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https://issues.apache.org/jira/browse/NIFI-2417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15509909#comment-15509909
]
ASF GitHub Bot commented on NIFI-2417:
--------------------------------------
Github user mattyb149 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/733#discussion_r79827737
--- Diff:
nifi-nar-bundles/nifi-elasticsearch-bundle/nifi-elasticsearch-processors/src/main/java/org/apache/nifi/processors/elasticsearch/QueryElasticsearchHttp.java
---
@@ -0,0 +1,410 @@
+/*
+ * 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.processors.elasticsearch;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.nifi.annotation.behavior.EventDriven;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.SupportsBatching;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnScheduled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ComponentLog;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.stream.io.ByteArrayInputStream;
+import org.codehaus.jackson.JsonNode;
+
+import okhttp3.HttpUrl;
+import okhttp3.OkHttpClient;
+import okhttp3.Response;
+import okhttp3.ResponseBody;
+
+@InputRequirement(InputRequirement.Requirement.INPUT_ALLOWED)
+@EventDriven
+@SupportsBatching
+@Tags({ "elasticsearch", "query", "read", "get", "http" })
+@CapabilityDescription("Queries Elasticsearch using the specified
connection properties. "
+ + "Note that the full body of each page of documents will be read
into memory before being "
+ + "written to Flow Files for transfer. Also note that the
Elasticsearch max_result_window index "
+ + "setting is the upper bound on the number of records that can be
retrieved using this query. "
+ + "To retrieve more records, use the ScrollElasticsearchHttp
processor.")
+@WritesAttributes({
+ @WritesAttribute(attribute = "filename", description = "The
filename attribute is set to the document identifier"),
+ @WritesAttribute(attribute = "es.index", description = "The
Elasticsearch index containing the document"),
+ @WritesAttribute(attribute = "es.type", description = "The
Elasticsearch document type"),
+ @WritesAttribute(attribute = "es.result.*", description = "If
Target is 'Flow file attributes', the JSON attributes of "
+ + "each result will be placed into corresponding
attributes with this prefix.") })
+public class QueryElasticsearchHttp extends
AbstractElasticsearchHttpProcessor {
+
+ private static final String FIELD_INCLUDE_QUERY_PARAM =
"_source_include";
+ private static final String QUERY_QUERY_PARAM = "q";
+ private static final String SORT_QUERY_PARAM = "sort";
+ private static final String FROM_QUERY_PARAM = "from";
+ private static final String SIZE_QUERY_PARAM = "size";
+
+ public static final String TARGET_FLOW_FILE_CONTENT = "Flow file
content";
+ public static final String TARGET_FLOW_FILE_ATTRIBUTES = "Flow file
attributes";
+ private static final String ATTRIBUTE_PREFIX = "es.result.";
+
+ public static final Relationship REL_SUCCESS = new
Relationship.Builder()
+ .name("success")
+ .description(
+ "All FlowFiles that are read from Elasticsearch are
routed to this relationship.")
+ .build();
+
+ public static final Relationship REL_FAILURE = new
Relationship.Builder()
+ .name("failure")
+ .description(
+ "All FlowFiles that cannot be read from Elasticsearch
are routed to this relationship. Note that only incoming "
+ + "flow files will be routed to
failure.").build();
+
+ public static final Relationship REL_RETRY = new Relationship.Builder()
+ .name("retry")
+ .description(
+ "A FlowFile is routed to this relationship if the
document cannot be fetched but attempting the operation again may "
+ + "succeed. Note that if the processor has no
incoming connections, flow files may still be sent to this relationship "
+ + "based on the processor properties and the
results of the fetch operation.")
+ .build();
+
+ public static final PropertyDescriptor QUERY = new
PropertyDescriptor.Builder()
+ .name("query-es-query").displayName("Query")
+ .description("The Lucene-style query to run against
ElasticSearch").required(true)
+
.expressionLanguageSupported(true).addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor INDEX = new
PropertyDescriptor.Builder()
+ .name("query-es-index").displayName("Index")
+ .description("The name of the index to read
from").required(true)
+
.expressionLanguageSupported(true).addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor TYPE = new
PropertyDescriptor.Builder()
+ .name("query-es-type")
+ .displayName("Type")
+ .description(
+ "The (optional) type of this document, used by
Elasticsearch for indexing and searching. If the property is empty or set "
+ + "to _all, the first document matching the
identifier across all types will be retrieved.")
+ .required(false).expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build();
+
+ public static final PropertyDescriptor FIELDS = new
PropertyDescriptor.Builder()
+ .name("query-es-fields")
+ .displayName("Fields")
+ .description(
+ "A comma-separated list of fields to retrieve from the
document. If the Fields property is left blank, "
+ + "then the entire document's source will be
retrieved.")
+ .required(false).expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build();
+
+ public static final PropertyDescriptor SORT = new
PropertyDescriptor.Builder()
+ .name("query-es-sort")
+ .displayName("Sort")
+ .description(
+ "A sort parameter (e.g., timestamp:asc). If the Sort
property is left blank, "
+ + "then the results will be retrieved in
document order.")
