/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.solr.update;
import static org.apache.solr.update.processor.DistributedUpdateProcessor.DistribPhase.FROMLEADER;
import static org.apache.solr.update.processor.DistributingUpdateProcessorFactory.DISTRIB_UPDATE_PARAM;
import java.io.IOException;
import java.net.ConnectException;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.http.NoHttpResponseException;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.cloud.ZkController;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrInputDocument;
import org.apache.solr.common.params.ModifiableSolrParams;
import org.apache.solr.common.util.StrUtils;
import org.apache.solr.core.SolrCore;
import org.apache.solr.handler.component.HttpShardHandlerFactory;
import org.apache.solr.handler.component.ShardHandler;
import org.apache.solr.handler.component.ShardHandlerFactory;
import org.apache.solr.handler.component.ShardRequest;
import org.apache.solr.handler.component.ShardResponse;
import org.apache.solr.request.LocalSolrQueryRequest;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.response.SolrQueryResponse;
import org.apache.solr.update.processor.UpdateRequestProcessor;
import org.apache.solr.update.processor.UpdateRequestProcessorChain;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** @lucene.experimental */
public class PeerSync {
public static Logger log = LoggerFactory.getLogger(PeerSync.class);
public boolean debug = log.isDebugEnabled();
private List<String> replicas;
private int nUpdates;
private int maxUpdates; // maximum number of updates to request before failing
private UpdateHandler uhandler;
private UpdateLog ulog;
private HttpShardHandlerFactory shardHandlerFactory;
private ShardHandler shardHandler;
private UpdateLog.RecentUpdates recentUpdates;
private List<Long> startingVersions;
private List<Long> ourUpdates;
private Set<Long> ourUpdateSet;
private Set<Long> requestedUpdateSet;
private long ourLowThreshold; // 20th percentile
private long ourHighThreshold; // 80th percentile
private final boolean cantReachIsSuccess;
private final boolean getNoVersionsIsSuccess;
private final HttpClient client;
private final boolean onlyIfActive;
// comparator that sorts by absolute value, putting highest first
private static Comparator<Long> absComparator = new Comparator<Long>() {
@Override
public int compare(Long o1, Long o2) {
long l1 = Math.abs(o1);
long l2 = Math.abs(o2);
if (l1 >l2) return -1;
if (l1 < l2) return 1;
return 0;
}
};
// comparator that sorts update records by absolute value of version, putting lowest first
private static Comparator<Object> updateRecordComparator = new Comparator<Object>() {
@Override
public int compare(Object o1, Object o2) {
if (!(o1 instanceof List)) return 1;
if (!(o2 instanceof List)) return -1;
List lst1 = (List)o1;
List lst2 = (List)o2;
long l1 = Math.abs((Long)lst1.get(1));
long l2 = Math.abs((Long)lst2.get(1));
if (l1 >l2) return 1;
if (l1 < l2) return -1;
return 0;
}
};
private static class SyncShardRequest extends ShardRequest {
List<Long> reportedVersions;
List<Long> requestedUpdates;
Exception updateException;
}
public PeerSync(SolrCore core, List<String> replicas, int nUpdates) {
this(core, replicas, nUpdates, false, true);
}
public PeerSync(SolrCore core, List<String> replicas, int nUpdates, boolean cantReachIsSuccess, boolean getNoVersionsIsSuccess) {
this(core, replicas, nUpdates, cantReachIsSuccess, getNoVersionsIsSuccess, false);
}
public PeerSync(SolrCore core, List<String> replicas, int nUpdates, boolean cantReachIsSuccess, boolean getNoVersionsIsSuccess, boolean onlyIfActive) {
this.replicas = replicas;
this.nUpdates = nUpdates;
this.maxUpdates = nUpdates;
this.cantReachIsSuccess = cantReachIsSuccess;
this.getNoVersionsIsSuccess = getNoVersionsIsSuccess;
this.client = core.getCoreDescriptor().getCoreContainer().getUpdateShardHandler().getHttpClient();
this.onlyIfActive = onlyIfActive;
uhandler = core.getUpdateHandler();
ulog = uhandler.getUpdateLog();
// TODO: shutdown
shardHandlerFactory = (HttpShardHandlerFactory) core.getCoreDescriptor().getCoreContainer().getShardHandlerFactory();
shardHandler = shardHandlerFactory.getShardHandler(client);
}
/** optional list of updates we had before possibly receiving new updates */
public void setStartingVersions(List<Long> startingVersions) {
this.startingVersions = startingVersions;
}
public long percentile(List<Long> arr, float frac) {
int elem = (int) (arr.size() * frac);
return Math.abs(arr.get(elem));
}
// start of peersync related debug messages. includes the core name for correlation.
private String msg() {
ZkController zkController = uhandler.core.getCoreDescriptor().getCoreContainer().getZkController();
String myURL = "";
if (zkController != null) {
myURL = zkController.getBaseUrl();
}
// TODO: core name turns up blank in many tests - find URL if cloud enabled?
return "PeerSync: core="+uhandler.core.getName()+ " url="+myURL +" ";
}
/** Returns true if peer sync was successful, meaning that this core may not be considered to have the latest updates
* when considering the last N updates between it and it's peers.
