merge from github and rebase

parse/src/main/java/com/alibaba/otter/canal/parse/inbound/mysql/tsdb/DatabaseTableMeta.java

@@ -13,9 +13,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.regex.Pattern;
-import com.alibaba.otter.canal.parse.driver.mysql.packets.server.FieldPacket;
-import com.alibaba.polardbx.druid.sql.repository.Schema;
-import org.apache.commons.beanutils.BeanUtils;
+
 import org.apache.commons.lang.ObjectUtils;
 import org.apache.commons.lang.StringUtils;
 import org.slf4j.Logger;
@@ -40,6 +38,7 @@ import com.alibaba.otter.canal.parse.inbound.mysql.tsdb.dao.MetaHistoryDO;
 import com.alibaba.otter.canal.parse.inbound.mysql.tsdb.dao.MetaSnapshotDAO;
 import com.alibaba.otter.canal.parse.inbound.mysql.tsdb.dao.MetaSnapshotDO;
 import com.alibaba.otter.canal.protocol.position.EntryPosition;
+import com.alibaba.polardbx.druid.sql.repository.Schema;
 
 /**
  * 基于db远程管理 see internal class: CanalTableMeta , ConsoleTableMetaTSDB
@@ -52,7 +51,8 @@ public class DatabaseTableMeta implements TableMetaTSDB {
     public static final EntryPosition       INIT_POSITION       = new EntryPosition("0", 0L, -2L, -1L);
     private static Logger                   logger              = LoggerFactory.getLogger(DatabaseTableMeta.class);
     private static Pattern                  pattern             = Pattern.compile("Duplicate entry '.*' for key '*'");
-    private static Pattern                  h2Pattern           = Pattern.compile("Unique index or primary key violation");
+    private static Pattern                  h2Pattern           = Pattern
+        .compile("Unique index or primary key violation");
     private static ScheduledExecutorService scheduler           = Executors.newSingleThreadScheduledExecutor(r -> {
                                                                     Thread thread = new Thread(r,
                                                                         "[scheduler-table-meta-snapshot]");
@@ -63,7 +63,7 @@ public class DatabaseTableMeta implements TableMetaTSDB {
     private AtomicBoolean                   initialized         = new AtomicBoolean(false);
     private String                          destination;
     private MemoryTableMeta                 memoryTableMeta;
-    private volatile MysqlConnection        connection;                                                                    // 查询meta信息的链接
+    private volatile MysqlConnection        connection;                                                               // 查询meta信息的链接
     private CanalEventFilter                filter;
     private CanalEventFilter                blackFilter;
     private Map<String, List<String>>       fieldFilterMap      = new HashMap<>();
@@ -80,6 +80,143 @@ public class DatabaseTableMeta implements TableMetaTSDB {
 
