/**
*
*/
package com.thinkbiganalytics.nifi.v2.init;
/*-
* #%L
* thinkbig-nifi-core-processors
* %%
* Copyright (C) 2017 ThinkBig Analytics
* %%
* Licensed 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.
* #L%
*/
import com.thinkbiganalytics.metadata.rest.model.feed.InitializationStatus;
import com.thinkbiganalytics.metadata.rest.model.feed.InitializationStatus.State;
import com.thinkbiganalytics.nifi.v2.common.CommonProperties;
import com.thinkbiganalytics.nifi.v2.common.FeedProcessor;
import org.apache.nifi.annotation.behavior.EventDriven;
import org.apache.nifi.annotation.behavior.InputRequirement;
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.AllowableValue;
import org.apache.nifi.components.PropertyDescriptor;
import org.apache.nifi.flowfile.FlowFile;
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.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;
/**
*/
@EventDriven
@InputRequirement(InputRequirement.Requirement.INPUT_ALLOWED)
@Tags({"feed", "initialize", "initialization", "thinkbig"})
@CapabilityDescription("Controls setup of a feed by routing to an initialization flow.")
public class InitializeFeed extends FeedProcessor {
protected static final AllowableValue[] FAIL_STRATEGY_VALUES = new AllowableValue[]{
new AllowableValue("FAIL", "Fail", "Immediately fail the flow file"),
new AllowableValue("RETRY", "Retry", "Retry initialization (if the appropriate time delay has expired) and penalize the flow file.")
};
protected static final PropertyDescriptor FAILURE_STRATEGY = new PropertyDescriptor.Builder()
.name("Initialization Failure Strategy")
.description("Indicates how this processor should behave when a flow file arrives after feed initialization has failed.")
.allowableValues(FAIL_STRATEGY_VALUES)
.defaultValue("RETRY")
.required(true)
.build();
protected static final PropertyDescriptor RETRY_DELAY = new PropertyDescriptor.Builder()
.name("Initialization Retry Delay (seconds)")
.description("The minimum amount of seconds to delay before an arriving flow file should trigger another attempt to "
+ "initialize a feed that has previously failed initialization. Any flow file arriving before this "
+ "delay has expired will be immediately failed.")
.required(false)
.defaultValue("60")
.addValidator(StandardValidators.POSITIVE_INTEGER_VALIDATOR)
.expressionLanguageSupported(true)
.build();
protected static final PropertyDescriptor MAX_INIT_ATTEMPTS = new PropertyDescriptor.Builder()
.name("Max Initialization Attempts")
.description("The maximum number of times initialization will be retried where there are failures. There is no limit if unset.")
.required(true)
.defaultValue("5")
.addValidator(StandardValidators.POSITIVE_INTEGER_VALIDATOR)
.expressionLanguageSupported(true)
.build();
Relationship REL_INITIALIZE = new Relationship.Builder()
.name("Initialize")
.description("Begin initialization")
.build();
private Map<String, AtomicInteger> retryCounts = Collections.synchronizedMap(new HashMap<>());
@OnScheduled
public void scheduled(ProcessContext context) {
super.scheduled(context);
this.retryCounts.clear();
}
/* (non-Javadoc)
* @see org.apache.nifi.processor.AbstractProcessor#onTrigger(org.apache.nifi.processor.ProcessContext, org.apache.nifi.processor.ProcessSession)
*/
@Override
public void onTrigger(ProcessContext context, ProcessSession session) throws ProcessException {
FlowFile inputFF = session.get();
if (inputFF != null) {
inputFF = initialize(context, session, inputFF);
InitializationStatus status = getMetadataRecorder().getInitializationStatus(getFeedId(context, inputFF))
.orElse(new InitializationStatus(State.PENDING));
switch (status.getState()) {
case PENDING:
pending(context, session, inputFF);
break;
case IN_PROGRESS:
inProgress(context, session, inputFF);
break;
case FAILED:
failed(context, session, inputFF, status.getTimestamp());
break;
default:
success(context, session, inputFF);
}
}
}
@Override
protected void addProperties(List<PropertyDescriptor> list) {
super.addProperties(list);
list.add(FAILURE_STRATEGY);
list.add(RETRY_DELAY);
list.add(MAX_INIT_ATTEMPTS);
}
@Override
protected void addRelationships(Set<Relationship> set) {
super.addRelationships(set);
set.add(CommonProperties.REL_SUCCESS);
set.add(CommonProperties.REL_FAILURE);
set.add(REL_INITIALIZE);
}
private void pending(ProcessContext context, ProcessSession session, FlowFile inputFF) {
beginInitialization(context, session, inputFF);
rejectFlowFile(session, inputFF);
}
private void inProgress(ProcessContext context, ProcessSession session, FlowFile inputFF) {
rejectFlowFile(session, inputFF);
}
private void failed(ProcessContext context, ProcessSession session, FlowFile inputFF, DateTime failTime) {
String strategy = context.getProperty(FAILURE_STRATEGY).getValue();
if (strategy.equals("RETRY")) {
int delay = context.getProperty(RETRY_DELAY).asInteger();
int max = context.getProperty(MAX_INIT_ATTEMPTS).asInteger();
AtomicInteger count = getRetryCount(context, inputFF);
if (count.getAndIncrement() >= max) {
count.set(max);
session.transfer(inputFF, CommonProperties.REL_FAILURE);
} else if (failTime.plusSeconds(delay).isBefore(DateTime.now(DateTimeZone.UTC))) {
beginInitialization(context, session, inputFF);
rejectFlowFile(session, inputFF);
} else {
session.transfer(inputFF, CommonProperties.REL_FAILURE);
}
} else {
session.transfer(inputFF, CommonProperties.REL_FAILURE);
}
}
private void success(ProcessContext context, ProcessSession session, FlowFile inputFF) {
session.transfer(inputFF, CommonProperties.REL_SUCCESS);
}
private void beginInitialization(ProcessContext context, ProcessSession session, FlowFile inputFF) {
getMetadataRecorder().startFeedInitialization(getFeedId(context, inputFF));
FlowFile initFF = session.create(inputFF);
session.transfer(initFF, REL_INITIALIZE);
}
private void rejectFlowFile(ProcessSession session, FlowFile inputFF) {
FlowFile penalizedFF = session.penalize(inputFF);
session.transfer(penalizedFF);
}
private AtomicInteger getRetryCount(ProcessContext context, FlowFile inputFF) {
return this.retryCounts.computeIfAbsent(getFeedId(context, inputFF), k -> new AtomicInteger(0));
}
}