* A commit is not performed.
*/
public boolean sync() {
if (ulog == null) {
return false;
}
log.info(msg() + "START replicas=" + replicas + " nUpdates=" + nUpdates);
// TODO: does it ever make sense to allow sync when buffering or applying buffered? Someone might request that we do it...
if (!(ulog.getState() == UpdateLog.State.ACTIVE || ulog.getState()==UpdateLog.State.REPLAYING)) {
log.error(msg() + "ERROR, update log not in ACTIVE or REPLAY state. " + ulog);
// return false;
}
if (debug) {
if (startingVersions != null) {
log.debug(msg() + "startingVersions=" + startingVersions.size() + " " + startingVersions);
}
}
// Fire off the requests before getting our own recent updates (for better concurrency)
// This also allows us to avoid getting updates we don't need... if we got our updates and then got their updates, they would
// have newer stuff that we also had (assuming updates are going on and are being forwarded).
for (String replica : replicas) {
requestVersions(replica);
}
recentUpdates = ulog.getRecentUpdates();
try {
ourUpdates = recentUpdates.getVersions(nUpdates);
} finally {
recentUpdates.close();
}
Collections.sort(ourUpdates, absComparator);
if (startingVersions != null) {
if (startingVersions.size() == 0) {
log.warn("no frame of reference to tell if we've missed updates");
return false;
}
Collections.sort(startingVersions, absComparator);
ourLowThreshold = percentile(startingVersions, 0.8f);
ourHighThreshold = percentile(startingVersions, 0.2f);
// now make sure that the starting updates overlap our updates
// there shouldn't be reorders, so any overlap will do.
long smallestNewUpdate = Math.abs(ourUpdates.get(ourUpdates.size()-1));
if (Math.abs(startingVersions.get(0)) < smallestNewUpdate) {
log.warn(msg() + "too many updates received since start - startingUpdates no longer overlaps with our currentUpdates");
return false;
}
// let's merge the lists
List<Long> newList = new ArrayList<>(ourUpdates);
for (Long ver : startingVersions) {
if (Math.abs(ver) < smallestNewUpdate) {
newList.add(ver);
}
}
ourUpdates = newList;
} else {
if (ourUpdates.size() > 0) {
ourLowThreshold = percentile(ourUpdates, 0.8f);
ourHighThreshold = percentile(ourUpdates, 0.2f);
} else {
// we have no versions and hence no frame of reference to tell if we can use a peers
// updates to bring us into sync
log.info(msg() + "DONE. We have no versions. sync failed.");
return false;
}
}
ourUpdateSet = new HashSet<>(ourUpdates);
requestedUpdateSet = new HashSet<>(ourUpdates);
for(;;) {
ShardResponse srsp = shardHandler.takeCompletedOrError();
if (srsp == null) break;
boolean success = handleResponse(srsp);
if (!success) {
log.info(msg() + "DONE. sync failed");
shardHandler.cancelAll();
return false;
}
}
log.info(msg() + "DONE. sync succeeded");
return true;
}
private void requestVersions(String replica) {
SyncShardRequest sreq = new SyncShardRequest();
sreq.purpose = 1;
sreq.shards = new String[]{replica};
sreq.actualShards = sreq.shards;
sreq.params = new ModifiableSolrParams();
sreq.params.set("qt","/get");
sreq.params.set("distrib",false);
sreq.params.set("getVersions",nUpdates);
shardHandler.submit(sreq, replica, sreq.params);
}
private boolean handleResponse(ShardResponse srsp) {
ShardRequest sreq = srsp.getShardRequest();
if (srsp.getException() != null) {
// TODO: look at this more thoroughly - we don't want
// to fail on connection exceptions, but it may make sense
// to determine this based on the number of fails
//
// If the replica went down between asking for versions and asking for specific updates, that
// shouldn't be treated as success since we counted on getting those updates back (and avoided
// redundantly asking other replicas for them).
