Refactoring SolverRemote module to implement circuit optimization #526 (#530)

* release notes

* refactoring and creating test for the use case

* refactoring

* clean code

* refactoring packages

* release notes

* refactoring

* creating temp test

* release notes

* [Gradle Release Plugin] - new version commit:  '3.25.6-snapshot'.

Author: mageddo

RELEASE-NOTES.md

@@ -1,3 +1,6 @@
+## 3.25.6
+* Refactoring SolverRemote module to implement circuit optimization #526
+
 ## 3.25.5
 * Change the caching strategy to minimize the locks and prevent deadlocks #522
 

gradle.properties

@@ -1 +1 @@
-version=3.25.5-snapshot
+version=3.25.6-snapshot

src/main/java/com/mageddo/dnsproxyserver/solver/SimpleResolver.java

@@ -13,8 +13,8 @@ public SimpleResolver(String hostname) throws UnknownHostException {
     super(hostname);
   }
 
-  public SimpleResolver(InetSocketAddress host) {
-    super(host);
+  public SimpleResolver(InetSocketAddress addr) {
+    super(addr);
   }
 
   public SimpleResolver(InetAddress host) {

src/main/java/com/mageddo/dnsproxyserver/solver/SolverRemote.java

@@ -2,9 +2,9 @@
 
 import com.mageddo.commons.circuitbreaker.CircuitCheckException;
 import com.mageddo.dns.utils.Messages;
+import com.mageddo.dnsproxyserver.solver.remote.application.CircuitBreakerService;
 import com.mageddo.dnsproxyserver.solver.remote.Request;
 import com.mageddo.dnsproxyserver.solver.remote.Result;
-import com.mageddo.dnsproxyserver.solver.remote.CircuitBreakerService;
 import com.mageddo.net.NetExecutorWatchdog;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -16,6 +16,7 @@
 import javax.inject.Inject;
 import javax.inject.Singleton;
 import java.io.IOException;
+import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
@@ -39,7 +40,6 @@ public class SolverRemote implements Solver, AutoCloseable {
   @Override
   public Response handle(Message query) {
     final var stopWatch = StopWatch.createStarted();
-
     final var result = this.queryResultFromAvailableResolvers(query, stopWatch);
     log.debug(
       "status=finally, time={}, success={}, error={}",
@@ -55,12 +55,14 @@ public Response handle(Message query) {
   Result queryResultFromAvailableResolvers(Message query, StopWatch stopWatch) {
     final var lastErrorMsg = new AtomicReference<Message>();
     // fixme #526 better to exclude open circuits.
-    for (int i = 0; i < this.delegate.resolvers().size(); i++) {
+    final var resolvers = this.findResolversWithNonOpenCircuit();
+    for (int i = 0; i < resolvers.size(); i++) {
 
-      final var resolver = this.delegate.resolvers().get(i);
+      final var resolver = resolvers.get(i);
       final var request = this.buildRequest(query, i, stopWatch, resolver);
 
       final var result = this.safeQueryResult(request);
+
       if (result.hasSuccessMessage()) {
         return result;
       } else if (result.hasErrorMessage()) {
@@ -71,6 +73,10 @@ Result queryResultFromAvailableResolvers(Message query, StopWatch stopWatch) {
     return Result.fromErrorMessage(lastErrorMsg.get());
   }
 
+  List<Resolver> findResolversWithNonOpenCircuit() {
+    return this.delegate.resolvers();
+  }
+
   Request buildRequest(Message query, int resolverIndex, StopWatch stopWatch, Resolver resolver) {
     return Request
       .builder()

src/main/java/com/mageddo/dnsproxyserver/solver/remote/CircuitBreakerService.java

@@ -0,0 +1,7 @@
+package com.mageddo.dnsproxyserver.solver.remote;
+
+public enum CircuitStatus {
+  OPEN,
+  CLOSED,
+  HALF_OPEN
+}

src/main/java/com/mageddo/dnsproxyserver/solver/remote/CircuitStatus.java

@@ -1,6 +1,6 @@
 package com.mageddo.dnsproxyserver.solver.remote.application;
 
-import com.mageddo.dnsproxyserver.solver.remote.CircuitBreakerService;
+import com.mageddo.dnsproxyserver.solver.remote.CircuitStatus;
 import com.mageddo.dnsproxyserver.solver.remote.Result;
 
 import java.net.InetSocketAddress;
@@ -11,4 +11,9 @@ public class CircuitBreakerNonResilientService implements CircuitBreakerService
   public Result safeHandle(final InetSocketAddress resolverAddress, Supplier<Result> sup) {
     return sup.get();
   }
+
+  @Override
+  public CircuitStatus getCircuitStatus(InetSocketAddress resolverAddress) {
+    return null;
+  }
 }

src/main/java/com/mageddo/dnsproxyserver/solver/remote/application/CircuitBreakerNonResilientService.java

@@ -0,0 +1,14 @@
+package com.mageddo.dnsproxyserver.solver.remote.application;
+
+import com.mageddo.dnsproxyserver.solver.remote.CircuitStatus;
+import com.mageddo.dnsproxyserver.solver.remote.Result;
+
+import java.net.InetSocketAddress;
+import java.util.function.Supplier;
+
+public interface CircuitBreakerService {
+
+  Result safeHandle(final InetSocketAddress resolverAddress, Supplier<Result> sup);
+
+  CircuitStatus getCircuitStatus(InetSocketAddress resolverAddress);
+}

src/main/java/com/mageddo/dnsproxyserver/solver/remote/application/CircuitBreakerService.java