     }
 
+    public static boolean compareTableMeta(TableMeta source, TableMeta target) {
+        if (!StringUtils.equalsIgnoreCase(source.getSchema(), target.getSchema())) {
+            return false;
+        }
+
+        if (!StringUtils.equalsIgnoreCase(source.getTable(), target.getTable())) {
+            return false;
+        }
+
+        List<FieldMeta> sourceFields = source.getFields();
+        List<FieldMeta> targetFields = target.getFields();
+        if (sourceFields.size() != targetFields.size()) {
+            return false;
+        }
+
+        /**
+         * MySQL DDL的一些默认行为:
+         *
+         * <pre>
+         * 1. Timestamp类型的列在第一次添加时，未指定默认值会默认为CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
+         * 2. Timestamp类型的列在第二次时，必须指定默认值
+         * 3. BLOB和TEXT类型不存在NULL、NOT NULL属性
+         * 4. 部分数据类型是synonyms，实际show create table时会转成对应类型
+         * 5. 非BLOB和TEXT类型在默认未指定NULL、NOT NULL时，默认default null
+         * 6. 在列变更时，不仅变更列名数据类型，同时各个约束中列名也会变更，同时如果约束中包含key length，则变更后的数据类型不应违背key length的约束（有长度的应大于key length；BLOB、TEXT应有key length；可以在存在key length情况下变更为无key length的数据类型，约束中key length忽略；等等）
+         * 7. 字符集每列（char类、eumn、set）默认保存，指定使用指定的，未指定使用表默认的，不受修改表默认字符集而改变，同表默认时，字符集显示省略
+         * 8. 新建表默认innodb引擎，latin1字符集
+         * 9. BLOB、TEXT会根据给定长度自动转换为对应的TINY、MEDIUM，LONG类型，长度和字符集也有关
+         * 10. unique约束在没有指定索引名是非幂等的，会自动以约束索引第一个列名称命名，同时以_2,_3这种形式添加后缀
+         * </pre>
+         */
+
+        for (int i = 0; i < sourceFields.size(); i++) {
+            FieldMeta sourceField = sourceFields.get(i);
+            FieldMeta targetField = targetFields.get(i);
+            if (!StringUtils.equalsIgnoreCase(sourceField.getColumnName(), targetField.getColumnName())) {
+                return false;
+            }
+
+            // if (!StringUtils.equalsIgnoreCase(sourceField.getColumnType(),
+            // targetField.getColumnType())) {
+            // return false;
+            // }
+
+            // https://github.com/alibaba/canal/issues/1100
+            // 支持一下 int vs int(10)
+            if ((sourceField.isUnsigned() && !targetField.isUnsigned())
+                || (!sourceField.isUnsigned() && targetField.isUnsigned())) {
+                return false;
+            }
+
+            String sourceColumnType = StringUtils.removeEndIgnoreCase(sourceField.getColumnType(), "zerofill").trim();
+            String targetColumnType = StringUtils.removeEndIgnoreCase(targetField.getColumnType(), "zerofill").trim();
+
+            String sign = sourceField.isUnsigned() ? "unsigned" : "signed";
+            sourceColumnType = StringUtils.removeEndIgnoreCase(sourceColumnType, sign).trim();
+            targetColumnType = StringUtils.removeEndIgnoreCase(targetColumnType, sign).trim();
+
+            boolean columnTypeCompare = false;
+            columnTypeCompare |= StringUtils.containsIgnoreCase(sourceColumnType, targetColumnType);
+            columnTypeCompare |= StringUtils.containsIgnoreCase(targetColumnType, sourceColumnType);
+            if (!columnTypeCompare) {
+                // 去掉精度参数再对比一次
+                sourceColumnType = synonymsType(StringUtils.substringBefore(sourceColumnType, "(")).trim();
+                targetColumnType = synonymsType(StringUtils.substringBefore(targetColumnType, "(")).trim();
+                columnTypeCompare |= StringUtils.containsIgnoreCase(sourceColumnType, targetColumnType);
+                columnTypeCompare |= StringUtils.containsIgnoreCase(targetColumnType, sourceColumnType);
+                if (!columnTypeCompare) {
+                    return false;
+                }
+            }
+
+            // if (!StringUtils.equalsIgnoreCase(sourceField.getDefaultValue(),
+            // targetField.getDefaultValue())) {
+            // return false;
+            // }
+
+            // BLOB, TEXT, GEOMETRY or JSON默认都是nullable，可以忽略比较，但比较了也是对齐
+            if (StringUtils.containsIgnoreCase(sourceColumnType, "timestamp")
+                || StringUtils.containsIgnoreCase(targetColumnType, "timestamp")) {
+                // timestamp可能会加default current_timestamp默认值,忽略对比nullable
+            } else {
+                if (sourceField.isNullable() != targetField.isNullable()) {
+                    return false;
+                }
+            }
+
+            // mysql会有一种处理,针对show create只有uk没有pk时，会在desc默认将uk当做pk
+            boolean isSourcePkOrUk = sourceField.isKey() || sourceField.isUnique();
+            boolean isTargetPkOrUk = targetField.isKey() || targetField.isUnique();
+            if (isSourcePkOrUk != isTargetPkOrUk) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * <pre>
+     * synonyms处理
+     * 1. BOOL/BOOLEAN => TINYINT
+     * 2. DEC/NUMERIC/FIXED => DECIMAL
+     * 3. INTEGER => INT
+     * </pre>
+     *
+     * @param originType
+     * @return
+     */
+    private static String synonymsType(String originType) {
+        if (StringUtils.equalsIgnoreCase(originType, "bool") || StringUtils.equalsIgnoreCase(originType, "boolean")) {
+            return "tinyint";
+        } else
+            if (StringUtils.equalsIgnoreCase(originType, "dec") || StringUtils.equalsIgnoreCase(originType, "numeric")
+                || StringUtils.equalsIgnoreCase(originType, "fixed")) {
+                    return "decimal";
+                } else if (StringUtils.equalsIgnoreCase(originType, "integer")) {
+                    return "int";
+                } else if (StringUtils.equalsIgnoreCase(originType, "real")
+                           || StringUtils.equalsIgnoreCase(originType, "double precision")) {
+                               return "double";
+                           }
+
+        // BLOB、TEXT会根据给定长度自动转换为对应的TINY、MEDIUM，LONG类型，长度和字符集也有关，统一按照blob对比
+        if (StringUtils.equalsIgnoreCase(originType, "tinyblob")
+            || StringUtils.equalsIgnoreCase(originType, "mediumblob")
+            || StringUtils.equalsIgnoreCase(originType, "longblob")) {
+            return "blob";
+        } else if (StringUtils.equalsIgnoreCase(originType, "tinytext")
+                   || StringUtils.equalsIgnoreCase(originType, "mediumtext")
+                   || StringUtils.equalsIgnoreCase(originType, "longtext")) {
+                       return "text";
+                   }
+
+        return originType;
+    }
+
     @Override
     public boolean init(final String destination) {
         if (initialized.compareAndSet(false, true)) {
@@ -121,8 +258,9 @@ public class DatabaseTableMeta implements TableMetaTSDB {
             try {
                 connection.disconnect();
             } catch (IOException e) {
-                logger.error("ERROR # disconnect meta connection for address:{}", connection.getConnector()
-                    .getAddress(), e);
+                logger.error("ERROR # disconnect meta connection for address:{}",
+                    connection.getConnector().getAddress(),
+                    e);
             }
         }
 