+ .required(false).expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build();
+
+ public static final PropertyDescriptor PAGE_SIZE = new
PropertyDescriptor.Builder()
+ .name("query-es-size").displayName("Page
Size").defaultValue("20")
+ .description("Determines how many documents to return per page
during scrolling.")
+ .required(true).expressionLanguageSupported(true)
+
.addValidator(StandardValidators.POSITIVE_INTEGER_VALIDATOR).build();
+
+ public static final PropertyDescriptor LIMIT = new
PropertyDescriptor.Builder()
+ .name("query-es-limit").displayName("Limit")
+ .description("If set, limits the number of results that will
be returned.")
+ .required(false).expressionLanguageSupported(true)
+
.addValidator(StandardValidators.POSITIVE_INTEGER_VALIDATOR).build();
+
+ public static final PropertyDescriptor TARGET = new
PropertyDescriptor.Builder()
+ .name("query-es-target")
+ .displayName("Target")
+ .description(
+ "Indicates where the results should be placed. In the
case of 'Flow file content', the JSON "
+ + "response will be written as the content of
the flow file. In the case of 'Flow file attributes', "
+ + "the original flow file (if applicable) will
be cloned for each result, and all return fields will be placed "
+ + "in a flow file attribute of the same name,
but prefixed by 'es.result.'")
+ .required(true).expressionLanguageSupported(false)
+ .defaultValue(TARGET_FLOW_FILE_CONTENT)
+ .allowableValues(TARGET_FLOW_FILE_CONTENT,
TARGET_FLOW_FILE_ATTRIBUTES)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR).build();
+
+ @Override
+ public Set<Relationship> getRelationships() {
+ final Set<Relationship> relationships = new HashSet<>();
+ relationships.add(REL_SUCCESS);
+ relationships.add(REL_FAILURE);
+ relationships.add(REL_RETRY);
+ return Collections.unmodifiableSet(relationships);
+ }
+
+ @Override
+ public final List<PropertyDescriptor>
getSupportedPropertyDescriptors() {
+ final List<PropertyDescriptor> descriptors = new ArrayList<>();
+ descriptors.add(ES_URL);
+ descriptors.add(PROP_SSL_CONTEXT_SERVICE);
+ descriptors.add(USERNAME);
+ descriptors.add(PASSWORD);
+ descriptors.add(CONNECT_TIMEOUT);
+ descriptors.add(RESPONSE_TIMEOUT);
+ descriptors.add(QUERY);
+ descriptors.add(PAGE_SIZE);
+ descriptors.add(INDEX);
+ descriptors.add(TYPE);
+ descriptors.add(FIELDS);
+ descriptors.add(SORT);
+ descriptors.add(LIMIT);
+ descriptors.add(TARGET);
+
+ return Collections.unmodifiableList(descriptors);
+ }
+
+ @OnScheduled
+ public void setup(ProcessContext context) {
+ super.setup(context);
+ }
+
+ @Override
+ public void onTrigger(final ProcessContext context, final
ProcessSession session)
+ throws ProcessException {
+
+ FlowFile flowFile = null;
+ if (context.hasIncomingConnection()) {
+ flowFile = session.get();
+
+ // If we have no FlowFile, and all incoming connections are
self-loops then we can
+ // continue on.
+ // However, if we have no FlowFile and we have connections
coming from other Processors,
+ // then
+ // we know that we should run only if we have a FlowFile.
+ if (flowFile == null && context.hasNonLoopConnection()) {
+ return;
+ }
+ }
+
+ OkHttpClient okHttpClient = getClient();
+
+ final String index =
context.getProperty(INDEX).evaluateAttributeExpressions(flowFile)
+ .getValue();
+ final String query =
context.getProperty(QUERY).evaluateAttributeExpressions(flowFile)
+ .getValue();
+ final String docType =
context.getProperty(TYPE).evaluateAttributeExpressions(flowFile)
+ .getValue();
+ final int pageSize =
context.getProperty(PAGE_SIZE).evaluateAttributeExpressions(flowFile)
+ .asInteger().intValue();
+ final Integer limit = context.getProperty(LIMIT).isSet() ?
context.getProperty(LIMIT)
+
.evaluateAttributeExpressions(flowFile).asInteger().intValue() : null;
+ final String fields = context.getProperty(FIELDS).isSet() ?
context.getProperty(FIELDS)
+ .evaluateAttributeExpressions(flowFile).getValue() : null;
+ final String sort = context.getProperty(SORT).isSet() ?
