Github user JPercivall commented on a diff in the pull request:
https://github.com/apache/nifi/pull/237#discussion_r56178725
--- Diff:
nifi-nar-bundles/nifi-cassandra-bundle/nifi-cassandra-processors/src/main/java/org/apache/nifi/processors/cassandra/PutCassandraQL.java
---
@@ -0,0 +1,403 @@
+/*
+ * 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.cassandra;
+
+import com.datastax.driver.core.BoundStatement;
+import com.datastax.driver.core.DataType;
+import com.datastax.driver.core.PreparedStatement;
+import com.datastax.driver.core.ResultSetFuture;
+import com.datastax.driver.core.Session;
+import com.datastax.driver.core.exceptions.AuthenticationException;
+import com.datastax.driver.core.exceptions.InvalidTypeException;
+import com.datastax.driver.core.exceptions.NoHostAvailableException;
+import com.datastax.driver.core.exceptions.QueryExecutionException;
+import com.datastax.driver.core.exceptions.QueryValidationException;
+import org.apache.nifi.annotation.behavior.EventDriven;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.ReadsAttribute;
+import org.apache.nifi.annotation.behavior.ReadsAttributes;
+import org.apache.nifi.annotation.behavior.SupportsBatching;
+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.annotation.lifecycle.OnShutdown;
+import org.apache.nifi.annotation.lifecycle.OnUnscheduled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ProcessorLog;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.ProcessorInitializationContext;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.io.InputStreamCallback;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.stream.io.StreamUtils;
+import org.apache.nifi.util.StringUtils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+@SupportsBatching
+@Tags({"cassandra", "cql", "put", "insert", "update", "set"})
+@EventDriven
+@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED)
+@CapabilityDescription("Execute provided Cassandra Query Language (CQL)
statement. The content of an incoming FlowFile "
+ + "is expected to be the CQL command to execute. The CQL command
may use the ? to escape parameters. In this "
+ + "case, the parameters to use must exist as FlowFile attributes
with the naming convention cql.args.N.type "
+ + "and cql.args.N.value, where N is a positive integer. The
cql.args.N.type is expected to be "
+ + "a lowercase string indicating the Cassandra type. The content
of the FlowFile is expected to be in UTF-8 format.")
+@ReadsAttributes({
+ @ReadsAttribute(attribute = "cql.args.N.type",
+ description = "Incoming FlowFiles are expected to be
parameterized CQL statements. The type of each "
+ + "parameter is specified as a lowercase string
corresponding to the Cassandra data type (text, "
+ + "int, boolean, e.g.). In the case of
collections, the primitive type(s) of the elements in the "
+ + "collection should be comma-delimited, follow
the collection type, and be enclosed in angle brackets "
+ + "(< and >), for example set<text> or
map<timestamp, int>."),
+ @ReadsAttribute(attribute = "cql.args.N.value",
+ description = "Incoming FlowFiles are expected to be
parameterized CQL statements. The value of the "
+ + "parameters are specified as cql.args.1.value,
cql.args.2.value, cql.args.3.value, and so on. The "
+ + " type of the cql.args.1.value parameter is
specified by the cql.args.1.type attribute.")
+})
+public class PutCassandraQL extends AbstractCassandraProcessor {
+
+ static final PropertyDescriptor STATEMENT_TIMEOUT = new
PropertyDescriptor.Builder()
+ .name("Max Wait Time")
+ .description("The maximum amount of time allowed for a running
CQL select query. Must be of format "
+ + "<duration> <TimeUnit> where <duration> is a
non-negative integer and TimeUnit is a supported "
+ + "Time Unit, such as: nanos, millis, secs, mins, hrs,
days. A value of zero means there is no limit. ")
+ .defaultValue("0 seconds")
+ .required(true)
+ .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR)
+ .build();
+ static final PropertyDescriptor BATCH_SIZE = new
PropertyDescriptor.Builder()
+ .name("Batch Size")
+ .description("The preferred number of FlowFiles to put to
Cassandra in a single transaction")
+ .required(true)
+ .addValidator(StandardValidators.POSITIVE_INTEGER_VALIDATOR)
+ .defaultValue("100")
+ .build();
+
+ private static final Pattern CQL_TYPE_ATTRIBUTE_PATTERN =
Pattern.compile("cql\\.args\\.(\\d+)\\.type");
+
+ // Matches on top-level type (primitive types like text,int) and also
for
+ private static final Pattern CQL_TYPE_PATTERN =
Pattern.compile("([^<]+)(<([^,>]+)(,([^,>]+))*>)?");
+
+
+ @Override
+ protected void init(final ProcessorInitializationContext context) {
+ final List<PropertyDescriptor> descriptors = new ArrayList<>();
+ descriptors.add(CONTACT_POINTS);
+ descriptors.add(KEYSPACE);
+ descriptors.add(PROP_SSL_CONTEXT_SERVICE);
+ descriptors.add(CLIENT_AUTH);
+ descriptors.add(USERNAME);
+ descriptors.add(PASSWORD);
+ descriptors.add(STATEMENT_TIMEOUT);
+ descriptors.add(BATCH_SIZE);
+ descriptors.add(CONSISTENCY_LEVEL);
+ descriptors.add(CHARSET);
+ this.descriptors = Collections.unmodifiableList(descriptors);
+
+ final Set<Relationship> relationships = new HashSet<>();
+ relationships.add(REL_SUCCESS);
+ relationships.add(REL_FAILURE);
+ relationships.add(REL_RETRY);
+ this.relationships = Collections.unmodifiableSet(relationships);
+ }
+
+ @Override
+ protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ return descriptors;
+ }
+
+ @Override
+ public Set<Relationship> getRelationships() {
+ return relationships;
+ }
+
+
+ @OnScheduled
+ public void onScheduled(final ProcessContext context) {
+ ProcessorLog log = getLogger();
+ try {
+ connectToCassandra(context);
+ } catch (final NoHostAvailableException nhae) {
+ log.error("No host in the Cassandra cluster can be contacted
successfully to execute this statement", nhae);
+ // Log up to 10 error messages. Otherwise if a 1000-node
cluster was specified but there was no connectivity,
+ // a thousand error messages would be logged. However we would
like information from Cassandra itself, so
+ // cap the error limit at 10, format the messages, and don't
include the stack trace (it is displayed by the
+ // logger message above).