@@ -234,7 +372,7 @@ public class DatabaseTableMeta implements TableMetaTSDB {
 
                 StringBuilder sql = new StringBuilder();
                 for (String table : tables) {
-                    sql.append("show create table `" + schema + "`.`" + StringUtils.replace(table,"`","``") + "`;");
+                    sql.append("show create table `" + schema + "`.`" + StringUtils.replace(table, "`", "``") + "`;");
                 }
 
                 List<ResultSetPacket> packets = connection.queryMulti(sql.toString());
@@ -370,7 +508,7 @@ public class DatabaseTableMeta implements TableMetaTSDB {
             snapshotDO.setBinlogOffest(position.getPosition());
             snapshotDO.setBinlogMasterId(String.valueOf(position.getServerId()));
             snapshotDO.setBinlogTimestamp(position.getTimestamp());
-            snapshotDO.setData(JSON.toJSONString(schemaDdls,JSONWriter.Feature.LargeObject));
+            snapshotDO.setData(JSON.toJSONString(schemaDdls, JSONWriter.Feature.LargeObject));
             try {
                 metaSnapshotDAO.insert(snapshotDO);
             } catch (Throwable e) {
@@ -466,9 +604,8 @@ public class DatabaseTableMeta implements TableMetaTSDB {
 
     private boolean applyHistoryOnMemory(EntryPosition position, EntryPosition rollbackPosition) {
         try {
-            List<MetaHistoryDO> metaHistoryDOList = metaHistoryDAO.findByTimestamp(destination,
-                position.getTimestamp(),
-                rollbackPosition.getTimestamp());
+            List<MetaHistoryDO> metaHistoryDOList = metaHistoryDAO
+                .findByTimestamp(destination, position.getTimestamp(), rollbackPosition.getTimestamp());
             if (metaHistoryDOList == null) {
                 return true;
             }
@@ -490,8 +627,8 @@ public class DatabaseTableMeta implements TableMetaTSDB {
                     continue;
                 } else if (rollbackPosition.getServerId().equals(snapshotPosition.getServerId())
                            && snapshotPosition.compareTo(rollbackPosition) > 0) {
-                    continue;
-                }
+                               continue;
+                           }
 
