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Flume >> mail # user >> Handling malformed data when using custom AvroEventSerializer and HDFS Sink


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Re: Handling malformed data when using custom AvroEventSerializer and HDFS Sink
Thanks Wolfgang!  That is very nice.
On Thu, Jan 2, 2014 at 6:49 PM, Wolfgang Hoschek <[EMAIL PROTECTED]>wrote:

> FWIW, here is an example for how this could be handled in a
> MorphlineInterceptor:
>
> morphlines : [
>   {
>     id : morphline1
>     importCommands : ["org.kitesdk.**"]
>
>     commands : [
>       {
>         tryRules {
>           catchExceptions: true
>           rules : [
>             # first rule
>             {
>               commands : [
>                 # save initial state
>                 { setValues { _tmp : "@{_attachment_body}" } }
>
>                 # if JSON parsing succeeds replace _attachment_body with
> JSON jackson object
>                 { readJson {} }
>
>                 # if we reach here the JSON parsing has succeeded
>                 # restore state prior to readJson command
>                 { setValues { _attachment_body : "@{_tmp}" } }
>                 { setValues { _tmp : [] } }
>                 { setValues { _attachment_mimetype : [] } }
>               ]
>             }
>
>             # second rule is executed if the previous rule failed or threw
> an exception
>             {
>               commands : [
>                 { logDebug { format : "Marking event as malformed for
> downstream sink: {}", args: ["@{}"] } }
>                 { addValues { malformed : true } }
>               ]
>             }
>
>           ]
>         }
>       }
>     ]
>   }
> ]
>
> Also see
> http://kitesdk.org/docs/current/kite-morphlines/morphlinesReferenceGuide.html#tryRules
>
> Wolfgang.
>
> On Jan 3, 2014, at 2:03 AM, ed wrote:
>
> > Thank you Brock, Devin and Jimmy for the great information.  Dumping
> null values in the the EventSerializer write method looks really easy to do
> but I think using the custom interceptor to validate then tag the event for
> proper good/bad routing sounds like a great idea and seems to fit into the
> Flume way of doing things better.
> >
> > Thank you again!
> >
> > ~Ed
> >
> >
> > On Fri, Jan 3, 2014 at 2:40 AM, Devin Suiter RDX <[EMAIL PROTECTED]>
> wrote:
> > Yes, the regex interceptors and selectors can be very powerful -
> experimenting with them was really exciting.
> >
> > Brock, thanks for validating the ML idea - as with most things, the
> simplest solution is probably the way to go, and in this use case, the
> morphlines might be overkill.
> >
> > Devin Suiter
> > Jr. Data Solutions Software Engineer
> >
> > 100 Sandusky Street | 2nd Floor | Pittsburgh, PA 15212
> > Google Voice: 412-256-8556 | www.rdx.com
> >
> >
> > On Thu, Jan 2, 2014 at 12:27 PM, Brock Noland <[EMAIL PROTECTED]>
> wrote:
> > Jimmy, great to hear that method is working for you!
> >
> > Devin, regarding the morphlines question. Since ML can have arbitrary
> java plugins it *can* do just about anything. I generally think of ML as
> the T in ETL. Doing the validation in ML might make sense. In general
> though I think adding the custom header field as probably the best option
> for dealing with bad data.
> >
> > Once again, thank you everyone for using our software!
> >
> >
> > On Thu, Jan 2, 2014 at 10:10 AM, Jimmy <[EMAIL PROTECTED]> wrote:
> > We are doing similar thing what Brock mentioned - simple interceptor for
> JSON validation with updating custom field in the header, then flume HDFS
> sink pushes the data to good/bad target directory based on this custom
> field.... then watch for bad directory in separate process.
> >
> > You could add notification to the flume flow, we wanted to keep it very
> simple.
> >
> >
> >
> >
> > ---------- Forwarded message ----------
> > From: Devin Suiter RDX <[EMAIL PROTECTED]>
> > Date: Thu, Jan 2, 2014 at 7:40 AM
> > Subject: Re: Handling malformed data when using custom
> AvroEventSerializer and HDFS Sink
> > To: [EMAIL PROTECTED]
> >
> >
> > Just throwing this out there, since I haven't had time to dig into the
> API with a big fork, but, can morphlines offer any assistance here?
> >
> > Some kind of an interceptor that would parse for malformed data, package
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