+ log.error(nhae.getCustomMessage(10, true, false));
+ throw new ProcessException(nhae);
+ } catch (final AuthenticationException ae) {
+ log.error("Invalid username/password combination", ae);
+ throw new ProcessException(ae);
+ }
+ }
+
+ @Override
+ public void onTrigger(final ProcessContext context, final
ProcessSession session) throws ProcessException {
+ final int batchSize = context.getProperty(BATCH_SIZE).asInteger();
+ ProcessorLog logger = getLogger();
+ final List<FlowFile> flowFiles = session.get(batchSize);
+ if (flowFiles == null) {
+ return;
+ }
+
+ final long startNanos = System.nanoTime();
+ final long statementTimeout =
context.getProperty(STATEMENT_TIMEOUT).asTimePeriod(TimeUnit.MILLISECONDS);
+ final Charset charset =
Charset.forName(context.getProperty(CHARSET).getValue());
+
+ // The documentation for the driver recommends the session remain
open the entire time the processor is running
+ // and states that it is thread-safe. This is why
connectionSession is not in a try-with-resources.
+ final Session connectionSession = cassandraSession.get();
+
+ for (FlowFile flowFile : flowFiles) {
+ String cql = getCQL(session, flowFile, charset);
+ try {
+ PreparedStatement statement =
connectionSession.prepare(cql);
+ BoundStatement boundStatement = statement.bind();
+
+ Map<String, String> attributes = flowFile.getAttributes();
+ for (final Map.Entry<String, String> entry :
attributes.entrySet()) {
+ final String key = entry.getKey();
+ final Matcher matcher =
CQL_TYPE_ATTRIBUTE_PATTERN.matcher(key);
+ if (matcher.matches()) {
+ final int parameterIndex =
Integer.parseInt(matcher.group(1));
+ String paramType = entry.getValue();
+ if (StringUtils.isEmpty(paramType)) {
+ throw new ProcessException("Value of the " +
key + " attribute is null or empty, it must contain a valid value");
+ }
+
+ paramType = paramType.trim();
+ final String valueAttrName = "cql.args." +
parameterIndex + ".value";
+ final String parameterValue =
attributes.get(valueAttrName);
+
+ try {
+ setStatementObject(boundStatement,
parameterIndex - 1, valueAttrName, parameterValue, paramType);
+ } catch (final InvalidTypeException |
IllegalArgumentException e) {
+ throw new ProcessException("The value of the "
+ valueAttrName + " is '" + parameterValue
+ + "', which cannot be converted into
the necessary data type: " + paramType, e);
+ }
+ }
+ }
+
+ try {
+ ResultSetFuture future =
connectionSession.executeAsync(boundStatement);
+ if (statementTimeout > 0) {
+ future.getUninterruptibly(statementTimeout,
TimeUnit.MILLISECONDS);
+ } else {
+ future.getUninterruptibly();
+ }
+ // Emit a Provenance SEND event
+ final long transmissionMillis =
TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos);
+
+ // This isn't a real URI but since Cassandra is
distributed we just use the cluster name
+ String transitUri = "cassandra://" +
connectionSession.getCluster().getMetadata().getClusterName();
+ session.getProvenanceReporter().send(flowFile,
transitUri, transmissionMillis, true);
+ session.transfer(flowFile, REL_SUCCESS);
+
+ } catch (final TimeoutException e) {
+ throw new ProcessException(e);
+ }
+
+
+ } catch (final NoHostAvailableException nhae) {
+ getLogger().error("No host in the Cassandra cluster can be
contacted successfully to execute this statement", nhae);
+ // Log up to 10 error messages. Otherwise if a 1000-node
cluster was specified but there was no connectivity,
+ // a thousand error messages would be logged. However we
would like information from Cassandra itself, so
+ // cap the error limit at 10, format the messages, and
don't include the stack trace (it is displayed by the
+ // logger message above).
+ getLogger().error(nhae.getCustomMessage(10, true, false));
+ flowFile = session.penalize(flowFile);
+ session.transfer(flowFile, REL_RETRY);
+
+ } catch (final QueryExecutionException qee) {
+ logger.error("Cannot execute the statement with the
requested consistency level successfully", qee);
+ // The incoming flow file should be penalized
+ flowFile = session.penalize(flowFile);
+ session.transfer(flowFile, REL_RETRY);
+
+ } catch (final QueryValidationException qve) {
+ logger.error("The CQL statement {} is invalid due to
syntax error, authorization issue, or another "
+ + "validation problem; routing {} to
failure",
+ new Object[]{cql, flowFile}, qve);
+ flowFile = session.penalize(flowFile);
+ session.transfer(flowFile, REL_FAILURE);
+
+ } catch (final ProcessException e) {
+ if (flowFile == null) {
--- End diff --
Since PutCassandraQL is not a source processor the FlowFile will never be
null here.
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