001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.namespace;
019
020import java.io.IOException;
021import org.apache.hadoop.hbase.HBaseIOException;
022import org.apache.hadoop.hbase.NamespaceDescriptor;
023import org.apache.hadoop.hbase.TableExistsException;
024import org.apache.hadoop.hbase.TableName;
025import org.apache.hadoop.hbase.client.RegionInfo;
026import org.apache.hadoop.hbase.master.MasterServices;
027import org.apache.hadoop.hbase.quotas.QuotaExceededException;
028import org.apache.yetus.audience.InterfaceAudience;
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * The Class NamespaceAuditor performs checks to ensure operations like table creation and region
034 * splitting preserve namespace quota. The namespace quota can be specified while namespace
035 * creation.
036 */
037@InterfaceAudience.Private
038public class NamespaceAuditor {
039  private static final Logger LOG = LoggerFactory.getLogger(NamespaceAuditor.class);
040  private NamespaceStateManager stateManager;
041  private MasterServices masterServices;
042
043  public NamespaceAuditor(MasterServices masterServices) {
044    this.masterServices = masterServices;
045    stateManager = new NamespaceStateManager(masterServices);
046  }
047
048  public void start() throws IOException {
049    stateManager.start();
050    LOG.info("NamespaceAuditor started.");
051  }
052
053  /**
054   * Check quota to create table. We add the table information to namespace state cache, assuming
055   * the operation will pass. If the operation fails, then the next time namespace state chore runs
056   * namespace state cache will be corrected.
057   * @param tName   - The table name to check quota.
058   * @param regions - Number of regions that will be added.
059   * @throws IOException Signals that an I/O exception has occurred.
060   */
061  public void checkQuotaToCreateTable(TableName tName, int regions) throws IOException {
062    if (stateManager.isInitialized()) {
063      // We do this check to fail fast.
064      if (masterServices.getTableDescriptors().exists(tName)) {
065        throw new TableExistsException(tName);
066      }
067      stateManager.checkAndUpdateNamespaceTableCount(tName, regions);
068    } else {
069      checkTableTypeAndThrowException(tName);
070    }
071  }
072
073  /**
074   * Check and update region count quota for an existing table.
075   * @param tName   - table name for which region count to be updated.
076   * @param regions - Number of regions that will be added.
077   * @throws IOException Signals that an I/O exception has occurred.
078   */
079  public void checkQuotaToUpdateRegion(TableName tName, int regions) throws IOException {
080    if (stateManager.isInitialized()) {
081      stateManager.checkAndUpdateNamespaceRegionCount(tName, regions);
082    } else {
083      checkTableTypeAndThrowException(tName);
084    }
085  }
086
087  private void checkTableTypeAndThrowException(TableName name) throws IOException {
088    if (name.isSystemTable()) {
089      LOG.debug("Namespace auditor checks not performed for table " + name.getNameAsString());
090    } else {
091      throw new HBaseIOException(
092        name + " is being created even before namespace auditor has been initialized.");
093    }
094  }
095
096  /**
097   * Get region count for table
098   * @param tName - table name
099   * @return cached region count, or -1 if table status not found
100   * @throws IOException Signals that the namespace auditor has not been initialized
101   */
102  public int getRegionCountOfTable(TableName tName) throws IOException {
103    if (stateManager.isInitialized()) {
104      NamespaceTableAndRegionInfo state = stateManager.getState(tName.getNamespaceAsString());
105      return state != null ? state.getRegionCountOfTable(tName) : -1;
106    }
107    checkTableTypeAndThrowException(tName);
108    return -1;
109  }
110
111  public void checkQuotaToSplitRegion(RegionInfo hri) throws IOException {
112    if (!stateManager.isInitialized()) {
113      throw new IOException(
114        "Split operation is being performed even before namespace auditor is initialized.");
115    } else if (
116      !stateManager.checkAndUpdateNamespaceRegionCount(hri.getTable(), hri.getRegionName(), 1)
117    ) {
118      throw new QuotaExceededException("Region split not possible for :" + hri.getEncodedName()
119        + " as quota limits are exceeded ");
120    }
121  }
122
123  public void updateQuotaForRegionMerge(RegionInfo mergedRegion) throws IOException {
124    if (!stateManager.isInitialized()) {
125      throw new IOException(
126        "Merge operation is being performed even before namespace auditor is initialized.");
127    } else if (
128      !stateManager.checkAndUpdateNamespaceRegionCount(mergedRegion.getTable(),
129        mergedRegion.getRegionName(), -1)
130    ) {
131      throw new QuotaExceededException("Region merge not possible for :"
132        + mergedRegion.getEncodedName() + " as quota limits are exceeded ");
133    }
134  }
135
136  public void addNamespace(NamespaceDescriptor ns) throws IOException {
137    stateManager.addNamespace(ns.getName());
138  }
139
140  public void deleteNamespace(String namespace) throws IOException {
141    stateManager.deleteNamespace(namespace);
142  }
143
144  public void removeFromNamespaceUsage(TableName tableName) throws IOException {
145    stateManager.removeTable(tableName);
146  }
147
148  public void removeRegionFromNamespaceUsage(RegionInfo hri) throws IOException {
149    stateManager.removeRegionFromTable(hri);
150  }
151
152  /**
153   * @param namespace The name of the namespace
154   * @return An instance of NamespaceTableAndRegionInfo
155   */
156  public NamespaceTableAndRegionInfo getState(String namespace) {
157    if (stateManager.isInitialized()) {
158      return stateManager.getState(namespace);
159    }
160    return null;
161  }
162
163  /**
164   * Checks if namespace auditor is initialized. Used only for testing.
165   * @return true, if is initialized
166   */
167  public boolean isInitialized() {
168    return stateManager.isInitialized();
169  }
170}