com.uber.cadence.workflow.Saga Maven / Gradle / Ivy
/*
* Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Modifications copyright (C) 2017 Uber Technologies, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"). You may not
* use this file except in compliance with the License. A copy of the License is
* located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.uber.cadence.workflow;
import java.util.ArrayList;
import java.util.List;
/**
* This class implements the logic to execute compensation operations that is
* often required in Saga applications. The following is a skeleton to show of how it is supposed to
* be used in workflow code:
*
*
* Saga saga = new Saga(options);
* try {
* String r = activity.foo();
* saga.addCompensation(activity::cleanupFoo, arg2, r);
* Promise r2 = Async.function(activity::bar);
* r2.thenApply(r->saga.addCompensation(activity.cleanupBar(r));
* ...
* useR2(r2.get());
* } catch (Exception e) {
* saga.compensate();
* // Other error handling if needed.
* }
*
*/
public final class Saga {
private final Options options;
private final List> compensationOps = new ArrayList<>();
public static final class Options {
private final boolean parallelCompensation;
private final boolean continueWithError;
private Options(boolean parallelCompensation, boolean continueWithError) {
this.parallelCompensation = parallelCompensation;
this.continueWithError = continueWithError;
}
public static final class Builder {
private boolean parallelCompensation = true;
private boolean continueWithError = true;
/**
* This decides if the compensation operations are run in parallel. If parallelCompensation is
* false, then the compensation operations will be run the reverse order as they are added.
*
* @param parallelCompensation
* @return option builder
*/
public Builder setParallelCompensation(boolean parallelCompensation) {
this.parallelCompensation = parallelCompensation;
return this;
}
/**
* continueWithError gives user the option to bail out of compensation operations if exception
* is thrown while running them. This is useful only when parallelCompensation is false. If
* parallel compensation is set to true, then all the compensation operations will be fired no
* matter what and caller will receive exceptions back if there's any.
*
* @param continueWithError whether to proceed with the next compensation operation if the
* previous throws exception. This only applies to sequential compensation.
* @return option builder
*/
public Builder setContinueWithError(boolean continueWithError) {
this.continueWithError = continueWithError;
return this;
}
public Options build() {
return new Options(parallelCompensation, continueWithError);
}
}
}
public static class CompensationException extends RuntimeException {
public CompensationException(Throwable cause) {
super("Exception from saga compensate", cause);
}
}
public Saga(Options options) {
this.options = options;
}
public void compensate() {
if (options.parallelCompensation) {
List results = new ArrayList<>();
for (Functions.Func f : compensationOps) {
results.add(f.apply());
}
CompensationException sagaException = null;
for (Promise p : results) {
try {
p.get();
} catch (Exception e) {
if (sagaException == null) {
sagaException = new CompensationException(e);
} else {
sagaException.addSuppressed(e);
}
}
}
if (sagaException != null) {
throw sagaException;
}
} else {
for (int i = compensationOps.size() - 1; i >= 0; i--) {
Functions.Func f = compensationOps.get(i);
try {
Promise result = f.apply();
result.get();
} catch (Exception e) {
if (!options.continueWithError) {
throw e;
}
}
}
}
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
*/
public void addCompensation(Functions.Proc operation) {
compensationOps.add(() -> Async.procedure(operation));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
*/
public void addCompensation(Functions.Proc1 operation, A1 arg1) {
compensationOps.add(() -> Async.procedure(operation, arg1));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
*/
public void addCompensation(Functions.Proc2 operation, A1 arg1, A2 arg2) {
compensationOps.add(() -> Async.procedure(operation, arg1, arg2));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
*/
public void addCompensation(
Functions.Proc3 operation, A1 arg1, A2 arg2, A3 arg3) {
compensationOps.add(() -> Async.procedure(operation, arg1, arg2, arg3));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
*/
public void addCompensation(
Functions.Proc4 operation, A1 arg1, A2 arg2, A3 arg3, A4 arg4) {
compensationOps.add(() -> Async.procedure(operation, arg1, arg2, arg3, arg4));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
* @param arg5 fifth operation function parameter
*/
public void addCompensation(
Functions.Proc5 operation, A1 arg1, A2 arg2, A3 arg3, A4 arg4, A5 arg5) {
compensationOps.add(() -> Async.procedure(operation, arg1, arg2, arg3, arg4, arg5));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
* @param arg5 fifth operation function parameter
* @param arg6 sixth operation function parameter
*/
public void addCompensation(
Functions.Proc6 operation,
A1 arg1,
A2 arg2,
A3 arg3,
A4 arg4,
A5 arg5,
A6 arg6) {
compensationOps.add(() -> Async.procedure(operation, arg1, arg2, arg3, arg4, arg5, arg6));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
*/
public void addCompensation(Functions.Func operation) {
compensationOps.add(() -> Async.function(operation));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
*/
public void addCompensation(Functions.Func1 operation, A1 arg1) {
compensationOps.add(() -> Async.function(operation, arg1));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
*/
public void addCompensation(Functions.Func2 operation, A1 arg1, A2 arg2) {
compensationOps.add(() -> Async.function(operation, arg1, arg2));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
*/
public void addCompensation(
Functions.Func3 operation, A1 arg1, A2 arg2, A3 arg3) {
compensationOps.add(() -> Async.function(operation, arg1, arg2, arg3));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
*/
public void addCompensation(
Functions.Func4 operation, A1 arg1, A2 arg2, A3 arg3, A4 arg4) {
compensationOps.add(() -> Async.function(operation, arg1, arg2, arg3, arg4));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
* @param arg5 fifth operation function parameter
*/
public void addCompensation(
Functions.Func5 operation,
A1 arg1,
A2 arg2,
A3 arg3,
A4 arg4,
A5 arg5) {
compensationOps.add(() -> Async.function(operation, arg1, arg2, arg3, arg4, arg5));
}
/**
* Add compensation operation for saga.
*
* @param operation to be executed during compensation.
* @param arg1 first operation function parameter
* @param arg2 second operation function parameter
* @param arg3 third operation function parameter
* @param arg4 fourth operation function parameter
* @param arg5 fifth operation function parameter
* @param arg6 sixth operation function parameter
*/
public void addCompensation(
Functions.Func6 operation,
A1 arg1,
A2 arg2,
A3 arg3,
A4 arg4,
A5 arg5,
A6 arg6) {
compensationOps.add(() -> Async.function(operation, arg1, arg2, arg3, arg4, arg5, arg6));
}
}
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