                 // 记录到内存
                 if (!memoryTableMeta.apply(snapshotPosition, useSchema, sqlData, null)) {
@@ -515,156 +652,18 @@ public class DatabaseTableMeta implements TableMetaTSDB {
 
     private String getFullName(String schema, String table) {
         StringBuilder builder = new StringBuilder();
-        return builder.append(structureSchema(schema)).append('.').append('`').append(StringUtils.replace(table,"`","``")).append('`').toString();
-    }
-
-    public static boolean compareTableMeta(TableMeta source, TableMeta target) {
-        if (!StringUtils.equalsIgnoreCase(source.getSchema(), target.getSchema())) {
-            return false;
-        }
-
-        if (!StringUtils.equalsIgnoreCase(source.getTable(), target.getTable())) {
-            return false;
-        }
-
-        List<FieldMeta> sourceFields = source.getFields();
-        List<FieldMeta> targetFields = target.getFields();
-        if (sourceFields.size() != targetFields.size()) {
-            return false;
-        }
-
-        /**
-         * MySQL DDL的一些默认行为:
-         * 
-         * <pre>
-         * 1. Timestamp类型的列在第一次添加时，未指定默认值会默认为CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
-         * 2. Timestamp类型的列在第二次时，必须指定默认值
-         * 3. BLOB和TEXT类型不存在NULL、NOT NULL属性
-         * 4. 部分数据类型是synonyms，实际show create table时会转成对应类型
-         * 5. 非BLOB和TEXT类型在默认未指定NULL、NOT NULL时，默认default null
-         * 6. 在列变更时，不仅变更列名数据类型，同时各个约束中列名也会变更，同时如果约束中包含key length，则变更后的数据类型不应违背key length的约束（有长度的应大于key length；BLOB、TEXT应有key length；可以在存在key length情况下变更为无key length的数据类型，约束中key length忽略；等等）
-         * 7. 字符集每列（char类、eumn、set）默认保存，指定使用指定的，未指定使用表默认的，不受修改表默认字符集而改变，同表默认时，字符集显示省略
-         * 8. 新建表默认innodb引擎，latin1字符集
-         * 9. BLOB、TEXT会根据给定长度自动转换为对应的TINY、MEDIUM，LONG类型，长度和字符集也有关
-         * 10. unique约束在没有指定索引名是非幂等的，会自动以约束索引第一个列名称命名，同时以_2,_3这种形式添加后缀
-         * </pre>
-         */
-
-        for (int i = 0; i < sourceFields.size(); i++) {
-            FieldMeta sourceField = sourceFields.get(i);
-            FieldMeta targetField = targetFields.get(i);
-            if (!StringUtils.equalsIgnoreCase(sourceField.getColumnName(), targetField.getColumnName())) {
-                return false;
-            }
-
-            // if (!StringUtils.equalsIgnoreCase(sourceField.getColumnType(),
-            // targetField.getColumnType())) {
-            // return false;
-            // }
-
-            // https://github.com/alibaba/canal/issues/1100
-            // 支持一下 int vs int(10)
-            if ((sourceField.isUnsigned() && !targetField.isUnsigned())
-                || (!sourceField.isUnsigned() && targetField.isUnsigned())) {
-                return false;
-            }
-
-            String sourceColumnType = StringUtils.removeEndIgnoreCase(sourceField.getColumnType(), "zerofill").trim();
-            String targetColumnType = StringUtils.removeEndIgnoreCase(targetField.getColumnType(), "zerofill").trim();
-
-            String sign = sourceField.isUnsigned() ? "unsigned" : "signed";
-            sourceColumnType = StringUtils.removeEndIgnoreCase(sourceColumnType, sign).trim();
-            targetColumnType = StringUtils.removeEndIgnoreCase(targetColumnType, sign).trim();
-
-            boolean columnTypeCompare = false;
-            columnTypeCompare |= StringUtils.containsIgnoreCase(sourceColumnType, targetColumnType);
-            columnTypeCompare |= StringUtils.containsIgnoreCase(targetColumnType, sourceColumnType);
