Issue with Vertica UDF (Scalar function)
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.
Comments
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
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
@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
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