I don't think MergeContent supports multiple attribute names for the correlation attribute, but you could put an UpdateAttribute processor right before it and make a new attribute like: combined = ${attribute1}_${attribute2} and then use "combined" in MergeContent ... View more

If I'm understanding the scenario correctly, you would probably do something like this... - ExecuteSQL/QueryDatabaseTable to get data from the database, produces Avro - ConvertAvroToJSON or ConvertAvroToCSV, I'm going to use JSON going forward - SplitJSON to split each record into its own flow file - EvaluateJSONPath to extract DoA, DoB, and DoC into flow file attributes From here it kind of depends the logic you want to happen and whether those three fields are mutually exclusive (only one is ever true) or if 2 out of 3 can be true, but you would use RouteOnAttribute with a property like DoA = ${DoA:equals("true")} to send everything that matches that to that relationship, and then send that relationship to the processors you want to perform the logic when DoA is true. You could have a series of RouteOnAttribute processors, or you could have one with complex statements like: ${DoA:equals("true"):and( ${DoB:equals("false")} )} You can take a look at the expression language guide for more detail on constructing the right expressions: https://nifi.apache.org/docs/nifi-docs/html/expression-language-guide.html ... View more

There is no local authentication. NiFi provides authentication with 2-way SSL (certificates), Kerberos, or LDAP. You can also implement your own identity provider to authenticate users however you like: https://github.com/apache/nifi/blob/d1129706e235548daaf4eecf7001b244300761e9/nifi-framework-api/src/main/java/org/apache/nifi/authentication/LoginIdentityProvider.java You would create a NAR with your implementation and put it in NiFI lib. ... View more

PutHBaseCell is used to write a single cell to HBase and it uses the content of the FlowFile as the value of the cell, the column family and column qualifier come from properties in the processor. If you want to write multiple values then you would want to use PutHBaseJSON which takes a flat JSON document and uses the field names as column qualifiers and the value of each field as the value for that column qualifier. The column family is a property in the processor. It doesn't support writing to multiple column families, so you would need to take your original data and split it into two JSON documents, one for column family 1 and one for column family 2. You could then have two PutHBaseJSON processors for each column family, or you could have one where the column family was set to ${col.family} and you could set an attribute "col.family" on each flow file upstream to specify which column family goes with that flow file. ... View more

This is actually a little bit challenging to do right now... I'm assuming that after you get the CSV from Kafka you then used SplitText to split it into individual lines, and then converted each of those to CQL somehow? There currently isn't a great way to count that all of the flow files from the original CSV have reached a certain point in the flow, but there are a few JIRA tickets open to be able to do something like this. The idea would be have a processor that could act as barrier after the Cassandra processor and could wait for all N flow files before allowing anything to proceed, and at that point you could then send a notification to the user. One of the relevant JIRAs is this one: https://issues.apache.org/jira/browse/NIFI-1926 ... View more