src/org/objectweb/cjdbc/controller/loadbalancer/raidb1/RAIDb1ec_WRR.java

説明を見る。

package org.objectweb.cjdbc.controller.loadbalancer.raidb1;

import java.sql.SQLException;
import java.util.HashMap;

import org.objectweb.cjdbc.common.i18n.Translate;
import org.objectweb.cjdbc.common.sql.NotImplementedException;
import org.objectweb.cjdbc.common.sql.SelectRequest;
import org.objectweb.cjdbc.common.sql.StoredProcedure;
import org.objectweb.cjdbc.common.xml.DatabasesXmlTags;
import org.objectweb.cjdbc.controller.cache.metadata.MetadataCache;
import org.objectweb.cjdbc.controller.loadbalancer.WeightedBalancer;
import org.objectweb.cjdbc.controller.loadbalancer.policies.WaitForCompletionPolicy;
import org.objectweb.cjdbc.controller.loadbalancer.policies.errorchecking.ErrorCheckingPolicy;
import org.objectweb.cjdbc.controller.virtualdatabase.ControllerResultSet;
import org.objectweb.cjdbc.controller.virtualdatabase.VirtualDatabase;

public class RAIDb1ec_WRR extends RAIDb1ec
{
  /*
   * How the code is organized ? 1. Member variables 2. Constructor(s) 3.
   * Request handling 4. Debug/Monitoring
   */

  //  private int index; // index in the backend vector the Round-Robin
  private HashMap weights;

  /*
   * Constructors
   */

  public RAIDb1ec_WRR(VirtualDatabase vdb,
      WaitForCompletionPolicy waitForCompletionPolicy,
      ErrorCheckingPolicy errorCheckingPolicy, int nbOfConcurrentReads)
      throws SQLException
  {
    super(vdb, waitForCompletionPolicy, errorCheckingPolicy,
        nbOfConcurrentReads);
    // index = -1;
  }

  /*
   * Request Handling
   */

  public ControllerResultSet execReadRequest(SelectRequest request, MetadataCache metadataCache)
      throws SQLException
  {
    throw new NotImplementedException(this.getClass().getName()
        + ":execReadRequest");
  }

  public ControllerResultSet execReadOnlyReadStoredProcedure(StoredProcedure proc, MetadataCache metadataCache)
      throws SQLException
  {
    throw new NotImplementedException(this.getClass().getName()
        + ":execReadStoredProcedure");
  }

  /*
   * Backends management
   */

  public void setWeight(String name, int w) throws SQLException
  {
    if (logger.isDebugEnabled())
      logger.debug(Translate.get("loadbalancer.weight.set", new String[]{
          String.valueOf(w), name}));

    weights.put(name, new Integer(w));
  }

  /*
   * Debug/Monitoring
   */

  public String getInformation()
  {
    // We don't lock since we don't need a top accurate value
    int size = vdb.getBackends().size();

    if (size == 0)
      return "RAIDb-1 Error Checking with Weighted Round-Robin Request load balancer: "
          + "!!!Warning!!! No backend nodes found\n";
    else
      return "RAIDb-1 Error Checking with Weighted Round-Robin Request load balancer ("
          + size + " backends)\n";
  }

  public String getRaidb1Xml()
  {
    return WeightedBalancer.getRaidbXml(weights,
        DatabasesXmlTags.ELT_RAIDb_1ec_WeightedRoundRobin);
  }
}

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