Paul, Streaming is used to minimize memory usage on both sides and reduce latency
I think it is documented in the manual but a blog post would be most appreciated Michael Sent from mobile device Am 25.12.2013 um 17:36 schrieb Paul Grenyer <[email protected]>: > Hi Michael > > Thanks for this it's good to hear how it works. However, it sounds > like correct behaviour has been traded for implementation. I assume > streaming is used because a client might issue a high number of > statements? > > Is this behaviour documented anywhere? If not I'll knock up a blog post. > > Thanks > Paul > > > On 24 December 2013 22:17, Michael Hunger > <[email protected]> wrote: >> Hi Paul, >> >> in this endpoint data is streamed from and to the server. >> >> So that the headers for the response are sent immediately, before any query >> is executed. Then the query results are pulled through lazily and sent to >> the client. >> >> At any stage errors can happen, parsing, starting the execution or returning >> results (imagine division by zero in the last row of your results). >> Also this endpoint can consume multiple statements, so the first x might be >> successful and already stream back data to the client and only the last one >> might fail. Which is the reported in the errors block. >> >> That's why the request doesn't fail as such but errors are returned. As we >> never know if there will be any errors when processing the statements and >> streaming back results or not, so we cannot hold off sending the headers to >> the client >> before the queries are actually parsed, run and fetched through. >> >> >> HTH >> >> Michael >> >> Am 24.12.2013 um 12:27 schrieb Paul Grenyer <[email protected]>: >> >>> Hi >>> >>> This is my first post and a continuation of a discussion with the >>> @neo4j account on twitter. >>> >>> Having read this web page: >>> >>> http://docs.neo4j.org/chunked/milestone/rest-api-transactional.html >>> >>> I constructed the body of a REST POST to >>> http://<myserver>/db/data/transaction/<tx> like this: >>> >>> { >>> "statements":[{ >>> "statement":"MATCH (u:User{username:{username}}), (r:Role >>> name:{rolename}})\nCREATE(u)-[:HAS_ROLE]-\u003e(r)", >>> "parameters":{ >>> "props":{ >>> "username":"user1","rolename":"ROLE_REST_USER" >>> } >>> } >>> }] >>> } >>> >>> I received no error code back from Neo4j by way of the POST. When my >>> update wasn't applied to the database I had to look at the response >>> message to see the problem: >>> >>> { >>> "commit":"http://localhost:7474/db/data/transaction/32/commit";, >>> "results":[], >>> "transaction":{"expires":"Tue,24 Dec 2013 11:16:17+0000"}, >>> "errors":[{ >>> "code":"Neo.ClientError.Statement.ParameterMissing", >>> "message":"Expected a parameter named username" >>> }] >>> } >>> >>> With a little bit of guess work I figured that the 'props' element >>> under 'parameters' wasn't required, rejigged the JSON and it worked. >>> >>> However, I'm left thinking that: >>> >>> 1. The documentation at the above link may need correcting (or perhaps >>> I'm just being dumb and missing something). >>> 2. The POST should have returned an error code. >>> >>> What do you guys think? >>> >>> >>> -- >>> Thanks >>> Paul >>> >>> Paul Grenyer >>> e: [email protected] >>> b: paulgrenyer.blogspot.com >>> t: pjgrenyer >>> >>> Have you thought what Naked Element could do for you? >>> http://nakedelement.co.uk/ >>> >>> It's time to get technical: http://norfolkdevelopers.com >>> >>> Norfolk Developers Conference is coming: http://nordevcon.com/ >>> >>> Enjoyed working with me? Something I could work on? Give me honest, >>> anonymous feedback: https://www.get3sixty.com/:wehop >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Neo4j" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> For more options, visit https://groups.google.com/groups/opt_out. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Neo4j" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/groups/opt_out. > > > > -- > Thanks > Paul > > Paul Grenyer > e: [email protected] > b: paulgrenyer.blogspot.com > t: pjgrenyer > > Have you thought what Naked Element could do for you? > http://nakedelement.co.uk/ > > It's time to get technical: http://norfolkdevelopers.com > > Norfolk Developers Conference is coming: http://nordevcon.com/ > > Enjoyed working with me? Something I could work on? Give me honest, > anonymous feedback: https://www.get3sixty.com/:wehop > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