if (cantReachIsSuccess && sreq.purpose == 1 && srsp.getException() instanceof SolrServerException) {
Throwable solrException = ((SolrServerException) srsp.getException())
.getRootCause();
boolean connectTimeoutExceptionInChain = connectTimeoutExceptionInChain(srsp.getException());
if (connectTimeoutExceptionInChain || solrException instanceof ConnectException || solrException instanceof ConnectTimeoutException
|| solrException instanceof NoHttpResponseException || solrException instanceof SocketException) {
log.warn(msg() + " couldn't connect to " + srsp.getShardAddress() + ", counting as success");
return true;
}
}
if (cantReachIsSuccess && sreq.purpose == 1 && srsp.getException() instanceof SolrException && ((SolrException) srsp.getException()).code() == 503) {
log.warn(msg() + " got a 503 from " + srsp.getShardAddress() + ", counting as success");
return true;
}
if (cantReachIsSuccess && sreq.purpose == 1 && srsp.getException() instanceof SolrException && ((SolrException) srsp.getException()).code() == 404) {
log.warn(msg() + " got a 404 from " + srsp.getShardAddress() + ", counting as success. " +
"Perhaps /get is not registered?");
return true;
}
// TODO: we should return the above information so that when we can request a recovery through zookeeper, we do
// that for these nodes
// TODO: at least log???
// srsp.getException().printStackTrace(System.out);
log.warn(msg() + " exception talking to " + srsp.getShardAddress() + ", failed", srsp.getException());
return false;
}
if (sreq.purpose == 1) {
return handleVersions(srsp);
} else {
return handleUpdates(srsp);
}
}
// sometimes the root exception is a SocketTimeoutException, but ConnectTimeoutException
// is in the chain
private boolean connectTimeoutExceptionInChain(Throwable exception) {
Throwable t = exception;
while (true) {
if (t instanceof ConnectTimeoutException) {
return true;
}
Throwable cause = t.getCause();
if (cause != null) {
t = cause;
} else {
return false;
}
}
}
private boolean handleVersions(ShardResponse srsp) {
// we retrieved the last N updates from the replica
List<Long> otherVersions = (List<Long>)srsp.getSolrResponse().getResponse().get("versions");
// TODO: how to handle short lists?
SyncShardRequest sreq = (SyncShardRequest) srsp.getShardRequest();
sreq.reportedVersions = otherVersions;
log.info(msg() + " Received " + otherVersions.size() + " versions from " + sreq.shards[0] );
if (otherVersions.size() == 0) {
return getNoVersionsIsSuccess;
}
boolean completeList = otherVersions.size() < nUpdates; // do we have their complete list of updates?
Collections.sort(otherVersions, absComparator);
if (debug) {
log.debug(msg() + " sorted versions from " + sreq.shards[0] + " = " + otherVersions);
}
long otherHigh = percentile(otherVersions, .2f);
long otherLow = percentile(otherVersions, .8f);
if (ourHighThreshold < otherLow) {
// Small overlap between version windows and ours is older
// This means that we might miss updates if we attempted to use this method.
// Since there exists just one replica that is so much newer, we must
// fail the sync.
log.info(msg() + " Our versions are too old. ourHighThreshold="+ourHighThreshold + " otherLowThreshold="+otherLow);
return false;
}
if (ourLowThreshold > otherHigh) {
// Small overlap between windows and ours is newer.
// Using this list to sync would result in requesting/replaying results we don't need
// and possibly bringing deleted docs back to life.
log.info(msg() + " Our versions are newer. ourLowThreshold="+ourLowThreshold + " otherHigh="+otherHigh);
return true;
}
List<Long> toRequest = new ArrayList<>();
for (Long otherVersion : otherVersions) {
// stop when the entries get old enough that reorders may lead us to see updates we don't need
if (!completeList && Math.abs(otherVersion) < ourLowThreshold) break;
if (ourUpdateSet.contains(otherVersion) || requestedUpdateSet.contains(otherVersion)) {
// we either have this update, or already requested it
// TODO: what if the shard we previously requested this from returns failure (because it goes
// down)
continue;
}
toRequest.add(otherVersion);
requestedUpdateSet.add(otherVersion);
}
sreq.requestedUpdates = toRequest;
if (toRequest.isEmpty()) {
log.info(msg() + " Our versions are newer. ourLowThreshold="+ourLowThreshold + " otherHigh="+otherHigh);
// we had (or already requested) all the updates referenced by the replica
return true;
}
if (toRequest.size() > maxUpdates) {
log.info(msg() + " Failing due to needing too many updates:" + maxUpdates);
return false;
}
return requestUpdates(srsp, toRequest);
}
private boolean requestUpdates(ShardResponse srsp, List<Long> toRequest) {
