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https://issues.apache.org/jira/browse/NIFI-3644?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15955645#comment-15955645
]
ASF GitHub Bot commented on NIFI-3644:
--------------------------------------
Github user bbende commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1645#discussion_r109752585
--- Diff:
nifi-nar-bundles/nifi-standard-services/nifi-hbase_1_1_2-client-service-bundle/nifi-hbase_1_1_2-client-service/src/main/java/org/apache/nifi/hbase/HBase_1_1_2_ClientMapCacheService.java
---
@@ -0,0 +1,224 @@
+/*
+ * 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.nifi.hbase;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.SeeAlso;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnEnabled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.controller.AbstractControllerService;
+import org.apache.nifi.controller.ConfigurationContext;
+
+import org.apache.nifi.distributed.cache.client.DistributedMapCacheClient;
+import org.apache.nifi.distributed.cache.client.Serializer;
+import org.apache.nifi.distributed.cache.client.Deserializer;
+import java.io.ByteArrayOutputStream;
+import org.apache.nifi.reporting.InitializationException;
+
+import java.nio.charset.StandardCharsets;
+import org.apache.nifi.hbase.scan.ResultCell;
+import org.apache.nifi.hbase.scan.ResultHandler;
+import org.apache.nifi.hbase.scan.Column;
+import org.apache.nifi.hbase.put.PutColumn;
+
+
+import org.apache.nifi.processor.util.StandardValidators;
+
+@Tags({"distributed", "cache", "state", "map", "cluster","hbase"})
+@SeeAlso(classNames =
{"org.apache.nifi.distributed.cache.server.map.DistributedMapCacheClient",
"org.apache.nifi.hbase.HBase_1_1_2_ClientService"})
+@CapabilityDescription("Provides the ability to use an HBase table as a
cache, in place of a DistributedMapCache."
+ + " Uses a HBase_1_1_2_ClientService controller to communicate with
HBase.")
+
+public class HBase_1_1_2_ClientMapCacheService extends
AbstractControllerService implements DistributedMapCacheClient {
+
+ static final PropertyDescriptor HBASE_CLIENT_SERVICE = new
PropertyDescriptor.Builder()
+ .name("HBase Client Service")
+ .description("Specifies the HBase Client Controller Service to use
for accessing HBase.")
+ .required(true)
+ .identifiesControllerService(HBaseClientService.class)
+ .build();
+
+ public static final PropertyDescriptor HBASE_CACHE_TABLE_NAME = new
PropertyDescriptor.Builder()
+ .name("HBase Cache Table Name")
+ .description("Name of the table on HBase to use for the cache.")
+ .required(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor HBASE_COLUMN_FAMILY = new
PropertyDescriptor.Builder()
+ .name("HBase Column Family")
+ .description("Name of the column family on HBase to use for the
cache.")
