[ 
https://issues.apache.org/jira/browse/NIFI-3682?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15976661#comment-15976661
 ] 

ASF GitHub Bot commented on NIFI-3682:
--------------------------------------

Github user markap14 commented on a diff in the pull request:

    https://github.com/apache/nifi/pull/1682#discussion_r112449062
  
    --- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/grok/GrokReader.java
 ---
    @@ -23,38 +23,58 @@
     import java.io.Reader;
     import java.util.ArrayList;
     import java.util.List;
    +import java.util.Map;
    +import java.util.regex.Matcher;
     
     import org.apache.nifi.annotation.documentation.CapabilityDescription;
     import org.apache.nifi.annotation.documentation.Tags;
     import org.apache.nifi.annotation.lifecycle.OnEnabled;
    +import org.apache.nifi.components.AllowableValue;
     import org.apache.nifi.components.PropertyDescriptor;
     import org.apache.nifi.controller.ConfigurationContext;
     import org.apache.nifi.flowfile.FlowFile;
     import org.apache.nifi.logging.ComponentLog;
     import org.apache.nifi.processor.util.StandardValidators;
    +import org.apache.nifi.schema.access.SchemaAccessStrategy;
    +import org.apache.nifi.schema.access.SchemaNotFoundException;
    +import org.apache.nifi.schemaregistry.services.SchemaRegistry;
     import org.apache.nifi.serialization.RecordReader;
    -import org.apache.nifi.serialization.RowRecordReaderFactory;
    -import org.apache.nifi.serialization.SchemaRegistryRecordReader;
    +import org.apache.nifi.serialization.RecordReaderFactory;
    +import org.apache.nifi.serialization.SchemaRegistryService;
    +import org.apache.nifi.serialization.SimpleRecordSchema;
    +import org.apache.nifi.serialization.record.DataType;
    +import org.apache.nifi.serialization.record.RecordField;
    +import org.apache.nifi.serialization.record.RecordFieldType;
     import org.apache.nifi.serialization.record.RecordSchema;
     
     import io.thekraken.grok.api.Grok;
    +import io.thekraken.grok.api.GrokUtils;
     import io.thekraken.grok.api.exception.GrokException;
     
     @Tags({"grok", "logs", "logfiles", "parse", "unstructured", "text", 
"record", "reader", "regex", "pattern", "logstash"})
     @CapabilityDescription("Provides a mechanism for reading unstructured text 
data, such as log files, and structuring the data "
         + "so that it can be processed. The service is configured using Grok 
patterns. "
         + "The service reads from a stream of data and splits each message 
that it finds into a separate Record, each containing the fields that are 
configured. "
    -    + "If a line in the input does not match the expected message pattern, 
the line of text is considered to be part of the previous "
    -    + "message, with the exception of stack traces. A stack trace that is 
found at the end of a log message is considered to be part "
    -    + "of the previous message but is added to the 'STACK_TRACE' field of 
the Record. If a record has no stack trace, it will have a NULL value "
    -    + "for the STACK_TRACE field. All fields that are parsed are 
considered to be of type String by default. If there is need to change the type 
of a field, "
    -    + "this can be accomplished by configuring the Schema Registry to use 
and adding the appropriate schema.")
    -public class GrokReader extends SchemaRegistryRecordReader implements 
RowRecordReaderFactory {
    +    + "If a line in the input does not match the expected message pattern, 
the line of text is either considered to be part of the previous "
    +    + "message or is skipped, depending on the configuration,, with the 
exception of stack traces. A stack trace that is found at the end of "
    +    + "a log message is considered to be part of the previous message but 
is added to the 'stackTrace' field of the Record. If a record has "
    +    + "no stack trace, it will have a NULL value for the stackTrace field. 
All fields that are parsed are considered to be of type String by default. "
    --- End diff --
    
    I'll preface this comment with the disclaimer that I have little experience 
with LogStash and Grok. However, through my "extensive" google-based research, 
it looks like Grok itself doesn't really provide all of the necessary means for 
easily capturing stack traces. LogStash, for instance, adds on top of that to 
allow for multiline filters, multiline codecs, etc. There are several different 
approaches used in LogStash to capture stack traces, though, and it appears to 
be one of the very common problems that people run into. Perhaps it would make 
sense to introduce a LogStash reader at some point that could add more of those 
capabilities into reading log messages. But for now it made sense to me to 
instead simply check for a stack trace ourselves, since it is such a very 
common problem and I wanted to make it as easy as possible for users


> Add "Schema Access Strategy" to Record Readers and Writers
> ----------------------------------------------------------
>
>                 Key: NIFI-3682
>                 URL: https://issues.apache.org/jira/browse/NIFI-3682
>             Project: Apache NiFi
>          Issue Type: Improvement
>          Components: Extensions
>            Reporter: Mark Payne
>            Assignee: Mark Payne
>             Fix For: 1.2.0
>
>
> Currently the record readers are mostly configured with a Schema Registry 
> service and the name of the schema. We should instead allow user to choose 
> one of several strategies for determining the schema: Schema Registry + 
> schema.name attribute, Schema Registry + identifier and version embedded at 
> start of record/stream, avro.schema attribute, embedded schema for cases like 
> Avro where the schema can be embedded in the content itself.
> On the writer side, we should also expose these options in order to convey 
> the schema information to others.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to