reduceContext.errors

Property Description	Holds serialized errors that were thrown during previous attempts to execute the reduce function on the current key and its values. This iterator may also hold the SSS_APP_SERVER_RESTART error code, which is recorded if the function is interrupted by an application server restart. For an overview of events that can cause the map function to be invoked multiple times for a key-value pair, see System Response After a Map/Reduce Interruption.
Type	iterator
Since	2018.1

Members

Member	Type	Required/Optional	Description
iterator().each(parameters)	function	required	Executes one time for each error.

parameters

Member	Type	Required/Optional	Description
iteratorFunction(key, error, executionNo) See also functionParameters.	function	required	Provides logic to be executed during each iteration.

functionParameters

Parameter	Type	Required/Optional	Description
key	string	optional	Represents the key-value pair that the reduce function was attempting to process when the error occurred.
error	string	optional	A serialization of the error thrown.
executionNo	number	optional	Indicates whether the error occurred during the first or a subsequent attempt to process the key.

Syntax

The following snippets shows three ways you could use this iterator.

This code is not a functional example. For a complete script sample, see Map/Reduce Script Samples.

          //Add additional code
...

// Create a log entry showing each full serialized error, and the corresponding key.

context.errors.iterator().each(function (key, error, executionNo){
    log.error({
        title:  'Reduce error for key: ' + key + ', execution no  ' + executionNo,
        details: error
    });
    return true;
});


// Log only the name and description of each error thrown.

context.errors.iterator().each(function (key, error, executionNo){
    var errorObject = JSON.parse(error);
    log.error({
        title: 'Reduce error for key ' + key + ', execution no.  ' + executionNo,
        details: errorObject.name + ': ' + errorObject.message
    });
    return true;
});


// Calculate and log the number of errors encountered.

var errorCount = 0;
context.errors.iterator().each(function() {
    errorCount ++;
    return true;
});

log.audit ({
    title: 'Errors for reduce key: ' + context.key, 
    details: 'Total number of errors: ' + errorCount 
}); 

        

Related Topics

reduceContext

reduceContext.isRestarted

reduceContext.executionNo

reduceContext.key

reduceContext.values

reduceContext.write(options)

General Notices