All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.solr.cloud.SyncStrategy Maven / Gradle / Ivy

Go to download

Apache Solr (module: core)

There is a newer version: 9.6.1
Show newest version
/*
 * 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.cloud;

import static org.apache.solr.common.params.CommonParams.DISTRIB;

import java.io.IOException;
import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
import org.apache.http.client.HttpClient;
import org.apache.solr.client.solrj.SolrClient;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.impl.HttpSolrClient;
import org.apache.solr.client.solrj.request.CoreAdminRequest.RequestRecovery;
import org.apache.solr.common.cloud.ZkCoreNodeProps;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.params.CoreAdminParams.CoreAdminAction;
import org.apache.solr.common.params.ModifiableSolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.SuppressForbidden;
import org.apache.solr.core.CoreContainer;
import org.apache.solr.core.CoreDescriptor;
import org.apache.solr.core.SolrCore;
import org.apache.solr.handler.component.ShardHandler;
import org.apache.solr.handler.component.ShardRequest;
import org.apache.solr.handler.component.ShardResponse;
import org.apache.solr.update.PeerSync;
import org.apache.solr.update.UpdateShardHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SyncStrategy {
  private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

  private final boolean SKIP_AUTO_RECOVERY = Boolean.getBoolean("solrcloud.skip.autorecovery");

  private final ShardHandler shardHandler;

  private volatile boolean isClosed;

  private final HttpClient client;

  private final ExecutorService updateExecutor;

  private final List recoveryRequests = new ArrayList<>();

  private static class RecoveryRequest {
    ZkNodeProps leaderProps;
    String baseUrl;
    String coreName;
  }

  public SyncStrategy(CoreContainer cc) {
    UpdateShardHandler updateShardHandler = cc.getUpdateShardHandler();
    client = updateShardHandler.getDefaultHttpClient();
    shardHandler = cc.getShardHandlerFactory().getShardHandler();
    updateExecutor = updateShardHandler.getUpdateExecutor();
  }

  private static class ShardCoreRequest extends ShardRequest {
    String coreName;
    public String baseUrl;
  }

  public PeerSync.PeerSyncResult sync(
      ZkController zkController, SolrCore core, ZkNodeProps leaderProps) {
    return sync(zkController, core, leaderProps, false);
  }

  public PeerSync.PeerSyncResult sync(
      ZkController zkController,
      SolrCore core,
      ZkNodeProps leaderProps,
      boolean peerSyncOnlyWithActive) {
    if (SKIP_AUTO_RECOVERY) {
      return PeerSync.PeerSyncResult.success();
    }

    if (isClosed) {
      log.warn("Closed, skipping sync up.");
      return PeerSync.PeerSyncResult.failure();
    }

    recoveryRequests.clear();

    if (log.isInfoEnabled()) {
      log.info("Sync replicas to {}", ZkCoreNodeProps.getCoreUrl(leaderProps));
    }

    if (core.getUpdateHandler().getUpdateLog() == null) {
      log.error("No UpdateLog found - cannot sync");
      return PeerSync.PeerSyncResult.failure();
    }

    return syncReplicas(zkController, core, leaderProps, peerSyncOnlyWithActive);
  }

  private PeerSync.PeerSyncResult syncReplicas(
      ZkController zkController,
      SolrCore core,
      ZkNodeProps leaderProps,
      boolean peerSyncOnlyWithActive) {
    if (isClosed) {
      log.info("We have been closed, won't sync with replicas");
      return PeerSync.PeerSyncResult.failure();
    }
    boolean success = false;
    PeerSync.PeerSyncResult result = null;
    assert core != null;
    assert core.getCoreDescriptor() != null;
    CloudDescriptor cloudDesc = core.getCoreDescriptor().getCloudDescriptor();
    String collection = cloudDesc.getCollectionName();
    String shardId = cloudDesc.getShardId();