context.getProperty(SORT)
+ .evaluateAttributeExpressions(flowFile).getValue() : null;
+ final boolean targetIsContent =
context.getProperty(TARGET).getValue()
+ .equals(TARGET_FLOW_FILE_CONTENT);
+
+ // Authentication
+ final String username = context.getProperty(USERNAME).getValue();
+ final String password = context.getProperty(PASSWORD).getValue();
+
+ final ComponentLog logger = getLogger();
+
+ int fromIndex = 0;
+ int numResults;
+
+ try {
+ logger.debug("Querying {}/{} from Elasticsearch: {}", new
Object[] { index, docType,
+ query });
+
+ final long startNanos = System.nanoTime();
+ // read the url property from the context
+ final String urlstr =
StringUtils.trimToEmpty(context.getProperty(ES_URL).getValue());
+
+ boolean hitLimit = false;
+ do {
+ int mPageSize = pageSize;
+ if (limit != null && limit <= (fromIndex + pageSize)) {
+ mPageSize = limit - fromIndex;
+ hitLimit = true;
+ }
+
+ final URL queryUrl = buildRequestURL(urlstr, query, index,
docType, fields, sort,
+ mPageSize, fromIndex);
+
+ final Response getResponse =
sendRequestToElasticsearch(okHttpClient, queryUrl,
+ username, password, "GET", null);
+ numResults = this.getPage(getResponse, queryUrl, context,
session, flowFile,
+ logger, startNanos, targetIsContent);
+ fromIndex += pageSize;
+ } while (numResults > 0 && !hitLimit);
+
+ if (flowFile != null) {
+ session.remove(flowFile);
+ }
+ } catch (IOException ioe) {
+ logger.error(
+ "Failed to read from Elasticsearch due to {}, this may
indicate an error in configuration "
+ + "(hosts, username/password, etc.). Routing
to retry",
+ new Object[] { ioe.getLocalizedMessage() }, ioe);
+ if (flowFile != null) {
+ session.transfer(flowFile, REL_RETRY);
+ }
+ context.yield();
+
+ } catch (RetryableException e) {
+ logger.error(e.getMessage(), new Object[] {
e.getLocalizedMessage() }, e);
+ if (flowFile != null) {
+ session.transfer(flowFile, REL_RETRY);
+ }
+ context.yield();
+ } catch (Exception e) {
+ logger.error("Failed to read {} from Elasticsearch due to {}",
new Object[] { flowFile,
+ e.getLocalizedMessage() }, e);
+ if (flowFile != null) {
+ session.transfer(flowFile, REL_FAILURE);
+ }
+ context.yield();
+ }
+ }
+
+ private int getPage(final Response getResponse, final URL url, final
ProcessContext context,
+ final ProcessSession session, FlowFile flowFile, final
ComponentLog logger,
+ final long startNanos, boolean targetIsContent)
+ throws IOException {
+ List<FlowFile> page = new ArrayList<>();
+ final int statusCode = getResponse.code();
+
+ if (isSuccess(statusCode)) {
+ ResponseBody body = getResponse.body();
+ final byte[] bodyBytes = body.bytes();
+ JsonNode responseJson = parseJsonResponse(new
ByteArrayInputStream(bodyBytes));
+ JsonNode hits = responseJson.get("hits").get("hits");
+
+ for(int i = 0; i < hits.size(); i++) {
+ JsonNode hit = hits.get(i);
+ String retrievedId = hit.get("_id").asText();
+ String retrievedIndex = hit.get("_index").asText();
+ String retrievedType = hit.get("_type").asText();
+
+ FlowFile documentFlowFile = null;
+ if (flowFile != null) {
+ documentFlowFile = targetIsContent ?
session.create(flowFile) : session.clone(flowFile);
+ } else {
+ documentFlowFile = session.create();
+ }
+
+ JsonNode source = hit.get("_source");
+ documentFlowFile = session.putAttribute(documentFlowFile,
"es.index", retrievedIndex);
+ documentFlowFile = session.putAttribute(documentFlowFile,
"es.type", retrievedType);
+
+ if (targetIsContent) {
+ documentFlowFile =
session.putAttribute(documentFlowFile, "filename", retrievedId);
+ documentFlowFile = session.write(documentFlowFile, out
-> {
--- End diff --
Since _source is a JSON object, I recommend setting the mime.type attribute
to application/json when the target is content.
> Implement Query and Scroll processors for ElasticSearch
> -------------------------------------------------------
>
> Key: NIFI-2417
> URL: https://issues.apache.org/jira/browse/NIFI-2417
> Project: Apache NiFi
> Issue Type: New Feature
> Components: Extensions
> Affects Versions: 1.0.0
> Reporter: Joseph Gresock
> Assignee: Joseph Gresock
> Priority: Minor
> Fix For: 1.1.0
>
>
> FetchElasticsearchHttp allows users to select a single document from
> Elasticsearch in NiFi, but there is no way to run a query to retrieve
> multiple documents.
> We should add a QueryElasticsearchHttp processor for running a query and
> returning a flow file per result, for small result sets. This should allow
> both input and non-input execution.
> A separate ScrollElasticsearchHttp processor would also be useful for
> scrolling through a huge result set. This should use the state manager to
> maintain the scroll_id value, and use this as input to the next scroll page.
> As a result, this processor should not allow flow file input, but should
> retrieve one page per run.
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