@@ -1,8 +1,9 @@
-package com.mageddo.dnsproxyserver.solver.remote.application;
+package com.mageddo.dnsproxyserver.solver.remote.application.failsafe;
 
 import com.mageddo.commons.circuitbreaker.CircuitCheckException;
 import com.mageddo.commons.lang.tuple.Pair;
 import com.mageddo.dnsproxyserver.config.application.ConfigService;
+import com.mageddo.dnsproxyserver.solver.remote.CircuitStatus;
 import com.mageddo.dnsproxyserver.solver.remote.Result;
 import com.mageddo.dnsproxyserver.solver.remote.dataprovider.SolverConsistencyGuaranteeDAO;
 import com.mageddo.dnsproxyserver.solver.remote.mapper.CircuitBreakerStateMapper;
@@ -30,7 +31,7 @@ public class CircuitBreakerFactory {
 
   private final Map<InetSocketAddress, CircuitBreaker<Result>> circuitBreakerMap = new ConcurrentHashMap<>();
   private final ConfigService configService;
-  private final CircuitBreakerCheckerService circuitBreakerCheckerService;
+  private final CircuitBreakerPingCheckerService circuitBreakerCheckerService;
   private final SolverConsistencyGuaranteeDAO solverConsistencyGuaranteeDAO;
 
   public Result check(InetSocketAddress remoteAddress, Supplier<Result> sup) {
@@ -53,12 +54,12 @@ CircuitBreaker<Result> buildCircuitBreaker(
       .withFailureThreshold(config.getFailureThreshold(), config.getFailureThresholdCapacity())
       .withSuccessThreshold(config.getSuccessThreshold())
       .withDelay(config.getTestDelay())
-      .onClose(build("CLOSED", address))
-      .onOpen(build("OPEN", address))
+      .onClose(build(CircuitStatus.CLOSED, address))
+      .onOpen(build(CircuitStatus.OPEN, address))
       .build();
   }
 
-  EventListener<CircuitBreakerStateChangedEvent> build(String actualStateName, InetSocketAddress address) {
+  EventListener<CircuitBreakerStateChangedEvent> build(CircuitStatus actualStateName, InetSocketAddress address) {
     return event -> {
       final var previousStateName = CircuitBreakerStateMapper.toStateNameFrom(event);
       if (isHalfOpenToOpen(previousStateName, actualStateName)) {
@@ -75,8 +76,8 @@ EventListener<CircuitBreakerStateChangedEvent> build(String actualStateName, Ine
     };
   }
 
-  private static boolean isHalfOpenToOpen(String previousStateName, String actualStateName) {
-    return "HALF_OPEN".equals(previousStateName) && "OPEN".equals(actualStateName);
+  private static boolean isHalfOpenToOpen(CircuitStatus previousStateName, CircuitStatus actualStateName) {
+    return CircuitStatus.HALF_OPEN.equals(previousStateName) && CircuitStatus.OPEN.equals(actualStateName);
   }
 
   void flushCache() {
@@ -122,6 +123,10 @@ public List<Stats> stats() {
       .toList();
   }
 
+  public CircuitStatus getStatus(InetSocketAddress remoteAddress) {
+    return CircuitBreakerStateMapper.fromFailSafeCircuitBreaker(this.circuitBreakerMap.get(remoteAddress));
+  }
+
   private Stats toStats(InetSocketAddress remoteAddr) {
     final var circuitBreaker = this.circuitBreakerMap.get(remoteAddr);
     final var state = circuitBreaker.getState().name();

…e/application/CircuitBreakerFactory.java …tion/failsafe/CircuitBreakerFactory.javasrc/main/java/com/mageddo/dnsproxyserver/solver/remote/application/CircuitBreakerFactory.java renamed to src/main/java/com/mageddo/dnsproxyserver/solver/remote/application/failsafe/CircuitBreakerFactory.java src/main/java/com/mageddo/dnsproxyserver/solver/remote/application/CircuitBreakerFactory.java renamed to src/main/java/com/mageddo/dnsproxyserver/solver/remote/application/failsafe/CircuitBreakerFactory.java

@@ -1,8 +1,9 @@
-package com.mageddo.dnsproxyserver.solver.remote.application;
+package com.mageddo.dnsproxyserver.solver.remote.application.failsafe;
 
 import com.mageddo.commons.circuitbreaker.CircuitCheckException;
-import com.mageddo.dnsproxyserver.solver.remote.CircuitBreakerService;
+import com.mageddo.dnsproxyserver.solver.remote.CircuitStatus;
 import com.mageddo.dnsproxyserver.solver.remote.Result;
+import com.mageddo.dnsproxyserver.solver.remote.application.CircuitBreakerService;
 import dev.failsafe.CircuitBreakerOpenException;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
@@ -45,4 +46,9 @@ public String getStatus() {
   public void resetCircuitBreakerFactory() {
     this.circuitBreakerFactory.reset();
   }
+
+  @Override
+  public CircuitStatus getCircuitStatus(InetSocketAddress resolverAddress) {
+    return this.circuitBreakerFactory.getStatus(resolverAddress);
+  }
 }