Mohit, I see. I think this is an issue because the Avro Writer expects that the data must be in the proper schema, or else it will throw an Exception when trying to write the data. To address this, we should update ValidateRecord to support a different Record Writer to use for valid data vs. invalid data. There already is a JIRA [1] for this improvement.
In the meantime, it probably makes sense to use a CSV Reader and a CSV Writer for the Validate Record processor, then use ConvertRecord only for the valid records. Or, since you're running into this issue it may make sense for your use case to continue on with the ConvertCSVToAvro processor for now. But splitting the records up to run against that Processor may result in lower performance, as you've noted. Thanks -Mark [1] https://issues.apache.org/jira/browse/NIFI-4883 On Apr 2, 2018, at 10:26 AM, Mohit <[email protected]<mailto:[email protected]>> wrote: Mark, Error:- ValidateRecord[id=5a9c3616-ab7c-17c1-ffff-ffffe6c2fc5d] ValidateRecord[id=5a9c3616-ab7c-17c1-ffff-ffffe6c2fc5d] failed to process due to org.apache.nifi.serialization.record.util.IllegalTypeConversionException: Cannot convert value mohit of type class java.lang.String because no compatible types exist in the UNION for field name; rolling back session: Cannot convert value mohit of type class java.lang.String because no compatible types exist in the UNION for field name I have a file with only one record :- mohit,25 Just to check how it works, I’ve given incorrect schema: (int for string field) {"type":"record","name":"test","namespace":"test","fields":[{"name":"name","type":["null","int"],"default":null},{"name":"age","type":["null","string"],"default":null}]} It doesn’t pass the record to invalid relationship. But it keeps the file in the queue prior to validateRecord processor. Mohit From: Mark Payne <[email protected]<mailto:[email protected]>> Sent: 02 April 2018 19:53 To: [email protected]<mailto:[email protected]> Subject: Re: ConvertCSVToAvro taking a lot of time when passing single record as an input. What is the error that you're seeing? On Apr 2, 2018, at 10:22 AM, Mohit <[email protected]<mailto:[email protected]>> wrote: Hi Mark, I tried the ValidateRecord processor, it is converting the flowfile if it is valid. But If the records are not valid, it is passing to the invalid relationship. Instead it keeps on throwing bulletins keeping the flowfile in the queue. Any suggestion? Mohit From: Mark Payne <[email protected]<mailto:[email protected]>> Sent: 02 April 2018 19:02 To: [email protected]<mailto:[email protected]> Subject: Re: ConvertCSVToAvro taking a lot of time when passing single record as an input. Mohit, You can certainly dial back that number of Concurrent Tasks. Setting that to something like 10 is a pretty big number. Setting it to a thousand means that you'll likely starve out other processors that are waiting on a thread and will generally perform a lot worse because you have 1,000 different threads competing with each other to try to pull the next FlowFile. You can use the ValidateRecord processor and configure a schema that indicates what you expect the data to look like. Then you can route any invalid records to one route and valid records to another route. This will ensure that all data that goes to the 'valid' relationship is routed one way and any other data is routed to the 'invalid' relationship. Thanks -Mark On Apr 2, 2018, at 9:22 AM, Mohit <[email protected]<mailto:[email protected]>> wrote: Hi Mark, The main intention to use such flow is to track bad records. The records which doesn’t get converted should be tracked somewhere. For that purpose I’m using Split-Merge approach. Meanwhile, I’m able to improve the performance by increasing the ‘Concurrent Tasks’ to 1000. Now ConvertCSVToAvro is able to convert 6-7k per second, which though not optimum but quite better than 45-50 records per seconds. Is there any other improvement I can do? Mohit From: Mark Payne <[email protected]<mailto:[email protected]>> Sent: 02 April 2018 18:30 To: [email protected]<mailto:[email protected]> Subject: Re: ConvertCSVToAvro taking a lot of time when passing single record as an input. Mohit, I agree that 45-50 records per second is quite slow. I'm not very familiar with the implementation of ConvertCSVToAvro, but it may well be that it must perform some sort of initialization for each FlowFile that it receives, which would explain why it's fast for a single incoming FlowFile and slow for a large number. Additionally, when you start splitting the data like that, you're generating a lot more FlowFiles, which means a lot more updates to both the FlowFile Repository and the Provenance Repository. As a result, you're basically taxing the NiFi framework far more than if you keep the data as a single FlowFile. On my laptop, though, I would expect more than 45-50 FlowFiles per second through most processors, but I don't know what kind of hardware you are running on. In general, though, it is best to keep data together instead of splitting it apart. Since the ConvertCSVToAvro can handle many CSV records, is there a reason to split the data to begin with? Also, I would recommend you look at using the Record-based processors [1][2] such as ConvertRecord instead of the ConvertABCtoXYZ processors, as those are older processors and often don't work as well and the Record-oriented processors often allow you to keep data together as a single FlowFile throughout your entire flow, which makes the performance far better and makes the flow much easier to design. Thanks -Mark [1] https://blogs.apache.org/nifi/entry/record-oriented-data-with-nifi [2] https://bryanbende.com/development/2017/06/20/apache-nifi-records-and-schema-registries On Apr 2, 2018, at 8:49 AM, Mohit <[email protected]<mailto:[email protected]>> wrote: Hi, I’m trying to capture bad records from ConvertCSVToAvro processor. For that, I’m using two SplitText processors in a row to create chunks and then each record per flow file. My flow is - ListFile -> FetchFile -> SplitText(10000 records) -> SplitText(1 record) -> ConvertCSVToAvro -> *(futher processing) I have a 10 MB file with 15 columns per row and 64000 records. Normal flow (without SplitText) completes in few seconds. But when I’m using the above flow, ConvertCSVToAvro processor works drastically slow(45-50 rec/sec). I’m not able to conclude where I’m doing wrong in the flow. I’m using Nifi 1.5.0 . Any quick input would be appreciated. Thanks, Mohit
