[
https://issues.apache.org/jira/browse/SOLR-6364?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18132139#comment-18132139
]
Nick Shanin commented on SOLR-6364:
-----------------------------------
>From code reading against apache/main b73f03976fa, the JSON response writer
>emits numFound and start through writeLong as bare JSON numbers, and no
>existing option quotes 64-bit values
>(solr/core/src/java/org/apache/solr/response/JSONWriter.java:145-148). The
>open choice is whether Solr should add an opt-in response option that writes
>64-bit values as JSON strings. Option one adds that opt-in, which keeps
>_version_ exact for JavaScript clients but needs a new request parameter.
>Option two closes the ticket as a client-side precision limit of JavaScript
>number parsing, with no server change. Which of these two options do you
>prefer?
🤖 AI-generated 🤖
> _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.
--
This message was sent by Atlassian Jira
(v10.3.26#10030026)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