String replica = srsp.getShardRequest().shards[0];
log.info(msg() + "Requesting updates from " + replica + "n=" + toRequest.size() + " versions=" + toRequest);
// reuse our original request object
ShardRequest sreq = srsp.getShardRequest();
sreq.purpose = 0;
sreq.params = new ModifiableSolrParams();
sreq.params.set("qt", "/get");
sreq.params.set("distrib", false);
sreq.params.set("getUpdates", StrUtils.join(toRequest, ','));
sreq.params.set("onlyIfActive", onlyIfActive);
sreq.responses.clear(); // needs to be zeroed for correct correlation to occur
shardHandler.submit(sreq, sreq.shards[0], sreq.params);
return true;
}
private boolean handleUpdates(ShardResponse srsp) {
// we retrieved the last N updates from the replica
List<Object> updates = (List<Object>)srsp.getSolrResponse().getResponse().get("updates");
SyncShardRequest sreq = (SyncShardRequest) srsp.getShardRequest();
if (updates.size() < sreq.requestedUpdates.size()) {
log.error(msg() + " Requested " + sreq.requestedUpdates.size() + " updates from " + sreq.shards[0] + " but retrieved " + updates.size());
return false;
}
ModifiableSolrParams params = new ModifiableSolrParams();
params.set(DISTRIB_UPDATE_PARAM, FROMLEADER.toString());
params.set("peersync",true); // debugging
SolrQueryRequest req = new LocalSolrQueryRequest(uhandler.core, params);
SolrQueryResponse rsp = new SolrQueryResponse();
UpdateRequestProcessorChain processorChain = req.getCore().getUpdateProcessingChain(null);
UpdateRequestProcessor proc = processorChain.createProcessor(req, rsp);
Collections.sort(updates, updateRecordComparator);
Object o = null;
long lastVersion = 0;
try {
// Apply oldest updates first
for (Object obj : updates) {
// should currently be a List<Oper,Ver,Doc/Id>
o = obj;
List<Object> entry = (List<Object>)o;
if (debug) {
log.debug(msg() + "raw update record " + o);
}
int oper = (Integer)entry.get(0) & UpdateLog.OPERATION_MASK;
long version = (Long) entry.get(1);
if (version == lastVersion && version != 0) continue;
lastVersion = version;
switch (oper) {
case UpdateLog.ADD:
{
// byte[] idBytes = (byte[]) entry.get(2);
SolrInputDocument sdoc = (SolrInputDocument)entry.get(entry.size()-1);
AddUpdateCommand cmd = new AddUpdateCommand(req);
// cmd.setIndexedId(new BytesRef(idBytes));
cmd.solrDoc = sdoc;
cmd.setVersion(version);
cmd.setFlags(UpdateCommand.PEER_SYNC | UpdateCommand.IGNORE_AUTOCOMMIT);
if (debug) {
log.debug(msg() + "add " + cmd);
}
proc.processAdd(cmd);
break;
}
case UpdateLog.DELETE:
{
byte[] idBytes = (byte[]) entry.get(2);
DeleteUpdateCommand cmd = new DeleteUpdateCommand(req);
cmd.setIndexedId(new BytesRef(idBytes));
cmd.setVersion(version);
cmd.setFlags(UpdateCommand.PEER_SYNC | UpdateCommand.IGNORE_AUTOCOMMIT);
if (debug) {
log.debug(msg() + "delete " + cmd);
}
proc.processDelete(cmd);
break;
}
case UpdateLog.DELETE_BY_QUERY:
{
String query = (String)entry.get(2);
DeleteUpdateCommand cmd = new DeleteUpdateCommand(req);
cmd.query = query;
cmd.setVersion(version);
cmd.setFlags(UpdateCommand.PEER_SYNC | UpdateCommand.IGNORE_AUTOCOMMIT);
if (debug) {
log.debug(msg() + "deleteByQuery " + cmd);
}
proc.processDelete(cmd);
break;
}
default:
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Unknown Operation! " + oper);
}
}
}
catch (IOException e) {
// TODO: should this be handled separately as a problem with us?
// I guess it probably already will by causing replication to be kicked off.
sreq.updateException = e;
log.error(msg() + "Error applying updates from " + sreq.shards + " ,update=" + o, e);
return false;
}
catch (Exception e) {
sreq.updateException = e;
log.error(msg() + "Error applying updates from " + sreq.shards + " ,update=" + o, e);
return false;
}
finally {
try {
proc.finish();
} catch (Exception e) {
sreq.updateException = e;
log.error(msg() + "Error applying updates from " + sreq.shards + " ,finish()", e);
return false;
}
}
return true;
}
/** Requests and applies recent updates from peers */
public static void sync(SolrCore core, List<String> replicas, int nUpdates) {
ShardHandlerFactory shardHandlerFactory = core.getCoreDescriptor().getCoreContainer().getShardHandlerFactory();
ShardHandler shardHandler = shardHandlerFactory.getShardHandler();
for (String replica : replicas) {
ShardRequest sreq = new ShardRequest();
sreq.shards = new String[]{replica};
sreq.params = new ModifiableSolrParams();
sreq.params.set("qt","/get");
sreq.params.set("distrib", false);
sreq.params.set("getVersions",nUpdates);
shardHandler.submit(sreq, replica, sreq.params);
}
for (String replica : replicas) {
ShardResponse srsp = shardHandler.takeCompletedOrError();
}
}
}