MultiProcessor

Terminology

• CREATEMULTIPROCESSOR: Creates and loads a multi-processor
• MULTIPROCESS: run a multiprocessor

MultiProcessor example

Processors can operate on the result of one operation. When a user may wishes to combine the results of two or more operations a MultiProcessor is used.

API

A MutliProcess has all the results of all the executed steps res.getOptRes(). Params are supplied from the user in the request.

package org.usergrid.vx.experimental;

import java.util.List;
import java.util.Map;

public interface MultiProcessor {
  public List<Map> multiProcess(Map<Integer,Object> results, Map params);
}

Example

The user wishes to run two slice operations and do a server side union of the results.

  req.add( IntraOp.setKeyspaceOp("myks") ); //0
  req.add( IntraOp.setColumnFamilyOp("mycf") ); //1
  req.add( IntraOp.setAutotimestampOp() ); //2
  req.add( IntraOp.assumeOp("myks", "mycf", "value", "UTF-8")); //3
  req.add( IntraOp.setOp("rowzz", "col1", "7")); //4
  req.add( IntraOp.setOp("rowzz", "col2", "8")); //5
  req.add( IntraOp.setOp("rowyy", "col4", "9")); //6
  req.add( IntraOp.setOp("rowyy", "col2", "7")); //7

Perform two slice operations.

  req.add( IntraOp.sliceOp("rowzz", "a", "z", 100));//8
  req.add( IntraOp.sliceOp("rowyy", "a", "z", 100));//9

Create the union MultiProcess.

   req.add( IntraOp.createMultiProcess("union", "groovy", 
   "public class Union implements org.usergrid.vx.experimental.MultiProcessor { \n"+
   "  public List<Map> multiProcess(Map<Integer,Object> results, Map params){ \n"+
   "    java.util.HashMap s = new java.util.HashMap(); \n"+
   "    List<Integer> ids = (List<Integer>) params.get(\"steps\");\n"+
   "    for (Integer id: ids) { \n"+
   "      List<Map> rows = results.get(id); \n"+
   "      for (Map row: rows){ \n"+
   "        s.put(row.get(\"value\"),\"\"); \n"+
   "      } \n"+
   "    } \n"+ 
   "    List<HashMap> ret = new ArrayList<HashMap>(); \n"+
   "    ret.add(s) \n"+
   "    return ret; \n" +
   "  } \n"+
   "} \n" )); //10 

Create the parameters that will tell the MultiProcess what result ids to include.

Map paramsMap = new HashMap();
List<Integer> steps = new ArrayList<Integer>();
steps.add(8);
steps.add(9);
paramsMap.put("steps", steps);
req.add( IntraOp.multiProcess("union", paramsMap)); //11

The results contain the results after being send to the processor.

List<Map> x = (List<Map>) res.getOpsRes().get(11);
Set<String> expectedResults = new HashSet<String>();
expectedResults.addAll( Arrays.asList(new String[] { "7", "8", "9"}));
Assert.assertEquals(expectedResults, x.get(0).keySet());