HBASE-21723 Remove ConnectionImplementation and related classes

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncConnectionConfiguration.java

@@ -39,8 +39,6 @@
 import static org.apache.hadoop.hbase.HConstants.HBASE_RPC_READ_TIMEOUT_KEY;
 import static org.apache.hadoop.hbase.HConstants.HBASE_RPC_TIMEOUT_KEY;
 import static org.apache.hadoop.hbase.HConstants.HBASE_RPC_WRITE_TIMEOUT_KEY;
-import static org.apache.hadoop.hbase.client.AsyncProcess.DEFAULT_START_LOG_ERRORS_AFTER_COUNT;
-import static org.apache.hadoop.hbase.client.AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY;
 import static org.apache.hadoop.hbase.client.ConnectionConfiguration.MAX_KEYVALUE_SIZE_DEFAULT;
 import static org.apache.hadoop.hbase.client.ConnectionConfiguration.MAX_KEYVALUE_SIZE_KEY;
 import static org.apache.hadoop.hbase.client.ConnectionConfiguration.PRIMARY_CALL_TIMEOUT_MICROSECOND;
@@ -66,6 +64,16 @@ class AsyncConnectionConfiguration {
 
   private static final Logger LOG = LoggerFactory.getLogger(AsyncConnectionConfiguration.class);
 
+  /**
+   * Configure the number of failures after which the client will start logging. A few failures
+   * is fine: region moved, then is not opened, then is overloaded. We try to have an acceptable
+   * heuristic for the number of errors we don't log. 5 was chosen because we wait for 1s at
+   * this stage.
+   */
+  public static final String START_LOG_ERRORS_AFTER_COUNT_KEY =
+      "hbase.client.start.log.errors.counter";
+  public static final int DEFAULT_START_LOG_ERRORS_AFTER_COUNT = 5;
+
   private final long metaOperationTimeoutNs;
 
   // timeout for a whole operation such as get, put or delete. Notice that scan will not be effected

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncMetaRegionLocator.java

@@ -31,6 +31,8 @@
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.yetus.audience.InterfaceAudience;
 
+import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
+
 /**
  * The asynchronous locator for meta region.
  */
@@ -133,4 +135,17 @@ void clearCache(ServerName serverName) {
       }
     }
   }
+
+  // only used for testing whether we have cached the location for a region.
+  @VisibleForTesting
+  RegionLocations getRegionLocationInCache() {
+    return metaRegionLocations.get();
+  }
+
+  // only used for testing whether we have cached the location for a table.
+  @VisibleForTesting
+  int getNumberOfCachedRegionLocations() {
+    RegionLocations locs = metaRegionLocations.get();
+    return locs != null ? locs.numNonNullElements() : 0;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncNonMetaRegionLocator.java

@@ -654,4 +654,14 @@ RegionLocations getRegionLocationInCache(TableName tableName, byte[] row) {
     }
     return locateRowInCache(tableCache, tableName, row, RegionReplicaUtil.DEFAULT_REPLICA_ID);
   }
+
+  // only used for testing whether we have cached the location for a table.
+  @VisibleForTesting
+  int getNumberOfCachedRegionLocations(TableName tableName) {
+    TableCache tableCache = cache.get(tableName);
+    if (tableCache == null) {
+      return 0;
+    }
+    return tableCache.cache.values().stream().mapToInt(RegionLocations::numNonNullElements).sum();
+  }
 }