    // first sync ourselves - we are the potential leader after all
    try {
      result =
          syncWithReplicas(
              zkController, core, leaderProps, collection, shardId, peerSyncOnlyWithActive);
      success = result.isSuccess();
    } catch (Exception e) {
      log.error("Sync Failed", e);
    }
    try {
      if (isClosed) {
        log.info("We have been closed, won't attempt to sync replicas back to leader");
        return PeerSync.PeerSyncResult.failure();
      }

      if (success) {
        log.info("Sync Success - now sync replicas to me");

        syncToMe(
            zkController,
            collection,
            shardId,
            leaderProps,
            core.getCoreDescriptor(),
            core.getUpdateHandler().getUpdateLog().getNumRecordsToKeep());

      } else {
        log.info("Leader's attempt to sync with shard failed, moving to the next candidate");
        // lets see who seems ahead...
      }

    } catch (Exception e) {
      log.error("Sync Failed", e);
    }

    return result == null ? PeerSync.PeerSyncResult.failure() : result;
  }

  private PeerSync.PeerSyncResult syncWithReplicas(
      ZkController zkController,
      SolrCore core,
      ZkNodeProps props,
      String collection,
      String shardId,
      boolean peerSyncOnlyWithActive)
      throws Exception {
    List nodes =
        zkController
            .getZkStateReader()
            .getReplicaProps(
                collection,
                shardId,
                core.getCoreDescriptor().getCloudDescriptor().getCoreNodeName());

    if (isClosed) {
      log.info("We have been closed, won't sync with replicas");
      return PeerSync.PeerSyncResult.failure();
    }

    if (nodes == null) {
      // I have no replicas
      return PeerSync.PeerSyncResult.success();
    }

    List syncWith = new ArrayList<>(nodes.size());
    for (ZkCoreNodeProps node : nodes) {
      syncWith.add(node.getCoreUrl());
    }

    // if we can't reach a replica for sync, we still consider the overall sync a success
    // TODO: as an assurance, we should still try and tell the sync nodes that we couldn't reach
    // to recover once more?
    // Fingerprinting here is off because the we currently rely on having at least one of the nodes
    // return "true", and if replicas are out-of-sync we still need to pick one as leader.  A
    // followup sync from the replica to the new leader (with fingerprinting on) should then fail
    // and initiate recovery-by-replication.
    try (PeerSync peerSync =
        new PeerSync(
            core,
            syncWith,
            core.getUpdateHandler().getUpdateLog().getNumRecordsToKeep(),
            true,
            peerSyncOnlyWithActive,
            false)) {
      return peerSync.sync();
    }
  }

  private void syncToMe(
      ZkController zkController,
      String collection,
      String shardId,
      ZkNodeProps leaderProps,
      CoreDescriptor cd,
      int nUpdates) {

    if (isClosed) {
      log.info("We have been closed, won't sync replicas to me.");
      return;
    }

    // sync everyone else
    // TODO: we should do this in parallel at least
    List nodes =
        zkController
            .getZkStateReader()
            .getReplicaProps(collection, shardId, cd.getCloudDescriptor().getCoreNodeName());
    if (nodes == null) {
      if (log.isInfoEnabled()) {
        log.info("{} has no replicas", ZkCoreNodeProps.getCoreUrl(leaderProps));
      }
      return;
    }

    ZkCoreNodeProps zkLeader = new ZkCoreNodeProps(leaderProps);
    for (ZkCoreNodeProps node : nodes) {
      try {
        if (log.isInfoEnabled()) {
          log.info(
              "{}: try and ask {} to sync",
              ZkCoreNodeProps.getCoreUrl(leaderProps),
              node.getCoreUrl());
        }

        requestSync(
            node.getBaseUrl(),
            node.getCoreUrl(),
            zkLeader.getCoreUrl(),
            node.getCoreName(),
            nUpdates);