-            if (!columnTypeCompare) {
-                // 去掉精度参数再对比一次
-                sourceColumnType = synonymsType(StringUtils.substringBefore(sourceColumnType, "(")).trim();
-                targetColumnType = synonymsType(StringUtils.substringBefore(targetColumnType, "(")).trim();
-                columnTypeCompare |= StringUtils.containsIgnoreCase(sourceColumnType, targetColumnType);
-                columnTypeCompare |= StringUtils.containsIgnoreCase(targetColumnType, sourceColumnType);
-                if (!columnTypeCompare) {
-                    return false;
-                }
-            }
-
-            // if (!StringUtils.equalsIgnoreCase(sourceField.getDefaultValue(),
-            // targetField.getDefaultValue())) {
-            // return false;
-            // }
-
-            // BLOB, TEXT, GEOMETRY or JSON默认都是nullable，可以忽略比较，但比较了也是对齐
-            if (StringUtils.containsIgnoreCase(sourceColumnType, "timestamp")
-                || StringUtils.containsIgnoreCase(targetColumnType, "timestamp")) {
-                // timestamp可能会加default current_timestamp默认值,忽略对比nullable
-            } else {
-                if (sourceField.isNullable() != targetField.isNullable()) {
-                    return false;
-                }
-            }
-
-            // mysql会有一种处理,针对show create只有uk没有pk时，会在desc默认将uk当做pk
-            boolean isSourcePkOrUk = sourceField.isKey() || sourceField.isUnique();
-            boolean isTargetPkOrUk = targetField.isKey() || targetField.isUnique();
-            if (isSourcePkOrUk != isTargetPkOrUk) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-    /**
-     * <pre>
-     * synonyms处理 
-     * 1. BOOL/BOOLEAN => TINYINT 
-     * 2. DEC/NUMERIC/FIXED => DECIMAL
-     * 3. INTEGER => INT
-     * 
-     * 
-     * </pre>
-     * 
-     * @param originType
-     * @return
-     */
-    private static String synonymsType(String originType) {
-        if (StringUtils.equalsIgnoreCase(originType, "bool") || StringUtils.equalsIgnoreCase(originType, "boolean")) {
-            return "tinyint";
-        } else if (StringUtils.equalsIgnoreCase(originType, "dec")
-                   || StringUtils.equalsIgnoreCase(originType, "numeric")
-                   || StringUtils.equalsIgnoreCase(originType, "fixed")) {
-            return "decimal";
-        } else if (StringUtils.equalsIgnoreCase(originType, "integer")) {
-            return "int";
-        } else if (StringUtils.equalsIgnoreCase(originType, "real")
-                   || StringUtils.equalsIgnoreCase(originType, "double precision")) {
-            return "double";
-        }
-
-        // BLOB、TEXT会根据给定长度自动转换为对应的TINY、MEDIUM，LONG类型，长度和字符集也有关，统一按照blob对比
-        if (StringUtils.equalsIgnoreCase(originType, "tinyblob")
-            || StringUtils.equalsIgnoreCase(originType, "mediumblob")
-            || StringUtils.equalsIgnoreCase(originType, "longblob")) {
-            return "blob";
-        } else if (StringUtils.equalsIgnoreCase(originType, "tinytext")
-                   || StringUtils.equalsIgnoreCase(originType, "mediumtext")
-                   || StringUtils.equalsIgnoreCase(originType, "longtext")) {
-            return "text";
-        }
-
-        return originType;
+        return builder.append(structureSchema(schema))
+            .append('.')
+            .append('`')
+            .append(StringUtils.replace(table, "`", "``"))
+            .append('`')
+            .toString();
     }
 