+ .required(true)
+ .defaultValue("f")
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor HBASE_COLUMN_QUALIFIER = new
PropertyDescriptor.Builder()
+ .name("HBase Column Qualifier")
+ .description("Name of the column qualifier on HBase to use for the
cache")
+ .defaultValue("q")
+ .required(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ @Override
+ protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ final List<PropertyDescriptor> descriptors = new ArrayList<>();
+ descriptors.add(HBASE_CACHE_TABLE_NAME);
+ descriptors.add(HBASE_CLIENT_SERVICE);
+ descriptors.add(HBASE_COLUMN_FAMILY);
+ descriptors.add(HBASE_COLUMN_QUALIFIER);
+ return descriptors;
+ }
+
+ private String hBaseCacheTableName;
+ private HBaseClientService hBaseClientService;
+
+ private String hBaseColumnFamily;
+ private byte[] hBaseColumnFamilyBytes;
+
+ private String hBaseColumnQualifier;
+ private byte[] hBaseColumnQualifierBytes;
+
+ @OnEnabled
+ public void onConfigured(final ConfigurationContext context) throws
InitializationException{
+ hBaseCacheTableName =
context.getProperty(HBASE_CACHE_TABLE_NAME).getValue();
+ hBaseClientService =
context.getProperty(HBASE_CLIENT_SERVICE).asControllerService(HBaseClientService.class);
+ hBaseColumnFamily =
context.getProperty(HBASE_COLUMN_FAMILY).getValue();
+ hBaseColumnQualifier =
context.getProperty(HBASE_COLUMN_QUALIFIER).getValue();
+
+ hBaseColumnFamilyBytes =
hBaseColumnFamily.getBytes(StandardCharsets.UTF_8);
+ hBaseColumnQualifierBytes =
hBaseColumnQualifier.getBytes(StandardCharsets.UTF_8);
+ }
+
+ private <T> byte[] serialize(final T value, final Serializer<T>
serializer) throws IOException {
+ final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+ serializer.serialize(value, baos);
+ return baos.toByteArray();
+ }
+ private <T> T deserialize(final byte[] value, final Deserializer<T>
deserializer) throws IOException {
+ return deserializer.deserialize(value);
+ }
+
+
+ @Override
+ public <K, V> boolean putIfAbsent(final K key, final V value, final
Serializer<K> keySerializer, final Serializer<V> valueSerializer) throws
IOException {
+ if (containsKey(key, keySerializer)) {
+ put(key, value, keySerializer, valueSerializer);
+ return true;
+ } else return false;
+ }
+
+ @Override
+ public <K, V> void put(final K key, final V value, final Serializer<K>
keySerializer, final Serializer<V> valueSerializer) throws IOException {
+
+ List<PutColumn> putColumns = new ArrayList<PutColumn>(1);
+ final byte[] rowIdBytes = serialize(key, keySerializer);
+ final byte[] valueBytes = serialize(value, valueSerializer);
+
+ final PutColumn putColumn = new PutColumn(hBaseColumnFamilyBytes,
hBaseColumnQualifierBytes, valueBytes);
+ putColumns.add(putColumn);
+
+ hBaseClientService.put(hBaseCacheTableName, rowIdBytes,
putColumns);
+ }
+
+ @Override
+ public <K> boolean containsKey(final K key, final Serializer<K>
keySerializer) throws IOException {
+ final byte[] rowIdBytes = serialize(key, keySerializer);
+ final HBaseRowHandler handler = new HBaseRowHandler();
+
+ final List<Column> columnsList = new ArrayList<Column>(0);
+
+ hBaseClientService.scan(hBaseCacheTableName, rowIdBytes, rowIdBytes,
columnsList, handler);
+ return (handler.numRows() > 0);
+ }
+
+ @Override
+ public <K, V> V getAndPutIfAbsent(final K key, final V value, final
Serializer<K> keySerializer, final Serializer<V> valueSerializer, final
Deserializer<V> valueDeserializer) throws IOException {
--- End diff --
For putIfAbsent and getAndPutIfAbsent, they currently require two client
calls (a get + conditional write). This could be problematic in that you can't
ensure that after doing the get that something else hasn't modified the value
before you do the write, this could happen for example in a cluster where two
nodes go to do a putIfAbsent at the same time with the same key.
It looks like HBase has some atomic checkAndMutate operations:
https://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Table.html
I think we should see if we can use these in place of the two calls,
although admittedly I have not used them myself.
> Add DetectDuplicateUsingHBase processor
> ---------------------------------------
>
> Key: NIFI-3644
> URL: https://issues.apache.org/jira/browse/NIFI-3644
> Project: Apache NiFi
> Issue Type: Improvement
> Components: Extensions
> Reporter: Bjorn Olsen
> Priority: Minor
>
> The DetectDuplicate processor makes use of a distributed map cache for
> maintaining a list of unique file identifiers (such as hashes).
> The distributed map cache functionality could be provided by an HBase table,
> which then allows for reliably storing a huge volume of file identifiers and
> auditing information. The downside of this approach is of course that HBase
> is required.
> Storing the unique file identifiers in a reliable, query-able manner along
> with some audit information is of benefit to several use cases.
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