Issue with Vertica UDF (Scalar function)

madhura

I was develping a USDF (user defined scalar function) in java for Vertica Analytic Database v7.1.2-5.

I was running it like : select dec_udf(c1) from test_table;

Table is like : create table test_table(c1 varchar(100));

 

The UDF is running fine for some rows(of this table), but it is not picking other rows. The processBlock method is not being entered for those rows. 

 

Code : 

public class MyFunctionFactory extends ScalarFunctionFactory {


public MyFunctionFactory() {
// Tell HP Vertica that any NULL arguments results in a NULL return value
       strict = strictness.RETURN_NULL_ON_NULL_INPUT;
    }


@Override
    public void getPrototype(ServerInterface serverInterface, ColumnTypes argTypes,ColumnTypes returnType) {
        argTypes.addLongVarchar();
        returnType.addLongVarchar();
    }

public void getReturnType(ServerInterface srvInterface, SizedColumnTypes argTypes,
                              SizedColumnTypes returnType) {
        returnType.addLongVarchar(500);
    }


@Override
    public ScalarFunction createScalarFunction(ServerInterface serverInterface) {
        serverInterface.log("Inside CreateScalarFunction");
return new MyFunction(serverInterface);
    }

public class MyFunction extends ScalarFunction {
        String text=null;
        boolean val=true;

        MyFunction(ServerInterface serverInterface){
            serverInterface.log("Inside MyFunction constructor");
        }

@Override
        public void setup(ServerInterface serverInterface, SizedColumnTypes sizedColumnTypes) {
            //some initialization 
            serverInterface.log("Exiting setup method");
        }

@Override
        public void processBlock(ServerInterface srvInterface, BlockReader argReader, BlockWriter resWriter)
        {

            srvInterface.log("Entered the process block");
try {
int i = 0;
                srvInterface.log("no. of rows to be processed are :"+argReader.getNumRows());
do {
// The input and output objects have already loaded
                    // the first row, so you can start reading and writing
                    // values immediately.

                    // Get the argument from the BlockReader
                    srvInterface.log("Entered the process block do-while");
                    srvInterface.log("ROW NUM : " + ++i);
                    srvInterface.log("no. of columns to be processed are :"+argReader.getNumCols());
encryptedText = argReader.getString(0);
                    srvInterface.log("First row of Text = " + text);
                    srvInterface.log("Length of first row = " + argReader.getStringLength(0));


// Process the arguments and come up with a result. For this
                    // example, just add the two arguments together.
                    

                    resWriter.setString(text);

// Advance the output BlocKWriter to the next row.
                    resWriter.next();
// Continue processing input rows until there are no more.


                    val = argReader.next();
if(val == false){
                        srvInterface.log("no input to process next");
                    }
                    srvInterface.log("current value is : "+val);
                } while (val);
            }catch(UdfException udfexception){
                srvInterface.log("UDF Exception here : " + udfexception);
            }
catch (DestroyInvocation destroyInvocation){
                srvInterface.log("Destroy Invocation Exception here : " + destroyInvocation);
            }
catch(Throwable e){
                srvInterface.log("encountered unknown exception. " + e.getMessage());
            }
            srvInterface.log("Exiting this process block method");
        }

    }

 

test_table : 

 

id   | c1
----+-----------------------
1   | somedataisthere

 

 

 

Logs : 

2015-12-31 00:22:51.605 [Java-29849] 0x0b [UserMessage] dec_udf - Inside CreateScalarFunction
2015-12-31 00:22:51.607 [Java-29849] 0x0b [UserMessage] dec_udf  - Inside MyFunction constructor
2015-12-31 00:22:51.607 [Java-29849] 0x0b [UserMessage] dec_udf  - Entered inside setup method
2015-12-31 00:22:52.490 [Java-29849] 0x0b [UserMessage] dec_udf  - Exiting setup method
2015-12-31 00:22:55.933 [Java-29849] 0x0a Socket closed successfully
2015-12-31 00:22:55.936 [Java-29849] 0x0c Exiting UDx side process

 

Why is it not entering the processBlock method for the row in that table? When I tried testing it on another table, with same data, the processBlock is entering for that. Why is it behaving non-deterministically?

 

Please help me resolve this.Thanks.

[Deleted User]

Madhura,

 

Please file a support case for this question:

 

If you already have a MyVertica account, login to MyVertica to file or track a support ticket.

 

If you are a Vertica customer, but need a MyVertica account, just complete the form located on the Customer Sign-Up Form page.

 

Thanks,

 

Sarah L

madhura

Hi Sarah L,

 

This issue got resolved, apparently the some node was down when I was running this. Now it is woking fine. How to close this issue? I couldn't see any option like that, please let me know where it is.

 

Thanks for your response.

 

Madhura

---

SarahL wrote:

Madhura,

 

Please file a support case for this question:

 

If you already have a MyVertica account, login to MyVertica to file or track a support ticket.

 

If you are a Vertica customer, but need a MyVertica account, just complete the form located on the Customer Sign-Up Form page.

 

Thanks,

 

Sarah L

---

 

madhura

@Sarah L, But I still have a point of confusion on why it is not logging the statements properly? For each row, the process-Block method should have been invoked but from the logs, it doesnt seem like, process block is called.

 

These are the relevant logs : 

 

2016-01-03 20:56:20.355 [Java-2281] 0x01 UDx side process (Java) started
2016-01-03 20:56:20.580 [Java-2281] 0x0a Loading VerticaClassLoader
2016-01-03 20:56:21.120 [Java-2281] 0x0b [UserMessage] myfunction - Inside CreateScalarFunction
2016-01-03 20:56:21.121 [Java-2281] 0x0b [UserMessage] myfunction - Inside MyFunction constructor
2016-01-03 20:56:21.122 [Java-2281] 0x0b [UserMessage] myfunction - Exiting setup method
2016-01-03 20:56:25.545 [Java-2281] 0x0a Socket closed successfully
2016-01-03 20:56:25.548 [Java-2281] 0x0c Exiting UDx side process

 

It should log this

srvInterface.log("Entered the process block");  

 

Am I not understading correctly? process-block method doesnt trigger for each row? If not, why it is missing the logs?

 

I am new to Vertica, any help would be appreciated.Thanks.

 

Madhura

[Deleted User]

Madhura,

 

I am not the right person to answer this question, but if you file a support case, you will get a prompt response from our excellent support team.

 

Try the links in my previous response to open a case.

 

Sarah