     private int snapshotExpire(int expireTimestamp) {
         return metaSnapshotDAO.deleteByTimestamp(destination, expireTimestamp);
     }
 
-    public void setConnection(MysqlConnection connection) {
-        this.connection = connection;
-    }
-
     public void setFilter(CanalEventFilter filter) {
         this.filter = filter;
     }
@@ -689,22 +688,22 @@ public class DatabaseTableMeta implements TableMetaTSDB {
         this.blackFilter = blackFilter;
     }
 
-    public void setFieldFilterMap(Map<String, List<String>> fieldFilterMap) {
-        this.fieldFilterMap = fieldFilterMap;
-    }
-
-    public void setFieldBlackFilterMap(Map<String, List<String>> fieldBlackFilterMap) {
-        this.fieldBlackFilterMap = fieldBlackFilterMap;
-    }
-
     public Map<String, List<String>> getFieldFilterMap() {
         return fieldFilterMap;
     }
 
+    public void setFieldFilterMap(Map<String, List<String>> fieldFilterMap) {
+        this.fieldFilterMap = fieldFilterMap;
+    }
+
     public Map<String, List<String>> getFieldBlackFilterMap() {
         return fieldBlackFilterMap;
     }
 
+    public void setFieldBlackFilterMap(Map<String, List<String>> fieldBlackFilterMap) {
+        this.fieldBlackFilterMap = fieldBlackFilterMap;
+    }
+
     public int getSnapshotInterval() {
         return snapshotInterval;
     }
@@ -725,6 +724,10 @@ public class DatabaseTableMeta implements TableMetaTSDB {
         return connection;
     }
 
+    public void setConnection(MysqlConnection connection) {
+        this.connection = connection;
+    }
+
     public boolean isUkDuplicateException(Throwable t) {
         if (pattern.matcher(t.getMessage()).find() || h2Pattern.matcher(t.getMessage()).find()) {
             // 违反外键约束时也抛出这种异常，所以这里还要判断包含字符串Duplicate entry

prometheus/src/main/java/com/alibaba/otter/canal/prometheus/impl/StoreCollector.java

@@ -1,16 +1,7 @@
 package com.alibaba.otter.canal.prometheus.impl;
 
-import com.alibaba.otter.canal.instance.core.CanalInstance;
-import com.alibaba.otter.canal.prometheus.InstanceRegistry;
-import com.alibaba.otter.canal.store.CanalEventStore;
-import com.alibaba.otter.canal.store.memory.MemoryEventStoreWithBuffer;
-import com.alibaba.otter.canal.store.model.BatchMode;
-import com.google.common.base.Preconditions;
-import io.prometheus.client.Collector;
-import io.prometheus.client.CounterMetricFamily;
-import io.prometheus.client.GaugeMetricFamily;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import static com.alibaba.otter.canal.prometheus.CanalInstanceExports.DEST;
+import static com.alibaba.otter.canal.prometheus.CanalInstanceExports.DEST_LABELS_LIST;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -20,15 +11,27 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicLong;
 
-import static com.alibaba.otter.canal.prometheus.CanalInstanceExports.DEST;
-import static com.alibaba.otter.canal.prometheus.CanalInstanceExports.DEST_LABELS_LIST;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.alibaba.otter.canal.instance.core.CanalInstance;
+import com.alibaba.otter.canal.prometheus.InstanceRegistry;
+import com.alibaba.otter.canal.store.CanalEventStore;
+import com.alibaba.otter.canal.store.memory.MemoryEventStoreWithBuffer;
+import com.alibaba.otter.canal.store.model.BatchMode;
+import com.google.common.base.Preconditions;
+
+import io.prometheus.client.Collector;
+import io.prometheus.client.CounterMetricFamily;
+import io.prometheus.client.GaugeMetricFamily;
 
 /**
  * @author Chuanyi Li
  */
 public class StoreCollector extends Collector implements InstanceRegistry {
 
-    private static final Logger                             logger           = LoggerFactory.getLogger(SinkCollector.class);
+    private static final Logger                             logger           = LoggerFactory
+        .getLogger(SinkCollector.class);
     private static final String                             PRODUCE          = "canal_instance_store_produce_seq";
     private static final String                             CONSUME          = "canal_instance_store_consume_seq";
     private static final String                             STORE            = "canal_instance_store";
@@ -54,10 +57,7 @@ public class StoreCollector extends Collector implements InstanceRegistry {
     private final ConcurrentMap<String, StoreMetricsHolder> instances        = new ConcurrentHashMap<>();
     private final List<String>                              storeLabelsList  = Arrays.asList(DEST, "batchMode", "size");
 
