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https://issues.apache.org/jira/browse/NIFI-5064?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16469167#comment-16469167
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ASF GitHub Bot commented on NIFI-5064:
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Github user pvillard31 commented on the issue:
https://github.com/apache/nifi/pull/2621
Hi @junegunn - I tested your changes on a simple workflow and what you
propose here makes a lot of sense. I don't see any breaking change and the
error handling looks OK to me. I'm a +1 and will merge to master. Thanks for
your work and your very detailed JIRA. Really appreciated.
> Fixes and improvements to PutKudu processor
> -------------------------------------------
>
> Key: NIFI-5064
> URL: https://issues.apache.org/jira/browse/NIFI-5064
> Project: Apache NiFi
> Issue Type: Improvement
> Affects Versions: 1.6.0
> Reporter: Junegunn Choi
> Priority: Major
>
> 1. Currently, PutKudu fails with NPE on null or missing values.
> 2. {{IllegalArgumentException}} on 16-bit integer columns because of [a
> missing {{break}} in case clause for INT16
> columns|https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-nar-bundles/nifi-kudu-bundle/nifi-kudu-processors/src/main/java/org/apache/nifi/processors/kudu/PutKudu.java#L112-L115].
> 3. Also, {{IllegalArgumentException}} on 8-bit integer columns. We need a
> separate case clause for INT8 columns where {{PartialRow#addByte}} instead of
> {{PartialRow#addShort}} is be used.
> 4. NIFI-4384 added batch size parameter, however, it only applies to
> FlowFiles with multiple records. {{KuduSession}} is created and closed for
> each FlowFile, so if a FlowFile contains only a single record, no batching
> takes place. A workaround would be to use a preprocessor to concatenate
> multiple FlowFiles, but since {{PutHBase}} and {{PutSQL}} use
> {{session.get(batchSize)}} to handle multiple FlowFiles at once, I think we
> can take the same approach here with PutKudu as it simplifies the data flow.
> 5. {{PutKudu}} depends on kudu-client 1.3.0. But we can safely update to
> 1.7.0.
> - [https://github.com/apache/kudu/blob/1.7.0/docs/release_notes.adoc]
> - [https://github.com/apache/kudu/blob/1.7.0/docs/prior_release_notes.adoc]
> A notable change in Kudu 1.7.0 is the addition of Decimal type.
> 6. {{PutKudu}} has {{Skip head line}} property for ignoring the first record
> in a FlowFile. I suppose this was added to handle header lines in CSV files,
> but I really don't think it's something {{PutKudu}} should handle.
> {{CSVReader}} already has {{Treat First Line as Header}} option, so we should
> tell the users to use it instead as we don't want to have the same option
> here and there. Also, the default value of {{Skip head line}} is {{true}},
> and I found it very confusing as my use case was to stream-process
> single-record FlowFiles. We can keep this property for backward
> compatibility, but we should at least deprecate it and change the default
> value to {{false}}.
> 7. Server-side errors such as uniqueness constraint violation are not checked
> and simply ignored. When flush mode is set to {{AUTO_FLUSH_SYNC}}, we should
> check the return value of {{KuduSession#apply}} to see it has {{RowError}},
> but PutKudu currently ignores it. For example, on uniqueness constraint
> violation, we get a {{RowError}} saying "_Already present: key already
> present (error 0)_".
> On the other hand, when flush mode is set to {{AUTO_FLUSH_BACKGROUND}},
> {{KuduSession#apply}}, understandably, returns null, and we should check the
> return value of {{KuduSession#getPendingErrors()}}. And when the mode is
> {{MANUAL_FLUSH}}, we should examine the return value of
> {{KuduSession#flush()}} or {{KuduSession#close()}}. In this case, we also
> have to make sure that we don't overflow the mutation buffer of
> {{KuduSession}} by calling {{flush()}} before too late.
> ----
> I'll create a pull request on GitHub. Since there are multiple issues to be
> addressed, I made separate commits for each issue mentioned above so that
> it's easier to review. You might want to squash them into one, or cherry-pick
> a subset of commits if you don't agree with some decisions I made.
> Please let me know what you think. We deployed the code to a production
> server last week and it's been running since without any issues steadily
> processing 20K records/second.
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