      } catch (Exception e) {
        log.error("Error syncing replica to leader", e);
      }
    }

    for (; ; ) {
      ShardResponse srsp = shardHandler.takeCompletedOrError();
      if (srsp == null) break;
      boolean success = handleResponse(srsp);
      if (srsp.getException() != null) {
        log.error("Sync request error", srsp.getException());
      }

      if (!success) {
        if (log.isInfoEnabled()) {
          log.info(
              "{}: Sync failed - we will ask replica ({}) to recover.",
              ZkCoreNodeProps.getCoreUrl(leaderProps),
              srsp.getShardAddress());
        }
        if (isClosed) {
          log.info("We have been closed, don't request that a replica recover");
        } else {
          RecoveryRequest rr = new RecoveryRequest();
          rr.leaderProps = leaderProps;
          rr.baseUrl = ((ShardCoreRequest) srsp.getShardRequest()).baseUrl;
          rr.coreName = ((ShardCoreRequest) srsp.getShardRequest()).coreName;
          recoveryRequests.add(rr);
        }
      } else {
        if (log.isInfoEnabled()) {
          log.info(
              "{}: sync completed with {}",
              ZkCoreNodeProps.getCoreUrl(leaderProps),
              srsp.getShardAddress());
        }
      }
    }
  }

  private boolean handleResponse(ShardResponse srsp) {
    NamedList response = srsp.getSolrResponse().getResponse();
    // TODO: why does this return null sometimes?
    if (response == null) {
      return false;
    }
    Boolean success = (Boolean) response.get("sync");

    if (success == null) {
      success = false;
    }

    return success;
  }

  private void requestSync(
      String baseUrl, String replica, String leaderUrl, String coreName, int nUpdates) {
    // TODO should we use peerSyncWithLeader instead?
    ShardCoreRequest sreq = new ShardCoreRequest();
    sreq.coreName = coreName;
    sreq.baseUrl = baseUrl;
    sreq.purpose = ShardRequest.PURPOSE_PRIVATE;
    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", Integer.toString(nUpdates));
    sreq.params.set("sync", leaderUrl);

    shardHandler.submit(sreq, replica, sreq.params);
  }

  public void close() {
    this.isClosed = true;
  }

  public void requestRecoveries() {
    for (RecoveryRequest rr : recoveryRequests) {
      try {
        requestRecovery(rr.leaderProps, rr.baseUrl, rr.coreName);
      } catch (SolrServerException | IOException e) {
        log.error("Problem requesting that a replica recover", e);
      }
    }
  }

  @SuppressForbidden(reason = "Passed to an executor with a naming thread factory")
  private void requestRecovery(
      final ZkNodeProps leaderProps, final String baseUrl, final String coreName)
      throws SolrServerException, IOException {
    Thread thread =
        new Thread(
            () -> {
              if (isClosed) {
                log.info("We have been closed, won't request recovery");
                return;
              }
              RequestRecovery recoverRequestCmd = new RequestRecovery();
              recoverRequestCmd.setAction(CoreAdminAction.REQUESTRECOVERY);
              recoverRequestCmd.setCoreName(coreName);

              try (SolrClient client =
                  new HttpSolrClient.Builder(baseUrl)
                      .withHttpClient(SyncStrategy.this.client)
                      .withConnectionTimeout(30000, TimeUnit.MILLISECONDS)
                      .withSocketTimeout(120000, TimeUnit.MILLISECONDS)
                      .build()) {
                client.request(recoverRequestCmd);
              } catch (Throwable t) {
                log.error(
                    "{}: Could not tell a replica to recover",
                    ZkCoreNodeProps.getCoreUrl(leaderProps),
                    t);
                if (t instanceof Error) {
                  throw (Error) t;
                }
              }
            });
    thread.setDaemon(true);
    updateExecutor.execute(thread);
  }

  public static ModifiableSolrParams params(String... params) {
    ModifiableSolrParams msp = new ModifiableSolrParams();
    for (int i = 0; i < params.length; i += 2) {
      msp.add(params[i], params[i + 1]);
    }
    return msp;
  }
}
 















© 2015 - 2024 Weber Informatics LLC | Privacy Policy