-    private StoreCollector() {}
-
-    private static class SingletonHolder {
-        private static final StoreCollector SINGLETON = new StoreCollector();
+    private StoreCollector(){
     }
 
     public static StoreCollector instance() {
@@ -67,28 +67,17 @@ public class StoreCollector extends Collector implements InstanceRegistry {
     @Override
     public List<MetricFamilySamples> collect() {
         List<MetricFamilySamples> mfs = new ArrayList<>();
-        CounterMetricFamily put = new CounterMetricFamily(PRODUCE,
-                PRODUCE_HELP, DEST_LABELS_LIST);
-        CounterMetricFamily ack = new CounterMetricFamily(CONSUME,
-                CONSUME_HELP, DEST_LABELS_LIST);
-        GaugeMetricFamily store = new GaugeMetricFamily(STORE,
-                STORE_HELP, storeLabelsList);
-        CounterMetricFamily putMem = new CounterMetricFamily(PRODUCE_MEM,
-                PRODUCE_MEM_HELP, DEST_LABELS_LIST);
-        CounterMetricFamily ackMem = new CounterMetricFamily(CONSUME_MEM,
-                CONSUME_MEM_HELP, DEST_LABELS_LIST);
-        GaugeMetricFamily putDelay = new GaugeMetricFamily(PUT_DELAY,
-                PUT_DELAY_HELP, DEST_LABELS_LIST);
-        GaugeMetricFamily getDelay = new GaugeMetricFamily(GET_DELAY,
-                GET_DELAY_HELP, DEST_LABELS_LIST);
-        GaugeMetricFamily ackDelay = new GaugeMetricFamily(ACK_DELAY,
-                ACK_DELAY_HELP, DEST_LABELS_LIST);
-        CounterMetricFamily putRows = new CounterMetricFamily(PUT_ROWS,
-                PUT_ROWS_HELP, DEST_LABELS_LIST);
-        CounterMetricFamily getRows = new CounterMetricFamily(GET_ROWS,
-                GET_ROWS_HELP, DEST_LABELS_LIST);
-        CounterMetricFamily ackRows = new CounterMetricFamily(ACK_ROWS,
-                ACK_ROWS_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily put = new CounterMetricFamily(PRODUCE, PRODUCE_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily ack = new CounterMetricFamily(CONSUME, CONSUME_HELP, DEST_LABELS_LIST);
+        GaugeMetricFamily store = new GaugeMetricFamily(STORE, STORE_HELP, storeLabelsList);
+        CounterMetricFamily putMem = new CounterMetricFamily(PRODUCE_MEM, PRODUCE_MEM_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily ackMem = new CounterMetricFamily(CONSUME_MEM, CONSUME_MEM_HELP, DEST_LABELS_LIST);
+        GaugeMetricFamily putDelay = new GaugeMetricFamily(PUT_DELAY, PUT_DELAY_HELP, DEST_LABELS_LIST);
+        GaugeMetricFamily getDelay = new GaugeMetricFamily(GET_DELAY, GET_DELAY_HELP, DEST_LABELS_LIST);
+        GaugeMetricFamily ackDelay = new GaugeMetricFamily(ACK_DELAY, ACK_DELAY_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily putRows = new CounterMetricFamily(PUT_ROWS, PUT_ROWS_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily getRows = new CounterMetricFamily(GET_ROWS, GET_ROWS_HELP, DEST_LABELS_LIST);
+        CounterMetricFamily ackRows = new CounterMetricFamily(ACK_ROWS, ACK_ROWS_HELP, DEST_LABELS_LIST);
         boolean hasMem = false;
         for (StoreMetricsHolder smh : instances.values()) {
             final boolean isMem = smh.batchMode.isMemSize();
@@ -174,7 +163,13 @@ public class StoreCollector extends Collector implements InstanceRegistry {
         instances.remove(destination);
     }
 
+    private static class SingletonHolder {
+
+        private static final StoreCollector SINGLETON = new StoreCollector();
+    }
+
     private static class StoreMetricsHolder {
+
         private AtomicLong   putSeq;
         private AtomicLong   ackSeq;
         private BatchMode    batchMode;