Current File : //home/waritko/yacy/source/net/yacy/cora/federate/solr/connector/ShardSelection.java
/**
* SolrChardingSelection
* Copyright 2011 by Michael Peter Christen
* First released 25.05.2011 at http://yacy.net
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.cora.federate.solr.connector;
import java.io.IOException;
import java.net.URL;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;
import net.yacy.cora.document.encoding.ASCII;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.search.schema.CollectionSchema;
import org.apache.solr.client.solrj.SolrClient;
import org.apache.solr.common.SolrInputDocument;
import org.apache.solr.common.SolrInputField;
public class ShardSelection implements Iterable<SolrClient> {
private final Method method; // the sharding method
private final AtomicLong shardID; // the next id that shall be given away
private final int dimension; // the number of chards
private final ArrayList<SolrClient> server;
public enum Method {
MODULO_HOST_MD5("hash-based calculation of storage targets, select all for retrieval"),
ROUND_ROBIN("round-robin of storage targets, select all for retrieval"),
SOLRCLOUD("round-robin of storage targets and round-robin for retrieval");
public final String description;
private Method(final String description) {
this.description = description;
}
}
public ShardSelection(final ArrayList<SolrClient> server, final Method method) {
this.server = server;
this.method = method;
this.dimension = server.size();
this.shardID = new AtomicLong(0);
}
public Method getMethod() {
return this.method;
}
private int selectRoundRobin() {
int rr = (int) (this.shardID.getAndIncrement() % this.dimension);
if (this.shardID.get() < 0) this.shardID.set(0);
return rr;
}
public SolrClient server4write(final SolrInputDocument solrdoc) throws IOException {
if (this.method == Method.MODULO_HOST_MD5) {
SolrInputField sif = solrdoc.getField(CollectionSchema.host_s.getSolrFieldName());
if (sif != null) {
final String host = (String) sif.getValue();
if (host != null && host.length() > 0) return server4write(host);
}
sif = solrdoc.getField(CollectionSchema.sku.getSolrFieldName());
if (sif != null) {
final String url = (String) sif.getValue();
if (url != null && url.length() > 0) try {
return server4write(new URL(url));
} catch (final IOException e) {
ConcurrentLog.logException(e);
return this.server.get(0);
}
}
return this.server.get(0);
}
// finally if no method matches use ROUND_ROBIN
return this.server.get(selectRoundRobin());
}
public SolrClient server4write(final String host) throws IOException {
if (host == null) throw new IOException("sharding - host url, host empty: " + host);
if (host.indexOf("://") >= 0) return server4write(new URL(host)); // security catch for accidantly using the wrong method
if (this.method == Method.MODULO_HOST_MD5) {
try {
final MessageDigest digest = MessageDigest.getInstance("MD5");
digest.update(ASCII.getBytes(host));
final byte[] md5 = digest.digest();
return this.server.get((0xff & md5[0]) % this.dimension);
} catch (final NoSuchAlgorithmException e) {
throw new IOException("sharding - no md5 available: " + e.getMessage());
}
}
// finally if no method matches use ROUND_ROBIN
return this.server.get(selectRoundRobin());
}
public SolrClient server4write(final URL url) throws IOException {
return server4write(url.getHost());
}
public List<SolrClient> server4read() {
if (this.method == Method.MODULO_HOST_MD5 || this.method == Method.ROUND_ROBIN) return this.server; // return all
// this is a SolrCloud, we select just one of the SolrCloud server(s)
ArrayList<SolrClient> a = new ArrayList<>(1);
a.add(this.server.get(selectRoundRobin()));
return a;
}
/**
* return all solr server
*/
@Override
public Iterator<SolrClient> iterator() {
return this.server.iterator();
}
}
Mini Shell