst-abcd", "version": 2, "type": "test", "title": ["title update"], "_version_": 1476172747866374100 }
> Response Error:
> {  "responseHeader": {    "status": 409,    "QTime": 51  },
>   "error": {    "msg": "version conflict for tst-abcd expected=1476172747866374100 actual=1476172747866374144",
>     "code": 409  }}
> >> notice how the error-message-string correctly mentions the real actual __version__ that is effective (not rounded to 100)
> [3] corrected update, using that effective number
> { "id": "tst-abcd", "version": 2, "type": "test", "title": ["title update"], "_version_": 1476172747866374144 }
> Response:
> {  "responseHeader": {    "status": 0,    "QTime": 597  },
>   "adds": [    "tst-abcd",    1476173026894545000  ] }
> Odd at first this behaviour is not shown with curl on the command line...
> [1] create
> $ curl "$solrbase/update?commit=true&versions=true" -H 'Content-type:application/json' -d '[{ "id": "tst-1234", "version": 1, "type": "test", "title": ["title"], "_version_": -1 }]'
> response: 
> {"responseHeader":{"status":0,"QTime":587},"adds":["tst-1234",1476163269470191616]}
> >> number is not rounded, looks good!
> [2] update 
> $ curl "$solrbase/update?commit=true&versions=true" -H 'Content-type:application/json' -d '[{ "id": "tst-1234", "version": 2, "type": "test", "title": ["title updated"], "_version_": 1476163269470191616 }]'
> response: 
> {"responseHeader":{"status":0,"QTime":512},"adds":["tst-1234",1476163320472928256]}
> All this was pretty much a mistery to me untill I came across this:
> http://stackoverflow.com/questions/15689790/parse-json-in-javascript-long-numbers-get-rounded
> This looks like passing down the too big numbers in the __version__ as strings should avoid the issue. Or use numbers that aren't that big, since apparently: "The largest number JavaScript can handle without loss of precision is 9007199254740992"  -- quoted from that stackoverflow page.
> There are more references (below) talking about this being a Javascript limitation rather then a pure json-spec issue, nevertheless... it might be easier to adapt solr to deal with this know Javascript limitation and thus helping out the Javascript clients out there?
> - http://stackoverflow.com/questions/307179/what-is-javascripts-max-int-whats-the-highest-integer-value-a-number-can-go-t
> - http://stackoverflow.com/questions/13502398/json-integers-limit-on-size
> In terms of backwards compatibility I don't see an easy way out for the moment.  
> - clients that expect __version__ to be numeric might not handle the string
> - in existing deployments it might be hard to reduce all the already existing __version__ to stay undere the limit...
> I still have to investigate into receiving and parsing XML replies from SOLR instead - making sure I keep the returned __version__ info in a Javascript string.  Hoping that might work as a timely (but not as elegant) workaround.



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